First Cast

[bitshird]

Well I guess I jumped in where the water was a bit over my head, <s>I went in</s> I mean stormed ahead of my ability, and cast my first PR blank, I read about 20 tutorials and thought I had a clue, WRONG, [:I] It set up OK but did have some air pockets, just pin holes which filled with CA.
The worst problem I had was getting the cast blank out of the PVC pipe, I had to cut the pipe on my table saw, I used a silicon spray mold release,that didn't let go, what is the secret to getting the casting out of PVC ? Should I have used Vaseline or something like that, Oh that’s not dust or crud, it's my weak attempt at using powdered mica pearl.
I used powder coating powder for my colorings and I guess I got lucky with the catalyst, it cured in about 18 hours,
Now we start a new addiction, [}] [8] [B)]

 

[gketell]

That is a very nice looking blank. A major improvement over my first.

I've read quite a war over whether PVC releases or not. For some the blanks shrink away from the pvc and just fall out. For others it is more like for you. Sadly no one has been able to tell us what makes the difference. Did you use new PVC or old? Can you look down in it (what's left of it) and see if there are any surface scratches?

I wonder if the difference could be the "kind" of PVC. Did you use sched 20/40/80? The one person whose blanks just fall out uses "white" so it could be either 20 or 40. But he also uses automotive paint colorants to tint his acrylic. Maybe the colorant makes a difference.

*SHRUG*

People say PAM baking release spray works.
GK

 

[Ligget]

At least you are trying, I think you learn more by actually trying it for yourself.

I can`t answer your qustions as I have never tried casting!

 

[Firefyter-emt]

I have used the PVC pipe and what I do is to use a block of wood with a 3/4" hole in it, I then use my 1/2" lathe knocker to pop it out of the tube. They pop right out for me, not quite fall out, but I don't need hammer either!

 

[bitshird]

Well the first thing is it was some old Sched. 20 once I cut the pipe in two places, it pulled off but not real easy, still had some surface adhesion, I'll get some new pipe tomorrow and try that, I'm also going to order a gallon of silmar 41, I paid 19.95 for a pint at Hobby Lobby, since the PVC uses just under 3 OZ for a blank I can maybe get 5 blanks, more likely 4 that makes them about 5.00 a blank. Still cheaper to buy the blanks but it costs for an education[)], I have some 1/2 in UHMW at school so I'll make a few single molds and one that will give me a block that I can saw 4 or 5 blanks from, I have to see what will fit under my vacuum bell jar, I guess the next trip to Memphis I get a pressure pot from Harbor Freight

 

[R2]

We all learn by experience Ken.At least you've tried and we (so far) non -casters can also pick up on tour experience. Best of luck next time.

 

[daveeisler]

I am new here and I read with great interest in casting, I read another site , and they use the rubbery baking molds found in Walmart. any thing here.

 

[ahoiberg]

yeah, the round ice cube trays from walmart work well. they're not quite tall enough to make a full sized blank out of, but you can just cast 2 smaller ones as homebrewed PR doesn't always follow a pattern like wood does.