Using 3/4 pvc to cast with

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corian king

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Hello all. Thanks to PTownsubbie I have been casting for awhile now using Freds molds and I like them.But I was thinking about making some longer molds using the 3/4 pvc.I know there is some people here that does this and I was wondering if you could give me some tips.Like what is the best way to get them out of the pipe once they are cured? I use the silmar 41 for all my casting. Thanks in advance for your help!!
 
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The cured resin in the pipe will shrink slightly so the blank pops out relatively easy. I prefer using the PVC method as you dont have near the waste with a round blank versus square.
I made a stand so that the pvc pipes stand up securely. I mix 2 colors and let them set up for about 6 minutes then pour the 2 colors into the pipe together (one color in each hand) and rotate both cups back and forth. It works well for me. Now im trying to figure out how I can mix 3 colors at the same time.
A little tip. If you dont let the resin set up enough before you pour, the heavier colors (metallics) will sink to the bottom.
 
I spray a little cooking spray on a paper towel and run that through the pipe. Then I seal the bottom of the pipe with some blue painters tape. When the blanks are done, I can usually push them out with my finger. If not a soft tap with dowel or screwdriver will do the trick.
 
never had a problem getting them out. just a little pressure and push using my drill press. DO NOT USE A CAP ON THE PIPE. IT WILL DREATE A NOTCH. i use painters tape over the end to seal and push right out. no spray, just push.
 
Our experience with PVC was not good!!

The blanks came out the first time or two we used a piece of PVC, but by the third or fourth time--they were REALLY stuck.

Yes I got them out by hammering with a dowel, but I also think I was generating internal cracks while doing this.

The "rubber" molds are definitely the better alternative.

FWIW!!!

Ed
 
Like Ed said, but you can use a silicon spray, Pam spray might work as well, just don't flood the pipe with either. Or just use a fresh piece of PVC every 4th or 5th blank
 
I have never done any casting, but have been considering it to the point I bought a mold. A thought ran thru this old brain, could a clear plastic tube like drills, parts ect come in be used. Don't try to remove casting from tube, just put on lathe and turn, cutting tube off as you go. Bob Brownell (Gunsmith Supply House) carries these tubes in several sizes. Some of you casters hollar back.

Ben
 
I never had to spray in it but once it did not make no difference ,got some bought molds but like you say i only use them if i want to add something to the blank, otherwise i use pvc, and let it set over night , and take tape off and a few taps of dowel, or i made a piece of corain and it slides right out, saves a lot of pr,
 
For 3 color mix I just mix 3 cups of different colors, pour 2 cups same time about 1/4 way up PVC then 3rd cup + another color to 1/2 way then finish with other colors to top. I use a piece of copper wire to stick down in the pvc and twist one time and bring it out. Don't stir it or your colors will mix. I've had good luck with that. I to after a few castings the pvc wont's to stick. Use Pam cooking spray and that will cure the sticking problem!
 
BKelley said:
I have never done any casting, but have been considering it to the point I bought a mold. A thought ran thru this old brain, could a clear plastic tube like drills, parts ect come in be used. Don't try to remove casting from tube, just put on lathe and turn, cutting tube off as you go. Bob Brownell (Gunsmith Supply House) carries these tubes in several sizes. Some of you casters hollar back.

Ben
Click to expand...

This may or may NOT work, depending on what type of "plastic" the sleeves are made of. I tried this a time or two and the resin "ate through" the sleeve before it could set up.

I'm realatively sure your idea would work, you just have to know what the material really is. For example, a #5 recycle code will hold resin just fine, and in fact you can use one of the "5" cups for a crude mold. The resin will eat completely through a #6 recycle code cup before you can get it completely mixed.

The "sleeves" I got had no information marked on the container. If I could find these sleeves that would contain PR unt it sets, I would love to use these as molds.

Until you find out what materials these sleeves are made from, I'd suggest filling them over a "catch tub" of some sort. I made a real mess that was difficult to clean.

WHEN YOU DO FIND that perfect "cheap" sleeve that won't melt, I'd be very interested in where you purchased them.

Respectfully submitted.
 
3/4" PVC pipe is so cheap that I just run them over the table saw, barely cutting through the PVC. Two passes on opposite sides and pull them apart.

I haven't messed with it for a while but if I remember correctly I could get about 16 blanks from an 8' length that cost about a buck at Menard's.
 
I made four yesterday that I ran a paper towel with Johnson's paste wax on it through the PVC before I poured. When I pulled the cork out of the bottom once it was cured, the blank came with it. Easiest release I have ever had.
 
Do you do "tube in" casting in PVC pipe? If so, is there a "jig" or some other trick that'll keep the tube in the middle.. I want to cast some coffee bean blanks and want to try gluing the beans to the tubes first. I've done a few bean molds (tubeless) with the layer method but takes way too long and wastes too much.
 
Ankrom Exotics said:
3/4" PVC pipe is so cheap that I just run them over the table saw, barely cutting through the PVC. Two passes on opposite sides and pull them apart.

I haven't messed with it for a while but if I remember correctly I could get about 16 blanks from an 8' length that cost about a buck at Menard's.
Click to expand...

+ 1
 
brownsfn2 said:
Will polycarbonate work?

I just ordered some of these earlier today:
Clear Polycarbonate Tubing: Amazon.com: Industrial & Scientific

It is pretty hard material so I am hoping so. I want to try again with these and be able to see what I am doing at the same time. If these can be reused each time then it did not seem that expensive to me.
Click to expand...

Its not about how hard the material is, its whether or not the PR will chemically react to it. The stuff that keeps the PR liquid is nasty stuff, it tries to liquefy a bunch of plastics. This is part of the reason that I've moved to a different resin entirely now. More expensive, but WAAAAAYYYYYY fewer problems.
 
Do you think the polycarbonate will react with the PR? I used a reynolds tupperware like container for my first pour and that stuff was thin. Did not have any issues though.
 
jzerger said:
Do you do "tube in" casting in PVC pipe? If so, is there a "jig" or some other trick that'll keep the tube in the middle.. I want to cast some coffee bean blanks and want to try gluing the beans to the tubes first. I've done a few bean molds (tubeless) with the layer method but takes way too long and wastes too much.
Click to expand...
If I were you, I'd get one of the tube in casting molds from Fred. You can still glue on your coffee beans, and eliminate the wasted resin.

http://www.penturners.org/forum/f172/ptownsubbie-silicone-molds-blanks-89323/
 
Bowl Slinger said:
The cured resin in the pipe will shrink slightly so the blank pops out relatively easy. I prefer using the PVC method as you dont have near the waste with a round blank versus square.
I made a stand so that the pvc pipes stand up securely. I mix 2 colors and let them set up for about 6 minutes then pour the 2 colors into the pipe together (one color in each hand) and rotate both cups back and forth. It works well for me. Now im trying to figure out how I can mix 3 colors at the same time.
A little tip. If you dont let the resin set up enough before you pour, the heavier colors (metallics) will sink to the bottom.
Click to expand...
hey i am new and would like to know more about pc and how the how to's...
 
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