View Full Version : Masking Tape just ate away KMR's Black finish?
I painted my AR today with Rustoleum, the results are alright, some oil on the lower kind of ruined it, but all in all its good.
I just took the tape off the front iron sight, I did not remove them when painting- I should have, but I usually keep them on since they do not come off, and noticed that the tape overlapped onto the rail. When I took it off the finish seemed all 'shriveled' up so I scratched it with my finger and it came right off and now it is white. The tape was on for around 8 hours, a couple of them were in the sun.
I will most likely spray it down real quick tomorrow, however, is the 'white' a finish as well?
This is no complaint about BCM, so I will not contact them, it is my fault. Also, as I understand the rail is still protected from corrosion by a clear finish, so I am not worried.
Freedoooom
06-06-14, 22:22
Really? You don't blame BCM for their rail finish not being able to resist masking tape?
Really? You don't blame BCM for their rail finish not being able to resist masking tape?
If I did not paint the rail, or actually took off the iron sights, this would not have happened.
My NSR handles duct tape.
TacticalMark
06-06-14, 23:04
IMHO masking tape shouldn't remove anodized finishes. I couldn't really tell from the picture, but clean the area off with de-greaser and reevaluate.
wildcard600
06-06-14, 23:07
holy crap. that seems like a pretty weak finish if masking tape and a couple hours in the sun removes it. Hope its just a fluke.
MorphCross
06-06-14, 23:40
IMHO masking tape shouldn't remove anodized finishes. I couldn't really tell from the picture, but clean the area off with de-greaser and reevaluate.
It is not an anodized finish. KMR rails are finished using a plasma deposition process that leaves the rail a light color. The black that peeled off was a color coating to make the rail a more standard color. The finish process closes the pores in the metal which keeps paint from sticking as well as anodizing sticks to aluminum.
A lot of this info is covered in the KMR discussion thread.
It is not an anodized finish. KMR rails are finished using a plasma deposition process that leaves the rail a light color. The black that peeled off was a color coating to make the rail a more standard color. The finish process closes the pores in the metal which keeps paint from sticking as well as anodizing sticks to aluminum.
A lot of this info is covered in the KMR discussion thread.
Thanks for that. I will just clean that area off and and spray with some paint.
jukeboxx13
06-07-14, 01:58
Damn, lets hope BCM can get the formula down in the future to prevent this.
Still love my KMR.
Damn, lets hope BCM can get the formula down in the future to prevent this.
Still love my KMR.
I see a Gen II improved finish 15" KMR in the future.
jukeboxx13
06-07-14, 05:19
I see a Gen II improved finish 15" KMR in the future.
With an 18" LW profile stainless barrel to be combined on a complete upper.:p
Cool. I've been dying to see what the finish under the black looks like. Yeah... I'd hit it with some flat black paint and move on.
Obscenejesster
06-07-14, 10:02
Does anyone know why BCM just didn't use Cerakote for the color? Is it because they didn't want to add more time to the process by baking them?
The only reason I ask is because I cerakoted my KMR and I've added/removed/moved accessories all up and down the rail without any color removal.
I would love to know what BCM used for the color. Also, maybe it's not the coatings fault. Maybe it's normally durable but when applied over the Plasma Disposition process, it doesn't stick well.
Maybe it's normally durable but when applied over the Plasma Disposition process, it doesn't stick well.
That's my understanding of it. I've run my KMRs like any other handguard and only have a few spots on the sharpest part of a couple of the PIC rail's slot edge that are shiny.
I honestly expected the top finish to be worse from all the sky is falling posts earlier this year. I've got worse finish damage on the upper an lower from normal use.
TacticalMark
06-07-14, 11:07
It is not an anodized finish. KMR rails are finished using a plasma deposition process that leaves the rail a light color. The black that peeled off was a color coating to make the rail a more standard color. The finish process closes the pores in the metal which keeps paint from sticking as well as anodizing sticks to aluminum.
A lot of this info is covered in the KMR discussion thread.
I didn't follow the KMR thread, but thanks for the info. I assumed it was anodized like the majority of rails on the market.
Obscenejesster
06-07-14, 11:40
That's my understanding of it. I've run my KMRs like any other handguard and only have a few spots on the sharpest part of a couple of the PIC rail's slot edge that are shiny.
I honestly expected the top finish to be worse from all the sky is falling posts earlier this year. I've got worse finish damage on the upper an lower from normal use.
Yea...I honestly can't comment on my experience with the finish since it was Cerakoted before put in use. Either way, its easily the best handguard I've ever used. It's weight and diameter did wonders on my RECCE build that has a heavier Stainless barrel. Now that rifle feels as light as other rifles of mine using light weight barrels and heavier handguards.
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I don't know if the KMR is anodized or not, but anodizing simply turns the aluminum a dull grey. The color that you see is added after. If the color is part of the anodizing process, it's a dye applied after the part is anodized
Obscenejesster
06-07-14, 20:13
I don't know if the KMR is anodized or not, but anodizing simply turns the aluminum a dull grey. The color that you see is added after. If the color is part of the anodizing process, it's a dye applied after the part is anodized
It's not anodized. They said it couldn't be anodized since 92% of the alloy is magnesium. They had to some Aerospace Plasma Disposition process (whatever that is) that they say is more durable and more resistant to corrosion than anodizing. The Plasma Disposition is done before the black coating is applied. I believe they said it was nearly clear so it can't be seen.
elephantrider
06-08-14, 04:11
Does anyone know why BCM just didn't use Cerakote for the color? Is it because they didn't want to add more time to the process by baking them?
The only reason I ask is because I cerakoted my KMR and I've added/removed/moved accessories all up and down the rail without any color removal.
I would love to know what BCM used for the color. Also, maybe it's not the coatings fault. Maybe it's normally durable but when applied over the Plasma Disposition process, it doesn't stick well.
My understanding is that Cerakote was not used because it really doesn't lend itself to production type manufacturing. Cerakote is very sensitive to part preparation, paint application, and the baking that is required. If any one of those is not done correctly then the Cerakote will be bad. It is more suited to one-at-a-time type application than getting parts out in quantity.
Obscenejesster
06-08-14, 09:10
My understanding is that Cerakote was not used because it really doesn't lend itself to production type manufacturing. Cerakote is very sensitive to part preparation, paint application, and the baking that is required. If any one of those is not done correctly then the Cerakote will be bad. It is more suited to one-at-a-time type application than getting parts out in quantity.
That's what I was thinking but I didn't know for sure.
My understanding is that Cerakote was not used because it really doesn't lend itself to production type manufacturing. Cerakote is very sensitive to part preparation, paint application, and the baking that is required. If any one of those is not done correctly then the Cerakote will be bad. It is more suited to one-at-a-time type application than getting parts out in quantity.
Yes I have read that someplace as well. If mine gets messed up I might look into the Cerakote as there is a local Cerakote place nearby.
Sexual_Meatball
06-09-14, 05:06
wow wouldnt of thought this would happen, especially from bcm. could you show us more pictures with better lighting too? it certainly does look raw.
Are you sure it's finish coming off vs masking tape staying put?? I've had masking tape leave nasty residue a couple of times.
Thankfully the black is just a cosmetic finish, but if it's peeling like that it still annoying.
Bright side being that you were painting it anyway? I have rubs on mine from lights, mounts and rail pieces; but I can't say that they bother me much.
Berserkr556
06-09-14, 14:17
You can tell who is from the barfcom, safe queen, fit and finish crew. They love to find any reason to bash BCM. If they'd actually take their AR out and shoot it they'd see you get scratches and scuffs. Maybe you people crying about the finish should read about it first.
You can tell who is from the barfcom, safe queen, fit and finish crew. They love to find any reason to bash BCM. If they'd actually take their AR out and shoot it they'd see you get scratches and scuffs. Maybe you people crying about the finish should read about it first.
Pretty, uncalled for I would say. I'm no safe queen addict, but given that I just dropped $300 on a rail I'd be pissed if something like tape peeled the finish off my part.
Could be a combo of the heat from drying the paint job in the sun and the 8 hours of the tape sticking on there.... I can't imagine there's a chemical issue with the tape, but who knows?
Could easily be a chemical reaction to the KMR finish caused by the tape adhesive, activated by the paint.
Ive seen it happen before on other things. Shitty masking tape causes issues. Use the green tape or go home.
Could easily be a chemical reaction to the KMR finish caused by the tape adhesive, activated by the paint.
Ive seen it happen before on other things. Shitty masking tape causes issues. Use the green tape or go home.
That's what I'm thinking. I'll admit though... I'm not willing to put a piece of tape on my rail to find out. :sarcastic:
I guess I could try it, but if something happened I'd have to be honest and feed the chicken little sky is falling crowd. I really don't want to foster that nonsense.
The top color coat of the KMR has been shown to be kinda weak, especially around the edges. It's OK to accept the truth here, and I'm happy to believe BCM when they say that clear primer/noncorrosive finish underneath is good to go and still does its job when the top layer is busted. The cutting edge weight and design of the KMR is worth it to me - and I paint my guns anyway.
Let's not turn this into another Mbus PRO crooked mounted sights drama thread where people pretend to ignore something with an issue because its from a favorite brand.
Does anyone know why BCM just didn't use Cerakote for the color? Is it because they didn't want to add more time to the process by baking them?
The only reason I ask is because I cerakoted my KMR and I've added/removed/moved accessories all up and down the rail without any color removal.
I would love to know what BCM used for the color. Also, maybe it's not the coatings fault. Maybe it's normally durable but when applied over the Plasma Disposition process, it doesn't stick well.
The problem is the inside of the handguard. The method we use now is able to deposit a color coat on the entire surface of the part inside and out. The baking wouldn't be a problem for us at all, it's the time taken to try and detail the inside of the parts.
The other consideration when it comes to using spray-on coatings is the variance in thickness. On one project I ran in the past, we had a coating variance of more than .003" which takes away usable tolerance in the machining operations. We wanted to avoid that if possible because we pride ourselves on very precise parts. This is one of the reasons we have one of the best lockups to the barrel nut that you'll find (not to mention the clamping method).
Luckily, the 'white' you see under the top coating is still very much protected and is an excellent base for paint. We're looking into what could have caused this and trying to ensure that we don't have repeats in the future. It's worth noting that a tape adhesion test is standard fare for coating tests (in addition to others) and ours are tested on every manufacturing lot, we've not had any issues to date. As such, I suspect the solvents in the paint might be a contributor here.
As always, if you're dissatisfied, get ahold of BCM customer service.
That's what I'm thinking. I'll admit though... I'm not willing to put a piece of tape on my rail to find out. :sarcastic:
I guess I could try it, but if something happened I'd have to be honest and feed the chicken little sky is falling crowd. I really don't want to foster that nonsense.
Part of coating adhesion tests is actually to use a diamond scribe to penetrate the coating, and then use tape to ensure the coating doesn't peel any farther. I'd have to dig up the actual standard that describes it, but I'm away from my work computer at the moment. We use this test on every lot to ensure that the coating(s) are adhering adequately and have had no issues. Assuming something else hasn't compromised the coating, there should be very little to no increase in the size of the 'white' spots. We used a very low threshold as far as the 'growth' of the scratch is concerned when developing the coating(s).
Obscenejesster
06-09-14, 19:32
The problem is the inside of the handguard. The method we use now is able to deposit a color coat on the entire surface of the part inside and out. The baking wouldn't be a problem for us at all, it's the time taken to try and detail the inside of the parts.
The other consideration when it comes to using spray-on coatings is the variance in thickness. On one project I ran in the past, we had a coating variance of more than .003" which takes away usable tolerance in the machining operations. We wanted to avoid that if possible because we pride ourselves on very precise parts. This is one of the reasons we have one of the best lockups to the barrel nut that you'll find (not to mention the clamping method).
Luckily, the 'white' you see under the top coating is still very much protected and is an excellent base for paint. We're looking into what could have caused this and trying to ensure that we don't have repeats in the future. It's worth noting that a tape adhesion test is standard fare for coating tests (in addition to others) and ours are tested on every manufacturing lot, we've not had any issues to date. As such, I suspect the solvents in the paint might be a contributor here.
As always, if you're dissatisfied, get ahold of BCM customer service.
Cool. thanks for the info. I'm definitely not dissatisfied with the KMR. It's the best damn handguard I've ever used and I'm looking for an excuse to buy another. I also agree that the lock up/clamping method is the best I've seen. It's extremely easy to install and it kinda makes me wonder why nobody else has thought of it.
In my personal opinion, I think the KMR is the best handguard currently on the market.
Cool. thanks for the info. I'm definitely not dissatisfied with the KMR. It's the best damn handguard I've ever used and I'm looking for an excuse to buy another. I also agree that the lock up/clamping method is the best I've seen. It's extremely easy to install and it kinda makes me wonder why nobody else has thought of it.
In my personal opinion, I think the KMR is the best handguard currently on the market.
Definitely appreciate the kind words.
My understanding is that Cerakote was not used because it really doesn't lend itself to production type manufacturing. Cerakote is very sensitive to part preparation, paint application, and the baking that is required. If any one of those is not done correctly then the Cerakote will be bad. It is more suited to one-at-a-time type application than getting parts out in quantity.
- Edit - saw Phreakish's answer above.
Thanks for that info Phreakish.
I did not make this thread to complain, I was also not very concerned but just surprised that tape took the finish off.
All in all, I am perfectly happy with the KMR.
Very cool. Always interesting to read what goes into the gear we use.
My KMR finish could wear off and show a gay pride rainbow underneath it, and I'd still run the piss out of it. I like it that much.
If I had to tap it on with a plastic faced hammer the end of the sight rail is where I would hit it. My tapping broke the surface tension of the coating and the loose flake just sat there waiting to be pulled off by the tape. How's that for a wild guess? GH
My KMR finish could wear off and show a gay pride rainbow underneath it, and I'd still run the piss out of it. I like it that much.
:sarcastic: That's true.
I have a beef to pick with BCM. :help:
After purchasing my 14.5" ELW w/13" KMR rail my Troy quad rail feels like a piece of crap! The lightweight, well thought out contoured design of the KMR has ruined me, I will never be able to go back to a quad rail. So know I have a rifle sitting in the safe that I don't want to use. Oh well, I guess it will be ready for the next panic and find a new home.
It's extremely easy to install and it kinda makes me wonder why nobody else has thought of it.
I think somebody already has thought of this kind of mounting several years ago (like 10?) and there is at least one other manufacturer who uses that. Of course details like screw placement (bottom or top) vary, but it is same general idea.
I think somebody already has thought of this kind of mounting several years ago (like 10?) and there is at least one other manufacturer who uses that. Of course details like screw placement (bottom or top) vary, but it is same general idea.
The screw placement is a critical feature and not just some variance from other designs.
The screw placement is a critical feature and not just some variance from other designs.
Screw placement on top is critical for this exact design, because of lack of bottom channel. But it does not make mounting principle any different*. It is just "upside down". Also removable clamping pieces reduce machining or welding (but can be easily lost - so no go for some applications).
*- unless I miss something extremely crucial by a mile - but I see same barrel nut design and same solution to retain handguard in place on barrel nut.
Well I guess I mean that had they put the mounting screws on the bottom like some handguards I've seen that have only a pic rail on top, it would be an inferior design in that it pulls the top rail's side walls apart.
Quiet Riot
06-10-14, 12:11
Screw placement on top is critical for this exact design, because of lack of bottom channel. But it does not make mounting principle any different*. It is just "upside down". Also removable clamping pieces reduce machining or welding (but can be easily lost - so no go for some applications).
*- unless I miss something extremely crucial by a mile - but I see same barrel nut design and same solution to retain handguard in place on barrel nut.
Actually, placing the screws on top of the barrel nut creates significantly different clamping forces than placing the screws underneath because they complete a ring of tension around the nut. When you clamp on the bottom, tension pulls the open gas tube channel down onto the barrel nut, prying it open, which forces the hand guard to make up for this weakness with more material (and weight) in places it isn't otherwise needed.
Explanation of the difference with visual aids starts at 3:43...
https://www.youtube.com/watch?v=-AjlvIsCFp0
Freedoooom
06-10-14, 13:52
How did this turn into praise BCM thread?
Obscenejesster
06-10-14, 14:11
How did this turn into praise BCM thread?
I suppose its easy to praise one of the best free float handguards ever made. When you sit back and look at the KMR you can tell how much research and design hours they put into it. They didn't just make something that looked different from what's currently on the market. They designed something that performed better as well.
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praise BCM
True dat! :cool:
donlapalma
06-10-14, 15:01
I suppose its easy to praise one of the best free float handguards ever made. When you sit back and look at the KMR you can tell how much research and design hours they put into it. They didn't just make something that looked different from what's currently on the market. They designed something that performed better as well.
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And to add to that, their Lead Engineer, Designer did just show up and educate our asses. There was quite a bit of hypothesizing going down in this thread and the record was set straight. Tells me that they are listening, are concerned and care about the quality of their products. I'm sure there are those who may not be impressed by such a thing, but I, for one, appreciate the proactiveness.
Freedoooom
06-10-14, 15:35
I suppose its easy to praise one of the best free float handguards ever made. When you sit back and look at the KMR you can tell how much research and design hours they put into it. They didn't just make something that looked different from what's currently on the market. They designed something that performed better as well.
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Its more fun to sit back and wonder if they had some bad tunnel vision. AP custom has made a handguard that weighs the same for half the price for quite a while now. And all AP custom does is buys carbon fiber tubes from Rock West Composites and then machines a barrel nut and mounting slots.
And to add to that, their Lead Engineer, Designer did just show up and educate our asses. There was quite a bit of hypothesizing going down in this thread and the record was set straight. Tells me that they are listening, are concerned and care about the quality of their products. I'm sure there are those who may not be impressed by such a thing, but I, for one, appreciate the proactiveness.
I seem to recall his post basically saying "its easy to fix our mistake."
Actually, placing the screws on top of the barrel nut creates significantly different clamping forces than placing the screws underneath because they complete a ring of tension around the nut. When you clamp on the bottom, tension pulls the open gas tube channel down onto the barrel nut, prying it open, which forces the hand guard to make up for this weakness with more material (and weight) in places it isn't otherwise needed.
Original design has a tab that engages slot in upper receiver that both prevent rotation or pulling top of rail down. Anyway, I do not criticize or dismiss KMR design. I just pointed out that barrel nut and mounting system is not new idea. Changed, maybe improved, but not new.
BTW What is barrel nut OD in KMR and distance from bore line to top of gas pipe channel? Always have creepy ideas coming to my mind ;)
Obscenejesster
06-10-14, 17:08
Its more fun to sit back and wonder if they had some bad tunnel vision. AP custom has made a handguard that weighs the same for half the price for quite a while now. And all AP custom does is buys carbon fiber tubes from Rock West Composites and then machines a barrel nut and mounting slots.
I seem to recall his post basically saying "its easy to fix our mistake."
Not really a fan of carbon fiber hand guards and proprietary mounting. I'd also rather have direct attach accessories rather than using screws to mount picatinny and then the accessory on top of that.
By the way, the AP hand guards are not the same weight as the KMR. The advertised weight you're looking at on their website is for just the hand guard. It isn't including the barrel nut and mounting hardware. If you compare apples to apples then the weight of the 13" KMR without the barrel nut is 5.6 ounces. Compare that to AP's 12" hand guard that weighs in at 7.8 ounces. Of course this is only comparing the weight of each handguard which is only one of the considerations when comparing hand guards. Beyond the advantages Keymod has over AP's proprietary mounting options, the KMR also offers more mounting options. I think the AP hand guards are fine for range use but they aren't really hard use oriented. They use the stock barrel nut with no anti rotation tabs.
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Obscenejesster
06-10-14, 17:11
Original design has a tab that engages slot in upper receiver that both prevent rotation or pulling top of rail down. Anyway, I do not criticize or dismiss KMR design. I just pointed out that barrel nut and mounting system is not new idea. Changed, maybe improved, but not new.
BTW What is barrel nut OD in KMR and distance from bore line to top of gas pipe channel? Always have creepy ideas coming to my mind ;)
I can't think of any other hand guards that use a barrel nut and lock up method like the KMR. I'm curious though. Can you show us a couple?
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I can't think of any other hand guards that use a barrel nut and lock up method like the KMR. I'm curious though. Can you show us a couple?
Original idea is HK416 free float, 4-rails handguard designed ca 2004. Later on it went on HK417 with slightly modified design. When Geissele made their rail upgrade for NSW HK416s (SMR-HK), same mounting method as on HK (actually 2 screw version a'la HK417) went to their SMR series of handguards. Those are designs I had in mind. Of course, KMR has barrel nut with wider slot, to accommodate 2 screws close to each other and mentioned benefits of moving clamping position up with no bottom channel like HK or Geissele rails have, but general idea of barrel nut and interfacing handguard with it is same. New rails for HK MR556A1-SD and MR762A1-SD share general shape with KMR, but still use traditional bottom screw as older HK rails (but they have top tab that "hooks" handguard into upper receiver).
Original idea is HK416 free float, 4-rails handguard designed ca 2004. Later on it went on HK417 with slightly modified design. When Geissele made their rail upgrade for NSW HK416s (SMR-HK), same mounting method as on HK (actually 2 screw version a'la HK417) went to their SMR series of handguards. Those are designs I had in mind. Of course, KMR has barrel nut with wider slot, to accommodate 2 screws close to each other and mentioned benefits of moving clamping position up with no bottom channel like HK or Geissele rails have, but general idea of barrel nut and interfacing handguard with it is same. New rails for HK MR556A1-SD and MR762A1-SD share general shape with KMR, but still use traditional bottom screw as older HK rails (but they have top tab that "hooks" handguard into upper receiver).
As far as handguards go, but the method used (Cross pin/bolt in a grooved feature) is no different than the firing pin retainer on an AR15 or a half dozen other designs. The KAC QD suppressors also used a similar feature for fastening, though with a cross-gate rather than screws or pins. Many pintle mounts have used a similar setup since who-knows-when, with a pin in a groove to retain the pivot mechanism. Point being, it's not a new design nor unique to the 416. The position of the screw over the top of the barrel nut rather than under it is a significant achievement in any case as no one else had yet fit it all and the benefits of doing so are numerous.
Point being, it's not a new design nor unique [...].
And this was a point of my original comment to: "it kinda makes me wonder why nobody else has thought of it". As you pointed, somebody did. Lot of people actually and HK416 handguard is just an example.
BTW Similar concept is used to fix barrel into receiver in new Polish MSBS rifle. But locking is achieved by two lugs that are fixed to stretching screw (to eliminate need of precise torquing on mounting).
mebiuspower
06-11-14, 08:06
As far as handguards go, but the method used (Cross pin/bolt in a grooved feature) is no different than the firing pin retainer on an AR15 or a half dozen other designs. The KAC QD suppressors also used a similar feature for fastening, though with a cross-gate rather than screws or pins. Many pintle mounts have used a similar setup since who-knows-when, with a pin in a groove to retain the pivot mechanism. Point being, it's not a new design nor unique to the 416. The position of the screw over the top of the barrel nut rather than under it is a significant achievement in any case as no one else had yet fit it all and the benefits of doing so are numerous.
It's a "simple" idea and not a new one at that, but yet no other manufacturer had thought of this when designing their handguards.
Just like their tool-less KM VG and KM QD sling mount. Simple yet brilliant designs compare to what came before. This is what I love about BCM.
And this was a point of my original comment to: "it kinda makes me wonder why nobody else has thought of it". As you pointed, somebody did.
My point was with respect to the screw over the barrel nut rather than under it, thereby eliminating the inherent weak clamping caused by having a channel or other shape within the material that is stressed under clamping. Obviously using a cross-bolt is not new. Our uninterrupted circumference of material around the barrel nut coupled with a cross bolt is the innovation.
Our uninterrupted circumference of material around the barrel nut coupled with a cross bolt is the innovation.
Yes. When I wrote: "Changed, maybe improved", I had exactly this innovation in mind. "Maybe" comes from obvious lack of opportunity to test it and ensure that in real life benefits are same as in theory or at least that befits are worth mentioning.. Especially, because I did not notice any myself, nor had feedback from military users around here about problems coming from handguard design on HK416* (and believe me, those guys are very vocal about anything bad that happens to their 416s).
* - other than early production, non-captive crossbolt coming loose sometimes, but this seem to be solved long ago.
However, with how your handguard profile is designed, with like what 345dgr(?) of uniterrupred circumference around barrel nut, there actually is no other (good) place to put cross bolts and tension it around it. So befits or no, this is most logical place to put nuts in your specific design.
BTW Can you answer my question from previous post: "What is barrel nut OD in KMR and distance from bore line to top of gas pipe channel?" I was wondering if KMR can be somehow forced on 416. You know, men is always stronger than matter! ;)
Why would you want to fit the KMR on an HK416? Even if you "forced" it on there, the top rail would not be even since the 416 has a taller receiver. It would be a ghetto solution at best and not worth the benefits of weight or profile.
Obscenejesster
06-11-14, 21:10
Yes. When I wrote: "Changed, maybe improved", I had exactly this innovation in mind. "Maybe" comes from obvious lack of opportunity to test it and ensure that in real life benefits are same as in theory or at least that befits are worth mentioning.. Especially, because I did not notice any myself, nor had feedback from military users around here about problems coming from handguard design on HK416* (and believe me, those guys are very vocal about anything bad that happens to their 416s).
* - other than early production, non-captive crossbolt coming loose sometimes, but this seem to be solved long ago.
However, with how your handguard profile is designed, with like what 345dgr(?) of uniterrupred circumference around barrel nut, there actually is no other (good) place to put cross bolts and tension it around it. So befits or no, this is most logical place to put nuts in your specific design.
BTW Can you answer my question from previous post: "What is barrel nut OD in KMR and distance from bore line to top of gas pipe channel?" I was wondering if KMR can be somehow forced on 416. You know, men is always stronger than matter! ;)
Wouldn't work....The inner diameter of the KMR isn't big enough to accommodate the 416's piston. Not to mention, the rails wouldn't line up with the receiver.
As far as handguards go, but the method used (Cross pin/bolt in a grooved feature) is no different than the firing pin retainer on an AR15 or a half dozen other designs. The KAC QD suppressors also used a similar feature for fastening, though with a cross-gate rather than screws or pins. Many pintle mounts have used a similar setup since who-knows-when, with a pin in a groove to retain the pivot mechanism. Point being, it's not a new design nor unique to the 416. The position of the screw over the top of the barrel nut rather than under it is a significant achievement in any case as no one else had yet fit it all and the benefits of doing so are numerous.
Since the 416 has been mentioned.....any chance Bravo would ever consider designing the KMR for the 416/MR556/MR223. I just installed the KMR on my Colt...unbelievable system, and it sure would be nice to have one for an HK platform as well...even using the current barrel nut like the Geissele rail does. I realize the design would need tweaking as some have already said but man, the KMR is awesome.
-masking tape removed original finish: now it's "custom"! (people pay extra for 'custom').
MorphCross
07-15-14, 13:45
-masking tape removed original finish: now it's "custom"! (people pay extra for 'custom').
Funny thing, if you actually read this thread you'll not only discover that it wasn't the finish, but a color coating applied over the finish. Last I checked people don't want a white handguard so BCM used a coating that sticks pretty well to the closed pore finish to give it a basic black look.
The original poster was satisfied by BCM's explanation as to what exactly happened and was more than happy to rattle-can the exposed white.
Freedoooom
07-15-14, 14:00
Funny thing, if you actually read this thread you'll not only discover that it wasn't the finish, but a color coating applied over the finish. Last I checked people don't want a white handguard so BCM used a coating that sticks pretty well to the closed pore finish to give it a basic black look.
The original poster was satisfied by BCM's explanation as to what exactly happened and was more than happy to rattle-can the exposed white.
In other words he was satisfied with the "its easy to fix our **** up," explanation.
In other words he was satisfied with the "its easy to fix our **** up," explanation.
I'll always fix something myself. I absolutely HATE having to return something to get looked at. Granted, someone in finishing probably touched that specific spot with bare hands or somehow the part wasn't clean.... but shit.... that's cosmetics. I only wish I had the time to make that a life problem.
I'll always fix something myself. I absolutely HATE having to return something to get looked at. Granted, someone in finishing probably touched that specific spot with bare hands or somehow the part wasn't clean.... but shit.... that's cosmetics. I only wish I had the time to make that a life problem.
To echo that sentiment, we've been trying to duplicate this result and have not been able to. Based on the thousands of parts we've had made and the number that have been subject to solvent soaks, paint jobs, adhesion and abrasion tests, we're confident it was an isolated incident. The unexpected (and sometimes unexplainable) happens at some point to any product.
What's important to us is that at the end of the day, the customer is happy. That seems to be the case in this event. If that was not the case, BCM has a pretty good reputation when it comes to turning a frown upside down so I'll let that speak for itself.
Funny thing, if you actually read this thread you'll not only discover that it wasn't the finish, but a color coating applied over the finish. Last I checked people don't want a white handguard so BCM used a coating that sticks pretty well to the closed pore finish to give it a basic black look.
The original poster was satisfied by BCM's explanation as to what exactly happened and was more than happy to rattle-can the exposed white.
The last coat on anything is the finish...that how it got the name.
The last coat on anything is the finish...that how it got the name.
Actually it comes from Finland.
Actually it comes from Finland.
I though it sounded good anyhow...lol
Funny thing, if you actually read this thread you'll not only discover that it wasn't the finish, but a color coating applied over the finish.
Funny thing, sarcasm flies rather cleanly right over your head...
wildcard600
07-15-14, 17:43
so if the black was the finish... is the white the swedish ? or the norwegian ?
so if the black was the finish... is the white the swedish ? or the norwegian ?
Might be more appropriately called the Basque coat?
MorphCross
07-15-14, 18:37
Funny thing, sarcasm flies rather cleanly right over your head...
Tone tends not to come through in text form. Use this: :sarcastic: if you feel like being facetious.
Singlestack Wonder
07-15-14, 19:04
Hopefully BCM will determine a finish that will at least be equivalent to anodizing in regards to durability.
wildcard600
07-15-14, 19:19
Might be more appropriately called the Basque coat?
This got me imagining a line of OD green lingerie emblazoned with the BCM logo. And to be honest I got a little too excited for my own good....
Heavy Metal
07-15-14, 19:23
The KKK took your finish away.....
So lapping came from Lapland?
Hopefully BCM will determine a finish that will at least be equivalent to anodizing in regards to durability.
Finishing our alloy is not easy. The method we're using is equivalent in terms of durability with respect to the substrate. Unfortunately, the hardest part of the coating is closest to the substrate, and is white in appearance.
Technology evolves all the time though, and we never rest when it comes to improvement.
While we are talking about finishes on the KMR, I'm contemplating cutting mine and I was wondering if you have any recommendations on re-doing the finish.
I wonder how well stuff will stick to the black finish, and I wonder how well stuff will stick to the bare, cut alloy.
Any thoughts / suggestions would be appreciated.
Thanks,
-john
While we are talking about finishes on the KMR, I'm contemplating cutting mine and I was wondering if you have any recommendations on re-doing the finish.
I wonder how well stuff will stick to the black finish, and I wonder how well stuff will stick to the bare, cut alloy.
Any thoughts / suggestions would be appreciated.
Thanks,
-john
I obviously can't recommend you do that. However, the cut surfaces can be painted over with some simple prep work with sandpaper. The original coating can be painted over top of. We have several dealers color coating using cerkote with excellent results. Our coating is actually a very good base for paint.
Bake the part at 300F for a half hour after cutting, let cool until it can be handled, then degrease with acetone. The prebake will help ensure the cut areas at the edge of the original finish will be sealed best.
To degrease, soak for 3-5 minutes and then air dry. Then apply the paint per the manufacturers recommendations. Lighter colors will require more coats for uniform appearance. Or you can apply a basecoat of black on the cut edges and then paint with the final color for best results. The thinner the added the color costs the better, thick paint will make pic rail and keymod accessories difficult to fit.
I obviously can't recommend you do that. However, the cut surfaces can be painted over with some simple prep work with sandpaper. The original coating can be painted over top of. We have several dealers color coating using cerkote with excellent results. Our coating is actually a very good base for paint.
Bake the part at 300F for a half hour after cutting, let cool until it can be handled, then degrease with acetone. The prebake will help ensure the cut areas at the edge of the original finish will be sealed best.
To degrease, soak for 3-5 minutes and then air dry. Then apply the paint per the manufacturers recommendations. Lighter colors will require more coats for uniform appearance. Or you can apply a basecoat of black on the cut edges and then paint with the final color for best results. The thinner the added the color costs the better, thick paint will make pic rail and keymod accessories difficult to fit.
Will soaking the cut rail in degreaser affect the factory black coating?
Will soaking the cut rail in degreaser affect the factory black coating?
No, but the cut edges might lift slightly thus the pre-bake suggestion. Doing it after the cut and prior to degreasing will help ensure that any slightly lifted edges from the cutting don't cause any ugly spots or other drama.
The dealers painting our parts are using this same method with excellent results.
No, but the cut edges might lift slightly thus the pre-bake suggestion. Doing it after the cut and prior to degreasing will help ensure that any slightly lifted edges from the cutting don't cause any ugly spots or other drama.
The dealers painting our parts are using this same method with excellent results.
Thank you, that makes perfect sense.
I obviously can't recommend you do that. However, the cut surfaces can be painted over with some simple prep work with sandpaper. The original coating can be painted over top of. We have several dealers color coating using cerkote with excellent results. Our coating is actually a very good base for paint.
Bake the part at 300F for a half hour after cutting, let cool until it can be handled, then degrease with acetone. The prebake will help ensure the cut areas at the edge of the original finish will be sealed best.
To degrease, soak for 3-5 minutes and then air dry. Then apply the paint per the manufacturers recommendations. Lighter colors will require more coats for uniform appearance. Or you can apply a basecoat of black on the cut edges and then paint with the final color for best results. The thinner the added the color costs the better, thick paint will make pic rail and keymod accessories difficult to fit.
Any thoughts about different coatings? I was interested in just touching things up, so I'd rather not sand the whole finish.
Thoughts if bake on cerakote or molycoat would stick to the KMR finish without sanding the whole thing?
Thanks,
-john
31291
Man. I'd just tape off the outer surface right up to that cut and rattle can it black. I've done cut down carry handles and spray paint holds up just fine.
I obviously can't recommend you do that. However, the cut surfaces can be painted over with some simple prep work with sandpaper. The original coating can be painted over top of. We have several dealers color coating using cerkote with excellent results. Our coating is actually a very good base for paint.
Bake the part at 300F for a half hour after cutting, let cool until it can be handled, then degrease with acetone. The prebake will help ensure the cut areas at the edge of the original finish will be sealed best.
To degrease, soak for 3-5 minutes and then air dry. Then apply the paint per the manufacturers recommendations. Lighter colors will require more coats for uniform appearance. Or you can apply a basecoat of black on the cut edges and then paint with the final color for best results. The thinner the added the color costs the better, thick paint will make pic rail and keymod accessories difficult to fit.
So If I understand this correctly you do not recommend blasting the KMR when using Cerakote. Will blasting the part to prep cause problems?
So If I understand this correctly you do not recommend blasting the KMR when using Cerakote. Will blasting the part to prep cause problems?
Correct. Just degrease and paint right over it. It will stick very well, no blast needed.
Any thoughts about different coatings? I was interested in just touching things up, so I'd rather not sand the whole finish.
Thoughts if bake on cerakote or molycoat would stick to the KMR finish without sanding the whole thing?
Thanks,
-john
31291
No need to sand the whole thing. Just degreaee and paint as you desire. Touch up the cut area or paint over the whole thing, doesn't matter.
Correct. Just degrease and paint right over it. It will stick very well, no blast needed.
Thank you.
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