Prepping metal for paint

[Justin]

Will be rattlecanning my rear bumper in the next few days. I'd like to get a fairly smooth paint job and cover the grinding marks (went over the deep stuff with 120 grit pad already), welding blems, etc. Bunch of questions:

1. I'm planning on using a self etching primer then sanding, can I use the same primer to lay down a second coat after sanding?
2. Do I need to grind the surface down to bare metal, or will a good cleaning with thinner and then a tack rag do the trick?
3. I may also pull my front bumper and paint it to match. Anything I need to do beyond scuffing the old paint up?
4. I'm planning to use a little bit of body glazing to fill some tiny spots in the welds. Anything that would work better?
5. Anything else I should know?

[Entourage]

Sand with 220. Wear rubber gloves so oils from your hand don't get on the metal. Use a paint prep product like Eastwood PRE to clean off all the oils and dirt. I have a can and happy to bring it when I grab the receiver hitch this week.

[Shawns Fords]

I would prep it as Entourage and Zillacon mentioned, but I would get some spot putty to fill in any imperfections you do not like, then primer and wetsand. I don't like painting raw metal without primer first. Depending on how nice you want it to look you can wetsand 220, 320, 400,600,800,1000 etc etc etc (as much as needed), then tack it dry then paint.

[plumbdoctor]

Charcoal lighter fluid works great if your in a pinch for a grease/wax skin oil remover.

[hockeydad4-22]

I would prep it as Entourage and Zillacon mentioned, but I would get some spot putty to fill in any imperfections you do not like, then primer and wetsand. I don't like painting raw metal without primer first. Depending on how nice you want it to look you can wetsand 220, 320, 400,600,800,1000 etc etc etc (as much as needed), then tack it dry then paint.

Total newb question here: This is the swing out spare tire carrier bumper we built. I know it is beefy and all but it is going to bounce around some, bang and clank. At the very least it is going to vibrate with a large spare on it. Will the bondo or other putty have a tendency to crack and chip out if it is used? It seems to me perhaps something that remains more flexable like good urethane caulk or seam sealer would be better.

Perhaps I am wrong. I am looking forward to hearing the answer myself.

thanks

[Entourage]

My bumpers look pretty good but could have used more sanding to take care of a couple of burrs and tinny balls of weld I found in a couple of places. I would say that a good sanding, a wire brush and primer like Zilla suggested, would be more than sufficient.

I am hoping that someone tries the spray Hammer finish - it think the grey/black would look awesome. I almost used it on my rear seat mount, but it would have shown so it seemed silly to spend $8.00 per can instead of $5.00.

[Justin]

Hockey, I used some small amounts of glazing putty to fill some minor imperfections. I'll let you know how it holds up. Chad, I think Greg used the hammered finish paint on their bumper. Looked good. I went with straight semi-gloss so I could put stickers on it if I ever wanted to.

[Viperwolf1]

Zilla used the hammer paint on his tcase and it looks really good.

[Shawns Fords]

Greg, the glazing putty shouldn't fall out, bondo shouldn't either, the correct way to appply is to a very coarse section and in small amounts, large areas that are filled with more than 1/4" or more will typically start to sepperate from the metal over time, but with a bumper like this, if he fills the imperfections in the metal, its just tiny spots here and there that need filled.

Does that make sense? LOL