Casting Molds, how do you make yours

[WoodfulProjects]

Heya all,
I've been thinking lately of starting to make some blanks by combining wood & epoxy.
Although I'm very familiar with wood, epoxy and molding silicone, might be useful to ask more experienced users about advice.
So, here I am.

What are your experiences? What do you make your molds out of? Do you use silicone molds (DIY)? If so, which sort of silicone do you use?

I ordered some TPU and I'll start printing some molds. This said, not sure its works well.. or this is the most cost effective approach.
Previously, before I had my 3d printer, used to make the mold out of wood (scraps glues together) + mold release. Although this was cost effective, it was not the most precise.

Cheers

 

[anthonyd]

Here is a link to a good video on making HDPE molds from a guy who sells hybrid blanks.

 

[BCnabe]

I've made several pen blank molds from cutting boards (made from UHMW????).

They are about 3/8"-1/2" thick. I cut them on the table saw and use #6 screws to assemble them.

There are initially some very small gaps where the pieces come together. I usually put tape on them for the first pour which will fill those small gaps. After that I take the tape off as they are sealed.

It works well and not a lot of cost.

 

[hooked]

I do 3D print some molds for alumilite casting. You can either use some sort of mold release or turn off the mold and make a new one each time. If you are going to do a lot of casting, a more substantial HDPE would probably be more time and cost-effective. For occasional or disposable use, 3D printing works well.

What has been working well for me with 3D-printed molds is to line them with red tuck tape (sheathing tape that may be another brand in Europe). I have never used it with epoxy resin myself, but I know I read about using tuck tape as a mold release from a guy who does epoxy river tables. It works great with alumilite.

 

[TDahl]

I use a combination of PVC pipes (for round blanks) and HDPE (for square and Hybrid blanks.) I purchased 12" x 12" x 1/2" HDPE from Amazon for about $20.00 and several thin cutting boards from the dollar store. The cutting boards are a little less than 1/8" thick and will fit into a typical saw blade kerf. I used the 1/2" HDPE for the sides of the mold, and the cutting board material for the bottoms of the molds. I cut rabbet into the sides and fastened the entire mold together using drywall screws. I have used these molds with mold release many times and never had any issues.

 

[pssherman]

I use 3/8" thick HDPE from McMaster Carr for my block molds. It is easy to cut on the sable saw and drilled on a drill press. I used a piece of 4x4 to act as a fence when drilling the edges. For my vertical casting, I use John's vertical casting system.

 

[WoodfulProjects]

Thanks all. I went with the HDPE for large casts. As per individual blanks, I made a bunch of silicone molds which will be easier to unmold.
Cheers