The Stovebolt Site Forums The Shop Area Paint and Body Shop deep scratches in fenders

Need some advice. I am working on the rear fenders of a '54 3100 for a friend. After repairing the rusted sections I started sanding off all the old body filler. Both fenders were completely covered with the stuff and I was wondering why. After some initial sanding the answer was clear. The PO or someone trying to do body work, had used a grinder to remove the old paint and primer. In the process they left some serious scratches in the metal all over the fenders. Seriously, there is hardly a place that isn't damaged. Apparently all the bondo was to hide their dirty work.

What can I do to fix this? I have been trying to sand some of the scrathes out but most are just too deep. Should I just use a skim coat of body filler, then prime? Or should I sand and then use a high build primer to fill the scrathes?

First apply epoxy primer, then you can either skim coat with body filler or polyester glaze.

Yep like Wilbur said , I think you have no choice but to prime and cover it with a skim coat and block it all out ,
well look at it this way youll get a good upper body workout !

If you have the fenders down to bare metal, you don't need to prime.

Apply a skim coat of filler. Really thin and sand with 80 grit until you start getting back down to the metal. Add another coat of skim coat and sand with 180 grit. Once you have it sanded and smooth, your can apply several coats of high fill primer and sand with 320 grit. Then add 2 coats of epoxy primer/sealer.

If you can't get the skim coat to spread thin enough, you can thin the filler with either Polyester filler thinner (which is just polyester resin) , or do what I do, I add some polyester resin to the filler until I get it to a nice smooth consistancy. It's cheaper than spending $30+ for Icing. :mad:

Don't pour the resin in your can of filler, just put some filler in a mixing cup and add polyester resin to it.

I think you will like the way it spreads, fills, and sands.

Frank

Appling epoxy primer to bare metal prior to body filler will aid in the filler's adhesion, durabilily and also add some corrosion protection. A few car manufactors now highly recommended that epoxy be applied to bare metal prior to filler because of those reasons.

I'm not saying that you can only apply filler to the bare metal, I'm just saying that you don't have to prime before filler you can go either way.
And you all know how paint suppliers love to sell you products that you don't need. And they will swear that you must to have it.

For years and years, we've applied filler straight to bare metal.

So why use twice the amount of epoxy primer than you have to. Apply your filler, and then apply your expoxy primer/sealer after you have your body work done.

The epoxy isn't going to help the filler stick any better than it would without it.

Frank

I agree, Frank. I have always applied filler to bare metal and never had a problem. If I remember right, that is the way the body work books that I read some 30 years ago said to do it. I am not saying that with all the improvements in products that it can't be done differently, but if something works, why change?

I have never had a situation such as this before, so I was just wondering if filler was the way to go.

I finally got all the old filler off of one fender. It was at least an 1/8" thick in some areas. Now I can start spreading it back on, but only enough to fill all the scratches and a few minor dents.

With the cost of material these days, we have to cut cost where we can and still do the job right.

I will spray a coat or two of epoxy primer/sealer if it's going to be a while before I can work the part. But this is just to prevent surface rust from forming. But usually I will just apply body filler right to the metal. And then use Lacquer primer as a surfacer. Now, I know a lot of these "modern" bodymen will yell and scream not to use Lacquer primer and list a whole list of reasons why not to. :mad:

But I've used it for years, and will continue using it. :blat: And the first reason for it, is that I can leave it in the spray gun and not have to worry about a "pot life". The second, it dries fast and I can sand it sooner, where with epoxy, you have to wait a couple of hours to sand. Third, it's cheap and easy to sand.

So I may be a little old fashion, but if it works, don't fix it. :hammering:

Frank