I am down to the last little bit of blocking on my 68. I have maybe a dozen spots here and there where I broke thru the urethane primer to the epoxy. Can I get by with a spot coat of primer in those places or do I need to coat the whole car and reblock? Most of the car is looking sweet! Nice and smooth...the primer is getting a good shine to it.

Also...should I finish off with a 600 grit? I've been using 400 and it looks pretty darn smooth to me. Just not sure how far to take things.

Thx!

If you have it straight and ready to paint just spot in your bare areas. Final grit depends on the type of paint your using. 400 is fine for base coat....I go 600 for lacquer jobs.

Will be shooting single stage (solid color) urethane. So would you suggest 600?

Thx

Are you painting it your self, or having someone else spray it for you?
The reason I ask, is some painters prefer to use sealer, while others don't. If you just sanded thru to the epoxy, and not bare metal, a coat of sealer prior to topcoat would do the trick.
Even if you have a couple SMALL areas of bare metal, the sealer will suffice.
400 should be fine for SS urethane.

I blocked my convertible using #400 and painted it with single stage urethane..came out mint.
3 coats too btw
I could have used 500 though,not sure how much difference it would have made,as its looks good.

Zman...

I am having someone else shoot it for me. I'll ask him what he prefers. The main reason I'm concerned is that I'm down to just a little bit of primer...not enough to do the whole car, but plenty to spot prime.

Plus, I'd rather not have to block the thing out again completely.

I've learned what I was always told. Blocking takes an eternity if you do it right. I'm so sick of sanding I could scream.

But man is it looking good though! Can wait for the paint!

http://www.chevelles.com/showroom/reverse-prime.jpg

I would suggest repriming the WHOLE ENTIRE part. If you broke throu on the fender then I would do the entire fender. Redoing the entire part will help ensure that the entire surface is brought into a equal level surface.

But if you do indeed just spot the primer I would HIGHLY suggest to use this method. It helps sanding, and even can produce a smoother transaction from NEW primer to old primer.

Sanding with either 400-600 wont make that much difference. I use 500 wet or 400 dry depending on what am doing...Eric

Depending on what sealer you are shooting it MIGHT NOT cover the spot! K93 a tintable sealer is probably the thinnest sealer PPG has to offer and it WONT cover a sand thro to bare metal. Now on the other if using NCP270/271/272 a break throu will be covered. K36 mixed as a sealer can cover a break throu depending on the size and depth. A REAL SWEET product from PPG is the new V-seal sealer, great product that hides poor prep work and body work. It WILL cover break throus.