air sander using 80 grit on my vette?

[JeffP1167]

This seems to be the best method so far in getting the paint knocked down fast after scraping all the clearcoat off this car. I hear conflicting stories on exactly what grit to use on a vette, it should be block sanded only, must be chemical stripped, all of those stories.

Basically what I am doing is only knocking the shitty color coat down fast yet only enough to the primer starts showing.

This way when I do the block sanding process it's not as much work. So will there be any bad effects from using this harsh grit? I don't plan on using it on corners and so on for that I will try like 180 or something.

So even if I take it down to primer with this grit, then block will the new primer cover it up?

 

[big_G]

As long as you follow up with progressively finer paper, down to 180 or 220 before applying primer/surfacer, your ok. If you go straight to sealer, better finish sand with 400 or 500 wet.

 

[gr8vet]

80 may be too aggressive, it will require alot more finish sanding. I was lucky on my 82 that it had never been repainted, the paint was dry and powdery, for lack of better description. I started with a air sander, using 300 grit, smoothed things out. Finished up with 300 using an electric sander. Primed with two coats, sanded again with 300 wet by hand of course. Sealed it with Dupont sealer, two coats base, three clears, and after 3 years now finish looks great and no lifting nor blistering. As long as your exsiting finsh is not lifting, you should be able to cover it as is. Seal it, do not skip this insurance policy for $60. You will get various opinions and can do several different methods. The above worked for me. Good Luck!
tt

 

[Ozzy]

This seems to be the best method so far in getting the paint knocked down fast after scraping all the clearcoat off this car. I hear conflicting stories on exactly what grit to use on a vette, it should be block sanded only, must be chemical stripped, all of those stories.

Basically what I am doing is only knocking the shitty color coat down fast yet only enough to the primer starts showing.

This way when I do the block sanding process it's not as much work. So will there be any bad effects from using this harsh grit? I don't plan on using it on corners and so on for that I will try like 180 or something.

So even if I take it down to primer with this grit, then block will the new primer cover it up?

Ask Barry K @ SPI

 

[JeffP1167]

As long as you follow up with progressively finer paper, down to 180 or 220 before applying primer/surfacer, your ok. If you go straight to sealer, better finish sand with 400 or 500 wet.

Once I get to the original primer then I do plan on block saning it down from there.

I'm not looking for a show quality paint job on the car just a paint job that looks nice from say 15 feet away. The car will be a daily driver and subject to all the daily dings and so on.

I basically razor bladed off the massive amounts of peeling clear coat. I am being careful not to take the primer down to much or use this aggresive sand paper on edges of the car and I also have not hit any spots on the car where it has touched the fiberglass.

this is after razor blading the cars clear coat. You can see one area where the primer has lifted from the glass, I have seen this same spot on other polo green cars so I assume this 1/4 panel will need extra attention.

I will post a picture of the after 80 grit sanding

 

[gr8vet]

A couple more bits of advice, and it's free so beware! LOL Hook up with a local paint supplier, MAKE SURE THAT ALL YOUR body fillers, primers, sealers, base and clear are compatible. DO NOT MIX brands, or be very careful if you do. ALWAYS use hardner in everything, so it will get hard and you can get back in and fix it. YOU MUST add some flex agent to any urathane, or "easily" flesible parts, not sure on the C4 what all flexes. On a C3 I put it on the front and rear bumpers. Also over the front fenders and hood. Really helps with rock chips. Whatever your brand sez to use for grit on paper, do what they say. Sometimes if you go to slick, i.e. 600 grit, may look good, but primer will not stick to it, it needs to bite into the underlying surface. Just my $.02 worth. I am assuming you are going to spray it? I sprayed my under a carport shed wraped in plastic, positive pressure fans. The trick is in the gun, Sata Jet300 works very well but will set you back $550. Worth every penny. I have never wet sanded the finish, it's just to slick to mess with.

tt

 

[010752]

Sanpaper has gotten really expensive, but if you buy the good stuff, you will see than finer grits work faster than the more course, cheap brands.

 

[JeffP1167]

Here is the primer I am at. I believe the yellow stuff to be from a re-painting the back of the car at some point in its life. The white parts on this car are still in pretty nice shape so I'm not to worried about the prepping of them at this point.