Basically smooth out your A pillar with bondo or whatever. Make it smooth because it will be the basis for your mold. Then you basically make the mold out of fiberglass wrapping it around the A pillar. You would have to ask others about relase agents so that you don't destory the mold pulling it off the A pillar. Then once you have the mold you can easily make the part you want.
essentially yes. Just add the foam you want, shape it, then add a skim coat of bondo, sand that to a perfect surface, then you can pull a mould off of it.
One little tip for cheapskates: Instead of bondo use drywall compound. This can be shaped easier, and is MUCH cheaper. Then take a primer (house latex or similar) like Klitz and spray prime it. Then you can take very fine sandpaper and wetsand it to perfection.
Add some release agent (PVA or Wax... some have luck with either... DO NOT USE BOTH!) Spray on your gel coat (generally for the mould in whatever color was cheapest at the time ) and then lay up as many layers of chopped/mat glass as you feel nessesary. Then you will have a mould that you will be able to pull pretty much infinate parts from... well, until you break it
For release agent you should use glaze or Vaseline. It worked great for me. If you use glaze, put a big coat and make sure it dries before applying the fiberglass for the mold.
Once I tried to make a mould with fabric instead of fiberglass. It worked pretty well and was as strong as fiberglass. I used an old shirt that I cutted in pieces. I used the same mixture as usual (hardener and resin). Once it dried it was also a lot easier to cut the fabric than fiberglass.
I would not use the fabric for parts but it could be great for molds. I hope it will work great for you. Good luck
I don't know if this helps but I tape up my parts with painters tape and then spray glue the tape. Then I use alum foil and wrap the part smoothly. I mix the resin 'not too hot' with about 10-12 drops of MEKP for every ounce off resin and lightly coat the part. Wait for this coat to get tacky and apply a layer of fiberglass cloth. dampen the cloth and wait for this layer to get tacky. Then with the same steps as above apply 5 layers of 1 oz mat. If either layer dries before the next you will need to sand before the next layer. After all layers are on and dried completely I add a layer of rage gold or kitty-hair for stregnth. On large parts you will need to make something for the part to fasten to so that it doesn't warp on you when the coats of resin cure. Whenever possible do this with the part in the car and don't pop it out until the kitty-hair (dyna-mat) and/or Rage-Gold cures. Then you have a negative of your part after you seperate them. The Alum foil works great for this. If you are making pods then you will not use the cloth. Just rip squares from fiberglass mat and apply about 2-3 layers. Mount your speaker rings with dowels and wrap the ring and the mold with grille cloth, panty hose, old T-shirt, etc to get a firm form. After that skins apply 3 layers of ripped mat, rage-gold and sand your fingers off. hahaha kidding. The amount of sanding depends on how you cover your POD. If you want to see how it is done... Go to Alpine's website and check out the demo cars. The URL is: http://ecominet2.alpine-usa.com/html/adc/adc_main.html