2017 F150 door prep for primer

[Cstrom]

I need to spray a 17' F150 door due to some damage from a shipping strap at the very top above window. The bottom has some rougher undercoating looking stuff from the factory. Best way to prep that for primer/sealer? Blast it? Or a meticulous scuffing with red Scotchbrite?

 

[Chris_Hamilton]

There is no need to prime or seal that. Repair the damaged area and blend. If you paint the whole thing you will find that it won't match the rest of the truck, especially with a color like silver. For the chipguard there is no need to do anything but scuff it by hand. Grey scotch-brite and Scuff Stuff. Any sanding paste will work but Presta Scuff Stuff is my favorite.

Scuff Stuff® Surface Prep

Scuff Stuff® is a high-performance scuffing agent that enhances paint adhesion by ensuring cleanliness and consistent surface profiling.

www.prestaproducts.com

Are you planning to repair the damaged area and blend? Even if you panel paint it, there is no need for sealer, only primer on your repair area. Keep it solid (no sand throughs in the repair area) and sand to 800 grit. Knock the texture on the rest of the panel down 800 grit wet. Only sand the texture out. Then gray scotchbrite and scuff stuff the entire panel. Blend the repair area and clear the entire panel.

Only reason I would seal that is if I was changing the color. If you are keeping it the same color you really don't want or need to base the whole panel. Blend the color in your repair area and clear the entire panel. Done right it's undetectable. Paint(base) the whole thing and you will find that it won't match.

 

[Cstrom]

I don't do a lot of repair work, so I'm curious on after finishing my filler work at 600 grit, should I just use reduced epoxy as a sealer then base to cover my filler and bare metal spots? Valspar 999 series is what I'm using, according to their tech sheet the base can be applied over existing paint if finished in 600-800 grit. Door is in great shape minus the one spot that was damaged from a strap.
I was planning on basing the whole door but that does make more sense to just base the area and re-clear the whole door.

 

[Cstrom]

Here's the spot-

 

[Chris_Hamilton]

That's an easy area to blend.

Don't have a lot of time ATM so I'll try to quickly walk you through it. First repair the area like normal. Prime it and do your finish sanding/blocking in 320 grit dry. Once it looks good then wet sand it and the entire door (minus the chipguard portion) with 800 grit wet. Keep in mind that you can not have any sandthroughs in the primer area. Your primer needs to extend out to the undamaged area. Make sure its feathered out perfectly. (if that's not clear say so I'll try to explain it better) Go in one direction (back and forth) so all your sanding scratches are in one direction. Do not sand any which way. Keep all the scratches going in one direction. Get the majority of the texture out of the clear. No need to get every bit, just the majority and then go over the entire panel with scuff stuff and a grey scotchbrite. Do not use red, it is too coarse.
When it's prepped and masked and ready, then spray your first coat of base on the primer area. Light/medium coats. Each coat extending out past the last coat (important). Tack between coats. Stop when you have coverage, meaning you can't tell the difference shade wise between the repair area and the original color. Remeber keep your coats light/medium. Do not spray it wet. Tack again and clear the entire panel.

Do a search here with my username and keywords "blending" and "blender". I've gone into a lot of detail on this in the past. It should be helpful.

 

[Cstrom]

Got it! Thank you very much! Local paint supplier carries Axalta Plas-stick 2310S cleaning paste. It's that the same thing? I can order the ones you mentioned if it's a big difference, I'm in no hurry

 

[Cstrom]

The only part I'm not sure on is my filler repair, which I did in steps of 80, 150, 320 and finally 600. Can I epoxy prime over the 600 or does it need to be closer to 320?

 

[texasking]

If you are going over filler with epoxy, spray 2 coats at 1:1. It will need to be lightly sanded with 600 before base after overnight dry. 180 or 220 is what I finish filler with. No reason to go any finer.

 

[Cstrom]

Noted, thank you very much!

 

[Chris_Hamilton]

Got it! Thank you very much! Local paint supplier carries Axalta Plas-stick 2310S cleaning paste. It's that the same thing? I can order the ones you mentioned if it's a big difference, I'm in no hurry

Never heard of it so I looked that up and it says on the Tech Sheet not for painted surfaces. I can't believe that your Jobber doesn't have a suitable sanding paste. Seeing you have an Axalta Jobber tell them you want Cromax 2311S sanding paste. 3M also makes a prep paste think its called 3M scuff it paint prep gel. Don't remember the part number. Norton makes one as well. Transtar 6338 is another one. I would check with someone other than who you talked too as it sounds like they don't have a clue. Very common item every refinish jobber carries.

 

[Cstrom]

I do have a unprimered plastic piece to paint as well (cab corner trim) so I'll keep it for that but I did order some Scuff Stuff as well. I'll give the spot repair a couple coats of 1:1 epoxy and finish with 800 like the rest of the door. Thanks a bunch for all your help!

 

[Cstrom]

From the factory looks like there is no primer on the cab corner plastic. Should I prime it or just Scuff Stuff that part and base? I tested a small piece and it sunk in water so I don't belive I need any adhesion promoter.