casting in pvc tube question

[demetry_07]

I want to cast in a 3/4 to 1 inch pvc tube. I am worried how to get the blank out. Is there any kind of preperation i need to do ahead of time or will the resin shrink a little?

Thanks for your time.
Adrian Milner

 

[DozerMite]

Use SCH40 and it will pop right out.

 

[Russianwolf]

if you are casting with polyester resin (castin craft, or Silmar 41), it will shrink slightly as it cures and comes out easily.


If you are using Alumilite (Polyurethane resin)....Good luck.

 

[THarvey]

If you have too much trouble getting the blank our of the PVC, you can always turn the PVC off.

 

[DozerMite]

if you are casting with polyester resin (castin craft, or Silmar 41), it will shrink slightly as it cures and comes out easily.


If you are using Alumilite (Polyurethane resin)....Good luck.

True, I don't use Alumilte so, I forget about it.

Real casters use PR.......:tongue::biggrin:

 

[Russianwolf]

if you are casting with polyester resin (castin craft, or Silmar 41), it will shrink slightly as it cures and comes out easily.


If you are using Alumilite (Polyurethane resin)....Good luck.

True, I don't use Alumilte so, I forget about it.

Real casters use PR.......:tongue::biggrin:

I have some of each in my shop. Have yet to make a successful Alumilite cast, but then I only have tried twice and was going for a clear cast which is difficult with it.

 

[el_d]

I have used parchment paper to line the PVC tube before pouring my PR with older tubes or wiped some PAM.

 

[simomatra]

Never had a problem with electrical pvc conduit, just a knock on the side and out it pops also you can use compressed air but then they fly out

 

[Craftdiggity]

For the first couple of casts, it will likely pop right out, especially if you are using only Mica powders to tint. I have found that Mixol tints tend to make the blank a bit more sticky and casting other materials like coffee beans and shredded money seems to do this as well. After several casts, the tube might start to stick more often.

What I do prior to casting is cut one side of the tube lengthwise on my bandsaw. I then tape over the slit and tape over one end. I cast the resin and if it sticks, I use a screwdriver to open the slit and pop the blank out.

 

[dgelnett]

I use a dowel that fits inside to pipe along with a clamp. Start cranking and all of a sudden it pops free.
I also cut off a small amount of the pipe the length of it to create a small 1/8 inch opening the full length. I then put a wine cork in each end of the pvc pipe and pour the PR in through the 1/8 inch opening. I think I get less bubbles but have no proof of that.

 

[interwood]

New to pen blank casting - what is SCH40?

Use SCH40 and it will pop right out.

Hi - I'm new to this. (But very much enjoying the forums here.)

Can someone tell me what SCH40 is please? Is it some form of mold release? I'm in Australia :island:, so if I can find out a few more details about what it is ... I might be able to get something similar.

Thanks in advance,

Chris

 

[TomW]

Use SCH40 and it will pop right out.

Hi - I'm new to this. (But very much enjoying the forums here.)

Can someone tell me what SCH40 is please? Is it some form of mold release? I'm in Australia :island:, so if I can find out a few more details about what it is ... I might be able to get something similar.

Thanks in advance,

Chris

SCH40= "Schedule 40" it is a designation for the thickness and pressure holding ability of the pipe. Any pvc that is sold to hold household pressures (up to about 100 pounds/square inch) is probably SCH40.

Tom

 

[interwood]

THanks Tom

From some other posts I thought that it was something extra added to the PVC. :redface:

After more reading it seems that many people are getting good results with PVC pipe and are able to reuse it many times over. Thanks for your answer.

Chris

 

[snyiper]

The common sizes used here in the US are Schedule 80 which is black/grey and very thick. Schedule 40 usually white and a bit thinner and schedule 20 which is also called thinwall.

 

[MyronW]

The Australian equivalent is probably PVC-U Pressure Pipe Solvent Weld Class 15.
Here's a brochure: Plasticoat

 

[KBs Pensnmore]

I cast in pvc tube all the time. I just put a smear of wax inside, and haven't had any problems.
Kryn

 

[clapiana]

What I do prior to casting is cut one side of the tube lengthwise on my bandsaw.

length wise as in ripping it? On your band saw must be tough what size gap do you have to cover with the tape?

 

[DurocShark]

If you pressure cast, it won't pop out nearly as easily.

I'm a huge fan of pipe casting. Even made a pipe rack for my pressure pot: http://blog.woodscrub.info/2011/02/harbor-freight-pressure-pot-and.html

One thing I recently started doing that seems to help keep the pipes lasting longer is wax. I first bought some of the "mold release" and it worked really well. So I make my own from mineral spirits and beeswax now. Spray it on the tubes, let it dry, then pour away! I used to only get 3 or 4 casts before the tubes would start warping. Since I started waxing the tubes, I've gotten 15 pours out of them and they're still going strong.

 

[jlord]

What I do prior to casting is cut one side of the tube lengthwise on my bandsaw.

length wise as in ripping it? On your band saw must be tough what size gap do you have to cover with the tape?

The gap would be the thickness of the blade.