[Skipr]

Hi all,
I posted this question before but I don't think I got my point across. I started sanding my car with a DA and 80 grit. I have a '65 Mustang. The fenders have a sharp edge. I noticed that the 80 grit actually caused some small irregularities on the sharp edges that you could feel. I eased off on the edges and I still get them. Do I need to use a finer grit after the 80 to get rid of the irregularities before primer or will hi-build primer cover these up?
Merry Christmas!!!
Walt

[Rambo_The_Dog]

Originally Posted by Skipr

Hi all,
I posted this question before but I don't think I got my point across. I started sanding my car with a DA and 80 grit. I have a '65 Mustang. The fenders have a sharp edge. I noticed that the 80 grit actually caused some small irregularities on the sharp edges that you could feel. I eased off on the edges and I still get them. Do I need to use a finer grit after the 80 to get rid of the irregularities before primer or will hi-build primer cover these up?
Merry Christmas!!!
Walt

Hi Walt,

80 grit on a DA should not bite into the metal that much unless you left the pad on edge and in the same spot or you are hitting some old lead repair..

You must be feeling the 80grit scratches or I guessing there was some damage done before - without a picture though I am guessing.

I take it you are trying to strip the car or knock the paint down to a manageable spot but for stripping I normally sand with 80-100 grit and then etch prime (for bare metal) and then use the high build primer. As you go through the process of bodywork and block sanding with subsequently higher grit sandpaper and re-priming should smooth out these irregularities.

If you have a digital camera and get a chance post a picture out here maybe we can see better what you are trying to describe.

Dan

[pmeisel]

I do a lot of resanding and repainting boat bottoms (actually mostly mine, over and over) -- based on a suggestion from a couple local pros I usually use 120 grit or 180 grit. It doesn't take much longer and you get a better surface. I'm no expert, but try it and see how it works for you.

From 80 I would jump to 180 -- but if I was starting fresh I'd try one piece of 120 and one of 180 from the get go.

From the 180 I go to 320, and then the VC17 if there are any sailboat racers on here!

[lbell101]

You shouldn't have any problems using 80 on the DA. Your bodywork and primers should sharpen your lines as needed. 80 can't take that much off unless you're trying hard to make it happen.

Larry

[Rambo_The_Dog]

Originally Posted by pmeisel

I do a lot of resanding and repainting boat bottoms (actually mostly mine, over and over) -- based on a suggestion from a couple local pros I usually use 120 grit or 180 grit. It doesn't take much longer and you get a better surface. I'm no expert, but try it and see how it works for you.

From 80 I would jump to 180 -- but if I was starting fresh I'd try one piece of 120 and one of 180 from the get go.

From the 180 I go to 320, and then the VC17 if there are any sailboat racers on here!

For metal re-finishing you want the base etch primer and first fill primer coat to have something better to stick to than 180 which IMO is too fine for that to happen...then your first block sanding should be with 150-180 grit with subsequent fill primer coats and blocking out to 320-400 for final finishing.

Fiberglass is a different beast because if you leave 80 grit scratches in the gelcoat it will shrink back and haunt you.