To Thin or Not to Thin

[Paul Zonneveld]

I have some projects that I will be spraying this weekend and I need some advice on thinning the finish or not. I am using the water based Deft laquer product with the Wagner HLVP conversion gun from Gleempaint. Should I need to thin the lacquer out of the can or is it not necessary? Would thinning give me a better finish (more coats but smoother finish?). Any advice would help.

[Tim Sproul]

I'm not familiar with Deft water based lacquer but do use Target Coating's water borne lacquer. I don't thin and I spray with conversion HVLP set ups. I've been very happy with the off the gun surface I'm able to achieve. Keep in mind that the surface you can achieve depends on a lot more factors than the finish - gun, weather, technique, and the surface you're finishing all affect the outcome.

For water borne finishes, don't exceed the maximum amount of water that Deft recommends. Doing so will likely lead to improper curing of the finish. Traditional nitrocellulose lacquer dissolved in acetone/lacquer thinner can be thinned until you're heart's content....but not water borne stuff. Most water-borne manufacturers sell specific products for thinning/retarding their water borne product(s). I've never needed it but I'm not spraying in 120 degree Arizona desert weather either.

[Steve Schoene]

Waterborne acyrlic finishes should be thinned very little if at all. Deft says "Thinning is not recommended". While makers of oil based varnish and paint lie about not thinning, the waterborne maker means it, and since the thinner would only be water or another non-VOC they have no regulatory incentive to mislead you.

[Jim Becker]

Also, when you add water to "thin" a water borne finish, you're truly upsetting the nature of the product. No more than a very little if you really feel it necessary, but these products tend to spray beautifully out of the container.

[Don Selke]

Paul:

I thin no more then 10% with water depending on the material that I am spraying and the nozzle size. I have to add retarder due to the dry air and heat here in the SW desert. Do all my spraying before 8AM and when it gets too hot do not spray at all. I was spraying a top for a project one day, before I completed the last pass, the first pass was dry.

[Larry Fox]

I use quite a bit of Target product, both the USL and the Conversion Varnish and I tend to thin it about 5%. I do it mostly because I was spraying it with a 3-stage turbine-based unit and it was really working hard. I found that it flows out very nicely and I have not experienced any issues related to thinning. However, as others have pointed out, pay attention to and follow the manufacturer's recomendations and you should be fine.