QB Primer Touch-Up

[Bill Palmer]

I'm finally getting ready to paint the interior of my RV-8A QB fuselage. Van's (Philippines) coated the interior with Sherwin Williams P60 G2 wash primer. In several places, I need to re-prime the interior aluminum where I nicked/abraded/sanded away the existing primer during the building process. Also, there are several areas of the primer with air-tool oil on the surface.

I'm thinking the following:

1. Wash the entire interior with a no-residue soap solution. Rinse with distilled water. Blow-dry.
2. Scuff primer touch-up areas (only) with Scotchbrite. Vacuum/remove Scotchbrite residue.
3. Clean touch-up areas (very lightly?) with lacquer thinner. (Probably removes some, or all, of the existing primer as well, but I'm planning to re-shoot/overlap anyway.)
4. Apply Sherwin Williams GBP-988 rattle-can primer to the touch-up areas (or some other rattle-can primer? - - Please Specify). (Overlap existing P60 G2 wash primer at the edges.)
5. Paint over the interior primer(s) with a high-quality, rattle-can enamel. Allow plenty of drying time and accelerate enamel hardening with heat, as possible.

As you can tell, I'm not planning to shoot the interior with my paint gun. For me, the paint-gun process is too much trouble for the interior so I'm attempting to go with some sort of rattle-can primer for wash-primer touch-ups. I plan to apply Dupli-Color or Rustoleum rattle-can enamel over the interior primer(s). For the exterior, I'm going with a paint-gun-applied, epoxy-primer-acrylic-urethane system.

Well, anyway, I would appreciate any suggestions regarding the proper rattle-can primer and process to use for touching-up my Van's-wash-primer QB interior.

THANK YOU!

Bill Palmer
RV-8A Still In-Work!

[SvingenB]

Primer ... Actually I think the only way to go is a Strontium Chromate epoxy primer made for airplanes. It is the only way to acheive proper mechanical and chemical protection and good corrosion inhibition. Alternatively, if you live in the US, just purchase a couple of Zinc Chromate cans, not nearly the same mechanical and chemical protection, but excellent corrosion inhibition.

[Rupester]

I'm doing something quite similar to your approach on my QB fuse .. all rattle-can paints. I think you (we) will be fine. As you know, 90% of painting is in the prep. Most of the paint products out there today are pretty good.

The painters I've talked to have few common recommendations, but one that shows up a lot is, use a primer and finish paint from the same mfgr to assure compatibility.

[JonJay]

The SW product requires repriming or mechanical roughing up if not top coated within a certain time limit, 12 hours or something like that. This is critical for a good bond.
My recommendations: rough up ALL of the interior you wish to top coat with a scotch bright pad, touch up areas you feel the primer was sanded through, thoroughly clean with a good quality Wax Remover/Degreaser (I used PrepAll, very good product), dont use MEK or harsher solvent as it will eat through the wash primer, top coat to your preference.
SW wash primer holds a top coat extremely well, better when shot over fresh, but well enough if you rough it up later. I shot PPG Concept over my interior and it is holding up very well. I have heard of good results from rattle can top coats as well.
Rough it up, clean it well.