Using laser Ed tile as a mold for casting pewter Christmas ornaments

[Roger Feeley]

Can this be done.

my mold would be a sandwich of materials with tiles on the outside where I would etch my copy/images. The center layer could be Masonite or something.

so I need a material that can stand up to 575 degrees Fahrenheit.
i need to laser it deep enough that the pewter image will show but not so deep that the metal won’t release.

these are for Christmas ornaments for my grandsons preschool.

i only need to cast 15 parts. I could make 15 single-use mdf molds.but that seems wrong to me.

[Kev Williams]

For only 15 pieces, single-use molds wouldn't be 'wrong', especially if you personalize them ;)

How about engraving a 'positive' in MDF, or plexiglass, then make a negative from that for your pewter pour from plaster? (I don't know much about casting, but I've read some have issues with plaster 'steaming', but seems that could be alleviated by baking the plaster in the oven awhile to get rid of any residual moisture)

A note about metal not releasing- Laser the MDF, plex or whatever in 5 or 6 depth steps, adding width to the engraving each subsequent step, which will create some draft angle to allow the molded part to release easier...

[Richard Coers]

You can get this stuff that melts at 117 degrees F. For consideration, paper ignites at 480 degrees F. https://www.rotometals.com/roto117f-low-melt-fusible-bismuth-based-ingot-alloy-ingot/

[Mel Fulks]

You can buy pourable silicone made for casting pewter . They have some that are stretchy for complex stuff and some
that is harder and non stretch.

[Roger Feeley]

You can get this stuff that melts at 117 degrees F. For consideration, paper ignites at 480 degrees F. https://www.rotometals.com/roto117f-low-melt-fusible-bismuth-based-ingot-alloy-ingot/

I have some stuff from rotometals that melts in the 300 degree neighborhood. Since these ornaments are for a preschool, I didn’t want metal that would melt in a hot cup of coffee.

I got some ‘hardboard’ from an art supply that is better than Masonite. I tested countertop laminate and it held up nicely. But Formica isn’t thick enough. I remember much thicker material back in the day. I called Formica and got right through to a tech support guy (kudos). He told me that the whole laminate industry went thin some years ago. I ordered some 1/8” phenolic from Amazon.

I also tested some sort of flooring that is plastic core and it seemed to do fine.

When I get my collection of test materials, I will head off to Nova Labs, my local maker space, to use one of their 100w lasers.

[Kev Williams]

If Formica worked, phenolic engraving stock should work, still available in 1/8" thick...