Air sander, what grit paper??

[BuddyP]

What grit of paper should be used when using a air sander on exterior panel surfaces? What is the harshest grit you want to use?

How about orbital sanders?

Thanks
Buddy P

[68protouring454]

usually 80 grit, if car has serious layers of paint you can go to 36, but i always switch to 80 before i get to bare metal, 36 thins the metal too quickly, you will want to use a decent dual action sander
jake

[High Plains Mopars]

I would only use 80 to take off multiple layers and stop before you get to the metal. Then use 120 to take off the final layer or original primer coat. 80 grit can leave some pretty nasty damage behind if taken all the way down to bare metal that will require additional work to smooth out.

[68protouring454]

you must not use very good primers etc, cause my urethane will cover 80 grit like no tomorrow, and if a da its not like your grinding it off, gotta be dirt dumb to put gouges in it with a da
jake

[High Plains Mopars]

I typically use PPG EPX-900, which is a pretty high quality, durable uerathane primer. I suppose a high build could be used to fill scratches if you don't mind dulling some of the character lines on your car, but if your taking it down to bare metal, why not do it carefully and end up with a nice metal instead of creating a situation that requires fillers and build.

I can use 80 grit with no problem, but I've seen a lot of guys, especially newbies, tear up a car with 80 grit. If the original post is asking what to use, my assumption is the experience may be limited, so why ruin good sheetmetal by getting too aggresive right off the bat.

[68protouring454]

agreed, but a newbie will not have the patience a body man does, and a multiple paint strip job is gonna suck with 80 grit, but like we both said, just be very cautious when getting into primer, metal, do not put sander up on edge keep it flat
jake

[gtome]

I just stripped mine with 40 grit on a 8" variable speed buffer. I did the entire car (except tight areas) in like an hour!! It had at least 2 more paint jobs since the original. Then just K36'ed the car with a 2.0 nozzle. I like to do it that way to quicken the pace, I use the K-36 like a sprayable bondo. Then just break out the long john and go to work.

[ProdigyCustoms]

I just stripped mine with 40 grit on a 8" variable speed buffer. I did the entire car (except tight areas) in like an hour!! It had at least 2 more paint jobs since the original. Then just K36'ed the car with a 2.0 nozzle. I like to do it that way to quicken the pace, I use the K-36 like a sprayable bondo. Then just break out the long john and go to work.

Ouch! And is this somehow easy then a few cans of striper? The last thing in the world I would ever want to do is hurry up early in the project so I can have more work later. I would chemical strip with plastic squeegees and steel wool, polish the metal with 180, fat prime the mud work and then thin prime everything else. Those 40 grit swirls will come back in a couple weeks, or maybe a couple years, but they will come back I promise.

I just do not understand all these high build fillers, spray bondos and primers. I guess it is because when I started when dinosaurs still roamed the planet, all we had was ****ty lacquer primer and nitro stain putty (hate that stuff). If your bodywork wasn't good, you were f--ked. I have used some of these products through the years, especially on Corvettes or over huge saves, and they have a purpose. But I do not understand using it as a normal step on ever job. Someone above mentioned disappearing body lines. I hate THICK looking cars. He is dead right.

[gtome]

I have done it that way before without any problems. But, like you said maybe it will end up comming back. When I spray heavy with the primer, I end up sanding lots of it back off. Like I said, I use it like a sprayable bondo, and use it to fill scratches and low spots. Then sand with a long board, so most of the primer is pretty thin by the time I am done sanding. It seems to me that I get the same end result, just this way only takes me half the time. I usually try to take the paint off in sections, so by the time I get close to the paint, the paper is dull, maybe thats why I dont really notice scratches very much?? I have used striper before, but I dont have a drain in my garage, and it makes a huge mess and smells really bad. In my oppinion having it blasted is the best way to go, but that only works if you are doing a frame off (or nearly). These are just my oppinions, I am in no way a professional. I have only done about 8 jobs, but the end result has been very good so far. I guess only time will tell if these methods will hold up....keep your fingers crossed for me.