Something I do to help ensure a long lasting paint job, Something you may find helpful Options

[rick 918-S]

Or should I say something I don't do. I never paint over an older repaint. Here is a photo of an area I sanded showing old laquer based red oxide primer. This and the fact that the repaint could have been an older enamel without hardner is a recipe for disaster. Todays chemically activated primers and paint finishes are designed for HSLA (high strength low alloy) steel. Todays body panels are thinner and harder. Because of this the products need to chemically bond to the steel. In order the give a mechanical bond with new steel you need a 36 grit scratch to create a bond. Anyone old enough to remember the cars that came off the assembly lines in the late 80's will likely remember the paint that was peeling off in sheets. This was due to the altering of the VOC's Volatile Organic Compounds. The sealers and paints flashed too fast and couldn't lock onto the HSLA steel. So the product line was modified to include a bonding action to correct the problem.

So, as a precaustion I never use new product over old repaints. The chemicals that allow these products to lock onto the HSLA steel will eat the old soft paint finishes.




Also I always strip the cowl vent ribs. Never use a grinder on the cowl top ribs. Notice how nice and round the stamping is? It's easy to grind these things flat and thin. Don't bother using a DA or MA sander either. That just gets the flat part sanded and you end up with a funny looking flat rib. The second issue is the new paint will not stick to the unsanded and likely wax covered sides of the ribs. I use the side edge of a hardened flat blade screw driver and simply scrap the paint off to the metal. This is best done with the fresh air blower removed but you can remove the two bolts from the side brackets and push it down low enough to slip in some masking paper. It's not easy but you can do it. I still need to do the wiper pockets but you get the idea. This is an area that you just can't rush.

[Elliot Cannon]

Those sanding marks seem kinda deep. Does the primer fill that to make it smooth or do you sand again with finer paper and then primer or...??? (IMG:style_emoticons/default/confused24.gif)

[scotty b]

Those sanding marks seem kinda deep. Does the primer fill that to make it smooth or do you sand again with finer paper and then primer or...??? (IMG:style_emoticons/default/confused24.gif)

I start at 80 grit. The etching primer, then sealer, then the high build primer will fill in most of that.

[rick 918-S]

Those sanding marks seem kinda deep. Does the primer fill that to make it smooth or do you sand again with finer paper and then primer or...??? (IMG:style_emoticons/default/confused24.gif)

I start at 80 grit. The etching primer, then sealer, then the high build primer will fill in most of that.

(IMG:style_emoticons/default/agree.gif) I strip with 36 grit because you can reduce your down force and cut the old finish off. Then sand again with 80 before etch primer.