Once cut the thinner webs between the cutouts get floppy, so it works better to have the foam glued to a rigid piece of cardboard,. It would be easier if I could glue the foam to the cardboard first, then do the cutouts. Will this be safe, or will the contact cement cause a fire? I’ve never cut anything that has had contact cement on it and don’t want to have a fire in my machine.
Any thoughts or experience with this?
It’ll probably be fine, but I would watch it carefully.
I’d also be sure the contact cement is fully cured and gassed out. That stuff is mad flammable when it’s not dry, I’m sure I don’t need to tell you… it’s the kind of thing you really need good ventilation for when you are gluing things up.
I guess I’ll glue one up and wait several days before trying it, and watch it like a hawk when I’m cutting it with the fire blanket nearby. I’m using the Loctite spray adhesive heavy duty, not the canned brush contact cement - still stinks of solvent though. I guess I might try a small 1" square first.
My inclination also would be to put the cardboard on top to get the full air assist. You don’t want the corrugations under the eva foam away from air to carry flame through the channels. EVA cuts fairly easily though so putting it on top with a higher power might not work. So yes, do some test cuts first on the sandwich as see how it works first.
Sorry for not letting everyone know the outcome.
To answer you - Yes and no.
I glued the mat board cardboard onto the EVA foam and let it dry/outgas fo a couple of days. I then placed it cardboard side up and figured I would cut the cardboard first, peel the cutout pieces off, then cut the foam.
The first half of the cardboard cutting went well, then it reached a point where there must have been some tension in the eva/foam interface because I watched the material pop up. This would have been fine if it wasn’t 10mm foam+ .05" matboard which makes it just under 1/2" when perfectly flat. Long story short, the exhaust port hit the material and knocked the entire laser assembly off of the tracks. It took 2 days and support staff and chat time before I got my GF running again. I am so glad I was watching closely and could power it off quickly.
If I had thought about it more, with the small amount of clearance I should have removed the crumb tray and placed the material lower.
As to the initial concern of catching fire, after leaving it to dry a day or so I don’t think that would be a problem.
I’ve gone back to cutting the foam and mat board separately, then gluing together.
Thanks to everyone for the suggestions.