Hey guys,
Well, both my bumpers were somewhat scraped up from the previous
owner...I wanted to redo the bumpers....I got the primer and the
paint and the clear gloss polish...so what I was wondering was what
kind of sand paper should I use? Also would I need anything else
for the job?

 

painting your own lowers is going to be quite a task...you should try to set up some kind of booth if you can to keep dust/crap off the wet paint...i'll let someone more experienced answer your question about grits, but i can tell you that wetsanding is the most important part to getting it to look clean. applying the primer, paint, dry time, climate, all those are factors also, but wetsanding is definitely the most important.

 

What color is is? What type of paint and primer are you using? Do you realize the paint job on the car is a base coat of color with a clear coat over that to give it its modern shine? Many paints require the use of a flex additive when painting bumpers, even in the primer sometimes, or will peel/flake off. You ARE going to scuff up the bumper before you shoot with either a red/gray scuff pad or a 600-800 wet sand right? For deep gouges, we will use 40-150 grit to smooth out the gouge area, sanding into the plastic if necessary and then going over that with 180-220. The problem you might have, I that professional shops use 1 - 6 coats primer that that lay on VERY think. I'd estimate i would take 8 coats of rattle can primer to build to 1 coat of "2k" primer.

I would recommend if you really want to do it cheaply to still have it done by a professional with professional materials and using base and clear paint, just do all of the prep work yourself(clean and scuff) and don't have them "cut and buff" it either(wet sand dust specs and orange peel, then buff).

Recommended reading:
Autobody101.com
Paintucation.com

 

The color's Sable Brown (Color code: LZ8P). I went to this autobody paint shop and when
I gave them the color code, they mixed the paint for me right then and there! I bought
this primer rattle can and a clear gloss rattle can from Walmart.
Here's the thing! I've never done this before! I thought that I'd be able to use any
kind of sand paper, so I bought one of those 3M "sanding sponges" The gouges
in the bumpers aren't that deep though, maybe 1.5mm at most.
And what's "40-150 grit"? Is that a filler? (hopefully u'r not thinking i'm an
idiot by now!). I'll start off by wet sanding, and then putting ~ 8 layers of primer
on it...then when all that dries, put 4 layers of paint on it. Then I put one coat of
clear gloss on it right?
Should that do the trick?
BTW, the paint they mixed for me, they gave me this spray can (smth like
the rattle can) where I can put the paint in and pretty much use it like an aresol.

Please lemme know what you think!

 

I wouldn't rattle-can anything but a temporary spot. I really wouldn't do it. When i mentioned 40-150 grit(grit the roughness of the sandpaper, higher is finer), the thing is we use a pneumatic sander that is designed to leave a smooth finish. If you do it by hand you will leave HUGE sanding scratches. You will have to sand smooth the surfaces you roughed up with the low grit back up to whatever grit the primer your using is designed to fill. To do that you'll have to sand the same spot with progressively lighter grits, ie, if you start with 80, go over it with around 150, then 220, then 320( or whatever the minimum grits listed in the primer instructions list), then clean and prime.

Only use the amount of coats is says you can use in the primer's instructions.

Take back the Wal-Mart clear, no rattle can clear are going to be near the shine of industrial clear, but at least buy a brand called Upol which should be at the auto body supply store you went to, if not, just buy what they recommend.

Take back the primer and get whatever the body supply guys recommend for bumpers.

Buy a solvent to use just before you put the primer and paint on and clean the heck out of the bumpers.

It the paint brand PPG, Dupont, or..? Ask the shop what is it exactly Let me know and ill tell you how likely it is going to match adjacent panels.( btw hopefully they used an electronic device to analyze your paint)

Your going to have to sand the primer flat starting with 220 - 320 and finishing with 400 - 600 dry, or 600 - 800 wet. Get really familiar with the term feather-edging before you apply color. Use the block for flattish spots, your hand for curved spots.

If your really going to use rattle-can products, follow the instructions to the letter, especially be careful to give the primer and clear enough time to dry between coats. Your clear is probably going to die-back anyway( that means looking horrible by loosing its gloss ) but at least give it a chance by following the re-coat times. Don't put on too heavy a coat with the clear, if you do adjust your time between coats accordingly.



ps. I still wouldn't do it... I'm only giving you these instructions because your asking, i would never recommend them.

pps. At least try a practice panel first to give you a better idea of what the final result is going to be.