I have a 99 corvette that needs to be touched up in a few spots, I don't want to paint the whole fender or door just touch it up and blend it into the old paint. I did this many times on differant cars, but that was 20 years ago and I would like to refresh how it is done.. I am using all dupont products and have everything I will need. I have the paint(color and clear), reducer and hardener for the clear and the stuff they use to blend the paint with. What is the best procedure to do this.
thanks
steve

if you want it to look right you will have to clear the whole panel that you are doing touch up on. no other way around it if you want it to look right.

Doing a clearcoat blend with todays urethanes isn't as easy as it was 20 years ago with probably lacquer products. Urethanes were out back then but most shops in my area were still doing spot repairs with lacquer.
It can be done successfully but if any thing happens wrong during the prep and application problems the blend will fail.
Your best results are with blending the color and clearing the complete door. A clear blend will eventually show with age sooner or later but I've got some out there that are 15 years old with no trace of problems.

Your first step is to clean the panel really well with wax and grease remover then do your repairs, when the primer is final sanded you'll need to also sand the area next to your repair with 800 grit-this is the area you'll blend your color into. Next sand beyond the 800 grit area with 2500 or 3000 grit beyond where your clear will end. Clean the area well. Start applying your color only over the repair area untill full coverage is reached, keep in mind that the overspray needs to be controlled with none falling in the clearcoat blend area. After the repair is covered completely apply more base and blend it out into the 800 grit scratches without blowing any overspray into your clearcoat blend area. Now apply your first coat of clear over the basecoat blend, apply the 2nd coat of clear past the first and into the 2500/3000 prepped area, use blending solvent to melt the fuzzy dry edge of the clear. The clear edge should be smooth if done right. Allow the repair to cure up a few days if possible then lightly sand with 2500 and carefully buff it to perfection at slow speed. Hope this makes sense. Blending is all about good prep and good gun control. Horizontal panels are the toughest-overspray control is more difficult. Some painters prefer to use a sharp tape line and sand that away, some will prep the blend area with scuff gel or heavy rubbing compound. For some repairs a blend makes good sense but for the basic door or fender repair clearing the complete panel is usually faster and usually makes a better repair.

Thanks for that really good explanation on how to blend. I have tried it a few times but have not had great success. After that detailed walk-through I might have to try it again. My problem has always been the clear line after I'm all done. You refered to blending solvent. Could you explain maybe how to use it and a recommended brand? Does it get added to the clear or sprayed by itself?

I have some issues on a 1/4 panel that has a nice recent paint job. Since there is no body line to stop at I'm faced with painting the whole back half of the car again. I'd like to avoid that--any help would be appreciated. Thanks.

Thanks for the refresher course. Thats pretty well how I did it. Always turned out good.

Thanks for that really good explanation on how to blend. I have tried it a few times but have not had great success. After that detailed walk-through I might have to try it again. My problem has always been the clear line after I'm all done. You refered to blending solvent. Could you explain maybe how to use it and a recommended brand? Does it get added to the clear or sprayed by itself?

I have some issues on a 1/4 panel that has a nice recent paint job. Since there is no body line to stop at I'm faced with painting the whole back half of the car again. I'd like to avoid that--any help would be appreciated. Thanks.

If your seeing the clear line after doing a blend it can be traced to three possible problems, #1 poor prep/dirty unscuffed surface, #2 contamination during the basecoat application-even a light trace amount of bc overspray in the clear blend area will ruin the clear blend, #3 the clear blend was buffed before it had a chance to cure good-remember you're buffing old clear(hard) and new clear (soft). The more cure time you give the blend before any buffing the better-also low speed, low pressure for less heat-the thin clear edge is fragile untill full cure is achieved-30 days.


Blending solvent is usually just called blender, it is a hot solvent designed to melt the overspray edge of your clear. Misting on a coat or two on the dry edge will wet or melt the dry edge allowing better adhesion. Do not mix it in your clear-keep the blending solvent clean because you want it to melt the edge without adding material-it needs to evaporate off cleanly. DuPont's Chromablender gets my vote for the best blending solvent-melts anything I've ever sprayed without problem. Load the blender in a seperate gun and have it ready for use imediately so you can use it after you shoot your last coat of clear. Some blending solvents will suggest adding 10% clear-don't do it-this is a carryover proceedure from the lacquer days and doesn't work well with modern urethanes. Blender is also available now in aresol for quick easy use-I haven't tried them. Bob

Thanks for the follow up info. You referred to some painters using a tape line to control overspray, then sanding/buffing it out. Would this be done on the base coat or the clear coat? Could I use this method on both?

BTW, great info about the left over clear coat line. I realized that I do buff it quicker than I should. I also have not been careful enough about using lighter grit paper toward the end of the blend. I've never even seen 2500 grit paper. I guess I need to buy some and give it a try. Thanks again.
Mike