View Full Version : Ti barrel nuts...hidden issues?
Will the popularity of Ti barrel nuts come home to roost as a problem after a few years/thousand rounds, especially on duty guns or firearms used in maritime environments?
http://www.service-partners.com/catalog/docs/Information/5-Galvanic_Compatibility.pdf
I doubt you will find a ti nut on anything other than a stunt gun. The guys that swim with guns could care less about saving the fraction of an ounce a ti nut offers.
I have wondered about this, but in the realm of suppressors, rather than barrel nuts.
There are quite a few suppressors out there with Titanium body/tubes and stainless steel inner components. I am wondering if these exhibit any galvanic corrosion issues, given that they see a lot of heat, fouling, and probably some moisture.
The gas block on the most current M-240 Machine gun is titanium.... it sees plenty of heat, fouling, and probably some moisture as well.
The gas block on the most current M-240 Machine gun is titanium.... it sees plenty of heat, fouling, and probably some moisture as well.
Interesting. Does it in any way contact aluminum?
Interesting. Does it in any way contact aluminum?
Wouldn't steel be more of an issue since iron has a higher electonegativity compared to Ti?
Ti is very corrosion resistant except in extreme environments. For example, nickel has a higher electronegativity, but corrodes favorably to Ti.
For the environment most rifles are in, I don't think it will cause an issue.
Wouldn't steel be more of an issue since iron has a higher electonegativity compared to Ti?
Ti is very corrosion resistant except in extreme environments. For example, nickel has a higher electronegativity, but corrodes favorably to Ti.
For the environment most rifles are in, I don't think it will cause an issue.
No, aluminum is much more prone to corrosion than steel when interfacing with Ti.
No, aluminum is much more prone to corrosion than steel when interfacing with Ti.
How would it corrode in normal conditions? Aluminum forms a protective barrier when oxidizing.
I'm not saying it doesnt, as I've heard it before, but more interested in the mechanics behind it. It doesn't seem analagous to the normal zinc/iron or zinc/copper galvanic process from what I can tell.
How would it corrode in normal conditions? Aluminum forms a protective barrier when oxidizing.
I'm not saying it doesnt, as I've heard it before, but more interested in the mechanics behind it. It doesn't seem analagous to the normal zinc/iron or zinc/copper galvanic process from what I can tell.
Ti and 7075 are a much worse combo than zinc and copper.
Same mechanism. Worse combi.
How about Ti and Anodized aluminum?
EDIT to add...
This might be a fun experiment, I wonder if we should setup our own test and see what we get. Perhaps some uppers assembled and submerged in salt water for a set time?
I could provide the parts to do so.
Ryan
How about Ti and Anodized aluminum?
EDIT to add...
This might be a fun experiment, I wonder if we should setup our own test and see what we get. Perhaps some uppers assembled and submerged in salt water for a set time?
I could provide the parts to do so.
Ryan
I'm going to perform the test using a buffer tube and V7 Ti castle nuts. Sounds cheaper...
Many gun parts are made from materials that corrode. If they are properly coated its not an issue, think anodized or parkerized.
Raw titanium on raw aluminum is a bad idea. But what about DLC titanium on Anodized aluminum? and assembled with proper lube or loctite.
That sounds good to me, so good in fact I'm giving it a shot.
I am building on a 2A Armament balios lite receiver set, I have been using many V7 Ti parts. Barrel nut (milspec), gas block and muzzle device. All titanium parts are DLC and anodized aluminum. I used rock set or royal purple high temp lube.
The final piece will be to replace the troy aluminum Mlok rail with the new;y released carbon fiber one.
I am looking forward to seeing how the final product all works, I plan on running it through some VTAC classes and seeing how it all holds up.
How about Ti and Anodized aluminum?
Mega and Hodge are doing that with the wedge lock barrel nut and rail. They seem like folks that would've tested it (especially since it's marketed as a hard use rail).
Metric Matt
09-03-15, 17:56
This article might shed some light on the subject. It looks like raw titanium in contact with raw aluminum in a corrosive environment is a bad thing.
http://www.corrosionist.com/Galvanic_Corrosion_Titanium.html
Yea, for your average rifle, I don't think it's going to matter. Your not shooting over a tub of HCl.
I think the reason we don't see much titanium on military adopted small arms is cost to benefit ratio.
Military procurement always comes down to cost.
Titanium is very expensive, it is hard to work. While lighter, the cost that comes at would never make it viable for a military small arm.
But think where we do use it, Aerospace, we have put this stuff on the moon. Okay, I know the moon is not a corrosive environment.
But what are the Russians up to with the stuff?, they love it and have lots of it. Well that make nuclear submarine hulls out of it, it must not do too bad in salt water...
ETA: Military use of titanium in maritime environment. Russian Alpha class sub.
34868
Doesn't the M240L have a Ti receiver? How are those holding up?
An M240 weighs 28 pounds empty, making parts of it out of titanium saves a lot of weight. Five and half pounds.
A barrel nut weight next to nothing, making that out of titanium doesn't do much....
Metric Matt
09-04-15, 12:14
An M240 weighs 28 pounds empty, making parts of it out of titanium saves a lot of weight. Five and half pounds.
A barrel nut weight next to nothing, making that out of titanium doesn't do much....
That is true, even if you use all of the Ti parts available for an AR, the weight savings can't be more than four or five ounces. But Ti does have the "cool" factor that many find appealing, myself included.
I think 4 or 5 ounces is a big deal.
4 or 5 ounces on Ti parts+
4 or 5 ounces on a barrel+
4 or 5 ounces on a light weight rail+
2 or 3 onces on a receiver set+
3 or 4 onces on a light stock
= All of the sudden you have lost and average of over a pound.
Metric Matt
09-04-15, 14:36
I think 4 or 5 ounces is a big deal.
4 or 5 ounces on Ti parts+
4 or 5 ounces on a barrel+
4 or 5 ounces on a light weight rail+
2 or 3 onces on a receiver set+
3 or 4 onces on a light stock
= All of the sudden you have lost and average of over a pound.
I agree it all adds up, if you are going for an ultralight build four or five ounces is significant. There is definitely a point of diminishing returns though when you start shaving a few grams for parts that cost several times more vs. steel.
BufordTJustice
09-05-15, 12:06
I haven't read the links in the thread yet, for once, but does this address aluminum with Type III hardcoat anodize being used against Ti?
I am using an uncoated V7 Weapons Ti KMR barrel nut (not the ionbond black). BUT, I liberally used Aeroshell 33 MS, like I do with every installation. This is on my patrol rifle.
I'll remove it in a few months to check on things. I'm the guy whose sweat makes his glock rust. I live I central Florida.
I think 4 or 5 ounces is a big deal.
4 or 5 ounces on Ti parts+
4 or 5 ounces on a barrel+
4 or 5 ounces on a light weight rail+
2 or 3 onces on a receiver set+
3 or 4 onces on a light stock
= All of the sudden you have lost and average of over a pound.
You aren't saving 4 or five ounces on a barrel. Titanium makes a horrible barrel
You aren't saving 4 or 5 ounces on a rail. Aluminum is lighter than titanium, a titanium rail will weight more.
You aren't saving 4 or five ounces on a receiver, it will weigh more, see above.
You aren't saving 4 or 5 ounces on a stock made from titanium, plastic and aluminum are lighter than titanium....
The only place you will save weight with titanium is using it where there are steel parts (except the barrel and bolt*), and most steel parts are so small the weight saving is minimal.
* titanium is unsuitable for barrels and not strong enough for bolts.
Metric Matt
09-05-15, 13:18
You aren't saving 4 or five ounces on a barrel. Titanium makes a horrible barrel
You aren't saving 4 or 5 ounces on a rail. Aluminum is lighter than titanium, a titanium rail will weight more.
You aren't saving 4 or five ounces on a receiver, it will weigh more, see above.
You aren't saving 4 or 5 ounces on a stock made from titanium, plastic and aluminum are lighter than titanium....
The only place you will save weight with titanium is using it where there are steel parts (except the barrel and bolt*), and most steel parts are so small the weight saving is minimal.
* titanium is unsuitable for barrels and not strong enough for bolts.
I don't think he was implying that barrels, stocks, rails, etc. are even available in titanium. I think he was just referencing the current wide variety of lightweight options available in those components.
I haven't read the links in the thread yet, for once, but does this address aluminum with Type III hardcoat anodize being used against Ti?
I am using an uncoated V7 Weapons Ti KMR barrel nut (not the ionbond black). BUT, I liberally used Aeroshell 33 MS, like I do with every installation. This is on my patrol rifle.
I'll remove it in a few months to check on things. I'm the guy whose sweat makes his glock rust. I live I central Florida.
Type 3 anodizing is far less important on titanium than aluminum. Aluminum is inherently soft, anodizing gives it a hard surface, titanium can be hardened, so a hard surface coat is not really any better than it natural state.
EDIT- didn't read carefully, see post below.
I'm going to perform the test using a buffer tube and V7 Ti castle nuts. Sounds cheaper...
If the receiver extension is anodized, your not going to see much corrosion. Anodizing forms an insulative barrier between the two materials.
Unless you remove/break through the anodizing, you do not have the good electrical bond necessary for galvanic action.
That is why they can get away with a steel barrel nut on an aluminum upper.
DD buffer tube (7075)
V7 Ti castle nut in the raw
Regular steel castle nut (had cosmoline on it, did not remove, not the purpose of this experiment) applied against Ti castle nut to provide tension/keep it against the threads better under load, although it's not on "very tight".
Sanded buffer tube in one section to break ano. to simulate poor ano/wear/whatever and create a worst-case scenario.
2 table spoons of sea-salt added to 1L of water, to approximate typical ocean environment (Wikipedia was my WAG for how much salt was needed).
Water was sourced from the tap, run through my Brita filter, before salt was added, so shouldn't be TOO much chlorine in it I wouldn't think. It sure tastes fine as compared to the taste out of the tap!
Placed in situ at the time of this post.
http://i58.tinypic.com/2isgyfa.jpg
http://i60.tinypic.com/2dac7x5.jpg
So now we wait 30 years. ;)
I honestly don't think you will see anything happen without some sort of electrical current being pushed through the solution, But this should be interesting for sure. I am going to do more of a real world test, and assemble some uppers with Ti nuts, and leave them out in the rocks in my yard. Sun, Sprinklers, rain, and some snow here soon, and see what we get as well.
Ryan
WS, You can probably accelerate the test by using a spray instead of submerging the sample. Just spritz it a couple of times a week. The water will evaporate and concentrate the salt. Personally I think you are peeing up a rope. You can fork anything up if you neglect it long enough. I hope I live to see meaningful results but at 62 I doubt I will.
This is ridiculous but I think it's a good thing to check everything out ourselves the best we can.
Kudos to WS6 for doing some work, I'll keep an eye out for results.
This is ridiculous but I think it's a good thing to check everything out ourselves the best we can.
Kudos to WS6 for doing some work, I'll keep an eye out for results.
What can I say, I never outgrew the "Go look it up yourself..." phase. I simply added "do" to "look it up", after I learned how full of crap "the books" and "the internet" and everything else was. My cousin (old hot-rod guy, owned a drag strip, raced dirt-track, etc.) used to say, "Don't believe anything you hear, and only half of what you see."
What can I say, I never outgrew the "Go look it up yourself..." phase. I simply added "do" to "look it up", after I learned how full of crap "the books" and "the internet" and everything else was. My cousin (old hot-rod guy, owned a drag strip, raced dirt-track, etc.) used to say, "Don't believe anything you hear, and only half of what you see."
I am down with this also!
Heck, who knows! perhaps that steel nut will waste away to oblivion, and the AL/Ti combo will be left over with nothing but a slight white film on it. If I had to guess, I would think the steel nut would be more of an anode then the small sections exposed on the tube.
I am down with this also!
Heck, who knows! perhaps that steel nut will waste away to oblivion, and the AL/Ti combo will be left over with nothing but a slight white film on it. If I had to guess, I would think the steel nut would be more of an anode then the small sections exposed on the tube.
The steel nut is rusting a tiny bit. I removed the assembly from the solution for a few hours today to expose it to air. basically, when I got home from work I took it out, and now it's going back in. Will repeat tomorrow. How long should I wait? I'm thinking 7 days of this is enough. Anyone leaving their weapon in salt-water (ocean) on/off without cleaning/drying for a week has more issues than Ti/AL interaction. I'll probably put it back in long-term and just report on it when the solution is 100% evaporated, after that.
I took a 7075 Buffer Tube and scuffed the ano off of the threads in one section. I then threaded a V7 raw Ti castle nut in place, and butted a 4140 or some such mil-spec castle nut up against it to apply tension on the threads/insure full dynamic contact. Then, I loaded 1L of water with 2 table spoons of sea-salt purchased from the store, placed this in a cup, and placed the assembly in said cup, removing it for a few hours each day to expose it to oxygen, etc. The test ran for roughly 80 hours, in this manner.
I could not discern ANY corrosion of any sort, aside that of the steel castle nut. Both the Ti, as expected, and the Al buffer tube, both on the scuffed and un-abraided sections, remained free of any sign of corrosion, either build-up, or darkening of the metal. There was simply no visual indication of corrosion that I could detect.
I did not take pictures because they would be IDENTICAL to the first set, except showing a rusted steel barrel nut.
*Copy of this sent to V7 by their request*
jerrysimons
09-12-15, 18:35
What can I say, I never outgrew the "Go look it up yourself..." phase. I simply added "do" to "look it up", after I learned how full of crap "the books" and "the internet" and everything else was. My cousin (old hot-rod guy, owned a drag strip, raced dirt-track, etc.) used to say, "Don't believe anything you hear, and only half of what you see."
Here, here! That's the spirit! Thanks
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