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Posted: 6/7/2006 6:57:23 PM EDT
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I was just watching a History Channel segment on adhesives and nails, and they stated that some industrial adhesives were being used in place of rivets. Ya think you could use such stuff for an AK build? |
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Don't listen to the naysayers, It might be possible....I stress MIGHT! Adhesives are replacing many, if not most, sheet metal fastening systems in the automotive industry. I know this because I work for a major automotive supplier here in metro Detroit. If you could find the correct adhesive, one that is strong enough, with the ability to withstand the heat + one that has the Shock & Shear strength.....I don't see why you couldn't use it. I just don't know if such a thing exists. If it does....I'd try it out myself! Think of it!!........Glue it together AK's! SWEET! Tall Shadow 
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I've actually been thinking along the same lines. I was using red loctite to hold some lower bolt rails in place in preparation for screwing them in, then I started thinking why not just depend on the red loctite! I haven't tried it yet, but one thing I do plan on trying is brazing the receiver to the front trunion, and still installing screws in the lower trunion holes just as a backup measure. The brazing material I plan on using has a high melting temp (1600+ F) and is nearly as strong as a weld, but has the advantages of still being un-doable if you need to and only requires a MAAP torch instead of a welding unit. (and it has nothing to do with the fact that I also suck at welding  )
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This is totally possible. There are actually advhesives out there that are just as strong as screws or rivets. I have seen someone machine parts on a lathe that were too small to hold with the jaws and used adhesives to hold them onto a larger piece. I didnt think it was gonna work, But it did. I think the biggest issue people are having with this is that the traditional way to do AKs is with rivets.....Anything else is just a travesty......Mostly becuase many of the people on this site feel as if they are some sort of collector. my guns are for shooting and thats the most important part to me! Go ahead guys tell me I am a liar and that I have never even touched a lathe.....I dunno, I just made it up anyways. |
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Probably do-able, but with a couple disadvantages. I'm guessing any adhesive that might work for an AK build probably can't be obtained cheaply or readily by the avg joe. Also, once it's done it's DONE...no do-overs. Tall_Shadow - What adhesives are you referring to? I also work for one of the Big 3 (not in the Body Shop though), and am not familiar with what you are referring to. I know of structural adhesives used to add rigidity, but not to actually bond pieces together. Like I said though, I'm not a Body Shop/Sheetmetal person either. --Otter |
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IIRC, certain aviation/industrial adhesives may do the job. The adhesive needed would have to be intended specifically to hold steel components together under thousands of pounds of shear stress. Unfortunately, most of us probably don't have access to the necessary adhesives. Loctite or the various forms of super glue most definitely will NOT hold. If you were able to get and use the right stuff, you might very well have a build that is stronger than a conventional rivet or screw build because no holes would need to be drilled in the receiver (or in the trunnion, for that matter). This would work great if you got a new never-used trunnion that hasn't had the rivet holes drilled. You could have solid metal bonded together without any holes theoretically taking away from the strength, which would ideally leave you with a result that is very similar to a weld build. |
Maybe in some parts of the autos, but where the engine attaches to the frame? I am sure they still bolt or weld the mounts in. Because thats the same as where the trunnion attaches to the rails. |
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I keep thinking of screw builds and those self tapping screws and laugh when I look at kvar's pic's on what happends when a rivet itn't supported correctly. In the end someone on here will end up DEAD. just because they cant do what i did... Big fing hammer knock the barrel pin out, rest the trunnion on something metal smack the barrel out and then rivet with a pin punch... (gee that was hard.. and im still alive) my stats = pc gamer no a metal worker... I didn't know jack before ak's now i can do it all weee.... but i still rivet with a pin punch and a hammer.. |
What Kvar pics?????Got a link.....As for using U-drive's...Iwill not start that  ...Glue could be interesting because the AUDI Sport coup's frame is glued together.... It has got to be a steel fastener for me...RIVET...U-Drive...or TIG,MIG,Heli-arch welded.... Please DON'T on U-drive's because it been over before...Glue just does not seem right on a firearm |
The only trouble with this approach would be that you are going to alter the heat treating of the trunnions, and more than likely, the barrel. High heat is not your friend with High pressure cartridges+Soft barrel -&- Trunnion = Face -&- Body parts a bloody mess! Please rethink this idea! Tall Shadow
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Look under the hood, or trunk, or on the inside of the doors. It is Way more popular over seas, but is quickly catching on here. As is stated above, Audi, and I think one or two others, are even using this process for structural components (IE: Framework, crossmembers, Etc.). The technology is out there, weather or not it is available to anyone other than big name manufacturing companies is not known to me. But it's out there! Now I doubt Wally-World has a tube of it in the automotive section.  But, if it is out there, someone knows about it/makes/sells it. We just need to get ahold of the right people/person. Tall Shadow
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No, It's not. Car: 100's of lbs of engine + Transmission + Torque to drive said car forward/reverse + steering +braking a TON or more of vehicle, being held together, all while in motion. AK: Hold a few lbs of components together in recoil, while action is locked (Shooting), then hold said components in alignment for cycling of the action. The rivets aren't containing the chamber pressure or holding the bolt closed against the cartridge's impingement! The bolt is locked into the breach face while this is going on. It is only unlocked by the action of the gas system. You could (I would guess) chamber a round, and set it off with nothing more than the bolt + barrel assembly & a striker......and have it be no more dangerous than when it is sitting in the rifle. The two are no where near the same thing. If adhesives are available for the first one, which is much! more demanding of a work envelope, then there must be something that would work in the second example....that We can get & use. Tall Shadow
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Watch a slow motion video of an AK firing. Then get back to us with your "e-knowledge." |
You're right, they are nowhere near the same thing. The type of stress that AK parts are subjected to are different than those that a car would be subjected to. It's apples and oranges. If an AK were put together and fired without the trunnion being secured properly, the trunnion, barrel, and entire front end of the weapon would fly out forwards and you would likely end up with the receiver cover and bolt carrier in your face. Not quite a KB, per se, but not safe at all. What would be a good start, IMO, is if someone knew or could find out exactly how much shear stress the receiver and trunnion are required to withstand without separating from each other. I think the necessary adhesives would be in the aviation world, not the automotive. There was a thread posted about this sometime last year and a member here (can't remember the name, unfortunately) who happens to work in aviation mentioned the properties of the adhesives used at his work. If anybody is friends with an aeronautical engineer or the like, might want to ask them about it. |
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heh heh heh... sounds interesting. the bolt and carrier slamming into the trunion, which creates shear forces. Surface area of the joint is the enemy of shear force. with an AK, there is (round guess) maybe two square inches max of surface area. Most glues are measured in thousands of pounds per square inch. however, before anybody gets excited, shock stresses have the ability to do more than a steady gradual aplication of force. I don't have the physics proofs, just from experience with building things. you apply 12 ton press to get out romy-g pin, or hit it with big f-ing hammer. I know my hammer isn't doing 12 tons of force... Anyways, metal prep would be most important. IT would need to be very clean, and perhaps acid etched (or other) . There are surely some methods which can be used to molecularly bond carbon chains to metal. In my old research job, we used to covalently bond carbon molecules to glass. covalent bonds are very very strong. Somebody google covalent "carbon metal bond"... there will be research papers... ???? after you form a molecular bond carbon-metal-carbon, you have in effect created a sigle molecure of a receiver/trunion, which would be extreamly strong. maybe even as strong as a two square inch weld. I'll get back to you on this, after a quick google search. The idea is an interesting one. At the very least, I think a slow fire weapon could be safely created, high tempurature being an enemy. And using a buffer and/or solid shoulder stock would be a good idea too. the doors on my old chevy truck were glued on... to adjust them, it took a torch and a jack... it';s like a rubbery compound, very strong stuff. (apparently) just remember that a lot of synthetic compounds degrade over time, and are suseptible to chemical attack (cleaning solvents/gun oils) you may build a stong AK, but you could never oil it.  |
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start here. Covalent_bond
first problem, is that ther surfaces will not be perfectly flush, therefor a quick and dirty metal-carbon-metal bond will only form where the surfaces are very very close and flat. Therefor this aproach is a bad one. (sorry) as a receiver/trunion interface is very uneven. A better aproach would be to find an epoxy like substance which will fill the microscopic voids between the two surfaces AND which will covailently bond to an Fe atom (that's "Iron") in effect, a glue. Which has probably already been invented... we just need to find it. I would think that a rubbery type of material would be durable. Whereas a crystaline bond would be more susseptible to stress fractures. also look into pakerize, to prep the surface. edit maybe try to pakerize the surface, then use JB Weld? (don't try this)gorilla glue?  deffinitely low heat aplicaiton only. (slow fire)
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What?, is Someone's oatmeal is a little more "flavorful" this morning?  I HAVE seen the AK video, I own AKs, there is one sitting not 2 feet from me as I'm typing this.I do mechanical design & engineering in My work EVERYDAY!(20+ years at this job alone.) The AK series, like the AR, or most (not all) other semi/full auto weapons, are a LOCKED BREACH type system.....The stresses/pressures, other than recoil, are all contained withing the BOLT/BREACH/BARREL! not in the receiver! It is not My knowledge that is flawed, Bro'....  Thanks for playing! Tall Shadow
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Great points! But remember, the actual area of the rivet(s) holding an AK together are/is quite small also...... Many modern adhesives are as strong, if not stronger, than the steel used in making the rivets... Most of the adhesives I've come in contact with that are being used for metal to metal bonding are, at least, somewhat flexible to avoid shock/vibration fracturing the bonding points. I do agree though, that surface area/cleanliness/surface to surface fit will play a BIG roll in how well an adhesive would work. Many adhesive are unaffected buy oil/grease. However!, there are always "Dry" lubricants, or coatings. The other great point brought up by Bob1984, was the fact that the aviation industry might be a better (or at least another) place to search for a suitable adhesive. OK!, This is a great brainstorming session! Let's keep going with it!!!  Tall Shadow
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Oh wow you're an engineer AND you own and AK. Let me bow to your model airplane designing skills. In all seriousness, a lot more goes on with a firearm then just the pressure resulting from discharge. "Other then recoil" I like how you try to omit probably the most important factor. I cant believe you people are actually talking about using glue to hold an AK trunnion onto the frame considering the forces involved. And saying glue holds together a body frame on a car ISN'T EVEN CLOSE TO BEING APPLICABLE. No one has given one example that is even remotely similar to glue being used on something that receives torque and lots of force. |
Here's the problem. If an AK is fired without the trunnion being secured, sure, it may be good for a few rounds. But the impact from the bolt carrier/bolt slamming back into battery after each shot is going to eventually push out the barrel/trunnion. Hopefully, the AK would stop firing by virtue of not being able to go into battery (the tang at the back of the bolt carrier prevents out of barrery fire) once the trunnion has started working loose. If not, you would eventually end up with all the (possibly destructive/dangerous) signs of excessive headspace. Then the rifle would stop working, one way or another (  ). Reverse-recoil is simple Newtonian physics. It is precisely this reverse-recoil that would be the cause of the barrel/trunnion working its' way out of the receiver. |
Yeah I agree I was actually thinking along those lines. Though I think it would be okay if I air-cooled the area and was careful, it's not worth it. Back to screws for me. This is a really interesting thread though, hopefully we can keep it going. |
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there is only one way to find out. Somebody needs to get some wicked glue, talk to an airplane shop/supplyer, and find out what is the most bad-ass metal to metal that can withstand shoke stress, shear forces, and preferably is solvent resisten (and doesn't degrade over time) I would trust that door hinge glue, at least for a short time, in slow fire, if the AK had a solid shoulder stock, and a foreward pistol grip. a person could hold the gun together tightly while firing. The shoulder stock (don't have it wedged in there, instead make it a part of the glue joint) held up against your shoulder will help the recoil energy transfer directly to your shoulder (not to the glue jopint of t he rear tang) and there is a LOT of surface are to play with here, you don't need to stop at the actual surface contact between trunion and receiver, fill that bad boy up with glue. same with the trunion. Fill it up with glue. IT will add lots of surface area to teh joint. And using the foregrip to hold the gun to your shoulder will keep the forward seciton from flying off too. SHould be good for at LEAST a few clips. I would think. Especialy with a strong 1.6mm heat treated receiuver, which would be resistent to the torsional forces of the firing sequence. Note: AK receivers "twist" a bit during firing, this is bad, but the glue may be strong enough to resist this That is another big reason why the glue would need to be flexible. Who is willing to build one up, and see what happens? tie it behind a tree, with a shoe string, and bump a few clips off. if it holds under this extream abuse, it will deffinitely hold up with it held to your shoulder.
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Okay, I'm game. Someone send me an AK kit, I'll build it with Devcon or Hysol, and then shoot the hell out of it until it fails. Yeah, I'll be wearing a face shield, I've seen waaaay too many workplace injuries. I do aircraft structural repair for a living, and have a fair amount of experience with high-strength adhesives. I'm not familiar with the inner operations of an AK, so where is that slow-motion video I can view. If all that is needed is a machinable material with high shear strength, then that is feasible. But at least two unknowns are differential thermal expansion of various rifle parts, and shock stress. Cleaning solvents would have to be carefully selected, and I'd do a serious visual inspection with a 10X loupe about every 100 rounds on the prototype. Didn't we debate this topic about 2 months ago? |
I duped?! Awwww, teh suckage!!! |
Well, Don't feel bad. IIRC, that thread ended with two distinct opinions, and no one attempting an actual adhesives build. If someone is willing to do some serious research, and is about to build an AK, I'll see if i can snarf some Devcon and scrim cloth for their use. This stuff is expensive, and I cannot guarantee that I can provide (free of charge) the most suitable epoxy formula for this application. However, if they have the $$$, Devcon has about a dozen different products/formulas for many industrial applications. The info was on the net last time I looked, and can be purchased by anyone.  |
I know what you're talking about - we do it all the time on helicopters, when dealing with composite repairs (LOCTITE Hysol EA.9309 is a good example). The adhesives are strong, but not THAT strong... Many times they are combined with screws or nuts to hold a piece (such as a rotor-blade tip-cap) in place... Other times, they are in-fact used to glue metal in place (such as the abrasion strip or spar on a rotor blade) and they do hold up... But eventually they fail, and we have to re-glue the 'disbonded' section.... Further, while they 'hold up' to being spun around at near-Mach speed & twisted all over the place by a pilot who knows that as long as he brings it back in one piece, we'll fix it for him, stuff that's been 'glued' can often be broken apart with a putty knife & some elbow grease.... Might it work? yes... But if it dis-bonds, you got yourself a Kaboom! Personally, I don't recommend adhesive for building firearms... The stuff we glue together isn't subjected tot he same lateral-sheer force imposed by (a) a gun firing, and moreso (b) the rather mechanically crude action of the AK, where the bolt slams into the front and back of the weapon each time it cycles (as opposed to being gradually slowed and stopped pre-impact by a spring, vis-a-vis more modern designs).... Plus, this shit isn't sold at Home Depot - you'd have to find someone to sell it to you.... My POL locker is kept stocked thanks to your annual contributions to the US treasury, so I have no idea where to actually BUY the shit from... |
LOL, wouldn't make a difference, as it simply limits the metal on metal contact between the bolt carrier and the rear of the receiver. Still might be funny if someone really did think along the lines of "Oh yeah, the superglue wil hold, I put a buffer in it..." |
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I have not seen the biggest issue we see on trucks - chemical decomposition of adhesives under high heat. Get that stuff over 400F in a oily dirty enviornment and watch is simply shrink to nothing and flake away. Happens a lot with ultra strong carbon fiber resins in F1, eg. like drive shafts. NOw the same thing on the F1** truck - new carbon type drive shaft coming, biggest issue - heat and chemical solvent attack. Also, we sometimes use loctite on shear joints, it works like champ. and when they say its not serviceable? we just tell them yea it is if you heat it over 400F it turns to goo. |
A couple of observations regarding the second illustration. It shows a round-head rivet being installed into a receiver/trunnion that has been dimpled/countersunk for a countersunk rivet. I would hope that everyone here is smarter than that. The red area on this image shows a gap between the rivet shank and the hole in the trunnion, as well as a properly formed shop head on the bottom of the rivet. Assuming these are regular solid rivets, the rivet shank would normally expand to fill that gap BEFORE the shop head was formed on the bottom of the rivet. At least that has been my experience in bucking a few hundred thousand solid rivets on aircraft, vehicles, and other projects. The structural adhesives that sparked this thread are often used to fill gaps when MECHANICAL rivets must be used, and the rivet is a little sloppy in the hole. BTW, anyone ever used mechanical (blind) rivets for some of their AK build? |
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