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Epoxy doesn't grip my barrel (coaxial)

Posted: Mon Aug 03, 2009 4:17 am
by frozebyte
Hello all,
I just wanted to ask a question regarding epoxy in a coaxial setup.
I recently found a small diameter pipe to use as my barrel and i used jsr's(i think) method of using epoxy to seal the barrel with the chamber. I created a base, poured epoxy from the top, and left it to set for a day.

After about 20hours, it fiddled around with it, and realised i needed an internal support for my barrel and i pushed it through, however, this was when my barrel came loose and could slide around. I put epoxy again, and left it to set, but the epoxy still refuses to grip my barrel.

Is it due to the smooth surface of the unsanded barrel? Or is my epoxy spoilt? (Im using a pretty new bottle of z-poxy, it worked well when i fibreglassed my bamboo bicycle) Any ideas?

Sorry for the long post, i want this mini to work :)

Cheers.

Posted: Mon Aug 03, 2009 4:27 am
by jackssmirkingrevenge
From my tutorial:
1) roughen the surfaces of the pipe where the epoxy is going to adhere. You can get by with rough sandpaper but I like to use a broken drill bit or file to make deeper grooves and promote better adhesion.
;)

Posted: Mon Aug 03, 2009 4:29 am
by theBOOM
Wait.. so your saying the epoxy isnt adhering to the material??? hm... you could get epoxy specially for metal... although I have had problems when using 5 minute epoxy and trying to adhere 2 surfaces to it (brass barrel to plastic chamber)... after letting it dry overnight I tried to pull the barrel out and it came out with ease...

As I said epoxy sometimes tends to fail... I would use jb weld I've had pretty good results with it so far.. or use marine epoxy like jsr did...

Oh.. I wish jsr gave us more tips and tricks about working with epoxy ... I know he made a thread but there are still things that I have questiones over... :roll:

Anwyay hope this helped.....

Posted: Mon Aug 03, 2009 4:41 am
by jackssmirkingrevenge
theBOOM wrote:I wish jsr gave us more tips and tricks about working with epoxy ... I know he made a thread but there are still things that I have questiones over... :roll:
Again, from my tutorial:
Any queries, feel free to ask
;)

Posted: Mon Aug 03, 2009 6:34 am
by frozebyte
i think my sandpaper is too fine, it smoothens my barrel instead :(
I'm facing the same problem as theBOOM, but this third time i hope it adheres. My epoxy is a finishing resin that can be used with fiberglass.

Cheers.

Posted: Mon Aug 03, 2009 6:39 am
by jackssmirkingrevenge
Image

Or use a hacksaw to cut some shallow grooves instead, without actually going through the barrel.

Posted: Mon Aug 03, 2009 6:52 am
by inonickname
I don't know if you can get one, but I knurl stuff before epoxy use now.. It not only leaves a rough finish (comparitively) but deep grooves for the epoxy to grip into, without actually changing the barrel diameter.

Posted: Mon Aug 03, 2009 7:22 am
by psycix
Make the surface rough. The rougher the better.
Cutting grooves or drilling holes makes even a better grip. You can also look into reinforcing by putting bolts through the chamber wall.

Posted: Mon Aug 03, 2009 7:22 am
by frozebyte
are those metal files? i've been waiting to get one :) i hope the third round of epoxy works, don't want to waste my last drop(literary) of epoxy :( Its really expensive here.