Painting questions

I just stripped the last of the original (sandglow) paint off of my '76B. I have a few questions:

1. Does it matter which primer I use over the bare metal, or should I wait to paint the primer until I have figured out which paint system/brand I'm going to use?

2. Does body filler (to cover some welds) go on before or after the primer?

3. Does anyone have recommendations on which paint system to go with? I'll be using a full paint booth and a respirator with 3M 6001/5010 filters, so I'm open to two-pack paints with hardener. I'm looking for a paint of reasonable quality and modest price. I talked to the Dupont paint supply store down the street and they quoted me over 800 dollars for a couple quarts of primer and british racing green paint, which is much more than I had budgeted for. Any recommendations? Anyone have experience with the stuff from www.paintforcars.com?

Thanks.

1 epoxy primer. Sandable is best in my opinion. Can be painted then anytime (virtually).

2. most distributors will say that you can fill over their primers. The argument over what has more "tooth" rages to this day.

Most will agree though that its better to cover the metal first, as there is going to be inevitably some moisture that gets UNDER the filler.

So, that seems to lean towards the primer camp first.

Landon

I use a good quality etch primer over all bare metal.. For initial filling I use light weight short strand fibreglass filler. It is waterproof.

Bondo type regular fillers are somewhat hydroscopic and encourage rust.

If you are not going to put the colour on right away use a epoxy type primer/sealer to reduce the chances of rust.

Hi-build primers are easier to work with.

Use products from one company for the primer/paint work. Most companies have a system that is designed around compatible product.

I only use bondo type products during the final finish fill and then a very thin layer.

If you are lucky you will only need about 60 hours to get ready for paint.

Using a guide coat before putting the colour on will help you find any deficiencies in the surface.

Once the colour is on you should colour sand and buff.

Thanks for the replies - follow-up question: how much paint, per coat, does an MGB take? Just talked to a jobber who quoted me 335$ for a gallon of Dupont etching primer plus a gallon of reducer. I'm guessing it'll take a good deal less than two gallons, but I don't want to end up short, either.

How much paint per coat is a tough question. However, keep in mind that for most topcoats the color is reduced 50/50 with the reducer and catalyst. So one gallon of color makes two sprayable gallons. I have trouble remembering, but I think on my roadster I used two quarts of silver basecoat and two quarts of clear, a quart of epoxy primer and a gallon of 2k high build primer. I did the filler work on bare metal, one good coat of epoxy, I used the whole gallon of high build 3 coats at a tiime with block sanding in between. In the end, I had to buy an extra quart of silver to fix a problem area. Which didn't match exactly. Which leads me to my one big lesson:

Buy enough paint so that you have some left over on the shelf for fixing mistakes.

Last friday I bought the supplies to paint my gt. I always use OMNI by PPG. I asked the paint jobber why its cheaper. He shrugged and smiled at me and said, "Less of a warranty, doesn't last as long, doesn't match well for spot repairs." None of which is a reason for me to spend more. I bought a gallon of mercedes mars red base for $135, it was over $600 per gallon in their "better" paint line. My total bill for a gallon of base, three quarts of clear, gallon of 2k plus the reducers/catalysts was $385. I should have about a quart of color left over for a rainy day. Check on the OMNI at a PPG jobber, it's good stuff.

I have used PPG Omni AU on 4 cars and when used with the other PPG recommended products it produces a nice finish that lasts. It is also easy to touch up with.

I do not use clear coat because of the amount of shine is so much different that the original factory finish.

But a gallon and you will not go wrong..

Thanks for the replies. Another question - can I use a phosphoric acid etcher and then a primer in lieu of a self-etching primer? Thanks.

xof Wrote:

Considering all the work, prep and the hope never to have to do it again, go with the best you can afford and take your time. Everyone I have spoken to about this at body shops told me to use epoxy on bare metal. I prepped the bare with Metal Ready, wiped it off, let it flash, scuffed it with 800, tack ragged it and shot epoxy. All body work was done over the epoxy, with 80 to scuff it for grip.

Itch got 4 coats of acrylic enamel, wet sanded between 2 and 3 then 4 coat of clear, then cut and buffed. Cost for all of thais was about $1200 in materials.

It looks like a mirror.

The reason PPG recomends epoxy under the filler is twofold. For one the adhesion is improved since the epoxy grips better than the polyester filler to bare metal. The other is corrosion prevention. The catalyst used in polyester filler is actually corrosive. I have had occasion to rework other shops work where they applied the filler directly over bare steel. Underneath the filler I have found a light coat of rust forming. Not what you want. I finish the bare steel with 80D on the DA, wipe with clean rags & thinner, then epoxy. Never had a problem with adhesion. That epoxy sticks to darn near anything like glue. Well it is glue sort of.
As in anything, there are shortcuts. Maybe OK for shops slamming out used car work but not for something you want to last the rest of your life. IMHO.