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This is why I don't like using metal fittings into PVC
Posted: Fri Dec 03, 2010 3:25 pm
by Selador
This morning, I decided to make a breech for a 1/2 inch barrel, out of a 1/2" ball valve.
Got that made.
Installed it on the gun with the 1/2" piston valve.
Took the airgun outside.
Laid it down on the porch, and went to get the air hose. (Lest I forget, it's pretty cold here. We still have about a foot of snow lingering from the last snowfall.
Almost back to the airgun, and I hear a
crack.
The 3/4 female fitting that is glued to the piston side of the 1/2 tee, cracked open.
It has a metal 3/4 inch adaptor threaded into it.
Because that 3/4 female adaptor is glued to the tee, the piston valve is now trash.
Now I can't test the breech loader until I get the 1" piston valve done, and the gun re-assembled with the 1 inch Pvalve in place of the 1/2 inch Pvalve.
Oh well, I guess I know what I'll be doing late tonight. LOL
Posted: Fri Dec 03, 2010 4:31 pm
by kickmeinthejunk
You have a better chance of this happening again if you plan on doing the same setup. When mixing pvc and metal your female threads should always be metal. You could use a steel coupling and attach a male adaptor to the pvc.
Posted: Fri Dec 03, 2010 4:34 pm
by jackssmirkingrevenge
Lest I forget, it's pretty cold here. We still have about a foot of snow lingering from the last snowfall.
There's your problem, PVC doesn't really like temperature extremes...
Posted: Fri Dec 03, 2010 4:34 pm
by Selador
kickmeinthejunk wrote:You have a better chance of this happening again if you plan on doing the same setup. When mixing pvc and metal your female threads should always be metal. You could use a steel coupling and attach a male adaptor to the pvc.
Ya think ???
jackssmirkingrevenge wrote:There's your problem, PVC doesn't really like temperature extremes...
Ya think ???

Posted: Fri Dec 03, 2010 5:06 pm
by Gun Freak
I don't like mixing metal and PVC fittings either. It seems the metal male threads are always too big for the female threads in the pvc.
Posted: Fri Dec 03, 2010 5:32 pm
by velocity3x
You could install one of these around the female before threading in the male.
Posted: Fri Dec 03, 2010 5:51 pm
by Selador
Gun Freak wrote:I don't like mixing metal and PVC fittings either. It seems the metal male threads are always too big for the female threads in the pvc.
True.
They don't seem to thread in as far as the male pvc fittings, do. Then when you tighten them because you think they should be going farther in... You get stressed pvc, like the above.
velocity3x wrote:You could install one of these around the female before threading in the male.
I was thinking that if I decided to try to save that 1/2" piston valve, I'd do something like force some epoxy into the crack, then put a hose clamp on it. (Then use a PVC adaptor in it the next time. LOL)
Thanks for reminding me of that, because I have a 1-1/4" piston valve that I had to use a metal nipple on. This reminds me that I really should put some hose clamps on that one, too.
~~~
BTW: to all...
If the 3/4 to 1/4 adaptor had been PVC, it would probably have been just fine, to then use a metal nipple inside of that.
That adaptor would have been very thick. And the metal pipe too small to make much of a difference.
But the metal 3/4 to 1/4 adaptor, was just too big, and the pvc it was screwed into, too thin.
Sometimes you pay for "Making do with what ya gots." I should have waited until I could get a pvc adaptor instead.
Posted: Sat Dec 04, 2010 11:49 am
by jackssmirkingrevenge
Because Portuguese sealer is better than bovine halitosis

Posted: Sat Dec 04, 2010 4:08 pm
by Selador
jackssmirkingrevenge wrote:Because Portuguese sealer is better than bovine halitosis

???
Posted: Sat Dec 04, 2010 4:18 pm
by jackssmirkingrevenge
Selador sounds better than Oxbreath...
Posted: Sat Dec 04, 2010 4:49 pm
by Selador
jackssmirkingrevenge wrote:Selador sounds better than Oxbreath...
Ah !
Yes.
I didn't realize how much I would grow to dislike that moniker.
Thanks to PCGUY, for changing it for me !
