Painting my hood

[Stewart A.]

Just finished repairing my hood and had to take it back to bare fiber glass. I have filled the highs and lows with filler and now don't know what to put on next. I want the top coat to be acrylic lacquer. Can anyone help me ? I plan on painting it in my garage so no nasty chemicals.
Stewy

[Chuck S.]

Re: Painting my hood

Just finished repairing my hood and had to take it back to bare fiber glass. I have filled the highs and lows with filler and now don't know what to put on next. I want the top coat to be acrylic lacquer. Can anyone help me ? I plan on painting it in my garage so no nasty chemicals...

If you don't have experience with the paint system you prefer, you have to read the product data sheets (PDS) to maintain compatibility between all the products. Use products all made by the same manufacturer, and designed to work with one another.

Pick the manufacturer and top coat product you want to use...since you say you want acrylic lacquer, I believe the default manufacturer is going to be PPG. That's good because PPG product data sheets are freely available, and are much easier for the non-professional to understand. This presumes that the PDS are still available for all the acrylic lacquer compatible products.

Typically, modern paint systems may have a primer coat, maybe a primer-surfacer layer (up to four or more coats may be required), a sealer coat, the color coat, and if it's a two stage system, finally the clear urethane top coat. The original paint was the bare minimum that could be used, and was consiberably simpler, requiring only a red oxide primer coat, a gray sealer coat, and then the acrylic lacquer.

Using the PDS, work backwards from the color coat to determine which products each respective top coat can be applied over, until you get down to the bare fiberglass. You have to select the type system you want to use...for example, whether to use a primer-surfacer or not. If the substrate is free of waviness or roughness, or if you want to keep the waviness, use of primer-surfacer is not required, only a good sanding primer.

[Stewart A.]

Re: Painting my hood

Thanks for your reply Chuck have you ever used spray putty as a base over bare glass. Stewy

[Chuck S.]

Re: Painting my hood

Thanks for your reply Chuck have you ever used spray putty as a base over bare glass. Stewy

Such as Evercoat Featherfill, etc?...No, I haven't used it, but it often comes up in paint discussions as an easier alternative to gelcoat.

Spray filler is used to smooth body surfaces, and smoothing out those original waves in the fiberglass is sacriledge to most restorers. If you need to repair numerous tiny stress cracks, or have made fiberglass repairs that need to be sealed, gelcoat would be the most reliable product. Make no mistake...gelcoat is a LOT of work; old men and young boys need not consider.

If I needed to smooth the body, and didn't have repairs to seal or tiny stress cracks, I would opt for PPG's catalyzed urethane primer-surfacer (K36?) in order to keep all paint products compatible and by the same manufacturer. Even if I used gelcoat, I would prime the gelcoat with epoxy primer, and then apply the primer-surfacer. PPG's K36 primer-surfacer is urethane baed, but it can be used under other paint systems if you confirm compatibility.

Gelcoat would be the exception to the one manufacturer rule since the most popular Corvette gelcoat is only sold by Eckler's, and it is essentially a catalyzed polyester resin with a waxy oxygen inhibitor. Application of PPG paint products over well-cured and preped gelcoat is the same as applying them to bare fiberglass.

[Stewart A.]

Re: Painting my hood

My mate just sprayed my hood which was bare glass. I went out and purchased ppg epoxy urathane and ppg polyester. I went to pick up the hood and noticed the new tin of epoxy urathane that I paid $50 dollars for was unopened, I asked the question and he said that the rep told him not to use it because its really designed for steel even though the data sheet says fiber glass. I rubbed the guide coat off the polyester with 120 then 180 and I must confess it looks very over restored. There is not a waver in the entire hood and very, very smooth. He is now painting high fill on it and I will leave it to gas off for a few weeks before top coating. One thing he mentioned to me I thought was strange he said he will rub it back until he uses the soft little pads of 500 grit before high filling which is very smooth, data sheet says 120 grit. My mate said he has been doing it for over 10 years like that and it works better because after a year you dont see the 120 scratches in the top coat from the polyester and high fill and he says that high fill sticks **** to blankets so don't worry its not going to delaminate. Strange !!! Ah. This will be the test pilot before I do the rest of car I'm sold on his methods yet. I'II give the hood a year of abuse and see what happens. stewy

[Chuck S.]

Re: Painting my hood

My mate just sprayed my hood which was bare glass. I went out and purchased ppg epoxy urathane and ppg polyester. I went to pick up the hood and noticed the new tin of epoxy urathane that I paid $50 dollars for was unopened, I asked the question and he said that the rep told him not to use it because its really designed for steel even though the data sheet says fiber glass. I rubbed the guide coat off the polyester with 120 then 180 and I must confess it looks very over restored. There is not a waver in the entire hood and very, very smooth. He is now painting high fill on it and I will leave it to gas off for a few weeks before top coating. One thing he mentioned to me I thought was strange he said he will rub it back until he uses the soft little pads of 500 grit before high filling which is very smooth, data sheet says 120 grit. My mate said he has been doing it for over 10 years like that and it works better because after a year you dont see the 120 scratches in the top coat from the polyester and high fill and he says that high fill sticks **** to blankets so don't worry its not going to delaminate. Strange !!! Ah. This will be the test pilot before I do the rest of car I'm sold on his methods yet. I'II give the hood a year of abuse and see what happens. stewy

I wasn't aware you were working with a painter, but I should have asked.

For future reference: Whenever a painter "recommends" a certain product or approach, he's telling you what he wants to do. If you have a different idea he didn't "invent", you run the risk of him being somewhat less than fully cooperative, or getting bad results.

As for any paint product being "made" for one type of body material or another, that is a concocted BS excuse...Who you gonna believe?...The people with PhD scientists working in laboratories to develop these products, or some bloke behind the counter that sells the stuff?

A solid, inert, properly prepped substrate is all that is required; if it ain't "melting", it will be fine. The only exception to this rule is plastic body panels or trim that are very flexible; e.g. front and rear fascias of modern cars. The type of paint doesn't change, but you can't put the paint on as thick, and special additives are necessary to allow more flexing of the paint film before it cracks.

Apparently, the surface came out smoother than you wanted. Either the "Feather-Fill" or PPG's K36 will do exactly the same thing...they allow you to block the surface flat; all the natural waviness that was in the fiberglass will be removed. The only difference is, the K36 will probably be more expensive. But, if you NEED a surfacer, then K36 is less likely to cause problems with other compatible PPG products. The bad news, Stewy, is that when you sanded the Feather-Fill off, you likely removed some of the original waviness out of the fiberglass anyway. Unfortunately, every time we prep a Corvette for paint, the original "waviness" of the fiberglass is reduced; sanding prep essentially "knocks the tops off" the waves, and smoothes the "undulations".

Go read my first post again: I said, "If the substrate is free of waviness or roughness, or if you want to keep the waviness, use of primer-surfacer is not required, only a good sanding primer." I knew I used the wrong word...I should have said use of primer-surfacer is not NECESSARY OR RECOMMENDED.

If you don't want the car to look "over-restored", I definitely would not use EITHER a primer-surfacer, or "Feather-Fill". Just prime it with either epoxy OR a sanding primer, lay on a sealing coat, and spray the lacquer. If you use PPG's DPLF epoxy primer, you won't even need the sanding primer OR a seal coat. The lacquer can go right on top of the epoxy, and will look more original because the total paint thickness is reduced. But, better tell your bud he'll have to spray the lacquer within about 72 hours, or the epoxy will have to be scuffed and resprayed again.

DON'T FORGET: I also said, if you have made fiberglass repairs, it is good insurance to seal those repairs with gelcoat before painting. In my opinion, Feather-Fill is NOT a substitute for gelcoat; it is a surfacer ONLY. Unless those repairs are sealed, you could have blistering problems later.

But remember...if your painter has a "better idea"...better do it his way. If you're paying this guy to paint your hood, and it blisters, you can always ask him to repaint the hood at his expense.

Edit:

..One thing he mentioned to me I thought was strange he said he will rub it back until he uses the soft little pads of 500 grit before high filling which is very smooth, data sheet says 120 grit. My mate said he has been doing it for over 10 years like that and it works better because after a year you dont see the 120 scratches in the top coat from the polyester and high fill and he says that high fill sticks **** to blankets so don't worry its not going to delaminate...

I just reread your post and realized what you were saying here...It's hard to argue with ten years experience, but I generally use a more coarse grit paper than what the PDS call for, particularly before the surfacer. There is no reason to use fine grit paper before a surfacer...I have seen K36 fill 36 grit grinder marks without a trace, and 80 grit is a cakewalk. It's not a good practice, but sometimes you miss things. Now, after the filler, particularly when using acrylic lacquer as your top coat, fine paper is good...but if the PDS says to use 400-600 grit prep for a top coat, I'll use 400 grit.