Replies

1. 
   Paul_Snyder | May 14, 2009 03:07am | #1

   More than likely the simple solution is to add more thinner. There are a number of factors that all play into determing the right amount to thin the finish, but the easy solution is to add thinner in 5% increments until it sprays nice.

   Some things that make a difference to getting a finish to spray well are the size of the needle/nozzle in the spray gun, whether it's a siphon or gravity fed gun, how old it is (technology and wear), whether the fluid and air passages in the gun are clean (especially the air supply to the cup), how many stages the turbine has and how well it's working, how long the air hose is, etc...

   So that's why I say the simple solution is to add more thinner in 5% increments until it sprays well. That way you don't have to buy and use a viscosity cup, or make sure you have the right needle/nozzle set for the viscosity of the material you're using based on the type of spray gun, and so forth. Fill the gun cup 1/2 way (e.g., 16 ounces) with the Opticlear or Optiset and add 15% thinner (2.5 ounces) and stir it in. Do some test spraying and see how it looks. Continue to add 5% more thinner and test spray until it works well. Depending on your set-up, I'd expect you to get good results somewhere in the 15% - 25% range.

   Keep each coat thin and add some reatarder if you get bubbles (solvent pop) or blushing.

   Paul
   http://www.finishwiz.com

2. 
   oldusty | May 14, 2009 06:53am | #2

    I have not used Chemcraft myself although one of my suppliers sells it .

         I have sprayed precat lac for many years , I use an airless pump . Look at the factory recommended specs for spraying and make sure your HVLP meets the capacity called for to start .

        With the airless I thin normal precat about 20% and it lays out like glass typically .

       I would not use retarder if the temperature is not an issue .

       Some lacquer materials have a shelf life and go bad , check the born date and lastly the   pattern is determined in part by the pressure adjustment and the tip size .

     Recently I sprayed a Rudd  brand Dura Cat semi gloss precat that does not get thinned , the factory rep said to use a 5 15 tip and turn the pressure all the way up well ,,, I certainly used alot of material on that kitchen but it was smooth and silky to the touch and had a perfect flow out quality .It was scary spraying a pattern that large but easy to control even though it was not thinned at all .

                  good luck      dusty

3. 
   integrity_woodworks | May 15, 2009 08:56am | #3

   How are you mixing the lacquer? by hand with a stick?drill and a wand !! been awhile but I used to spray it every day at one shop I worked at, there are a great deal of solids in the semi and the satin.the viscosity should be about 22  seconds,I would cut it about 15% thinner to start with ,which may need to be increased to about 20% and no retarder .by the way what exactly is the retarder? (no-blush works well when air is very cooled) winter cold ,but should not be needed except in the very humid summer periods summer . If it is spraying the gloss fine then I doubt it is the tip ,this product must be mixed well and Often!! I hope that helps.

   Dan