Scuffing frame for paint

7_Zero

7_Zero

Senior Member
I had my frame media blasted and epoxy primed about a year ago and I am now ready to paint it. I am using 400 grit paper to scuff the surface, however there are pitted and uneven areas that I cannot get the paper down into. Will this cause bad adhesion problems or would the scuffed areas around it be sufficient to hold the paint?

I was reading about some red Scotch-Brite pads, would these be sufficient to get into those small pits? Or would there be something more suited for this?

Also, I am dry sanding, would wet sanding be better?

Thanks!
 
we would just use the red pads and do the best we could. we would not use any type of sandpaper. your adhesion is gonna depend on the quality of the choice of color coat. ideally the color would have gone on during the open window of the epoxy. your media already got in there the best you are gonna get
 
Could you use a wire brush? I like/use a small stainless steel tooth brush like for many things! Welding supply company's sell them!
 
IMHO....
I would not wet sand because you will get residue in the areas you can't reach with paper. I did this a long time ago and products may have advanced...

What about a good wash down on the epoxy primer with lacquer thinner. Then a coat of sealer (preferably by the same mfg) and as soon as that flashes and cures, overcoat it with the paint of your choice. Be sure the final paint is compatable.
I will stand corrected but this worked fine awhile back.
 
Scuffing would be sufficient. The scuff pads were a real work-saver when they were introduced. They do get down into most uneven areas. Pits and scratches won't create any sort of peeling problem unless you put too heavy a topcoat on them to ''bury'' them. I always used a dry red scuff pad, wiped down well( wet rag, reducer or water) wipe dry a second time to totally remove any film, and then I sprayed a very thinned down coat of color initially to prevent any ''bridging'' of the topcoat. Remember that 90 degree sharp edges on metal invariably shed the paint coating when drying. A small rounding of any sheared edges prior to primer and paint will ensure full coverage on these edges, helping to prevent rust and corrosion formation down the road. If you sand thru your first primer, give a little touch-up with gun or can prior to topcoating. Gary
 
Sorry guys, the correct answer...

Read the directions for the epoxy or the next coating.

For maximum adhesion......

Typical instructions for epoxy would be to sand the epoxy first and then spray a coating of epoxy.
During the recoat window of the epoxy you then put the next layer of paint/ filler.

Epoxy cures and becomes super smooth. You need to get the correct grit scratch into the epoxy for the next layer at the very least. So you MUST read the directions for the product you are going to apply so you know which grit is correct for proper adhesion. Person XXXX telling you a red pad may not give you proper adhesion and peeling paint 5 years from now.

FWIW, you have to look at the areas with the pits. Kind of tough to get in the holes, just means you need the surrounding areas well adhered or use a soft product to do something scratch wise.

The reality is with restorations it is best to understand how the products work and do your best to make something happen for your case. In all likely hood there may be several 'correct' solutions. The key is to read what the products on both sides need to do the correct job.
 
Kevin in NJ said:
...the correct answer...

Read the directions for the epoxy or the next coating.

.
Click to expand...

X2.

Anything less than this and you are rolling the dice that you won't have adhesion (or other problems) with the top coat.

Ultimately, you'd want to decide on your paint SYSTEM before the first coat of primer goes on. All paints, reducers, hardners, etc. from the same line of the same manufacturer. ALL instructions followed (prep, recoat windows, gun nozzle sizes, pressures, etc).

BTW, it sounds like you are doing a VERY nice restoration! :)
 
You do not really need to stick with all the same paint. The chemistry is similar. I have found the SPI line of primers to be very very good with many pros using it under high end paints. SPI is very economical with a high solids content.
 
urethane is urethane, if that is your system. The reducers are compatible from mfg to mfg, whether enamel or urethane or whatever.

Have painted many many cars in 25 yrs
 
Thank you all for your replies. My compressor is not large enough to tackle a frame so i am having the same place that primed my frame do the painting as well. I do not have the tech sheet but they recommended 320-400 so that is why I was using 400 grit.

Paint work is all new to me so I am not sure how thorough the scuffing needs to be. I sprayed epoxy for the first time last year on the rear end and some suspension parts, it was a learning experience but very rewarding. I was smart enough to top coat within the window and am now wishing I had of planned out the process with my frame better. Live and learn I guess.
 
Some wise words from an old man I once met:
"Some people can just complicate screwing"....

That being said, use red scotch brite and it'll be fine. Your new paint will stick plenty well to the 400 grit and scotch brite. I've painted lots of cars and lots of Frames. All have been like what you're doing, only one did I spray "wet on wet". Your paint will stick just fine no matter what top coat your using. If it was the body, I'd say use the same material from the primer all the way to the top coat. But it's a frame... It will be just fine
 
Logan said:
Some wise words from an old man I once met:
"Some people can just complicate screwing"....

That being said, use red scotch brite and it'll be fine. Your new paint will stick plenty well to the 400 grit and scotch brite. I've painted lots of cars and lots of Frames. All have been like what you're doing, only one did I spray "wet on wet". Your paint will stick just fine no matter what top coat your using. If it was the body, I'd say use the same material from the primer all the way to the top coat. But it's a frame... It will be just fine
Click to expand...
+2 all the way.....
 
If it were a glossy paint job, scuff it enough to remove the shine. Epoxy is not that shiny, but scuff similarly.

We re-coat outside the epoxy window all the time with the red pads (they are rougher than the grey pads). That is what the pads were designed to do. We even use the red pads on brand new e-coated modern panels. You are trying to get the surface uniformly dull. You will use quite a few pads on a frame. Don't try to 'use the pad up' because it gets duller as you use it. We have never had a paint failure whether 2K primer, epoxy primer, single stage, or BC/CC. Even years later no failure. The urethane paint on my Deluxe Touring looks like it was done yesterday, but it was 25-30 yrs ago.
When you are done scuffing, be sure to wipe down with so-called pre-cleaner. It is designed for the purpose and will not leave a residue, and you will have a good base for adhesion of the next coat.
We load the pre-cleaner into a Sure Shot sprayer, pressurize it to 100 psi, and off we go. Get a roll of the blue wipes from a body supply house to wipe down right after you spray. The Sure Shot dispenses the cleaner very evenly and economically.
https://www.amazon.com/Sure-Shot-A1000G-Interior-Exterior/dp/B005POGY74?tag=atomicindus08-20

Blue lint free wipes:
http://www.autobodytoolmart.com/krew-400-shop-towels-blue-center-flow-p-12730.aspx
or similar from your local auto paint store

A small investment in some tools specific to the painting trade will make your life much easier

Listen to Logan, he knows what he is doing and is a good painter
 
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