[Ratchet]

The Car 87 Camaro ( See Journal)

Paint PPG Pure Gold Base
PPG Sunset Red Mid Coat
PPG 2002 Clear Coat

The Problem
We were buffing the clear coat and burned through on a corner (Yeah I know you should tape the corners) it went into the midcoat but did not hit the base so it was a pretty easy touch up with an air brush. Only problem is now when we went to buff out the repair area there is a line in the clear coat where we feathered in the repair. The New clear and the old clear that was on the car have two different gloss levels and it shows up like a sore thumb.

The Questions
Why did it do this and how do I get the line to go away?

Ric

[farna]

The only effective way to repair a base/clear paint job is to sand and clear the entire panel. Sorry to be the bearer of bad news!!

[BondoKing]

throw up a pic..
Is the new clear much more glossy than the buffed??
How far did you feather out the area??
did you use tape to make a line??... this is a no no in my opinon.. when you blend you dont need anything that can make edges anywhere near that area..

Does the color match, or is it the clear gloss only??

[Ratchet]

I'll try to get put up a pic tonight when I get home but there is like a physical line where the new clear overlaps the old clear. The entire area was sanded with 1500 grit (getting ready to buff when I made the cut in the paint) so it was already sanded and I just went ahead and sprayed some mid coat with an air brush in the small area that needed it. Then sprayed the clear over top. The area is only about 1/2 inch wide and 2 inches long.

Ric

[302 Z28]

The reason it does not match is that you now have a difference in the layers. You have some amount of top coat (color) on top of some remaining clear. You must remove enough clear back far enough from the repair so when you respray the top coat you do not get any on top of the existing clear coat, then re-clear coat the entire repaired area. The object is to not get any top coat (color) on top of any existing clear.

Vince

[Bee4Me]

It's called a blend line and you got 2 choices basically,
Redo the area and use a blending clear/agent for the repair,then buff REAL LIGHT around the blend/orig clear area or IF you can, just sand the whole panel and reclear it,which IMO would be the best way.

[old40ford]

the only way to get it right is to scuff the panel and clear the whole panel, its only clear so you won't have a matching problem and it will be over with a lot quicker than this thread.

[kenseth17]

Yep with base clear the proper way is to clear the whole panel. Sometimes you get lucky on a blend and its hard to see where it was blended, but not always. Like said before spray blending solvent or reducer on your blend edge and very carefully buff that area. The clear you apply won't melt in with the existing clear (like a lacquer repair) so you have a real thin coat of clear sitting on top of your old clear at the blend area and you see a line at that point.

[mitmaks]

you should've used blending agent, they have that for blending in for spot repairs

[mrcleanr6]

assuming that you've wetsanded the fresh clear so it is smooth into the old clear then this is what is happening. you sanded the old, hard, cured clearcoat then did your repair and sprayed fresh clear over it. i'm sure you let it cure overnight and now you have wetsanded and buffed it out. you get a line around the repair area because the fresh clear is softer than the old clear and the buffer is wearing the fresh stuff away faster than its buffing the old clear to a shine so you get a dull line around it. best thing to do is of course clear the whole panel but sometimes thats really not an option. use a turbo clear or very hard curing clear ususally made for spot repairs. spray it on and blend it in. put a curing lamp or some heat on it for atleast 4 hours or a better part of the day. make sure its really good and cured. let cool. now try to wetsand and buff it. bet the line isn't there anymore!!!

[AC/DC]

OK,so I understand, you burned an edge,you resprayed midcoat then spot cleared over a panel that was completely sanded,right? You have a wet sanded panel and you just spotted in the clear OR did you polish the panel then do the repair? If you spotted in the repair on a sanded panel that is where you made your mistake. By blending in the clear on a completely sanded panel then polished the panel you "rolled" the edge of the reclear. Back in the day,we used to spot repair panels(in the collision industry) by polishing the panel,clean it,scuff just however far we are blending in the clear, cover defect with color and then clear to the edge of the scuff marks and follow up with a mist of reducer or "melting agent" to flow in the edge of clear. Then we can lightly rub that edge to a shine. You CANNOT sand and buff these edges!!! Not enough material for that. Again,if your panel(entire panel) was sanded and you only spotted in part of it then polished it that would be the cause of your problem. Resand the entire panel and clear the ENTIRE panel. That is the right way and the only way it will last. If you insist on doing a repair like that again make sure you polish the panel first then scuff the area you want to spot and only scuff as far as your going to clear.
Now if you polished it first then repair it I would say that you still "rolled" the edge of the repair. Spotting in like that is now a thing of the past and is no longer acceptable. Yes guys,I know,some still do this and even the paint manufactures are coming out with their "quick repair" systems but it is still a hack job and always will be.

[onlythegood]

Originally Posted by AC/DC

OK,so I understand, you burned an edge,you resprayed midcoat then spot cleared over a panel that was completely sanded,right? You have a wet sanded panel and you just spotted in the clear OR did you polish the panel then do the repair? If you spotted in the repair on a sanded panel that is where you made your mistake. By blending in the clear on a completely sanded panel then polished the panel you "rolled" the edge of the reclear. Back in the day,we used to spot repair panels(in the collision industry) by polishing the panel,clean it,scuff just however far we are blending in the clear, cover defect with color and then clear to the edge of the scuff marks and follow up with a mist of reducer or "melting agent" to flow in the edge of clear. Then we can lightly rub that edge to a shine. You CANNOT sand and buff these edges!!! Not enough material for that. Again,if your panel(entire panel) was sanded and you only spotted in part of it then polished it that would be the cause of your problem. Resand the entire panel and clear the ENTIRE panel. That is the right way and the only way it will last. If you insist on doing a repair like that again make sure you polish the panel first then scuff the area you want to spot and only scuff as far as your going to clear.
Now if you polished it first then repair it I would say that you still "rolled" the edge of the repair. Spotting in like that is now a thing of the past and is no longer acceptable. Yes guys,I know,some still do this and even the paint manufactures are coming out with their "quick repair" systems but it is still a hack job and always will be.

I am having the same problem with mine. I have almost a grand tied up in this bc/cc job and too many hours. The only question I have is can you apply single stage over the bc ? or do I have to sand it down to the primer ?

[BondoKing]

No there is no need in putting ss over the bc/cc... all you need to do is make sure you have the area prepped right before the blend... If it is not a color issue and just a clear issue then just clear the whole panel as jim, vince and bob have pointed out... Fresh clear will melt and blend fine, but if you are having issues it only takes a few more minutes to sand the rest of the panel with 400 and clear it all...

and you dont need to go to the primer either... just feather out the painted area well, and make sure it all flows together

Check out this thread, it may help you with the blending... I might add that you should sand the area that is not going to be touched with anything with some 1500 or 2000 before you ever start spraying anything..... When you melt your clear you will have the area that is still sanded and it will be easy to know where your blend edge is so you dont buff it too hard... Gotta thank Bob for that helpful tidbit that I did not include in the original thread.. Always learning

Blending Clear

[kenseth17]

Makes sence mr clean. The times I had issues is when repairing a small defect on someones car, and then doing a blend on the panel with proper sanding and blending techniques, but since people tend to want thier cars back, don't have weeks to wait to buff the edge. Some blends tend to go better then others. I'll have to try using a turbo clear and see if it helps. When you have time and money( yours or someone elses) tied up into a paint job, and only have a small defect, it is tough sometimes to want to mess with the whole panel. Sometimes I've had blends the next day that i've buffed where you could hardly tell and other times they were noticeable when looking with the new clear area looking glossier then the old (even though it was fairly fresh) and a duller looking line where the blend was done. My other concern with this is mill thickness at the blend edge (even though there is more clear underneath), which is why I believe they don't recommend the procedure. The clear is going to be thin in the blended area, and wouldn't this lead to it possibly peeling there in the future?

[AC/DC]

Originally Posted by onlythegood

I am having the same problem with mine. I have almost a grand tied up in this bc/cc job and too many hours. The only question I have is can you apply single stage over the bc ? or do I have to sand it down to the primer ?

If the situation is right you can put SS over the bc, but the question is why would you want to? No need to sand to primer. Sand enough to fix defect. Really need to know your exact situation.
This is not meant as an insult but as a little insight. Why take a thousand plus dollar paint job and do a ten dollar repair?