Acrylic blank for silicone mold

I’m not sure where I should post this question…I want to make a 4” Round acrylic blank. It would be used to make a silicone Coaster mold from it. But I want it to have a lip around it. Is there a way to do that with acrylic and my Glowforge?

I am not sure if you are talking about making a mold for silicone with acrylic you cut in your Glowforge or, if you want to make a model coaster of acrylic from which to make a mold. These approaches might work for either, with variations in the specifics:

(1) Cut a ring of acrylic and adhere it to another sheet of acrylic with acrylic cement (e.g., Weld-On). That stuff softens the acrylic so that it fuses together. If done well, the joints can even be water-tight. If you want a shaped lip for coaster model, you could likely smooth and adjust using a rotary tool or something.

(2) Engrave a solid circle in a thicker piece of acrylic leaving an un-engraved area around the circle to make the lip. I’m not sure how smooth you could get the bottom of that engrave with the laser alone. A lot of people have experimented with things like de-focusing and washing with acetone or acrylic cement to smooth out stuff like that. You might get acceptable results just sanding it. The textured bottom might be okay, too, depending on what you are trying to achieve. You would have to experiment with settings to get the desired depth.

If you are making a model coaster, you could also experiment with doing a 3D engrave to shape the lip. I have played with that a little bit on acrylic and, it is workable. There are a number of posts in the forums with details. Let us know if you want to try it and, cannot find the info.

Just a few thoughts. I hope they spark something useful!


If you create an image with Gimp or similar that is different shades of gray from white (high)to black (low) you can use variable engrave to shape the texture and even do a ring that would work as a lip by having it go from black to white to black again in gradation or even use the GFUI outline feature to make a rim that is not engraved. I have been experimenting with this a lot to get stuff like this…


You could either use the laser to engrave the acrylic to form a lip around the edge, or if you want a texture-free surface you can solvent weld a thinner ring on top of an acrylic disc.

Here’s a mold I had made by engraving acrylic, you can see the texture left by the engraving transferred into the mold.


That’s a good idea I haven’t thought of. Thanks!

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Wow, that is very cool!!

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Whoa, that is really cool!! I love that!

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