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new sheet metal prep

Posted: Fri Jan 10, 2020 2:18 pm
by JoeG48
Does anyone know what is the best way to prep chemically treated fenders and other new sheet metal parts before painting ... Thanks for any help... Joe Gallagher ..joeg48@hotmail.com

Re: new sheet metal prep

Posted: Fri Jan 10, 2020 4:19 pm
by hah
If it is brand new metal lacquer thinner will do... ms251.
1. Lacquer thinner
2. Fineline surface cleaner(prep sol)
3. PPG DP product apply to bare metal or equivalent product
4. If need body work do it over the DP
5. If after body work and you sand to bare metal DPl afterwards
6. prime area repaired or prime entire part
7. If only area repaired was primed and sanded seal entire part then paint
8. If you primed entire part sand it then paint.

After sanding and blowing the dust … clean with Fineline prior to painting or re-priming part

I have it pretty close.. steps could vary dependent on what happens during each step.

Others may know more!

Re: new sheet metal prep

Posted: Fri Jan 10, 2020 4:21 pm
by hah
addendum
sand bare metal with 180/220

Re: new sheet metal prep

Posted: Fri Jan 10, 2020 7:06 pm
by Adam
It’s always best to follow the tech sheets for the primer and paint you are using. Advice from others may not be appropriate for your product, or may leave some details out.

Re: new sheet metal prep

Posted: Fri Jan 10, 2020 10:22 pm
by Scott_Conger
Adam

that has got to be the best answer I've ever seen given for this sort of question

Re: new sheet metal prep

Posted: Sat Jan 11, 2020 12:44 am
by Dollisdad
Wipe it down with lacquer thinner to get the surface oil and grit off from the manufacturing process. Take a paint brush and paint on a coat of metal prep. Then use a scotch brute pad and rub the surface to remove any matter that didn’t come off with the thinner. It will also remove surface rust. As soon as the metal prep touches the surface it will turn a lighter color. This tells you it is removing any remaining contaminates from the pores of the metal. Metal prep is neutralized with water, so when you are done cleaning the part (for example a fender) stand it on end and take a hose and rinse it off throughly. Be sure to wash out the joints between the panels really well. Then use a clean dry rag to wipe the water off while at the same time use compressed air to help blow it off and to make sure you get all the water out of the joints and the part is good and dry. Then you want to seal or prime the part within 10-15 min. I’ve done this for 50yrs. and never had paint lift. You get metal prep at automotive paint supply shops. Somethings you thin it. Sometimes you don’t. It will tell you on the container. Hope this helps.

Re: new sheet metal prep

Posted: Sat Jan 11, 2020 7:40 pm
by hah
As blazing saddles states, "we don't need no stink'n tech sheets". lol

Re: new sheet metal prep

Posted: Sat Jan 11, 2020 9:19 pm
by jiminbartow
“Porter Paints” has a great, very effective, easy to use, metal prep. Called “Metal Prep”. Jim Patrick

Re: new sheet metal prep

Posted: Sat Jan 11, 2020 10:53 pm
by david_dewey
DP primer spec sheet used to state that it bonds better to bare metal, not as well to "treated" metal. I haven't looked at the product for a number of years now, so things may have changed, but back when I did a corrosion resistance test, it verified that--and I thought it was an anomaly of my test, but a discussion with the paint rep confirmed it.