Sandblasting - Sanding, body filler, primer...

[TA_C10]

Guys I am wondering what is the correct order of things after sandblasting my cab and hood.

1. After welding up all the metal, can I put seam sealer on first or should I paint first?

2. Can I paint epoxy primer over fresh sandblasted metal without sanding it first? The media used was fine glass so it has a nice suttle pitting/roughness to it.

3. Body filler, can it go over direct metal or should I epoxy prime it first and then body filler? I was thinking body filler could go over both metal and primer, yes? I am using eastwood premium body filler. I am also using epoxy primer first, then 2k high build primer over the epoxy.

[cornerstone]

All of my research pointed to epoxy prime directly on the bare metal then any body work on top of that.

[TA_C10]

Originally Posted by cornerstone

All of my research pointed to epoxy prime directly on the bare metal then any body work on top of that.

Thanks, doing some more research myself. So much info out there...

Looks like I need to epoxy the cab first before I do anything. Then seam sealer all the seams and welds I made, then do body filler. Then I can start using the 2k high build urethane in multiple coats and block sand.

[Sparky dave]

Yes sounds like your on the right path. The traditional way was to apply body filler direct to metal but that was before the days of epoxy primer. Then 3 coats of 2 k filler primer. Then block sand with about 220 paper then most likely you will still have low spots so another couple of coats of 2k filler primer and block sand again with 320 then block sand again with 400 for solid colours or 600 for metallics, clean clean and more clean with panel wipe and your good to go. Use gloves so you don’t put finger grease on your primer. Good luck take your time don’t skip steps and it will look great

[randy500]

Buy rage gold filler, it spreads and sands much easier....saves money on sandpaper too since it doesn’t clog paper nearly as much

[HO455]

Plus getting primer on that nice "white metal" will prevent it from starting to rust. Especially important if your not in a heated work space and able to work on it 8 hours every day.
I also like the Rage Gold filler.

[TA_C10]

I love this site for it's members knowledge. You guys are awesome.

Panel wipe, gold filler, other paint products. Where are you guys getting your products? Right now I'm using summit racing and Eastwood. I get most products from summit as they are cheaper.

Right now I have purchased their epoxy primer and 2k urethane to seal and sand the car. I also got their paint prep gallon size. Is the paint prep same as the panel wipe?

I got their wax and grease remover too but I only plan to use that on direct metal to clean everything before I paint.

For bare metal I'm using "dry coat", just spray it on and let it dry. Supposed to last a year.

[webfoot]

I like autobodytoolmart.com and tcpglobal.com. I do my own body work and prefer 3M platinum plus filler sold under their marson line. Great value and spreads well with no pinholes.

For sanding blocks I love the adjustable flexible Sanders. Summit sells these in various lengths.

[randy500]

If your working where the sandblasted parts wont easily rust such as in a non-humid garage then do all the bodywork and then epoxy prime and re coat with filler primer in the recoat window of time so you don't have to sand it.

Epoxy prime then seam seal in the recoat window if possible, seam sealing outside of the recoat window is ok too.

Do not put anything on the sandblasted metal except epoxy primer, no rust preventative or panel wipe or wax and grease remover.

Only use was and grease remover if you feel there is something on the panel, keep your hands clean and the surface will be clean. You can introduce contaminates by wiping the panel. Think about it...if you encounter a spot on it with contaminates your likely to spread them all over the place.

If you get fish eyes in the epoxy then clean more, no fish eyes don't use wax and grease remover. I only use it on a very clean panel just prior to painting color to remove final sanding residue after I have washed the surface with soap and water and I am very sure the panel is completely dry.

When your wiping that crap on the panels, wipe some on some clean glass and look at the residue it leaves....do you want that under your paint?

2 more material tips...

Use Upol dolphin glaze to fill small imperfections, sands real easy and no pin holes
Try Upol primer, very cheap, applies nice, sands easy.
Buy both on amazon. Buy your sandpaper, tack rags, and other materials on amazon too. Only use 3m automotive masking tape.

Don't ever use POR 15 on anything, it doesn't last and doesn't cure anything, if you need por15 you need to do some sandblasting.
Use standard paint products from PPG or Axalta, leave the miracle stuff alone.

There is a cult-like following for Southern Polyurethanes...you can buy similar products from the major manufacturers on ebay…
the major manufacturer products cost more because they are proven.

There is an old saying...you will never be disappointed with the very best...same goes with buying from the major paint suppliers for color and clear at least.

Epoxy and filler primer from other than major manufacturers is fine if you let it dry long enough to shrink, etc.

Sanding....

Filler 40, then 80, if still straight then 220 grit

Primer filler (blocking) - sand dry 220 grit on a long board, use adhesive coated rolls of sandpaper from amazon, saves lots of time. Change paper often so it cuts without much pressure. Fill low spots in the guide-coat with upol dolphin glaze, then re-prime and block till perfect, its ok to re-prime small areas.

Final paint - 600 grit wet on a foam hand pad on a fresh coat of fully dried filler primer. To avoid problems with color coat transparency your final sand should be such that you did not cut through the last coat o primer and the surface is one even color.

Generally apply a light even coat of epoxy primer reduced as a sealer just before applying color. Only do this if you can apply it even and smooth otherwise skip it, this coat will show if you have body imperfections and if you have fish eye problems, then you can stop and fix your problems before applying the expensive top coat.

Avoid base clears if possible unless you can spray good and have a spray booth, this means no metallic colors, you will get better results. Each coat you will get dust, lint etc, the less coats applied mean less trapped contaminates.

If you do base clear, anything in the base will be magnified when the clear is applied.

It seems expensive but devilbis dekups save a lot of clean up and you can mix precise amounts of paint very easily. The cup liners can be reused if you let them dry the dried paint will blow right off of them, use the re-used liners and lids for undercoats and even top coats.

Buy good paint guns, the cheap ones work but not nearly as well as a Sata or equivalent. I just returned 2 Chinese guns that I thought would work for primer....they sucked.

Paint gun tip size, the recommendations are smaller than actually is useful for a beginner, the sizes are for precise paint application and will leave dry spots and streaks,

I would use at least 2.0 for primer and 1.6 for color and clear, adjust paint flow with needle when spraying to avoid runs.

For a novice, If you don't get a run or 2 then you applied it to dry.