Alumilite casting help

[Jeff E]

So i did my first casting attempt last night. It went sort of well. Aside from some starting temperature issues which i have figured out, i ran in to an unexpected problem. The mold i made was for a 3.5" x5.5" x .75" casting. I calculated the volume i needed to be just shy of 8oz. I marked a container for 4oz and then filled it on a scale with the part a to 4 oz. i then put an equal amount by weight of the part b. When i pulled it from the mold this morning it is only 1/2" thick. Which isn't good for much. I'm wondering if i somehow messed up my measurements or if the volume of the part b needed to hit the weight is much less than part a. Any help is appreciated as I'm looking to do another casting today and would like to solve this problem.

Thanks
Jeff


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[1080Wayne]

There is a difference in density of the two parts , as you should be able to see by comparing liquid levels in the two containers . That said , I wouldn`t have expected a one third loss . Did you measure volume of your mold by using water , or by calculation ? Water far more accurate . I try to shoot for about 10% over what should be needed to cover errors . Your half inch cast is not a waste . Perfectly good for slimlines , Euros , Sierra styles .

I`m assuming you are using Alumilite Clear .

 

[bmachin]

Did you tare out the weight of your container before you weighed out the A side? If I'm not mistaken the density difference between the A and B sides is only on the order of 5-10%. If you got a clear result your ratios are probably OK.

1080Wayne is right, you need to mix more than you think you will need. You are going to leave a fair amount behind in your mixing container. I always figure out how much I need by weight and go from there. You should check me on this but I believe the density of Alumilite Clear is 1.04 g/cc. Alumilite has calculators on its website to help you with this.

Bill

 

[Jeff E]

@1080Wayne I did it by calculation. I'll try water and see if that helps. And yes I'm using alumilite clear. I got lots of slimline kits so I'll give that a try. Never tried with a 1/2" blank but the colors turned out pretty good so I'd love for it not to be a waste.

@bmachin I also did tare out my container. I'll try mixing more this go around than i think i need.


Thanks for the help. Hopefully second time is the charm and I'll see if i can make something work with what i ended up with.


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[ramaroodle]

Well you didn't screw up the measurement of the resin or it would not have cured properly so I'd imagine you screwed up the needed volume calculation. It happens. Use rice instead of water to figure out the needed volume. If you do use water make sure every molecule of water is out of the mold before putting resin in it.

 

[ramaroodle]

Don't feel bad. This was my first attempt at casting when I only dried the mold out with a rag and there was water in the seams. That's why I use rice.