boombox re-build

[Few]

Saturnus,
I've just now found this thread and your contribution in which you described a method for making "glassfiber-aerogel-glassfiber laminate" panels.

Soak a wooden work area and a pressure piece of wood which depending on the size of sheets should at least 18mm thinck with olive oil. Place two of the sheet of glassfiber you've made on the work area. Paint these sheets with polyurethan glue mixed with 1/10th of water. Place some spacers in the corners, I'd suggest some matches with the sulphur broken off. Place one sheet over the other with the glued sides facing eachother. Put the pressure peice over the whole thing, and something heavy on top of that. Wait till it dries, and hardens.

I just want to be sure I'm understanding your method correctly. You make two rigid fiberglass/epoxy sheets and then glue them together using polyurethane glue plus water? Does the "aerogel" core refer to foamed polyurethane glue? If so, can you tell me what a typical panel thickness is once everything has cured? I don't have experience with the polyurethane glues and so I don't know how much they expand.

I've been interested in doing something like this but I'd be making large panels and would therefore need a lot of panel thickness (2-4 cm) in order to achieve sufficient rigidity. I'm guessing that the expanding glue trick won't yield that much thickness. I guess I could use a few layers of gatorboard as the core.

Finally, is it difficult to achieve a nice surface finish on the outer fiberglass layers?

Thanks.
Few

 

[Saturnus]

Don't aim for higher expansion than 2 or 3mm max in normal air pressure. If you vacuum packed the whole thing while it expanding and curring, I reckon you could get twice that thickness without any problems, and also get a more uniform "aerogel". And yes, the "aerogel is the polyurethane glue that bubbles up when it's curring in contact with moisture.

No, You just sand them down with fine sanding paper, and paint it after. You don't want the yellowish color the panels have in themselves.

But just experiment with it, it really easy to make, but take a little trial and error to get right. Just remember when you're working with epoxy to wear gloves and be in a very well ventilated place, preferably outside.

For thicker and more rigid boards, just take two boards instead of sheets and repeat the process.