Spotting in repairs

A

ADTKART

I am sure with all the experts here some have advise on how to spot in repairs on fresh paint without it lifting. For instances where the fresh paint has been damaged and you have to shoot more base over and you had to sand and expose the base under the clear.

I have mixed luck with it, but figured there has got to be a better way than "hit and miss". In case no one has noticed, materials have gotten on the pricey side, so I would love to have a way to only have to fix things once.

Aaron
 

Barry

Paint Fanatic
Staff member
This is a thread, we need on here bad and we should get a lot of good ideas as we have all been through this.

I no longer fight it myself, it won, say uncle.

I get my infrared and warm panel to about 110, then I step in front and lay first coat of base and let lamp do its thing for ten-30 minutes, step in front and spray second coat, bottom line that lamp stay on the spot until I'm done clearing and it still stays on for 30 minutes after that.
 
A

ADTKART

OK Barry.... that helps, but do you use the same reducer or use a faster one to keep it from melting the base?

Aaron
 
S

Senile Old Fart

are you guys taling about a base coat that was activated or non activated or both? Learning minds need to know the details.
 
My understanding is that if the base was activated to begin with then you should activate the base sprayed for repair.
If the spot is to bare metal then I start with epoxy and follow the same steps I used when painting the car.
If the spot is just to the base then I spray 2k over the spot to seal and level and then some intercoat clear, followed by base blended and the whole panel cleared.

My attempts at blending clear have been futile so far so I'll be watching what others have to say. Great idea for a Sticky Topic.
 
A

ADTKART

SOF... looking for information for either way, as I believe that it happens either way.

68..... The repairs I am referencing is when you sand a spot on a fresh job, you go thru the clear and into the base. The base is sensitive to the new base and the reducer in it. When spraying the new base on that spot, the original base will often wrinkle. Trying to collect information on how to avoid that wrinkle problem.

Aaron
 
S

Senile Old Fart

ADTKART;13210 said:
SOF... looking for information for either way, as I believe that it happens either way.

68..... The repairs I am referencing is when you sand a spot on a fresh job, you go thru the clear and into the base. The base is sensitive to the new base and the reducer in it. When spraying the new base on that spot, the original base will often wrinkle. Trying to collect information on how to avoid that wrinkle problem.

Aaron

Will it wrinkle if the original base was activated?
Will intercoat clear cause it to wrinkle?
Will epoxy cause it to wrinkle?
If epoxy does not cause it to wrinkle, then maybe Barry will package some epoxy without pigment in it for base coat sand through sealer?
pints maybe?
 
A

ADTKART

It is my understanding that the wrinkle is from the reducer attacking the base. It seems to me that a while back someone had posted that you should just dust on the new base so it doesn't attack the old.

I also wonder how long the base has to sit before it becomes sensitive, or is it just after you apply a clear to it? How long after that before it becomes where it isn't sensitive anymore? Hint.... a few years ago I took a job on a Dodge pick-up. The truck had been painted and the owner was not happy. He said that it needed more clear, and it was obvious that it had been short changed on that part. Figuring on simply scuf and shoot some clear, it seemed like an easy job. The truck had been painted for 3 years, but sat in a garage that whole time. I took a grey pad to the truck and hit base with it. The owner agreed to repainting the whole thing, figuring a quick scuf and shoot of base. The 3 year old base blew up on me!

I have, in the past, shot unreduced epoxy over spots and not had an issue. If you are using a fairly transparent base, you really don't want to introduce epoxy back into the mix if possible.

On the truck, i ended up painting each panel completely one at a time. I sprayed the base with the fastest reducer that I could and shot them as close as I could to be dry spray. Once I got it where I felt safe, I shot one normal coat, and then cleared. This was with a very long flash time between coats. One door, for instance, took me 3 days to complete. Then onto the next panel.

I am not the only one that has run into this type of problem, and I figure most everyone that has done much painting has hit it too. Just trying to get other ideas on how to correct this. I can get by the problem I currently have, but then someone else hits the same problem and they are in the same boat. Let's put our heads together and figure out the solution.

Aaron
 
B

Bob Hollinshead

Activating basecoat should be a requirement for all painters-this would help decrease the sensitivity on repairs. It's been a long time since I've had any lifting or frying on repairs but the basic rules have already been covered-thin applications of base, ample flash times and a heat lamp helps, and don't put your clear on too soon or it'll trap solvent and cause lifting. I really haven't had any lifting problems for a long time now, and never any problems on anything I've originally painted...Knock on wood. Also, some reducers are a lot stronger than others.
 
J

jeremyb

I think you have to consider the system you are using and the brand reducer selection as bob mentioned. Since switching to spi reducers....shooting any base I put it in makes it just about idiot proof. Don't know how barry has done this!!! I've gone over next day SPI clears with sikkens base, which is a hot base system, with spi reducer and zero problems. Of course, I didn't go to town with it...was very easy with it as always. Sikkens is a HOT base and has a tendency to start ringing out badly or lifting if shot too wet on these repairs. But, I think ALOT has to do with the type of reducer.
 

old sarge

Member
spot repairs

I have used dupont chroma base for years and never had a problem with sand thru repairs. PPG will bite me in the ass every time I try to spot in. I now think it is because of the base. When i have a problem now I recoat with 2 coats of waterborne primer and no more lifting.
 

strum456

Oldtimer
To activate your base, use a little of your clear activator. Some tech. sheets will tell you how much to use. I think Prospray is 8:1
 
A

ADTKART

I have had it happen when the base was activated and also when it wasn't. I really don't think that has much, if any, effect on it. The only reducers I have in the garage are SPI except for when I am shooting Dupont or SW, when I use their special crap.

Aaron
 
D

Deleted member 7

A coat of epoxy or 2k solves this problem for me.. Seals the area and I can lightly wet sand before I base to release those solvents and feather out nicely
 

Barry

Paint Fanatic
Staff member
This is some very good ideas here.

Bottom line is any base when you break through fresh clear can wrinkle and as pointed out it is applying the coats of base to fast or to wet to the repair.

The real problem comes in is if you do cause a wrinkle, even after you sand it down, you are in real trouble, if a light is not used, at that point even epoxy will wrinkle it and if you make it through on the second time around, I will guarantee you, you will see the repair show up a year or in my case 7 years down the road, if you look just right under the lights.

Time between coats when making these repairs are on your side, no such thing as to much flash time between coats of base in this case.

Activating the base is the best defense but on a 100% cure all.
 

orangejuiced86

Garage hack at night.....
I have an issue right now with a car I did last spring. You can see a ring on the trunk lid. I put down some shitty transtar epoxy and I think it shrunk up over time and you can see a halo. It's solid red. I am hoping I can wet sand it out.

If I cant. I hope that ring is sealed in with the clear and i can dust coat it and reclear.
 
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