Casting resins and urethane mold material input

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#1

I am working on a few new mold designs and have been looking into casting the detailed areas. The reason for casting is there will be multiple mold design attempts with various resin and air flow channel testing before moving on to the final mold design.

I am looking for a material which can be poured, will dry relatively hard, and will take a number of mold cycles. These will not be production molds, but rather for testing. Material used for the part is epoxy resin with 60-80 psi internal bladders, post cure temps under 120 F. Similar to the mold design below.

#2

you looked into DIY corian ?

#3

I have considered it. I can not find a lot of good info on making it, and where to source materials in the US. My thought was to make some temp molds that could be poured, a rigid outer mold with a pour-in inner mold to get all the detail. The thought was to save time and money while working on producing more detailed and rugged final production molds.

This is a basic drawing of how I am thinking of utilising DIY corian or a casting resin using 2 1/4" MDF as the bulk of the mold, so the corian is basically the mold surface will the detail. It would have two holes in the MDF for pouring in and venting the corian or casting resin.

#4

I have tried corian moulds with pre pregs curing at 100C.

The material is the usual 13mm thick and I had machined the surface away to create my mould/part shape. The pre preg carbon material released fine but the problem I had was simply the uneven expansion of the corian due to the differing thickness means that your mould then changes shape when heated.

#5

That’s good to know, I had considered trying a few parts using prepreg. I am using hand layup currently with a internal bladder at 60-80 psi. The entire mold is vacuum bagged and cured at room temp, the part is post cured out of the mold.

#6

Why don`t you use a high temp epoxy and fill it with aluminium powder? hard surface, easy to do. You could cast it in multitiple thin pours. Adhesion should be fine.

Or Poraver.

#7

Any input on where to source aluminum powder in the US? I am currently using Resin Research CE2000 with XS hardener, which can be cast fairly thick without excessive exotherm. CE2000 is not a high heat epoxy, but for the test molds I intend on using wet layup cured at room temp to 100 degrees F. If I will benefit using high temp resins I will spend the extra $$. The aluminum powder sounds like a good alternative to corian.

#8

This is how I made my own corian.
Now moving onto pre-pregs and using high temp resin and tooling coat to be able to with stand 120’C.

These type of moulds are super stable , bullet proof and had hundreds off pulls from them and are still like day one. All my production moulds are made like this now. Making moulds doesn’t come much easier.

Tim.

https://www.rcgroups.com/forums/showthread.php?t=2165394

#9

Looking into the DT-082 ATH for the molds, and using the Resin Research 2000CE and extra slow hardener. We will see what the quote for the 50lb bag will run.

https://www.freemansupply.com/products/tooling-plastics-fillers/ren-dt-081dt-082-liquid-tooling-resin-fillers