How Much Lacquer Thinner to Add?

You can add as much thinner as you need to spray effectively, and spray multiple coats — but stay within the specs for dry mil thickness of the coating. October 1, 2010

Question
How much lacquer thinner is safe to add to Magnamax white lacquer satin? I ask because the back of the can says 5-10%, but when I mix this amount it’s still too thick and doesn’t spray as I would like it to. I’m afraid of adding more thinner due to the unknown effects since I’m using Magnamax white lacquer for the first time. I use other ML Campbell products such as Magnamax clear lacquer and sometimes add up to 25% thinner with no problem. I’m not sure about the white lacquer.

Forum Responses
(Finishing Forum)
From contributor J:
Exactly what equipment are you spraying with? Including needle/nozzle size and is your paint holder pressurized? Also do you have a # 4 ford viscosity cup?



From the original questioner:
I use a low end HVLP 1.4 nozzle gravity gun. I have a regulator in the spray room set at 60psi and about half that on the gun. I don’t have a #4 viscosity cup.


From contributor F:
Use the ML Campbell lacquer thinner recommended by the tech sheet. Use as much as you need to thin your material out so that it sprays right. You may not get the hiding power that you would expect with the material only reduced 0% to 10%, meaning you might have to lay down additional coats, but that's the price you pay when you choose spraying equipment such as yours. Lay down additional coats and don't worry as long as your total coating weight (dry film thickness) is between 4- 5 dry mils.

The recommendation from the manufacturer about reduction quantities is based on VOC's and not on how your coating will perform. Your coating will perform as advertised if the total thickness is between that 4-5 dry mils and you haven't become a finishing maverick by venturing outside the recommendations from the tech sheet (other than varying the amount of reducer to suit your spraying needs).




From contributor R:
You can thin MagnaMax Pigmented to 30-35 seconds using a Ford #4 cup - MLC Standard Lacquer Thinner or Care Redcer. If you don't have a viscosity cup get one from your MLC distributor. They should have one and will make it easy on you to get a nice finish. Contributor F is correct, you don't want to over thin your products for hide, coating thickness, labor, etc.