My painter wants to dilute my Kilz (waterbased) undercoat to make it work better in his spray gun. This is exterior application on OSB. For protective coverage does this mean in order to get same protection that more coats need to be applied..or is this incorrect thinking? Frank Georgia My correct e-mail address is gno52 (not gn52) Fake adddress given to avoid spams
Yes...You are correct....I used to be a Paint Chemist..Retired now....It will reduce the 'Solids' of the paint...so when the 'volatiles' are gone for a particular 'thickness' shall we say...........There will be 'less' of the solid left ..thus thinner dried coat....So 'Yes' you would have to apply more coats..depending on how far he 'dilutes' your paint....
Bigbazza..Oz
to make it
application on OSB.
same protection
thinking?
It'll be fine IFF the paint's instruction include being able to spray it, and if the instructions are followed. To spray paint, it's almost always necessary to thin it to get it to operate correctly in a sprayer, and the manufacturers know that, and indicate on the can if it should not be thinned. It's not true that more coats need to be applied although the logic would seem to say that. If a gallong brushed on covers x00 sq ft, and a gallon sprayed on covers the same x00 sq ft, then that is exactly the same coverage. And that's what you'll get when the manufacturer's instructions are followed, especially by a professional painter.
All that said, I have a personal aversion to latex primers: I feel you should be using an oil based product. But that's my opinion.
Pop
It's correct, to a point. Most manufacturers provide a dilution ratio for spraying, but common sense is usually fine. Dilute by half, spray twice. Or similar. As long as the coverage rate of the original paint is used (in other words a 400 Sq Ft coverage for a can of paint isn't used for 800 Sq Ft just beacuse you thinned the paint) the end result is pretty close to the same.
The kicker is that many paints are actually applied heavier than need be, so dilution may vary. In addition, absorbtion by substrate can affect coverage as well. Plus this is a primer, where solid coverage is less of an issue than with colors.
When all is said, it's hard to apply too much paint and it costs far more for labor than paint, so an extra coat because you thinned the paint is cheap insurance of good coverage.
Jeff
No it's not. If you brush on the gallon straight from the can, you get a gallon (4 quarts) of paint on the surface. If you add a quart of water (just to make the math easy), then you have 5 quarts of "paint". If you then spray on 1 gallon of this to the surface, you are only getting 4/5 of a gallon of original paint on the surface (in terms of solids.) You'd have to spray on the entire 5 quarts on the same surface to get the whole gallon on there, and this will often result in dripping (especially since the paint is now thinner).
The second coat is twice as much labor.
I suspect Pop was talking about spaying one gallon (before dilution) and brushing one gallon. However it was not totally clear.
If he needs to thin to spray let him thin it. It wont require more paint , the water evporates and solids are left
I would be more worried about my painter. I can't imagine a professional painter using anything other than an airless for an exterior paint job. I can't imagine an airless that can't push Kilz.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Keep the whole world singing. . . . DanG
make it
OSB.
protection
thinking?
- Bigbazza -
- Nehmo - What did you do as a Paint Chemist? Did you have some particular education in the field? And besides being a chemist, do you have any actual experience painting?
I'm studying paint and stain now, and I'm amazed at how widely opinions of professional painters differ. I don't have the experience to tell who's right.
same
can, you get a
quart of water
"paint". If you
only getting 4/5 of a
solids.) You'd have to
the whole gallon on
since the paint is
Not if the painter is experienced and has good equipment and uses quality paints.
Pop
Putting Latex Kills on an exterior is not the best, Good old slow oil is. Your real question should be is my painter Smart. Answer ::::: No...
If your painter has to thin the paint then he is most likely using air to spray with an airless sprayer would not need to be diluted .Use a .015 tip and go for it. "If latex paint were ment to be thinned, the water would already be in the can"
Not true. Paint can be thinned for different purposes, but it can't be thickened.
LOL Did you read, or better yet UNDERSTAND, a single word I wrote?
Not when sprayed at the same time, locally painters charge by square foot, not hourly. YMMV.
Jeff
That's not the point. The point is labor costs money. They charge by the square foot knowing how much time it will take them. It takes more time to do 2 coats than 1. And their charge reflects this. i.e. it would cost less if they didn't have to.
Yes...I am (or was)..an Industrial Chemist...I am now retired....I worked 24 yrs in Research and Development.....I formulated paints..to shorten the query for you....I worked for Large World wide Paint Companies.....I have worked on Automotive ,House Paint,Industrial Coatings,Marine Paints, Industrial Maintenance Coatings..etc , etc,..Does that give me any experience ?....
I was answering a simple 'query' !
Bigbazza
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