Bryan, I think that Dave's estimate of about a gallon of base & a gallon of clear should see you through for the final finish. You will also need a gallon or so of primer. If the body needs a bit of filling / fairing, I'd also budget on a gallon of high-fill sprayable polyester resin/filler.
Chris, I am part way into the painting of my '40, and am leveraging off the 15 year experience of a professional who is doing the body-work on my '71 Corvette. He has tried just about everything over the years with finishing f/glass, & has settled on the following :
- Never use body-filler on any holes larger than the size of a match-head. Anything bigger, grind the area back, lay in glass & resin, consolidate with a grooved roller, & sand back after a week or so.
- Block back (flat stick sand) the whole body using 80-100 grade paper on a block at least 300mm long where possible (or a length of PVC pipe for concave curves).
- Decide on a paint manufacturer to go with for the whole process, from filler to primer, to base, to clear. We are using the 2-pack Spies Hecker (a DuPont Co) system : this starts with a high-build polyester filler (Raderal) which you can lay on up to 2mm thick if required. The idea here is to provide a uniform surface for the next sanding operation - you won't get the ripples that come with sanding across different materials (eg adjoining sections of raw glass, body filler, gel-coat). The Raderal should be blocked back at about 280-320 grade. After that, you run a couple of light coats of Vario primer over the lot, allow a week or so, & then block it all back with 600 grade paper.
- That is where I would hand it over to the professional for the base & clear.
The whole preparation process is really time-consuming, but it is easy to do & worth it in the end. I have the front clip in the Raderal filler, and have spent about 5 hours blocking back half of it - so I am guessing on about around 40 hours for the whole car.
The key to working with f/glass seems to be patience - any large areas of new glass should be left for a few weeks to stabilise before blocking back & painting.
Please feel free to give me call on 02 9988-3587 if you would like to discuss this further.
Kind Regards,
Peter D.