playing around with making a gauge panel out of 1/4 ply and mdf but I plan on painting it when done, will primer and bondo "cover" the wood grain (of the ply) when painted, will it fill the "end grain (for lack of better description) of the mdf? Want it to come out looking one solid piece...thanks-
it will have raised and relieved surfaces, I want it to basically look like one solid piece of "cast" material...
Wood,plywood with age shrinks and any paint will always have a hard time staying nice on wood. Make your panel of metal,or cover it with some thin metal so paint will stay fairly nice longer.
If you don't want to/can't fab the panel out of metal, MDF is the better chioce over plywood. MDF does not shrink or warp, unless satuated with liquid. Scuff any surfaces you plan on adhearing bondo to, to give it something to bite into. High build primer will hide the end grain. Painting it after you cut all your holes, will make it as water resistant as possible. I've worked with MDF for over 15 years in the car audio world, it's great stuff as long as you know how to work and finish it. Hope this helps.
Sculpt the shape you want in plaster, make a mold and cast it in fibreglass. Plywood or MDF will not last in an open car although they will last for 10 years or more in a closed car.
if kept at a consistant humidity and temperature it should last a decade or so how about making it like you suggest but using that as a plug to create a mold to lay up a glass dash?
I would make it out of mdf and then cover it with Fleece or fiberglass and resin. Check out this video. This guy covers the process. http://www.youtube.com/watch?v=G8cz_5eP81U
Can I make an observation with out the touchy feely police making a drama thread out of this? The wood dashboards on british imports used to be ply wood with a hard wood venir. I have seen many over the years that were just as solid as the day they left the factory. Many 30 or 40 years old, and a lot of them in the Pacific North West. OK that doesn't answer the question. Dan first you need to get some sealer of some sort on the wood to keep it from absorbing the primer, then if you are patient you can use high build primer to hid the grain prior to painting. Donot completely seal it up leave the back side untouched or it will dry rot. It has to breath.
thanks for the info. gonna start today making a hammer form, making one completely out of wood, one just cut from sheet metal and I am going to look into that video - fiberglass is another thing thing I know NOTHING about so am gonna play with that idea as well...thanks-
http://www.youtube.com/watch?v=G8cz_5eP81U thats pretty cool. lots of possibilities there that guy applies bondo as smooth as I do I had the sound turned off as I am waching this while the kids are working so maybe he covered this but what would I use as a "mold release" if I wanted to use the mdf as a "plug" and make a fiberglass part to pull off of it?? thanks-
Just your standard fiberglass release agent. I don't remember if it has a real name but you get it where you buy your glass supplies.
whenever I'm doing a one-off plug and mold, I use several coats of turtle wax or any wax with carnuba base for a release agent. (Many years in the boat industry).
Theres also the products called Medite and Medex, these are high moisture area and water resistant plywoods similar density to the MDF. good lumber yards and sign shops should have these.
Why not make it out of wood/MDO/Bondo, then have it cast in aluminum? Then you can polish it and not worry about it rotting? See my posts below for tips on how: http://www.jalopyjournal.com/forum/showthread.php?t=441108 http://www.jalopyjournal.com/forum/showthread.php?t=462249
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