# Casting



## Percy Legg (Jul 18, 2015)

I have a question about casting what do you guys use as molds for your Alumilite when casting your blanks, I guess what I am asking what materials do use to make them.


Question two when I cast a duck call blank using only Alumilite it was rubbery do I need to cast it over wood to give it more body and stability

Thanks Percy


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## JR Custom Calls (Jul 18, 2015)

I don't cast... But I know a little about it from reading up on it. A lot of guys I know use high density polyethylene for molds. Cheap cutting boards are a good source for small quantities.

I'd guess if your blank was rubbery, you didn't mix enough part 2 in. If you're not measuring by weight, you need to.

@Final Strut and @kris stratton both cast (pretty sure Kris does anyways)... Perhaps they can provide more input


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## Jerry B (Jul 18, 2015)

I have made molds from different materials, 1/2" plexiglass gotten from Ebay, and recently 3/4" melamine from Lowes
Zac Higgins has some excellent YouTube videos about casting Alumilite, is where I got the idea of using melamine
made 4 molds from it so far, have used them a dozen times and see no issues with it.

as for rubbery results, either your part B has gone bad, or you need to add more of it
Like JR says, should be measured by weight, 1:1 ratio to part A
if you're adding extras into your mix (dyes, pearlescents, etc) you need to remember to add extra part B also to compensate the extra volume/weight


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## Final Strut (Jul 18, 2015)

I use cutting boards for most of my molds. I do use some PVC tubes but it is risky because they can stick. If they stick the only way to get the blank out is to turn the PVC away.

As Jonathan suggested, if you blank is rubbery your mix ratio is probably off. Alumilite HAS to be mixed by weight. If you looked when you first got your kit you may have noticed that one bottle was fuller than the other. That is because the two components do not have the same specific gravity and there fore cannot be mixed by volume.

If you did measure it out by weight then I would guess that you didn't mix it well enough. When you first start with alumilite I would strongly recommend mixing you two components before you add your dye. When you mix pay attention to the change that the resin goes through. It will be cloudy and that turn clear. When it goes clear you know it is mixed well enough.

Reactions: Agree 1 | Useful 1


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## Percy Legg (Jul 18, 2015)

Thanks guys I did add color to the Alumilite mixture and that probably change it that was my first batch I will add more be next time.

Percy


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## Final Strut (Jul 18, 2015)

Percy Legg said:


> Thanks guys I did add color to the Alumilite mixture and that probably change it that was my first batch I will add more be next time.
> 
> Percy


Percy, I have been pouring Alumilite for about 3 or four years and have never added more part B to compensate for colorant. I do not think there is any reason to mess with the 1:1 ratio but I am defiantly open to learning something new if there is a reason. Maybe Curtis (@TurnTex ) will chime in on this one. He is our resident Alumilite expert.


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## kris stratton (Jul 18, 2015)

i like the cutting board molds myself,i have made a few from melamine as well and they are fine to use as well.if you continue to get into casting you are going to make many molds so i would just try them both and see which kind you like,if you order a 1/2 inch cutting board to cut up buy a couple ,you will use it.

Reactions: Agree 1


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## TurnTex (Jul 21, 2015)

Do not change the mix ratio! You are flirting with disaster if you do. If you casting was rubbery, it most certainly was not mixed thoroughly. Use clear cups as mentioned above and mix A &B first until it is completely clear. Then add your color. One drop per ounce works fine in most instances.

There are a number of videos on my site on workign with Alumilite. You can also find them on Alumilite's site! You can find them on this page: Directions, Tutorials, and Links

Reactions: Informative 1


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## TurnTex (Jul 21, 2015)

Also, if you are doing small pours of less than 5 oz, try heating the molds in a toaster oven at 150° F for 30 minutes before pouring. Small pours need extra heat to get a good, solid cure.

Reactions: Useful 1


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## TimR (Jul 21, 2015)

As for custom size molds where I've got an existing piece of wood to include, I cut to fit pieces of aluminum flashing around it, held together with duct tape and protruding up 1/4" or so above top of area to be filled. Pulls off easy enough.


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## TurnTex (Jul 21, 2015)

Tim, Next time try plain old cardboard with the edges taped. Then simply cut it off when using it. I even cut the cardboard with my tablesaw.

Reactions: Like 1 | Informative 1


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## Percy Legg (Jul 21, 2015)

Thanks guys for all the information can't wait to try it out.

Percy


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