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High Solid vs Low Solid1/12
A finisher told me that low solid products = low quality product. In other word he told me that the end product will be more fragile/prone to scratch etc.
Does that makes any sense? That would basically mean that when I thin my finish I am also reducing it's durability even if there is no set limit in the spec sheet.
Other than needing more coats to build the finish is there drawbacks when thinning finishes as long as you use the proper reducer and Apply more coats to compensate? That would go against what you always hear about many thinner coats > One heavy coat.
Should I try to shoot my finish with the viscosity they are provided as much as possible?
There's a bunch of things here.
It happens to be true that, in general, lower solid products are often of lower quality.
It is often harder and requires more thought to make high solids products that spray and work well.
Keep in mind if you have a 25% solid product, and a 50% solid product, and they cost the same, and you have to build the finish to the same dry thickness, you are paying twice if you use the 25% solid product.
As for effect on end result:
1. Yes, there are limits to thinning for basically all finishes. The exact amount depends on chemistry.
You will affect sheen (for sure) and film quality (depends) by thinning too much.
2. Whether building with low solids vs high solids ends with a worse end product depends on the chemistry.
For finishes that are completely breaking down the previous coat (like nitro lacquers), it won't matter.
It's not going to be like "one scratches, one doesn't scratch", but like "one resists being underwater for 20 hours before peeling, the other resists being underwater for 18 hours before peeling" or something.
3. This is all separate from the thickness of coats you spray. You want to spray what the product is meant for (thin coats, thick coats, etc) no matter what. You can't spray double thick coats of a low solids product and hope to get a good result.
In the end, a lot of these questions are answered by chemistry of finishes, and if you want to dive into this stuff as far as you are, it might be worth your time to start trying to understand that piece of it.
Good answer from DannyB. I'd add that many, if not most products are intended to be sprayed without thinning. Thinning is usually done to adjust for conditions like temperature or to get better penetration for first coats, etc.
thanks for you i depth answer.
You confirmed what I was already thinking about thinning RTS products. I had noticed that thinned coats tend to dry faster even with proper thinner wich has made my lacquer prone to scratch and chip. putting heavier coats solved the problem but was getting runs since the viscosity was water like.
I will keep my reducer when doing washcoats or toners and try to spray straight from the gallon as much as possible.
FYI I am spraying a catalyzed lacquer mohawk versalac
The product is designed for ideal temp/humidity levels when applied with the correct gun setup.
If you canít get it out of the gun, you have the wrong gun, wrong needle/nose set or not enough air. Then you should add some reducer.
If it wonít layout or isnít drying at the proper rate then add some reducer.
All products have a max amount of reducer. 5%,10%,20%. If you are adding more than 20% you are doing something wrong. At the very least you are wasting your time by not getting enough product down per pass.
Call up your tech and ask them about reduced rates. They will have a specific percentage for each of their products.
We are adding 25% to stealth.
Any concerns ? Thanks
I sprayed a lot of Stealth and had to reduce it about the same, but it's been probably 6-7 years since I've sprayed it because I found SW Kemvar to be a much more usable, predictable product.
I had to make a cocktail every day to get Stealth to work. The thinner mix that worked in the 75 degree morning didn't work in the 95 degree afternoon, and vice-versa.
I found KemVar to be much less effected by temperature. We thin it the same basically every day.
I'll start out by eliminating the phrase "low quality product" bexause it's meaningless. Your soluds contents doesn't determine the performance vs price of your finish. It does help you do the math to figure out if the product makes sense for production purposes. Example? Aerosol lacquers, these guys are low iin solids. Yet my Mohawk aerosols and my Konig aerosols are high quality products. The materials used in their mix as well as the mix themselves are all superb.
Don't get fooled into trying to use percent of solids of a coating as a way to determine if the particular coating is good. By this rule, polyester, regardless of who makes it is wonderful with its more than 90% solids content.
Is a 24% solids nitrocellulose lacquer from one company better than a 16% solids lacquer from another company?
You judge a coating by its performance and also perhaps by how much work you have to do in order for that coating to help you to earn a profit from its use.
Thinner coatings means more work to achieve your 4-5 dry mils, right? That dry mil thickness is an average that most film-forming finishes need in order to give maximum performance (for the finish to work as designed).
The parameters of a coating are:
There's probably more. Solids content of a coating tells you nothing about the parameters in my list, meaning it's not part of a discussion of, "Is this finish material good quality?"
Henny Youngman was asked by his friend, "Do you like your wife?" His answer was, "Compared to what?"
I make my 3% solids content washcoat of the finest of finishes.