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Posted: 10/27/2003 11:40:17 AM EDT
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A few years ago I purchased a brand-new Norinco MAK-90 in order to install a USA stock kit, and as such have a fixed-stock cousin for my pre-ban PolyTech Underfolder. In order to get it looking the way I wanted, I replaced the gas block and front sight with a set removed from one of those parts kits you can get at fun shows, in order to be able to install the cleaning rod. No problem. I then installed a wood USA parts kit that is a MAJOR disappointment. No biggie, K-Var makes some nice polymer kits that I can get. The embarassing question is this: I attached a muzzle brake to the rifle using, get this..., J-B Weld. Looks great, and it's on there rock-hard, but..... .....I haven't fired it yet. So, any ideas if this thing is going to come rocketing off when I fire this thing? That's it.... Please accept my sincerest apologies for my 
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If all else fails, is there any way to get it off and then installed properly? I really like the brake (about 1" long with four cuts across the top about 1/3 of the circumference of the brake, the cuts being perpandicular to the axis of the bore) and definitely want to keep it. |
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A few years back I JB welded a break on a SKS. Looked cacko... one day at the range it flew off. found it about 12 15 yards in front of the firing line. Picked it up pinned it on with the pin that came with the kit and it is still on the old dog. I just did not want to knock the old pin out.....Oh well those breaks are tough. Ken RSA |
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Unfortunately, this thing can't be pinned on. It's designed to be screwed on to the threads of a pre-ban weapon. So, how did I get around this little problem? Simple! I Dremeled the threads off the interior of the brake!  Keeps getting better, don't it? As such, if this thing launches downrange, I'm either going to have to get a different brake or have this one spot-welded on. I don't want the spot weld because it will look like complete caca. Guess I'll follow FOTL's advice and shoot it until the brake gets fed up and decides to leave. I'll get another brake properly installed then. |
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If you use a propane torch on the break to heat the metal, the JB weld will fail. Epoxies are heat sensitive. You do not need to get it red hot. Just hot enough to move it. this is often why they end up downrange. The epoxy was just fine when the gun was cold, it heated up and the epoxy bond was broken. Sheesh, and golfclub guy know that one. |
| Zaphod; It ain't gonna work. It may stay on a while if you got it on straight with equal clearance all around, but the JB will eventually fail in that application. To save the brake you have, use a propane torch to take it off. Clean everything up. Put a tight-fitting dowel rod into the bore. Take the whole mess to a welding shop and have them wire-weld the brake on, using the dowel as a guide to keep it straight. Of course, if you do this, you'll have to grind the weld off to take the front sight off, but that's usually never needed. The only other thing you can do is pick up a new brake, a die and a handle, thread the barrel and put it on right. Check all laws before threading the barrel. |
30 to 50 yds seems to be the area to start looking for a slant brake. The 74 style from 10 to 40 yds. I have tig welded several to the fsb with good results have not sent any down range yet. All it takes to undo JB weld is apply a little heat it will soften and the parts will seperate.
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Besides your surface prep of course, it will depend on which JB Weld you used. Quick set is good to about 450deg, but reg/slow set is good to about 600deg. Big difference in the chance of it lasting regardless of the ATFs 1100deg goal. As future options, a slipon adaptor and brake work great when tacked to the fsb. Chris at ak-103 has good US part brakes/adaptors with a hard chrome lined in the works, and Jason at IGF is gearing up for sets of US copies of Romy bits with the unwelded thread friendly pitch. |
Yeah, I'll probably take it off and get one of those that pin to the front sight. I can't thread the barrel because it's the PC-type which have been turned down to prevant some homicidal maniac from installing a super-deadly long-range armor-piercing flash suppressor on it.  Thanks! Oh, I used the regular JB Weld. Will any plumbing-type propane torch work? Edited to add:
So I guess the JBW advertisement claiming someone fixed an engine block with it is complete BS? |
A good TIG weld will be barely show up.. Go with the weld.. |
| Please don't get the idea from our comments that JB Weld is no good. In fact, I couldn't do without it around my shop and house. It's just that it is not adequate for the purpose in question here. I recently tried it to hold some bolts in on a Lawn Boy exhaust manifold, and that didn't work, either. Nothing wrong with the epoxy, I was just trying to extend it's application a bit too far. If you can take off the brake, clean everything up and have it welded to the sight base (as RS39 said), You will then be able to take the sight base/muzzle brake ass'y off if needed. I almost did the same thing to my SA85M, but decided to leave it original (I used to be always modifying things, now I want them all original - it's a function of aging). Bottom line, it's not worth all the trouble to put a brake on a semi-auto AK. |
LOL! LOOKS, man! LOOKS! Who said anything about FUNCTION! 
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Well, I went and fired the guy a few weeks ago, and guess what? It didn't work! Yes, sir! At the end of the first mag, I looked to find the brake missing. SOB took off about 30 yards. I'm amazed I found it... So, I am here to tell you that JB Weld does NOT work for holding on muzzle brakes. DOH! ETA: Holy thread resurrections, Batman! |
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