Thining latex paint with varnish

[3djedi]

I'm trying to spray latex paint via hvlp and find that it's too thick. When I try just using a brush I get terrible brush marks even when floetrol is added. I came across an article that recommends adding a water based varnish (polycrylic) to thin the paint for spraying. It adds durability to the paint as well as a shine. Which is great for my application. The article does not state how much to add though. They also said a product called Seal Krete Wet Look works great. Has anyone tried this or have any thoughts about it? Good or bad idea?

[Gregory Paolini]

You're absolutely right - Latex out of the can is too thick to spray - However, I generally thin it about 10% with distilled water, and move to a 2.3mm tip & air cap on my HVLP - It requires the fluid nozzle is wide open, but I get pretty good results this way.

Hope this helps

Gregory Paolini

[CessnaPilotBarry]

I go the other way... Paint into finish...

On many occasions, I've added up to ~ 20% Pratt and Lambert latex paint to ML Campbell Ultrastar water based "lacquer". I find using mostly clear finish creates a tough finish, with far less blocking than latex paint. Choose the clear finish with the sheen you want, the sheen of the latex doesn't seem to matter.

If you do this, test your exact combo on scrap first... Start with 10%, see if it's opaque enough. Reds, yellows, and oranges will probably need a tinted primer. Whites, pastels, and grays seem to cover very well and require less paint.

[3djedi]

That's interesting. I'm painting MDF and it's going to be pure white and glossy. I want it to almost look wet. So I would like to try your method of laquer with 10-20% paint mixed in. I already primed the material with zinnser 123 water based primer which is white. Do you think I could use polycrylic with the white paint mixed in? Or should I just go with the water based laquer? The paint I have is 100% acrylic latex from sherwin Williams.

[CessnaPilotBarry]

MDF is cheap! Lots of learning opportunity there... Try it!

I don't like to use Polycrylic in general, so I can't comment on it specifically. I greatly prefer the WB "fake lacquer", spray only, products, like ML Campbell, General Finishes, or Fuhr. Sherwin Williams makes a similar product, but I haven't used it. Since you have SW products, I might be inclined to give it a test.

I'd prime up 5 panels, shoot one with all clear,another with 5% paint, 10%, 15%, and 20% paint... Mark the bottom of each panel with the mix. I'd use the number of coats, at the wet thickness the product docs recommend, applied as directed. Let them all dry for a week, longer if able.

I would then visually inspect the coverage, opacity, sheen, etc... Next, I'd scratch them, put a wet glass on them, spill drops of beer, vinegar, booze, coffee, mustard, etc... Spill some beer into the woodworker, too... The clear only, over primer, panel is the "control". The panels with the paint shouldn't behave any differently. If they do, then you know that the mix on that panel is not one to use. If they all look good and perform well, I'd choose the panel with the least paint in the mix.

[3djedi]

Alright. Im gonna give it a try. I'm also going to try mixing polycrylic with the latex and see how it goes. I happen to have a can sitting around so might as well give it a try.

[3djedi]

So how do I measure this out? By weight or volume?

[CessnaPilotBarry]

I use volume, normally glass beakers or stainless steel measuring cups.

Take good notes and let us know how it works the the Polycrylic. Thanks!