Page 1 of 2

Boiling pvc

Posted: Wed Jul 19, 2006 6:51 pm
by richardbridges
How long should I boil 3" schedule 40 before it will be pliable enough to wrap around 2"?

Posted: Wed Jul 19, 2006 7:03 pm
by benstern
WHAT!!!!!!

Don't boil pvc! Where did you get the idea to boil pvc and how gullible are you to believe it?

Posted: Wed Jul 19, 2006 7:06 pm
by saladtossser
i think he meant heating it to change it's shape

Posted: Wed Jul 19, 2006 7:08 pm
by SpudStuff
no sh.it shirlock
boil it until it is pliable. the time varies

Posted: Wed Jul 19, 2006 8:02 pm
by saladtossser
keep diggin watson
actually, you might wanna consider using 2.5", or better yet, give us more details

Posted: Wed Jul 19, 2006 8:42 pm
by mark.f
He wants to know about boiling PVC to aid in Foxxlord's plans for a 3" piston, made by wrapping 3" SCH-40 around 2" SCH-40 with a slot cut out of it.

Posted: Wed Jul 19, 2006 8:51 pm
by spudshot
stick it in the oven at 350 for a few minutes, checking on it every now and again, i do this to make flat PVC sheets

Posted: Wed Jul 19, 2006 9:05 pm
by boilingleadbath
A few minutes should do - PVC isn't a great thermal insulator as far as plastics go, and it's fairly thin.

Posted: Wed Jul 19, 2006 10:30 pm
by singularity
what would you do with a flat pvc sheet?

Posted: Wed Jul 19, 2006 10:33 pm
by spudshot
its good for making large washers for pistons, its very hard to find metal washers larger than 1.5" diameter, its good for alot of other things as well, you could probably cut some triggers for different setups out of it, i just like to keep some on hand, so if i've got a few inches of 3-4" pipe left i'll saw them down the middle and stick em in the oven

Posted: Thu Jul 20, 2006 1:10 am
by sgort87
What in the HELL is this going to do?!

Posted: Thu Jul 20, 2006 8:22 am
by boilingleadbath
sgort, it should be obvious. PVC grows weaker - and more importantly, it's youngs modulus decreases - rapidly with temperature.
Check out the temperature deratings for the stuff if you don't believe me.

This makes it easier to bend, allowing it to be... bent.

Posted: Thu Jul 20, 2006 2:26 pm
by benstern
In heating it in the oven, does the pvc give off any fumes?
Also, will it stick to whatever it is on?

Posted: Thu Jul 20, 2006 2:32 pm
by )DEMON(
Just boil it because it is easy, like cooking noodles. Take it out and let it cool in the postition you want it in then do that until it is the shape you want. I have done it but the type of pvc I use could be slightly different. I got it right on my first try, I just left it to boil for a few minutes.

Posted: Fri Jul 21, 2006 8:15 am
by boilingleadbath
Benstern, it depends appon the temperature... but IIRC, pvc doesn't decompose until fairly high temperatures, so fumes should be limmited to a bit of monomer (vinyl cloride) outgassing.

I saw some nice data on it a while ago, but that's most of what I remember.