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Sand down base coat before clear?

Discussion in 'Body / Exterior / Interior / Cosmetics' started by cheese9988, Jul 8, 2004.

  1. cheese9988

    cheese9988 Senior Member

    Before I apply the basecoat, would it be a good idea to sand down the base coat after a couple layers? Or just apply the clear coat on top and sand that? I have been sanding down the primer with 600grit, should I start a lighter paper too?
  2. KCREX

    KCREX Member

    depens on quality of base coat. some basecoats spray on very smooth not requiring sanding. just wipe down over spray with tac cloth after every coat drys. some high quality paints wont have any overspray. dont just sand, wet sand. you dont want hard pieces to stick to the dry sand paper cause youll gouge the paint. if the base coat is rough, add more reducer to get the smooth feel. dont wet sand clear coat unless you have a polishing kit.
  3. cheese9988

    cheese9988 Senior Member

    I wet sand everything, dry sanding is too much of a pain on that stuff. I just wasn't sure if I should sand down the basecoat thats all. I assumed people just sprayed over it but I wanted to be sure first.
  4. swanny

    swanny Senior Member

    Unless you have more than 2 previous coats of base\clear there is no reason to sand it down. Buzz over it with 320-400 or a grey 3m scuffpad and spray.
  5. KCREX

    KCREX Member

    just make sure everything is smooth and the way you want it cause every layer effects the finished product.
  6. hcivic.com

    hcivic.com Senior Member

    well no this isnt true please don't post if you don't know. Body work is so difficult to fix if it is fucked up, by bad advise.

    and you wet sand with no less than 1000 grit paper, and if you do get a run you have two options. 1 run it off the car, works great very hard to do. 2 let it dryand sand it out.
  7. cheese9988

    cheese9988 Senior Member

    I have always wet sanded the primer with 600grit and it feels smooth to me, would you recommend sanding it down again with 1000grit?
  8. KCREX

    KCREX Member

    ok hcivic.com for one i am talking about "overspray" not a run and for two your telling a begining painter to try and push the run off the car.

    if your paint runs you should spray thinner coats or hold the gun further away.

    your right about dry sanding the run after you mess up.

    i use 600grit to wet sand primer and 1000 for paint and clearcoat and comes out perfect everytime.

    OVERSPRAY is that annoying mist that gets all over the place. thats why people mask. if you spray over the overspray you will see the imperfections in your next coat.

    overspray settles after you paint a coat. take a tac cloth and wipe the surface when it dries. itll remove the overspray and dust and whatevers left.
  9. tab

    tab Super Moderator

    OK for the primer. But there is no way you can just use 1000 grit for everything else. You obviously haven't tried your hand at black paint. 1000 grit, wet or dry, will leave sanding marks for sure.

    Cheese, listen to the seniors in here. You notice we hardly ever disagree. That's for a reason......We're fucking right.

    Driver1, XYSWANY, hcivic.com, and myself; I have read what they have to say several times. There have been very few times that I even thought to disagree with any of them, and that was just over preference issues.

    Other methods work, but why experiment in the realm of the unknown? Trust what is known, and learn right the first time.

    xyswany + hcivic= good advice

    KCREX, read more, talk less.

    He mentioned running the paint run down off the car, but it's hard to do.

    He did not say "dry sand the paint". He said, wait for the paint to dry, then sand it down. If you look upward, you will see that he would not use less than 1000 grit.

    I agree.

    I AM NOT AN EXPERT, but I have done this several times, and confer with professionals before every project, large or small. Let's just say that I'm on a first name basis with the folks at the auto paint store.
  10. cheese9988

    cheese9988 Senior Member

    Yes, it is black paint. Chrysler Prowler black to be exact. So you think that 1000 is still too heavy of a sand paper for black? Should I jump right up to 1500 grit for the clear coat or sand with 1000 and jump up?
  11. cheese9988

    cheese9988 Senior Member

    Well I put on the base coat, 2 coats to be exact. These are some pics of what they look like. The only question I have is that why I still get lines on the hood even though there are two coats on there now? Should I put a third/fourth coat on? I tried to get the best picture possible so I used to hood, but there is alot of glare so I took a bunch at different angles. Its a pic of the hood. Thanks!!!
  12. cheese9988

    cheese9988 Senior Member

    Also the paint looks a little gritty, almost like orange peel. Looks more like the primer texture that was underneath, it was sanded down though. Will this go away after a few coats?
  13. driver1

    driver1 Senior Member

    did u adlust your gun at all when you boguht it? guns do not come self adjusted you need at adjust the knobs on them to alter the fan width and the amount of product/air coming out of the gun. it looks to me as though this could be your problem, if u have out 2 coats on what i see in the pictures. Either that or you just have some serious learning to do on how to lay paint. otherwise than that your gonna need more basecoat on there.wetsand that base out with 1500 or so and try again. also see if u cant adjust your gun better as well.
  14. cheese9988

    cheese9988 Senior Member

    I had it adjusted to put down alot of paint, around 20 psi at the gun with a wide fan. I put the paint down so it looked "wet." Can you give me any other suggestions that might help. :) Also should I sand down what I have there before applying another coat then?
  15. hcivic.com

    hcivic.com Senior Member

    it looks like your pattern is not pefect. can you just hold the gun straight and shot some paper wothout moving the gun. then set it up it makes it easier.

    the middle looks good but the key is to thin the paint alittle more then practise keeping the gun an even hieght from the surface. ie walk along withought moving the guns height. This will probably fix the prob and black will take 3-5 coats depending on the paint your using and the primer ect. as foor sanding only use 1000 grit on the black to get out big runs then move on to a finer grit after.
    I almost forgot slow down you probly moving to fast
  16. cheese9988

    cheese9988 Senior Member

    Thanks guys! I didn't make a single run when spraying last night, I was acually impressed by that. :lol: Would you recommend sanding down the paint because it seems gritty? Or is that because of the primer? A guy at napa when I bought the paint said it would start out rough, but by the time it was all applied it should look smooth. But then again he wasn't a collision tech?
  17. hcivic.com

    hcivic.com Senior Member

    just run the last two coats thin. add about 5-10% extra reducer but be carfull it will run very easily when you do this
  18. cheese9988

    cheese9988 Senior Member

    Thanks! :D That should smooth out the paint you think?
  19. tab

    tab Super Moderator

    This is pretty much what I was going to say also. Besides needing to adjust your gun more, your pattern doesn't look right. You say you have a wide fan, and are putting out lots of paint, but your pattern is striped. It kinda looks like the gun was too close, forcing you to move faster. You need to slow down, and apply a wetter coat.

    Lay a tack coat, let that flash, then apply as many coats as you need to cover the primer completely. The base coat will not be all that shiny once it dries, but it should be very wet looking as you spray it. Keep in mind, a consistent pattern is important, but backing up slightly won't ruin a paintjob. With a color like black, you won't be able to cover in one coat, but you should finish laying all the color in one session. Allowing the coats to "flash" will keep the paint from running, but laying consecutive coats lets it all melt together, and lay out nicely.

    You'll get better. Just keep your chin up and practice more.

    Here's a project I did for my buddy Mitch last year. What you see hasn't even been buffed yet. This is a black pearl base, a coat of silver marbelizer(kinda fancy metallic), three coats of cobalt blue candy in a "intercoat clear"(no build, not like real clear coat), and seven coats of clear. I laid three coats of clear right after the intercoat. All in all, I laid eight coats of paint in one night. The next day, as per the instructions for the clear, I wetsanded with 500 grit, and laid four more coats. The last four coats, a little extra reducer, and a little more hardener were added, to make it lay out nicer.

    Pics of the project, a Jesse James West Coast Chopper
  20. cheese9988

    cheese9988 Senior Member

    Well I painted it again, much, much better this time! Only problem was is that the cup I had broken awhile ago and I fixed it with epoxy, well the paint ate through it as I was finishing and leaked on the passenger side. Didn't think that stuff was strong enough to eat that, my bad. So I think 1500grit would be good to sand down the drips with? I took a some more pictures, the hood came out great except for a drip or two where I need to sand it down.

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