Spot paint repair

[Ford79]

Hi all, I have a few questions about some paint repairs on my truck. There are some spots where ther paint is starting to chip/flake off an I want to take care of them before they rust through. A couple of the spots have surface rust already and others are just to the primer. What I want to know is what is the best approach to repairing these areas. Surface prep? How far to sand around the area to blend? Is rattle can primer/paint OK to use? Clear coat?

[Action4478]

What color is the truck ?....& where are the spots ?...

[Ford79]

Black and gray, the spots are all over, a few on the lower front fenders, a couple on the box, just above the wheel arch, a few on the lower doors and right at the rubber trim on the rear doors.

[DasCheckers]

Originally Posted by Ford79

Black and gray, the spots are all over, a few on the lower front fenders, a couple on the box, just above the wheel arch, a few on the lower doors and right at the rubber trim on the rear doors.

Ok man, how big are the spots?

Rattle can primers and paints are ok to use for touching up.
Make sure you get a self-etching primer though.
Your local body shop supply store should be able to help you out with all these questions better because they can see the truck in person.

[Ford79]

Originally Posted by DasCheckers

Ok man, how big are the spots?

Rattle can primers and paints are ok to use for touching up.
Make sure you get a self-etching primer though.
Your local body shop supply store should be able to help you out with all these questions better because they can see the truck in person.

The largest spot is about 2"x5", most are under 2"x2".

Planned on using self etching primer.
I'll do a search and see what I can come up with for a supply store around here, Thanks.

[cbass139]

I asked a the same thing about a older truck in another forum and got this answer from Axracer.
You can look up my touchup thread to see everything asked and all the answers but this might help

Feather a distance of 12-16" around the scrape using a rubber sanding block and 400 wet or dry sandpaper used wet. Don't try to sand with your fingers! If you can't afford a sanding block (<6.00) use a wood paint stir stick available for free at any paint store/dept. Dip the block into a large bucket of water with a small squirt of dishwashing detergent in it every minute or two. Don't press heavily on the block, let the sandpaper do the work, it will go surprising quickly! If feathered properly each layer of paint should be visible as ~ a 2" ring of color, the top finish paint layer should be dulled for ~ 6-8" around the last underlayer ring. Yes, you will have sanded the scratched area down to bare metal quite a bit larger than the original scratch. The area should resemble a soft blurry puddle with no hard sharp edges visible.
Wash the area with clean water, dry and wipe down the whole area twice with prep-sol used generously on 2 seperate clean lintfree cloths (old well washed cotton T-shirt is ideal. Leave it whole, cutting it up will free new loose fibers). Now spray the area with a couple coats of a self etching primer. Match the color of the primer to the same color as the primer you exposed by sanding just under the top color. If the top color was over another color coat, I'd use dark grey primer. Never use light color primer under a dark color unless that was what was done previously. Spray the primer so it extends ~ 1/2way over the scuffed area of the top coat. put on additional primer coats as necessary until there is no sign of the edges of the underlying layers visible after 1 hr drying time. This may require a number of coats depending on the concentration of primer pigment in the can. Don't be afraid to use as many coats as it takes.
Allow to dry overnight then LIGHTLY wet sand with 600 W or D paper on a long stick, concentrating on the edges of the primered area. Be very careful, the paper will cut thru the fresh primer VERY quickly! Should you cut thru the primer (called burning the paint) STOP, clean the area and reprime the thin area with at least as many coats of primer as you originally used. Next day once again LIGHTLY sand the newly added primer.
At this point you should have a slightly dulled primed area with no sign of the original work underneath and the top coat of color should be scuffed ~ 8" around it.
Now you are ready to add the color coat. Wash the entire area with prep-sol on a clean rag and allow to air dry. Spray the first LIGHT coat of color working from the center of the primed area outwards covering 1/2 the scuffed portion of the original top coat. Add additional color coats as necessary to get complete coverage following the recoat time instructions for the paint you are using religiously! The final color coat should extend out to just beyond the scuffed area.
Leave the fresh paint untouched for at least a week.
Let us know when you reach that point and we'll give instructions on blending and rubbing out the area.
Where you go now depends on a few different factors: Type of paint used, condition/type of the surrounding paint, how much effort you want to put into it (blend in locally vs renew entire truck) equipment available (high quality power buffer with foam and wool pads vs hand buff).
I will assume locally/by hand. There are paint type products out there for leveling/blending, or you could spray a couple more coats of the color double diluted with thinner, finishing with a coat of 10% paint/90% thinner. The idea is to extend the covered area slightly past the overspray of the previous coat to blend off the texture and gloss. This works well for single part colors. Give the paint plenty of time to cure, a couple weeks for single part. Use a machine grade (not hand grade it's too course if you don't know what you are doing) rubbing compound by hand on a wet but not drippy clean soft cotton cloth (old towel or T shirt) folded neatly into a palm sized pad. Keep the work area damp with a spray bottle of water. Work primarily from the newly painted area out concentrating on the over sprayed section. Wipe dry with clan cloths regularly to check progress. You should be able to feel the difference as you rub and the area gets smoother. Stop when there is no longer an appearance difference across the blended area.
At this point you can give the area a waxing with a good wax (NOT a polish or anything that's an opaque liquid product with compound in it) following the directions on the container. If you want a higher gloss use 3M Hand Glaze according to the directions on the bottle before waxing. If you use the hand glaze, you'll probably want to do the whole truck with it