Removing Blank from PVC

[melogic]

I just completed my first cast using Alumilite Clear and the 1" PVC as stated in another post. The blanks turned out great, but I had to cut the PVC from my blanks. I cleaned the PVC before casting and I put duck tape over one end and left the other end open and stood the PVC upright in a block of wood with holes drilled in it. Any ideas of why they didn't fall out on it's own as others have had it do? Any insight is appreciated. Thanks in advance!

 

[reed43]

Coat the inside with vaseline and they will come out much easer. Reed

 

[ctEaglesc]

Based on the cost of PVC why not chuck it up and "turn it off?

 

[melogic]

Originally posted by ctEaglesc
<br />Based on the cost of PVC why not chuck it up and "turn it off?

Well the PVC is about $6.50 for a 5' joint. That comes to roughly 65 cents additional cost per blank. I'd rather re-use them if I can. I will give the vaseline a try.

 

[JimGo]

Vaseline will work, as will most other waxes.

 

[mrplace]

Woww, where did you buy your PVC? I got like a 10' stick for less than that at home depot.

You can also use spray Pam, as in the cooking spray as a mold release.

 

[Skye]

Put a broomstick handle in the end and bang it out.

 

[mrplace]

Originally posted by Skye
<br />Put a broomstick handle in the end and bang it out.

That usually ends up cracking the blank if it is actually stuck to the PVC, I have shattered plenty. Not sure with Urethane, but mine was sticking because the cure time was to slow, because once I hadded just a tad more MEKP they stopped sticking.

 

[melogic]

These were getting hard before I poured the other 5 blanks (10 minutes or so). They were rock hard in just a couple of hours or so. I'll try a few different things. I got the PVC at my local Lowes.

 

[MesquiteMan]

Mark,

I tried casting some Alumilite in PVC and had the same issue. Alumilite does not shrink as much as PR which might be why. Maybe it just does not shrink enough to release itself.

 

[JimGo]

Another way to free PR is with Acetone.

 

[ctEaglesc]

Originally posted by melogic
<br />

Originally posted by ctEaglesc
<br />Based on the cost of PVC why not chuck it up and "turn it off?

Well the PVC is about $6.50 for a 5' joint. That comes to roughly 65 cents additional cost per blank. I'd rather re-use them if I can. I will give the vaseline a try.

<b>Are you using schedule 40??????????????????</b>
Look for a real plumbing suplly place (Not a Borg that comvenintly cuts it so they fit inside a Mini Cooper.)
Look for low pressure(thin wall) It comes in 20' sicks should be no more than $10.00 for 20'.
If you have a pick up truck you can load it in the bed by bending the full sticks into a horse shoe.
(Or bring some thing to cut it up with yourself.)[^]

 

[Alumilite]

Curtis is right. It comes down to the shrink. Alumilite's Water Clear has minimal shrink in the .002-.003" in/in. Throw in the fact that urethanes typically bond to pretty much anything and your part is stuck. We recommend and sell two different mold releases. Our UMR which pretty much releases anything from anything and secondly a Stoner (yeah, interesting name) Urethane Mold Release that is made for releasing urethane from anything. I believe the Stoner Urethane Mold Release is a silicone based release. If you have a silicone spray or mold release, that would also work well. I personally have never tried the cooking spray or Vaseline option because typically when we are pouring the Clear resin we want it to come out perfectly clear so we use silicone rubber molds and no mold release.

Mike
Alumilite
800 447-9344

 

[Skye]

Gets hard in 10 minutes? Does it produce a lot of heat as opposed to PR resin?

 

[Jerryconn]

I have only cast PR but I use Pam and my blanks slide right out!

 

[melogic]

This produced a fair amount of heat, but nothing I would call a GREAT amount.

 

[smoky10]

Mark try putting some wax paper in the PVC before you pour the PR in. It should slide out easily then.