Painting Prep

[treybrad]

Ok.. I've read up on painting quite a bit. Went and bought paint today even.. but I was looking over stuff tonight again and came across a question I'm not sure on..

Would I be better off removing all the old paint, down to metal using maybe a paint stripper, or just sanding everything down to smooth? I was thinking it'd be easier to get everything smooth if I went down to the metal, but maybe not. I just want this to come out good the 1st time...

Anyone know?

trey

[se7enty7]

personally, everytime I paint something I sand it rough then paint using light coats

[airbrush]

Personally i like removing all of it and starting fresh, although it is not really necessary. As long as the bike hasnt been repainted numerous times, layer after layer, then you alright to just scuff up the existing paint and go over that. I usually wet sand with a 400 grit(you should see no shiny spots when you are done) then apply primer and sand that with a 600, then you are ready to do your base color. The more time you spend in your prep job...the better the finish is going to turn out in the end.

[Dom]

If you do go the route of a chemical stripper(awesome results and the easiest way to go in my opinion) I used Home Depot Kleen Strip stripper for the tank which is great because it comes in an aerosol can.  Spray it on thick then wait 20 minutes and wipe it off with superfine steel wool.  For the plastic I used Captain Lee's plastic stripper(made for car bumpers, mirrors, spoilers, or anything plastic) which worked as well as the Kleen Strip.  Then I bought a combination etching primer(for bare metal) and high-build primer for the tank and for the plastic I bought a plastic specific primer.  Sand with 600 dry and lay the color.  Wipe with a tack cloth first.

Just for advice, don't go crazy with the color coat(if you plan on clear coating it), you just need enough to get full coverage, then quit.  Also, don't sand your color coat unless you have huge(I mean huge like a millimeter tall) drips, but just don't make any and you'll be fine :mrgreen: If the finish after the color coat isn't great, don't worry, you have several clear coats to go on top of that.

You can sand between clear coats if you like.  If they aren't fully dried or if you don't use a hardener it will be difficult to sand wet or dry.  Don't sand below 600 and if you use laquer paint use a laquer clear coat.  Laquer chemically bonds to previous laquer coats.  If you use two different types of aints for color and clearcoat, if you sand thru you to the color coat you are pretty much screwed...You will get what professional painters call an "@$$hole"...an interlaminary something or another... it's called that because that's what you feel like for having done it after all your prep work.

Wait a week before color sanding and a month after that to wax.  The clear coat will need a week to harden up to the point where it can be sanded but will still be releasing gases for another month.  Most clear coats need oxygen to fully harden.

Color sanding is with 1200-1500 grits.  Wet sand in one direction only.  Start with 1200.  Sand until you see all the shiny glazed spots disappear.  Sand a little bit then wipe dry with a cloth or squeegee and look at it in the light.  The surface should all have a uniform appearance.  Then wipe of the tank and wet sand with the 1500 in one direction.

When you are finished color sanding use Meguiar's #9 swirl remover.  This part is damn cool...  You can either use an electric buffer or polisher(no faster then 1000rpms) or do it by hand...it will still look great.

[pixelmonkey]

some consideration should come from....

what color of paint did the bike have?
how bad was it?
what will be the new color?
any interior rust?  <-- take care of it before painting
type of paint?
coats or paint?
coats of clear?


if you're shooting the same color as it was before, you can get away with sanding it down and shooting it. if it was bad, check for pitting in the paint / metal.  REMEMBER.... if you can feel any bump, it will show!

primer if your down to metal in some places

and listen to the above suggestions. you'll do fine!
chris<pixelmonkey>