this is a bit off-topic, but i want to do some carbon work for some motorcycle parts. i figured i can use my boardmaking skills and see what happens.
the question: i want some foam that i can shape a mold out of and lay carbon fiber on it. glass the mold eventually and pop my piece off of it. I know if i use the normal foam i use for my boards i will have to tear the carbon piece from the mold.
The process you described will work if you first seal the foam with fiberglass and a tooling primer. the tooling primer would need to be sanded and buffed, and waxed or PVA’d so the parts will release.
What you are doing can also be accomplished with a splash mold. This is a very common practice in tooling, and once you see it done, is not all that difficult. It would require taking you existing fender and coat with a mold release wax and/or PVA. The part is then splashed with plaster, which creates a copy or “plug” of the fender. This “plug” can then be leveled, shaped, flared, or modified (Bondo works well!) as you wish, then sealed with either a tooling primer or vinylester or epoxy tooling gel, and used as a “tool” for to lay-up your carbon part.
Depending how involved you want to get, you can look on the internet for additional info.
What I gave was the abbreviated version of the process, but with some extra steps can give a great look. If you are interested in more detail you can either give me a call or PM. I would be more than happy to discuss further or answer any questions.
I did the slab sided copy of the H1R fairing for Yamaha, as they thought their rounded fairings weren’t slippery enough. Sold it to Yam, as they were switching from aircooled TD-2’s to watercooled TD-3’s, and needed mods I couldn’t make without a full frame and engine.
Did some aero seats also, sold to DonVesco of Yamaha for a paltry $100.
Artist/designer is not important, but nose to the grindstone work ethic and meeting projected schedule is much more important.
I’ve made 50’s style wheelskirts for my old Ford… Handshaped PU, glassed, sanded and molds made from concrete. Mind you eliminate “Overhangs”, which will prevent being able to pull the molded piece out. Probably need what are called “Splits” in the mold…
I think what you are referring to is negative draft. Depending on the part and lament schedule or core material used you can work around some of the negative draft. Thats assuming there is enough flex in the part. You need to be very careful not to damage either the part or the tool when de-molding the part.
There are so many ways to build your tooling, and concrete is a good stable support. I use mostly epoxy and glass, as I ramp the temp. up and down in order to post cure the parts. You can use whatever works!!!