I am startign on my front fender and after completing some body work. I hit it with some self etching primer then put on some guide coat to block it out. Now I have some low spots and a couple high spots showing up. What do I have to do to the low spots to get filler to stick? I put some filler in but when I hit it with sand paper it fell out. What do I need to to do for prep to the low spots to get them filled in?

Thanks for your help.

Bob

 

Just a thought-seeing high and low spots after the first epoxy coat doesn't sound unusual. It means that everything isn't perfect. You may want to massage the low spots from the back side with just your hand and check for straightness with your largest sanding block while wiping water across it(if fixed, the low spot will be gone, if not, there will still be a wet spot where it is low).
Also, you are probably going to be putting on about three coats of high fill primer which will help smooth out the high and low spots, with progressive sanding in between each coat. The latest Muscle Car Review has an in depth article on painting a Chevelle where they used epoxy primer as a first coat and then as a sealer after the high fill primer. While filler may be necessary, you probably will want to get the metal as close as possible to have a great paint job!

 

Filler needs clean metal to stick to- a glazing putty works on primer. I would lay down some more coats of primer and then block again. A high fill primer should be thick enough to fill in small depressions...

 

Thanks for the help, I really appreciate it.

 

You might try some evercoat polyflex 411 to fill small depressions. I hear it doesnt need bare metal

 

Thats what I would suggest. I've used that stuff with good results for years.

 

You can not put body filler over self etching primer. If you used an epoxy primer you could. IMO self etching primer is for quick in and out repairs.

Either way Self etching primer and epoxy arent really"blocking" primers. If you have a lot of bodywork done, apply 2-3 coats of a polyester type primer, its like liquid body filler.