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DanB
01-08-2013, 08:49 PM
I have a difficult problem. A friend of mine bought this air gun and the previous owner glued the barrel in the action. The problem is when he glued it he didn't align it properly and the air transfer port doesn't line up correctly. To make a long story short this causes gun to get about 50-60 shots on a fill as opposed to over a hundred. The current owner is a bechrest shooter and sometimes needs more shots.
We have a strong suspicion that the person that glued it used Devcon. He put so much of he stuff on there that it got into the set screws that hold the barrel as well.
What do think is the best way to approach removing this barrel? I thought about soaking it in solvent for few weeks but I doubt it will work its way deep enough into the action to help. That leaves heat. At what temperature should I stop heating it? The receiver is aluminum.
Thanks,
Dan
http://www.danbrownphotography.com/galleries/albums/userpics/CIMG0016%7E0.jpg
http://www.danbrownphotography.com/galleries/albums/userpics/CIMG0017%7E0.jpg

alinwa
01-08-2013, 09:18 PM
Start with yer wife's electric iron, on high. It prolly won't work unless it's an older iron (say a prayer of thanks to the liberal gods)

Next try a heat gun, on low, Harbor Freight has them for ten bucks. Or an older hair dryer if your family has one.

bottom line is that Devcon will fail long before AL is affected, around 350F is tops for common epoxies.

epoxy=250F-350F
wood=250F
wood finishes 200F-300F
AL= 1200F+

Epoxies are actually fairly painless once you get past the fear factor :)

al

Dave Tooley
01-09-2013, 07:56 AM
Your problem lies with the lower portion acting as a heat sink. I would go straight to a propane torch and start at the junction of the upper and lower sections. Preheat that then work your way up each side.

If you get it apart a bit of advice. On reassembly it never hurts to have release agent on the screws when expoxies are in play.

Dave

Jerry W
01-09-2013, 08:29 AM
Like Al suggested, I'd give that clothing iron a chance before trying anything hotter. Set the iron on high, put it on the scope rail and let the heat soak in. Chances are, after about 15 minutes the epoxy will be as soft as peanut butter.

Let us know how it works.

Jerry

Edit to add: You should probably de-pressurized the tank first. I imagine the heat could affect the o-ring seals. Safety first!

alinwa
01-09-2013, 06:17 PM
Edit to add: You should probably de-pressurized the tank first. I imagine the heat could affect the o-ring seals. Safety first!

LO-frickin'-L!!!!

I forgot this is AN AIRGUN!!!

"yeahh shure den, just put 'er in da' wife's oven on t'ree hunnerd eh...."

DanB
01-09-2013, 08:41 PM
Oh yeah, it will be depressurized.
The side lever block has also been glued into the action. Looks like a screw broke off and instead of fixing it proper they used epoxy. I can't believe anyone would do such a thing.
Dan


Like Al suggested, I'd give that clothing iron a chance before trying anything hotter. Set the iron on high, put it on the scope rail and let the heat soak in. Chances are, after about 15 minutes the epoxy will be as soft as peanut butter.

Let us know how it works.

Jerry

Edit to add: You should probably de-pressurized the tank first. I imagine the heat could affect the o-ring seals. Safety first!

sgeorge
01-10-2013, 10:35 AM
A little bird told me that the epoxy might be a simple 5 minute variety rather than something more tenacious.

DanB
01-10-2013, 06:30 PM
Well I did it. I used the iron first and was able to get two of the three set screws out. Temp was around 200f.
http://www.danbrownphotography.com/galleries/albums/userpics/CIMG0019%7E0.jpg
The last screw required a little more heat so I used the heat gun.
http://www.danbrownphotography.com/galleries/albums/userpics/CIMG0020.jpg
There is some clean up to do but the risky business is over.
Thanks for the help guys.
Dan

Jerry W
01-10-2013, 07:01 PM
Wow, what a mess! I hope your friend got a good deal on the purchase.

alinwa
01-10-2013, 07:18 PM
well done :)