Problem touching up Stewarts Systems

Folks,Need to ask for some advice. I shot my fuselage with sport yellow last weekend, and got impatient on the final coat and had a few runs. When fully cured, I wet sanded down those areas with runs using 600 grit until i could not discern any bumps from the runs. I wiped off those areas first with damp rag, then wiped with isopropanol damp rag, let dry. Shot several fog coats, then slowly brought up the gloss. Using low angle lighting, I now see the desired gloss on the repair areas surrounded with a matte ring where my repair spray exceeded the wet sanded area. Why is this not curing to gloss? Do I need to wet sand my entire fuselage and reshoot the whole thing? Any experience in touching up this exceedingly touchy and frustrating paint system would be most appreciated.Thanks Wendel

Wendel, I am on my third project with Stewart’s and have had to do some touch up from operator error. I think that “spot” repairing is very difficult to make look uniform. I will mask off an area with the offending errors included and use finishing tape edge lines, bottom of longerons to top stringer, N numbers, or anything else that will hide the tape line. If I didn’t show you where I had put the tape you won’t find the line. The runs I have had to sand never seem to completely disappear, it’s like Spandex over a wart. Sand your blemish, rough up the rest of the area, clean and shoot. It takes longer to protect the rest of the structure than to sand and paint. I had just finished the wet coat on a rudder and it ended up on the floor. I sanded and re-shot. I applied N numbers and that didn’t go well, so I sanded between finishing tape lines, taped and shot that area again. You can’t tell. It won’t take as much paint the second tine, or third. I use the green 3M fine line tape for masking lines.

I have that problem with dope and enamel. I simply cut masking tape with my pinking shears, apply the tape so it looks like a surface tape belongs there, and spray the same coat everywhere in the masked area. When I compound the finish, it looks just like a surface tape edge.

There are folks who can blend paint so the fuzzy edge goes away, using successively thinner coats. I hired one of those experts to fix a buddy's C-180 cowl (he let me fly it, so I was trying to do something nice for him). This expert did Citations, and was the local guru. Cost me a lot of money. Six months later you could see where the paint interface was - all fuzzed out just like the OP's Stewart repair.

Wendel, let it dry for a few days and then take Maguire's #85 or #83, followed by Maguire's #7 on a buffer and it'll disappear. If it's really rough, you might sand with 1000, then 2000 grit paper first...that'll speed up the process.
I always try to use a 1" tape on the edge of the repair and peel the inside edges up, that seems to soften the line. Or like RobertC, mask it to a tape or some other existing line that will draw your attention away.
You also don't have to use as many coats usually.
John

Thanks for your advice. I will try the buffing suggestion, and if I cant make that work will reshoot that area using your taping ideas. I got too impatient on my color saturation coats by not letting it dry enough, parlty from drinking too much coffee then zipping myself up in a full body tyvek suit.

I have to leave the paint booth between coats....or inevitably I screw it up.

Hardtailjohn said:

I have to leave the paint booth between coats....or inevitably I screw it up.

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Me Too. And I usually leave it a little longer than they suggest; just to make sure it tacks up enough to hold another coat.