C-3 body paint question

[Mark A.]

I am in the process of removing all the steel bracketry from underneath my 69 coupe, and sandblasting and dipping the parts. My question is, the underside of the body needs to be cleaned up. I plan on sandblasting it with about 40# of pressure, and would like to paint it. If I can get a close color match, would this be advisable? I want to restore the car as close to original as possible.Thanks, Mark

[Wayne P.]

Re: C-3 body paint question

Not advisable for judging. It will make a nice looking job and ease cleaning.

[Dick W.]

Re: C-3 body paint question

Just wash the underside thoroughly and leave it alone. Only paint would be a little overspray from the blackout and very little undercoating.

Sandblasting will loosen the fibers in the glass. Do not do that.

[Mark A.]

Re: C-3 body paint question

Okay. I have the NCRS judging manuals, but they don't seem to say exactly where the blackout should be on the underbody. Also would blackout be the same as the chassis black paint I am going to use on the frame? Mark

[Dick W.]

Re: C-3 body paint question

Picture the car going down the assembly line. You are standing in a pit with the wheel openings just below eye level. Take a spray gun and make a quick pass, some days doing a better job than others. Blackout is not precise. It was never a "sharp" masked line. Varied from car to car, day to day.

I do not know what you are using on frame, but the paint was a satin, semi gloss about 75-80 degrees of gloss

[Mark A.]

Re: C-3 body paint question

Thanks again for the help Dick.

[Chuck S.]

Re: C-3 body paint question

You might try cleaning the underbody fiberglass first starting with mineral spirits (paint thinner). Mineral spirits is benign and will not damage your fiberglass, but I wouldn't want to use it on any areas, say the hood or fender, that have to be painted.

Once you have removed all the grease, tar, and road film, wipe the surface down again with lacquer thinner. Don't try to keep it wet with lacquer thinner for any period of time, just remove the mineral spirits residue.. Once you've wiped it down with lacquer thinner, follow that up with a soapy water bath. Your underbody fiberglass will come out as slick and shiny as the day it was built, and that's the way you want it to be for judging.

As to black out paint, the wheel wells and mufflers are about the extent of black out on the underbody/chassis, but a lot more was done...behind the front grill, radiator support, inner fenders, firewall, plenum, windshield frame, and the inside front of the doors about a foot or less back from the hinges.

[Greg L.]

Re: C-3 body paint question

Mark,

What Chuck says about using lacquer thinner is good advice but use caution around areas of factory overspray as the thinner might remove it if you are not carefull.

I used simple green, a few different types of brushes and the garden hose for rinsing when I cleaned mine and it came out really nice. Only problem I had was that I ended up being soaked from head to toe...literally!

[Chuck S.]

Re: C-3 body paint question

Hi Greg. I agree on that...If he wants to preserve ANY factory overspray on the underfloor, I probably would not use the lacquer thinner at all. My experience is once you start cleaning with lacquer thinner, it cleans SO WELL, there is never any place to stop without leaving a sharp line of demarcation.

The surface will look clean and shiny up to the point where you decide the overspray should start, and then you'll have overspray starting more abruptly than normal, and looking dirty in-between far-flung paint specks. I've been down that road before, and you end up having to take it ALL off, and just put the "overspray" back new.

BTW, Mark, use caution, rubber gloves, and eye protection with the lacquer thinner. You don't need your rags or paper towels wet enough to be dripping, and you definitely don't want to get that stuff in your eyes. Someone said MEK in your eyes causes cataracts...my opthalmologist says no, but after cataract surgery, I believe my doctor to be under-educated. (OK, it can be argued I'm old enough to be susceptible anyway. )