i'm not a professional but i think the DA is to be used only up to a certain point, then it's blocks and only blocks.

once you're on blocks and in the finer stages of paper you're not as much sanding as you are smoothing. all the body work should be at the microscopic finish level and the finer papers are for taking it to that special finished degree... just watch where you're sanding (smoothing) and keep moving.

if you're sanding with a DA i'm unsure if the body will show it... it's not really the proper tool...

 

Between sanding use some dark spray paint and must the whole car. Once all the mist paint is gone you will know that you have sanded it all.

 

Mist the car.... Damm auto correct.h

 

For wetsanding, I would not use a DA sander... by hand with a block.

In terms of telling the difference between 1000 and 1500, if you are pretty well smooth withg the 1000, not likely to SEE a difference with the naked eye, unless your really good, and have great lighting. Misting with black paint is one way, or just start at one spot and keep moving around. Point here in my experience, is if you did a good job with the 1000, if you don't hit every square millimeter with 1500, you still be just fine.

Having just thought about this, if you are talking about smoothing your clear coat finish, or your single stage paint, I would not mist dark paint. If you're talking about smoothing primer in prep for paint, you don't need to go down to 1500. That's more work than necessary. If clear coat, be careful you don't go through the clear, which can happen even with 1500 paper.

Mike

 

Definitly use the 1500 grit by hand and then finish in 2000 grit, also put a few drops of dish soap in your water for wet sanding. Finishing in a finer grit its easier to buff and less chance in burning through with the buffer. The finer grit you finish in the easier to buff, we finish in a 3000 grit
3m Trizac paper using a DA sander using the wet method. Use the newest 3m compound with a wool pad to start and then use the yellow foam cutting pad with the compound to finish the compounding stage. Next use a grey foam pad with the 3m grey polish and go over it. If your car is a dark color then you could take it to the next level and use the blue foam pad and the blue 3m swirl free polish.
Good Luck!

 

the reason i wanted to use a DA was because the car was painted over a moth ago and the clear is really hard.

when im sanding with 1500 i can see the water turn a milky white so i know its sanding but i guess im just paranoid because i dont want to go to go and buff it and i miss a spot and the buffing compound dosent take the sanding scratches out.

 

I wet sanded a 72 Cutlass with who knows how old the clear was. I personally would not use a mechanical device to do it. Much more control by hand. I would also go down to 2000 grit, it will make it easier to buff. It's quite possible, after you're all done, you will see spots you missed with the buffer, or spots that need more time. Just keep working on it, but take your time. If you see color in your water or on the paper STOP!

Good luck...

Mike

 

i decided to do it by hand and i did notice a little more reflection with the 1500 grit in certain light. im still undecided if im going to 2000 or not.

 

the clear, unless it was cut is the sprayed gloss finish. it's not going to be as flat as you think and you'll be sanding a bit. it has to be smooth... just don't go too far. take your time, keep it wet and rinse the paper often. soak the paper in the bucket for a while before you start...

again, don't be in a rush and enjoy it... it'll turn out great.

 

NO DA!!! Not at this point. Wet sand with the 1000, wipe the car down, wet sand with 1500 and you will fell it cutting as it will begin to slide more easily over the car. Your should be all done with your guide coating and dry sanding before you started wet sanding. You must use a block or rubber pad while doing and kind of sanding even when wet sanding or you will put waves in your paint.

 

the only place i used a DA was on the roof and that was just to try and see if it would work, it didnt so i got a 2 sided block for wetsanding. i have the 1000 grit done and i got about 1/3 car done last night in 1500.

i am taking my time and im paranoid about burning through so im taking it slow, but im feeling more comfortable doing it a second time around.