Loctite 272 lessons

[zzt]

When you use SF 7649 primer on the barrel threads and the comp threads, you have less than 20 seconds to get the comp on and clocked.

 

I cleaned all the old red off the barrel threads, then cleaned again with Slip #725, rinsed with water, then cleaned again with alcohol.  I let everything dry, then coated all the threads with SF 7629.  I waited ten minutes and coated again.  I let it evaporate for 30 minutes, then put Loctite 272 on the barrel threads.  I screwed the comp onto the barrel, wiped the excess that came out the back, and approximated the clocking.  I then put the barrel into the slide and tried to adjust the clocking.  I could not move the comp by hand.  I reassembled the pistol quickly, put a big adjustable wrench on the comp and turned it just enough to get it clocked correctly.  It took a great deal of effort.

 

The next time I do this I'll assemble the pistol, then put the Loctite on, screw on the comp and clock.    After that, I can pull back the slide and soak up any excess 272.

 

Geez!  The instructions say it speeds up set time, but 20 seconds?  Be warned.

[BeerBaron]

Yeah it reminds me of those vids of marines doing field strip drills putting their sidearms back together in seconds.

 

Its a race against the clock. 

 

i like to have a second pair of hands because it sets up so fast. If something goes bad you have someone to help wipe stuff etc if needed. 

[ShortBus]

I also clean and prep the threads and then put the gun together and then apply the chemicals so I can clock it quickly. 

[outerlimits]

this needs to be mentioned once again.

 

242 (blue)-little muscle

272 (red)-need copious amounts of heat

290 (green)-good luck

480 (black)-fuggedaboutit

 

the move is magnified as the thread diameter get's larger-YMMV

[tkheard]

zzz - your experience replicates mine! Except that I only got about 10 seconds before the comp was un movable. After I got it apart and cleaned everything up, I used a *very* small shot of the primer. The amine in the primer is the culprit. Too much and the 272 becomes like concrete!

[ShortBus]

1 hour ago, outerlimits said:

this needs to be mentioned once again.

 

242 (blue)-little muscle

272 (red)-need copious amounts of heat

290 (green)-good luck

480 (black)-fuggedaboutit

 

the move is magnified as the thread diameter get's larger-YMMV

 

 

I use 680 which is supposed to be the strongest and it still comes loose  gonna have to use my set screws. 

[Ming the Merciless]

20 hours ago, ShortBus said:

 

 

I use 680 which is supposed to be the strongest and it still comes loose  gonna have to use my set screws. 

 

 

If you are not using the primer/accelerator, make sure you let the Loctite set up for 24 hours at above 70 degrees F.

[ShortBus]

1 minute ago, Ming the Merciless said:

 

 

If you are not using the primer/accelerator, make sure you let the Loctite set up for 24 hours at above 70 degrees F.

 

I did the last time, lasted a lot longer but alas, it's loose. 

[zzt]

I thought about adding set screws while the comp was off, but decided against it.  This is the first time I've used the primer, so I'll see how much longer it lasts (if any).

 

To eliminate the loose comp problems, my next two builds use Trubore blanks with Eric's custom comp cut into them.

[Service Desk]

I use primer, but only ever put the 620 on the last 4 threads and use a set screw. So far so good with steel and alloy comps. YMMV.