Silver Soldering Question

[LuftPost]

Hey guys,
quick opinion poll before I start doing some soldering tomorrow. I've done several 1200° silver solders already, but always on fresh untainted threads. This time I'll be soldering threads that have had locktite on both sides, and I've picked, cleaned, and ran solvent on everything, but I'm curious if you all think I should put some flame to the threads to burn off any residual locktite before I seal it for good? The locktite was that clear, supposedly strong stuff (not really) that AAC provides with the Blackout's. I'm leaning towards flaming it, but I hate putting unnecessary stresses on the barrel since I'll be allowing it to cool before I solder it.
Thanks!

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[Velzey]

Yes burn it all off, then I use a small stainless wire brush then wipe it down good with acetone. Just enough flame to burn the old stuff off...no need to make the barrel red hot or even a dull orange.

 

[LuftPost]

Yeah, definitely not going for red hot on this exercise. Thanks, I figured I was leaning to the right path.

 

[nrc]

Burn it off - as others have said. You can do it at a low temp (blue benzomatic would do it...). Shouldn't stress the metal at all.

 

[ZigZagZeke]

Heat and wire brush. Clean metal is mandatory with silver solder. If you can find some lower temp silver solder (850F) use that. I've done miles of copper and stainless tubing and fittings with silver solder in my years as a power plant tech. Dirty metal = sloppy looking, bad joints.

 

[MarkAd]

ZigZag is right, With silver soldering cleanliness is godliness. If you doing steel to steel I would use grade III. It gives you a flat joint and has a lower melting point.

 

[iamme]

AAC uses rockset not locktite, at least on most their mounts now. And I'm doing to take a wile guess he's using 1200 to make for a permanent "new barrel length".

 

[ZigZagZeke]

AAC uses rockset not locktite, at least on most their mounts now. And I'm doing to take a wile guess he's using 1200 to make for a permanent "new barrel length".

I've used 850F on 2500psi stainless steel steam lines and on SS hydraulic lines without any failures.

 

[iamme]

I've used 850F on 2500psi stainless steel steam lines and on SS hydraulic lines without any failures.

Congratulations and here's your e-cookie. the above does not mean it meets atf requirements of permanent.

 

[MarkAd]

Congratulations and here's your e-cookie. the above does not mean it meets atf requirements of permanent.

Oh wize one impart your wisdom and explain exactly what the specs and requirements are.

 

[iamme]

Oh wize one impart your wisdom and explain exactly what the specs and requirements are.

Oh lazy one here's the link from a simple 5second google search that holds the information you seek
<broken link removed>

 

[Velzey]

Like anyone is ever going to check...

 

[ZigZagZeke]

Oh lazy one here's the link from a simple 5second google search that holds the information you seek
<broken link removed>

OK, if that's what he's after then fine, use the 1200F silver solder. But make darn sure the metal is clean. It's even more finicky than the lower temp stuff.

 

[LuftPost]

no no, barrel is 18" so ATF has no bearing on this. the Blackout loosened up with the rockset, I got a minor endcap strike on my 762SDN6 (which AAC warrantied), so I'm not putting faith in either locktite or rockset with mounting it again.
thanks for the suggestions though. I'm waiting on a small stainless brush from McMaster-Carr to get the threads in the Blackout and then I'm going to remedy my problem

 

[iamme]

Dang sucks that it loosened. Everything I've read the stuff is a PITA to deal with/remove

 

[LuftPost]

yeah, it held for about 250rds, but 1/4 turn later here it is. and it was put on correctly- solvented/cleaned with acetone twice, drop of rockset on each of the threaded parts, and used a 22mm crows foot with 25lbs torque if I remember right.

 

[LuftPost]

an update in case anyone is following this, I'm waiting for AAC to return the can before I silver the Blackout on; they emailed me today saying they begun work on repairing the can.
basically before i permanently attach it, i want to verify its still concentric to the bore...

 

[iamme]

Wait wait wait- you're perm attaching the mount or the can???

 

[LuftPost]

Wait wait wait- you're perm attaching the mount or the can???

The mount

After its all cleaned and i put the flux/silver mix on, index it correctly, i want to put the can on and verify alignment/concentricity before i heat her up...

 

[LuftPost]

can is on the way back to me. going to be soldering next week. will provide update and pics.