First PR cast went bad

[Brandon25]

Not including the candy corn casting (DNGT!) I did my first casting the other day. I used castin craft (2oz) 20 drops of catalyst (it was 58 degrees here) and for color I added quite a bit of white pearl acrylic paint (the kind of paint that someone said they have had success with) and some macro pearl pearlex and some russet red pearlex, all thrown in together in a PVC pipe with cooking spray as a release. Took a full day even just to not be liquid, about a day and a half for full gel. Yesterday, which was about a week after casting, the thing wouldn't come out of the PVC tube. So I cut the tube off, and not only does the color look like garbage (think very drab raspberry sherbet) but its as flexible as tire rubber. Tried to drill, still keeping hope, thinking maybe I've invented an "integral cushion grip" material or something....drill just OK, but what came out of the drill bit flutes didnt look at all like the acrylic from woodcraft, it was like white powder.

I've pretty much given up hope on this one, but what can I do in the future to get a better effect? Do you guys think it was the white acrylic paint? The temperature? Do you think it will harden anymore?

Thanks in advance.

 

[Russianwolf]

Brandon, I'm having long cure times too and I've been in the mid to high 60's. I'm going to try what some others have done and set up a hot box (incandescent bulb in a insulated box(I have an old cooler)) and see if that gets me back where my first casts were.

Some have also mentioned warming the PR before putting the catalyst in, but I haven't tried that yet either.

 

[Brandon25]

Well my catalyst and PR stays inside, around 70 degrees. You mean warm it up, like, sit the can in a sink of hot water first?
I thought about a hotbox- we have a mini fridge sitting in my basement collecting dust...but my wife might beat me senseless....

 

[DozerMite]

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[Russianwolf]

Brandon,
it sounds like you put way to much stuff in your PR. If you use acrylic paint, which I don't recommend, use only a little. Paint is nothing more than a pigment in a medium. The best results come from straight pigment. It will eventually harden.
Remember, this is the internet, just because someone says it will work doesn't mean that it does. Stick to the experienced casters.

I've been using acrylics in all my casting and never had an issue until the temp dropped into the mid 60's. In fact the pigments I got from MR. Fiberglass especially for the PR were Acrylic Paint.

Others who use straight powders have mentioned longer cure times when the temp drops below the 70's too.

Now, I may not be the most experienced caster but that doesn't mean that I can't see the trend here.

Careful throwing statements like that last one around, make you sound elitist and condescending.

 

[Brandon25]

Don't want to choose sides, so I'll just continue....

I put even what I thought was a LOT of acrylic in there. Like, if I squirted it out on the table, maybe a half-dollar sized puddle or more. for 2 oz. of PR.

 

[Russianwolf]

Well I'll tell you that I usually use about 15-20 drops of paint for about 8 ounces of PR. But I've used more in the past with no ill effects. The only reason I can say how many drops I used now is I'm trying to get repeatability on my casts.

 

[Brandon25]

yeah, I put waaay more than that. Maybe 40 drops in 2 oz? heck, I dunno. I'll set this thing to the side to see if it ever dries. It's not pretty anyway. Next time I'll try fewer drops. Might make it cure better and keep it from looking drab.

thanks

 

[workinforwood]

Hopefully there will be a special on alumilite coming soon..hint hint hint. Much easier to mix, and temperature is not a problem. It will be worth buying a gallon kit to play with and compare. You can't use acrylic paint in it though. I was just over there today. Colder the alumilite the longer the open time. At 40 degrees, you have almost 10 minutes before it gels. You heat your mold up nice and warm, not so warm you can't hold it in your hands though, then simply pour the mix in and set pressure for an hour and you are done and ready to mix some more. He said if you put paint in it, it won't make any difference to the cure time, just don't use water based paint or anything with water in it or wood that is wet. I have my gallon, just have to fix my pot leak. I know nothing, not an expert, just telling you what they told me when I asked them today and they are the manufacturer. People swear by the stuff, and swear at the price unfortunately.

 

[Russianwolf]

yeah, that may be a bit much. you just want to add enough to get the color and translucency that you want. I'll add more if I want the blank to be more opaque.

But you know even mistakes can be interesting sometimes. I have one that I'll cut this weekend. the idea I started with changed when the colors blended too much during the cure (gotta set up that hot box) but I think the final effect looks pretty cool too. I'll show it once I get one turned.

 

[maxwell_smart007]

I know that Alumilite ran an awesome week (or month?) long special last birthday bash. If you can wait until January, Carol might run one again!

 

[DozerMite]

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[hughbie]

once i get my cast to set, i put my casts in a toaster oven, dedicated to my pen turning.......150 degrees for about 2 hours......what goes in as soft and sticky....comes out like i had purchased it......toaster oven is cheap
but of course, you have to get your cast to set up first.....sounds like too much 'paint'......

 

[Brandon25]

Thanks all. I want to do some mixing of colors too, but obviously it'd be hard to catch the just-before-gel stage with a window as large as my setup time was. I might look for an old cooler or something. Too bad this stuff smells so bad.


As far as alumalite, that's way down the road for me. I dont have a pressure pot, and my tool budget will be next to nothing for a while. Never fear though. Pens, much less non-wood blanks, much less DIY casted blanks, are not my sole focus in turning. I just got a chuck and have tons of bowls I want to do too, so I can stay busy and try some things every now and then without getting frustrated too much.

 

[bdonald]

Well, it's been cooler here in MI, and I've noticed that it greatly affects the setup time with the PR. I did 4 stoppers and my first pen in pvc yesterday, when it was in the 60's, and today they came out of the molds fine, but the pen was bendable. So, I left it outside, and it got into the 70's for the better part of the day, and it hardened right up. I used the same recipe as you, cept for the paint, in regards to resin / cat . I think we just got into it at the wrong time, a couple of months late I'm resigning myself to a few casts over the next few days <up to 80 degrees> and putting it aside until next summer. Sounds like you got enough bowls to keep you busy till then though.

 

[grub32]

A little more info...

I think its best to use a dry colorant as any fluid will degrade the cast and a little too much may really have adverse affects on your final product. Remember, PR is a chemical compound and reacts with other compounds. It is also possible that the liquid used to dissolve the colorant in the paint is enough to change the physical characteristics of the PR.

Back in the day, I read about some of you using a hard to find solvent to break dissolve the dyes that had no affect on the PR drying process.

AS for me, I use some cheap powder coating paint and pearlex. Has worked pretty good so far. When I cast in the garage in the fall I use a halogen light along with the dehumidifier to help things out. Halogen about 10 inches over the top...Boy, was I mad when my wife threw away to old toaster oven before I could get my fingers on it. Its definitely a good walmart purchase at 12-15$.

my .02

Grub32

 

[bdonald]

Ok, are you putting the mold and all in the toaster oven? I'm using pill bottles and cpvc, which I'm not sure if they'll hold up in the oven, as well as the pvc wont be able to stand up straight. When you say set, do you mean enough to pull it out of the mold? Because that will be doable, got a toaster over sitting in the basement doing nothing!

 

[DozerMite]

I go from pour to lathe in 1 to 1-1/2 hours.