Polish Painter

I had to do a small repair on a trunk lid and bumper. Color silver/gold . Pretty new to blending. 3inch repair in center of trunk. Repaired area , scotchbite scuff paste rest of panel . Applied dbc 500 clear base to panel. Applied DBC color to repair area until covered. Mixed 50/50 with 500 blender and feathered into rest of panel staying about 6 inches away quarters. Cleared and looked fine on driveway and in shop. Problem had about 3 spots on bumper to repair , all on rear of bumper not sides . Spotted in with color each repair area and blended out a little. Looked at it outside and could see where I started and stopped between repair areas. Silverish what I sprayed and goldish original. looked fine within 3 feet but whan I stepped back about 12 ft more noticeable. Back in garage , basically colored rear of bumper and stopped where it starts to wrap around . Cleared looks alot better . Give me some advice " no matter how small the repair do you have to spray color almost on complete panel stayng 6- 8 inches away from next panel " ?? Are solid colors the same situation ? Seems like to me on that bumper if I had colored half of it and stopped in the middle it would have still been noticable. I just thought colors blended better than that . Give me some advice , Thanks

crazywelder

Like anything, blending paint takes practice and there are some rules.
1. First and foremost you need to decide if it will be easier to refinish the entire panel (bumper in your case) or spot repair.
2. Only in rare cases can you do more than 2 spot repairs on the same panel. Three spot repairs would be considered one repair.
3. You need to allow plenty of surface area to do the blend.
4. Blending is more artist effect than traditional paint procedure. The best experience came from '60s & '70s customs when blending full bodies was hot.
5. The PPG blender you used does not blend the color for you, it merely reduces the visual effect left from the blend edge which would be visible in certain lighting. The color match is up to the painters talent and eye.
6. The new paint will never be the same color as the original, it's up to the painter to fool the public.

In spot repairing of paint, the first coat is applied on the immediate area to be repaired. Subsequent coats extend beyond this area slightly and gradually further each coat. Finally a mist coat, blend coat, or fog coat extending beyond the color coats is applied. The final blend or fog coat is thin enough to allow just enough of the original paint to show-through. Even though the new color will never be a perfect match, the idea is to make the mis-match a gradual one.

The Olds hood below shows the blending effect. The gradual fading or blending is easier to see in this example with 2 different colors, notice there is no color edge. The idea when blending, is to allow enough surface area to fog the new paint into a gradual fade so there is no color break line, just a smooth transition and depending on the size of the origianl repair, it may take several inches or feet. If you make the blend area too small, there won't be enough room for the color transition between new and old, and there will be a noticable color difference such as the spots on your bumper. You always want to work frm an outside wdge when possible, and spraying is not back and forth like the traditional method, you spray in one direction from the edge. When spraying the center of a panel you also work in one direction from the center of the repair outward (center to right, and center to left). In one direction spraying, you fog the outer edge and raise the gun as you release the trigger. This will put down some dry spray which you can immediately wet down by spraying reducer over the edge from a second gun. The final fogging before clear, is not applied wet as in normal spraying.

When I replaced the bumpers on our Vette (also shown below) I blended new DBC/DCC paint into the original lacquer so the new bumpers and body would match without a complete repaint. I allowed enough surface area for a good color transition without touching adjacent panels, such as the hood. The lines I drew in the first photo show the paint layers and transition that I was talking about above. Notice after paint that I did not touch the hood or tire area with green, keep the repair to a minimum. The final repair after polishing is undetectable.







and just for fun.....

Polish Painter

Ahoover, Thanks alot for an explanation about blending, no one ever told me about spraying in one direction . I sprayed back and forth. Do you also use a blender and reduce after repair is covered ? Thanks for an in depth explanation. Would your final blend coat be something like 75% colorblender mixed with 25% base mixture ?

crazywelder

Glad that was helpful, as with any painting there are different methods to use for each job. Blending is a quick and economical fix, but will never be as perfect as painting the complete panel. I don't use the blenders, I just melt the edge with straight reducer right away after applying each coat of color or clear. I don't change the color mixture for the blending or fogging, same mix all the way through the color process. Once it's wet sanded and polished the edge is usually invisible.

I was thinking you are painting a bumper which is probably urethane. If it has the original factory paint you have to be careful of a couple things. After you blend the bumper, you will want to wet sand and polish the repair area. Factory paint on urethane is more difficult to polish as it tends to dull and not gloss up quickly if you use really aggressive products. As the bumper ages it gets easier to polish. I use worn out 2000 or finer paper to wet sand urethane painted bumpers prior to polish and very mild polishes with the power buffer.