Best material for casting

[Bitemeflys]

Hi All,

My name is George and I am new IAP. I have been trying to make some blanks at home but have not had a good success yet. I have a pressure pot good to 80 PSI and a vacuum chamber good to 26" (max for our altitude). I started using Allumilite Water Clear but find it takes to long to cure in the pressure pot and all my additives I use settle to the bottom. What do you use or recommend?

 

[Bitemeflys]

Sorry I forgot to mention I am working in small space at home and do not want to use anything that has a strong order like polyester resin.

 

[Jim Burr]

Those are the only choices you get. Maybe fiberglass or epoxy...but the smell issue will be there

 

[Falcon1220]

Welcome from a sunny Vancouver
If you go to the IAP library you will find a tab for "casting". There you will find all kinds of casting info.

 

[reddwil]

Hi All,

My name is George and I am new IAP. I have been trying to make some blanks at home but have not had a good success yet. I have a pressure pot good to 80 PSI and a vacuum chamber good to 26" (max for our altitude). I started using Allumilite Water Clear but find it takes to long to cure in the pressure pot and all my additives I use settle to the bottom. What do you use or recommend?

Are you sure your mixing the alumlite correctly. Has to be equal parts by weight. It should start to cure in 7 minutes and fully cure in a couple hours. Also be sure moisture is not getting into your pressure pot from your air compressor.

 

[darrin1200]

First cast I tried with water clear, took about 3 days to fully cure. After looking back I figured out that I did not mix it accurately.

After getting some tips from Dave Bell, my next batch worked perfect. He recommended that I switch to grams instead of ounces. I have a digital scale i got at Canadian Tire. I put the clear cup on it and zero the scale. I then add A to the cup to say, 200g, then add B until it reads 400g. I use a small paddle that I made, in my cordless drill to mix it up. Then added my dye and pearlex, and mix again. Then add to the mold, put it in the pressure pot and filler up.

Another critical tip was to heat the molds prior to filling. I use a thrift store toaster oven on the lowest setting. This is doubly important if you are using wood. The heat will help ensure absolutely all the moisture is out. Alumilite and water don't mix.

Hope this helps.

 

[Bitemeflys]

Thank you all for the help, i appreciate the information!! I do use a digital scale and measure in grams. The silicone mold is heated and dusted with baby to reduce surface tension, advise I got from Alumilte. I use a silicone spatula to mix before poring in the mold and stir and scrape the sides very well.

The two issues I have are metallic powders settling before cure time and if I have a wood in the cast I need to wait at least 2 to 3 days for the blank to cure hard enough or the drill bit is pushed out the blank during drilling.

Is it possible I have a bad batch of resin?

 

[Marko50]

Yes George, it is possible to have a bad or out of date, aged batch of Alumilite.

I only purchase mine directly from Alumilite because I always get their latest batch fresh off the line. If your part A is very yellow, then yes, you have an out of date batch. Call Alumilite and let them know if that is the case. They will usually send you a fresh batch free of charge. You should not have to wait more than 2, 3 hours at the most before you're ready to turn, even in a cold garage/shop. Make sure when you mix it up that you can see absolutely no striations in the mix. Keep mixing until it is perfectly clear. Don't worry about the amount of bubbles in it if you're using a pressure pot. Another tip: Don't go much past 4 minutes without getting it into that pressure pot or you will have missed your chance to clear out all the air. Just my .02¢

 

[Dick Mahany]

I use Alumilite clear (not "water clear") and had similar issues at first with large mica flakes and metal powders settling to the bottom. Now I use a timer and keep mixing until the time gets very close to the point where it starts to thicken or gel rapidly, and have much better suspension of the materials in the blank. Just a little too long though, and bubbles can be trapped where even the pressure pot won't help. Alumilite says about 7 minutes, but I've gone as long as 9 minutes and it can vary depending on the pigments and other materials that are mixed in.

 

[Bitemeflys]

Hi All, and thank you for all the help.

In the end I got it to work fairly well. I preheat the mold to 140 F while I mix everything into Part A of the Alumilite water clear. then I add Part B and mix very well and start a stopwatch. I mix again at 10 minutes runtime and pour into warm mold then right to the pressure pot at 70 PSI. the results have been much better!!