Paint Prep Help
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
Photo 3: I do not apply any type of filler on any sprayed product. I know it is done each and every day...and a long time ago...I would do it. But I also got "bit" by doing this due to the primer, sealer I was using at the time seemed "cured" but was not... and in time...the small areas re-surfaced and I could see where I applied the glazing putty. I do all my repair work and filling on the bare body before anything is sprayed.
HONESTLY...it is much like how you do a metal car...like how you wrote it in you post. By sandwiching the filler in between primers and thus making it so no filler touches bare steel. That is the RIGHT WAY...but I can guarantee that 99% of people doing it...do not do it that way. I do it that way....because I have seen cars when I grind down the filler or get it to "pop-off" do to improper adhesion and or prep....the metal under the filler has small rust spots in it. All I can do is shake my head and scream out " F-ing IDIOTS".
DUB, these statements seem to contradict each other. Can you clarify that for me?
HONESTLY...it is much like how you do a metal car...like how you wrote it in you post. By sandwiching the filler in between primers and thus making it so no filler touches bare steel. That is the RIGHT WAY...but I can guarantee that 99% of people doing it...do not do it that way. I do it that way....because I have seen cars when I grind down the filler or get it to "pop-off" do to improper adhesion and or prep....the metal under the filler has small rust spots in it. All I can do is shake my head and scream out " F-ing IDIOTS".
DUB, these statements seem to contradict each other. Can you clarify that for me?
Because the filler will get hard...and a solvent being used in the primer applied over it may have a lot of "bite" or penetrating properties to it can actually soften up the sprayed materials under the filler that was applied and cause for problems.
In the later quote when you read that applying a primer and applying a filler to it and then applying a primer over it is dealing with metal cars. NOT FIBERGLASS...which is what the first section is dealing with. There are special primers that can be applied to metal and yes...fiberglass ...that will allow the filler to adhere chemically...instead of a mechanical bond which is done through grinding and getting surface rough.
Different substrates have different repair procedures. They all do not get repaired the same...obviously because fiberglass does not rust. Urethane bumper covers are also different and so on.
I hope this cleared up the confusion...if not...please ask again. I do not want you to not understand what was written in a confusing way. I read all my written replies but forget that I do this all the time and forget that I may seem to leave out information that would allow someone who does not do it all the time to understand. Sorry about the contradiction you found.
DUB
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
I was confused when I read that I should not do any work to the bare material? Does this only apply to metal? Which would be the right way. Please clarify DUB
ON METAL..if you want it really right. Apply a primer that is designed for filler to be applied to it and do you body work and re-apply this primer so NO FILLER ever touches the bare steel.
EDIT: I forgot to ask. In your first post, you said 3 coats of the polyester primer will cover the 180 grit sand scratches, correct? Does that mean to just block sand the gel coat with 180 grit, spray the polyester primer (3 coats), then spray BC/CC? With no sanding on the polyester primer?
With your Corvette being a 1978 I believe...there is NO GELCOAT on it. So blocking your body and doing all repairs BEFORE you apply a polyester primer or what ever you choose is how I prefer to do it. SO..YES...block with 180 grit and prime. Then sand for painting or re-priming if needed. I personally do not like to use putties and these new soft, creamy body fillers for filling in minor imperfections. The reason being it that I take real care in getting things filled in with the Vette Panel Adhesive and when I go to prime...if I have any small pinhole that I missed...I know how to fill it in while priming. And I prefer to use the VPA due to its strength and hardness.
ON METAL..if you want it really right. Apply a primer that is designed for filler to be applied to it and do you body work and re-apply this primer so NO FILLER ever touches the bare steel.
EDIT: I forgot to ask. In your first post, you said 3 coats of the polyester primer will cover the 180 grit sand scratches, correct? Does that mean to just block sand the gel coat with 180 grit, spray the polyester primer (3 coats), then spray BC/CC? With no sanding on the polyester primer?
With your Corvette being a 1978 I believe...there is NO GELCOAT on it. So blocking your body and doing all repairs BEFORE you apply a polyester primer or what ever you choose is how I prefer to do it. SO..YES...block with 180 grit and prime. Then sand for painting or re-priming if needed. I personally do not like to use putties and these new soft, creamy body fillers for filling in minor imperfections. The reason being it that I take real care in getting things filled in with the Vette Panel Adhesive and when I go to prime...if I have any small pinhole that I missed...I know how to fill it in while priming. And I prefer to use the VPA due to its strength and hardness.
DUB
