Reducer For Metallic Paints

Machspeed

Machspeed

Member
I was talking to a friend of mine who painted his car and did what I thought was an incredible job. He's very meticulous and said he was not happy with the outcome, stating the metallics moved around a lot when he was spraying the clear. This is an individual who has painted many cars and done lots of restorations. He once owned an autobody shop for many years and retired out of a Vo Tech teaching autobody.

I do not know the specifics on the products that he used but he said something about a reducer that would better lock down the metallics in the basecoat. This is new to me. Any thoughts on this?

Thanks!
 
Regardless of your friends experience there is no real truth to that IMO. If a metallic moves around it's because it is sprayed too wet. I've never heard that before either and I don't think it's valid. At best using a faster reducer and spraying metallic wet would simply be a crutch to help with the wetness. Not what you want to do at all. Metallic moves around because it is going on too wet. Spray it correctly, it stops moving around.

With a modern metallic basecoat you want to spray light medium, to at most medium coats. Use a slower reducer as well. Spraying lightly allows for the metallic to orient correctly. Using a slower reducer keeps you from having dry edges and allows the metallic to orient. Now if someone sprayed wet and used slower reducer it would cause the metallic to pool and move around. But that is the fault of the painter not the products. Light medium to at most medium coats (it should never look "wet" going on), slow reducer and you will get a nice result.
 
forgive my ignorance, i have yet to spray metallic base, but wouldnt it be just about ready run or sag at the point the metallics are moving?
 
Treeslayer said:
forgive my ignorance, i have yet to spray metallic base, but wouldnt it be just about ready run or sag at the point the metallics are moving?
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Well it would have to be really wet to do that! "Moving" is a relative term. When you spray metallic (or solid but not as critical with solid) wet, it will have a sheen to it. It looks wet. That doesn't mean it's going to run though. When it looks wet, the metallic is moving around in those wetness "puddles". It will tend to clump together locally. The end result is called mottling.

If you spray it so it doesn't look wet going on you allow the metallic to "sit down" and it will orient correctly. Now using cheap reducer will make spraying lighter harder as will using a faster reducer, which is why you want to use the best reducer you can and usually slow or if extremely hot a very slow reducer. Sometimes a blend. With the slow reducer you can spray lighter and it lets the metallic "sit down" before the reducer flashes.

The better and slower (to a point) the reducer you use you will notice as you tack between coats that your tack cloth picks up very little overspray. The faster or lower quality reducer you use you will notice your tack getting very dirty between coats when tacking.
 
Chris_Hamilton said:
Well it would have to be really wet to do that! "Moving" is a relative term. When you spray metallic (or solid but not as critical with solid) wet, it will have a sheen to it. It looks wet. That doesn't mean it's going to run though. When it looks wet, the metallic is moving around in those wetness "puddles". It will tend to clump together locally. The end result is called mottling.

If you spray it so it doesn't look wet going on you allow the metallic to "sit down" and it will orient correctly. Now using cheap reducer will make spraying lighter harder as will using a faster reducer, which is why you want to use the best reducer you can and usually slow or if extremely hot a very slow reducer. Sometimes a blend. With the slow reducer you can spray lighter and it lets the metallic "sit down" before the reducer flashes.

The better and slower (to a point) the reducer you use you will notice as you tack between coats that your tack cloth picks up very little overspray. The faster or lower quality reducer you use you will notice your tack getting very dirty between coats when tacking.
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i think i understand Chris, the flakes are heavier than the paint and there fore can move in the suspension even though the paint isnt really moving, or at least not as much. a really thick coat [wet] would allow more movement of the metallic.
interesting on the reducer. would you say the same about hardeners? i have noticed some cheaper brands flash off super fast, while SPI is much slower. what i mean is cheap is about 10 min while SPI is more like 30.
 
Chris this leads to a some what taboo question..........could you use spi activator in a non spi branded urethane? and would you benefit from doing so? of course this all hypothetical.
 
Treeslayer said:
would you say the same about hardeners?
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Not really the same thing. Those products are designed to work with a specific clear or primer, etc. You also never should intermix hardener or activators. (don't know if that what you mean but thought I'd mention it) Also keep in mind most refinish products are marketed to the collision repair market where speed is the primary concern. 1-3 panels.

Any clear designed for overalls will have a longer activator time.How it looks going out the door is all that matters. SPI has their speed clear which is just as fast as anything while maintaining SPI quality.

Treeslayer said:
Chris this leads to a some what taboo question..........could you use spi activator in a non spi branded urethane? and would you benefit from doing so? of course this all hypothetical.
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No. Activators are designed to work with their respective clear or primer or whatever. You should never intermix. It usually won't work. Remember these products cure (get hard) by a chemical reaction, not by evaporation, so they are designed to be used together. Mixing and matching won't work.

Reducer is different because it is simply a solvent blend. It is not dependent on catalyzation or other chemical reaction. Reducer thins a product to allow it to spray correctly. Most basecoats use a very similar structure which allows one to use say SPI reducer with Motobase, or PPG DBC etc. There are a few which you should only use the manufacturers reducer but that is a different topic for another time.
 
Chris_Hamilton said:
Not really the same thing. Those products are designed to work with a specific clear or primer, etc. You also never should intermix hardener or activators. (don't know if that what you mean but thought I'd mention it) Also keep in mind most refinish products are marketed to the collision repair market where speed is the primary concern. 1-3 panels.

Any clear designed for overalls will have a longer activator time.How it looks going out the door is all that matters. SPI has their speed clear which is just as fast as anything while maintaining SPI quality.



No. Activators are designed to work with their respective clear or primer or whatever. You should never intermix. It usually won't work. Remember these products cure (get hard) by a chemical reaction, not by evaporation, so they are designed to be used together. Mixing and matching won't work.

Reducer is different because it is simply a solvent blend. It is not dependent on catalyzation or other chemical reaction. Reducer thins a product to allow it to spray correctly. Most basecoats use a very similar structure which allows one to use say SPI reducer with Motobase, or PPG DBC etc. There are a few which you should only use the manufacturers reducer but that is a different topic for another time.
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thanks for that.
i wonder if say, 5% spi reducer in some of these fast paints would slow um down just a little.......that fast flash time makes it hard to cover a large area fast enough to avoid dry edges.
 
Jim C said:
well he said the metallics were moving when he cleared it. to me that would mean he shot really wet or overreduced clear on top of base that was still to wet
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My guess is that what he thinks is happening when in reality it was as I described. I don't know about you and the other boys here but I've never seen that. But I have seen plenty of times base that is mottled and seeing it is hard in base and when you clear it it's there. Just my guess IDK.
 
Chris_Hamilton said:
My guess is that what he thinks is happening when in reality it was as I described. I don't know about you and the other boys here but I've never seen that. But I have seen plenty of times base that is mottled and seeing it is hard in base and when you clear it it's there. Just my guess IDK.
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that very well could be chris. maybe its there and not seeing it until its cleared. i have also had base move on me as well. rushing. not enough dry time on the base and clear that is too watery. the solvent just shifts it around making stripes. i think in most normal cases that would not happen. i will admit i have been know to push the limits a bit...:cool:
 
Below is the car that my friend painted and is in the process of finishing. Note, it is the same car that is in my Avatar. Same make, model and color as my car will be. In that, I took a very good look at it. I've got a pretty keen eye for a garbage paint job and this is not one of them. This thing is gorgeous!

As I said above, my friend is a perfectionist and admittedly finds fault in all that he does. How it could have been better is beyond me though. Still, he said the metallics moved when he cleared it and there are some areas he frowns upon. That said, this is the first full car he has painted in several years and admits that he has not really kept up with the changes in the industry. In that, I'm thinking he may have been fighting the use of some lower cost materials. He was not familiar with Wanda Paint, the paint that I told him I'd be spraying my car with, nor was he familiar with SPI products. In fact, I've been bragging about SPI products and he is eager to try them on his next project, a black 69 Mustang Mach 1. All this said, I think he was fighting the materials.

Chris, you use SPI reducer in all your basecoats?

IMG_7067 (1).JPEG
 
Maybe your friend is talking about adding intercoat clear to the base. When I painted my car nightmist blue metallic I had issues with tiger stripes and molting in my base coat. Thanks to Chris he explained how to mix intercoat clear with my last coat of base and that solved my issues. Also a let the base set overnight before spraying the clear
 
Kind of strange that he’s never heard of Wanda if he used to be a painter. They’re an Akzo Nobel brand so not exactly obscure.
 
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