I went crazy with my last coat of singlestage (PPG Delstar) and now I've got a bunch of runs in my paint. I've seen some good info on fixing paint runs but does anyone have pictures of thier technique? Any flawless ways to shave off a run? When is the best time to take care of runs?
-Karl

First I have to say I'm not a pro but have performed a half a dozen completes and get better every job. I've experienced mostly just couple small runs on the most recent job and they usually occur in spots where lighting was lacking. There is a big difference between a run and a sag. A run can be very sharp and has a leading and following edge. The leading edge is sharp and the following edge is sloped to the high point. I sand these out with a small hard rubber block first with 400 grit dry, then 600 wet, 1200 wet, 1500 wet and then buff. Just take off 80% of the high spot with the 400 and progressively more each grit. A 3 in long run could take 15 min. to flatten. When you wet sand, be careful to only sand the high spot, it's very easy to side sand the outer areas. That's the purpose of a hard block. Never use a sponge pad for this. Also, when wet sanding, take time and wipe the area dry very often to check your progress.

A sag is an entirely different animal and much more difficult to sand out, I've had only one vehicle with sags and it was also a single stage paint. These take a lot more time. I saved a cowl hood with a few sags by first wet sanding with 600 in a blocking pattern at 45 degree strokes, then 1200, then 1500 then buffing. I never could get it entirely flat, showed a large wave in the end. If it was a darker color it would have been too obvious and I would have repainted the hood. If you have multiple sags it may be easier to just sand and repaint. I'm sure others have some better info to add though.

Good Luck and may all your runs be small.:D

Jerry

I went crazy with my last coat of singlestage (PPG Delstar) and now I've got a bunch of runs in my paint. I've seen some good info on fixing paint runs but does anyone have pictures of thier technique? Any flawless ways to shave off a run? When is the best time to take care of runs?
-Karl


I always try to fix runs at about the 24 hour mark. This is long enough cure time to make the paint fully cured, but still soft enough to work with.

I usually start out with one of the "nib" files. These are small vixen files mounted to a small wood backer. You stroke the run in only the cut direction until it is mostly gone. I then switch to a small aluminum block wrapped with 600 grit wet-or-dry and block the run down until it is completely gone. Then color-sand as normal and polish.

I make my own aluminum blocks out of stock in the shop, and they are usually about 1" wide and 2" long and are usually made out of 3/8" or 1/2" stock. Whatever you have on hand. The thicker the stock, the easier it is to hold the block.
The key is to stay directly on top of the run and not sand any paint around the run. The hard surface of the aluminum block will assure a flat surface and will only cut the top of the run.

You can find the "nib" files at most paint and body suppliers or in Eastwood's catalog. I avoid using "run razors", as it is too easy to dig below the run, especially on curved surfaces.


Regards, John McGraw

Patience; you either have it to get a run out or forget it; and there are still no guarantees. Nib files work but in the wrong hands can scratch deeply. Not enough material will result in sanding through adjacent area if not cautious. Too heavy of build may uncover holes in the center of a bad run which is solvent pop. Once again the only way to learn is by doing and pictures won't teach you squat. Flat blocks and tickle it.

Flat blocks and tickle it.

That says it all. Great thread, very informative.

I'll give it a shot. I do have a couple of sags, mainly where the roof meets the sail panel. My worst runs are in the fender arch/lip area. There is stainless steel trim that covers the lip so I'll test fit it and focus on what isnt covered up by the trim. Now for my next thread...
-K

I use a razor blade and shave it off by holding the blade at about 90 degrees to the surface and pulling it across the run. Use a fresh blade, and be firm to keep it from chattering. It takes a touch to do it without messing it up.... :yes:

I use a razor blade and shave it off by holding the blade at about 90 degrees to the surface and pulling it across the run. Use a fresh blade, and be firm to keep it from chattering. It takes a touch to do it without messing it up.... :yes:
This is how I do it too, it works well as long as the paint is dry enough and you have plenty of light to see what you are doing.
Ron

I use the razor blade as described above, but bend the blade in a slight U shape (Paintucation video tip). It works great. Another great tool is Meguiars unigrit block. It is essentially a rectangular sanding stone and will only hit the high spots. The combo of the razor and the unigrit block is pretty fool proof.