Making large molds

[myxpykalix]

Hi guys...i haven't been here for a good while. I am contemplating doing some remodeling and was looking at these faux rock panels. The issue is they are $76.00 per 2'x4' panel. By the time you do a decent size wall or two you are into some serious money. I have made small molds in the past for people and they take them and go so i don't see the rest of the process.
Has anyone made any large molds and created anything like this? My thought was to cut one mold and make my own panels but i have no clue about what type of material (foam? spray foam?) to make the end product from and how feasible it might be? Anybody done anything like this before?

[bleeth]

As time is no factor just cut them out of insulation foam direct.
Plenty of sealers for foam you can then paint over. You can even seal with Shellac.
Of course, foam architectural elements like that are not made for a lot of physical contact.

[robtown]

As time is no factor just cut them out of insulation foam direct.
Plenty of sealers for foam you can then paint over. You can even seal with Shellac.
Of course, foam architectural elements like that are not made for a lot of physical contact.
You could do the same with mdf, it would be more durable.

[Joe Porter]

Good to hear from you again, Jack...joe

[mclimie]

(Part 1) Glove mold with thickened silicone (some are sold brush-on, some can be thickened with additives - see Smooth-On Thi-Vex). First coat, non thickened silicone (to avoid air bubbles on surface) - goes on thin - then a 2nd thickened coat after first is cured. To pour a block mold that big would cost a fortune. You can back it with anything really - but urethane foam would work. Then you'd have a mold to cast from. You can then do a similar process to creating the mold in the first place just with different materials. (Part 2) Do a print coat of hard urethane plastic (couple/few coats) and back with foam or something. You can even pre-prime in the mold to make your life easier. See this video:

https://www.youtube.com/watch?v=SzI329NopJA

Part 1 of my post is already done in the video - there are videos out there on creating "glove molds".

Marc


Marc

[mclimie]

Here's the glove mold process. The backer can be anything conformable that will cure rigid and cheap.

https://www.youtube.com/watch?v=KRvg0gyPEWs

Marc