LocTite 680 Strength?

brasssmanget

brasssmanget

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Anyone have experience with Loctite 680? I'm considering anchoring the pintle bolts in the sidewalls of a cannon barrel with this. The fit is very tight, but slip-fit size. I cut slits do let the excess escape when pressing in the bolts. Do you think this is strong enough, or is welding required?? Holes are 5/8"D X 3/4" deep.
 
The heat and sudden impact from firing the cannon may destroy the Loctite in short time. Suggest brazing or silver solder them in place. Leave about .002-.003" clearance around the pins, place a silver solder disk in bottom of flat bottom hole with flux, heat and watch the solder flow up around the pin to the surface. Let cool. Same process as for brazing carbide to a metal shank. Ken
 
Once again - thanks for the tips and suggestions. I'll probably go with silver solder or weld.....my heat source is limited to Mapp gas and propane - not sure if that's enough for these trunnions and barrrel....
 
MAPP gas might be a bit of a push for that cannon barrel, as it will be a huge heat sink and I don't think your torch will be able to direct enough heat at one spot fast enough for silver soldering to work. You can certainly try it, but don't be surprised if it doesn't get hot enough.
 
Agreed. Just not enough for the size, based on what I've used it for in the past.

I'm not even going to try silver soldering. Welding should work - albeit a bit messy and will require some post weld cleanup I'm sure......
 
How about turning threads to a tight fit and screwing the pintle bolts in?

Glenn
 
I considered doing that, but threading the barrel holes would have required setting up again on the mill for squareness of tap, and I already turned the trunnions, so that would mean making two more for threading. I don't want to restart a project - at least not yet. Welding will be faster and pretty solid too.......
 
Sure,
Understand and agree. One way to get more heat for welding would be to make a table top forge out of some fire brick - a three sided heat reflective shield to contain and redirect radiating heat from your barrel back into the joint. Then put one or two additional map gas burners on the part to maintain temperature while using another to do the actual soldering.

This is the set up a local cast iron repair shop uses to weld and braze large broken cast iron parts back together.
 
Someday maybe I'll have a makeshift forge/oven.....someday.......
 
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