I am mixing 4 to 1 like the instructions call for and my primer coats are extremely dry, possibly too much air, mix ratio, not sure. Can I add reducer or straight laq thinner to it to get a more wet spray of the primer?

And if so, do I need to change the 4 to 1 ratio?

Sean,
K36 should be mixed 5:1:1 using DT reducer and K201. You don't have to add reducer but it will help it flow and keep it open longer. Use DT885 if it's about 75 degrees when you spray.
K38 is a high build primer and does mix 4:1, I've never reduced it, and the P sheets for it don't say anything about reducing it.
The K36 is more of a surfacer than high build (although it still builds nice)
The K38 will definitely go on heavier and require more sanding, the K36 with 1 part reducer will flow out nice and smooth and make sanding before paint a snap.

The size of your gun tip will also make a huge difference, I use a 2.0mm tip on my Sata KLC, smaller tips will make it go on drier in appearance (more orange peel) unless you reduce it further. For air pressure I use 29psi. I wouldn't use anything smaller than a 1.8mm tip for spraying K36 and wouldn't use smaller than a 2.00 tip for K38. PPG recommends a 1.4 to 1.6 fluid tip, but I've found the nicest coverage with the 2.0, keep your passes quick and smooth and it add's very little weight.

Jeremy

LGM hit the nail on the head. K38 is almost considered a spray filler, we probably sell one or two gallons in a year's time. K36 is a much better choice over 38 for everday surfacing applications. If you are stuck with what you have for spray equipment go ahead and thin the 38 down with DT reducer - not lacquer thinner. Lacquer thinner, although having the capability to cut the product, is way too fast evaporating to use with a urethane product. Get yourself a quart of DT870 or 885 and have at it. Do not ever adjust the ratio of catalyst to product, those ratios are given for good reason.

Attached is a pic of my latest paint work. I did all the stage sound equipment for Carrie Underwood.

Dan
www.gocolours.com

The application I most use K38 for is primer in the mold before layup. I like it cause it fills the weave really well. But spraying it with 1.8 tip is so dry today that I thought I might just ask. I've used probably two gallons of the stuff over the past 3 years or so. I have a quart of k36 here, but I have never opened it.

Next layup I will give it a shot and see the difference.

Sean,
Another product that I've been wondering how it would work for your application is a product that I use all the time on cars.
It is by Evercoat and is called "Slick Sand". It is a high build Polyester primer. It sands awesome, you can apply paint directly to it, it fills fantastically, can be reduced to flow out smooth, dries quick, and once it's cured it is solid. That might be it's only flaw on a thin lay up like a fuselage, although it works fine on urethane and fiberglass bumpers.

https://www.autobodytoolmart.com/p-1...ID=41632055522

It's cheaper than the K36 as well. For cars it's awesome, I can spray on 3 or 4 coats and then block it and it's build is thick enough to get rid of 80 grit scratches as well as small dings. Of course I wouldn't use it that way on a jet or any plane, but the build is awesome, might be worth trying.

Sean,

It sounds to me like some of the solvents have evaporated from you K-38. I couple years ago i got the bright idea to re-package my K-36 into small, easy to use, PLASTIC squeeze bottles. That worked great for about the first 3 months, then the stuff started getting thicker and thicker even in the bottles that I hadn't used yet. It seems that the solvents were leaching through the plastic bottles.....Maybe that's why PPG sells the stuff in metal cans! Anyway, I found that I could resurrect most of it by adding reducer. The last of it was ONLY good for spraying in layups because it was too hard to get a smooth application when sprayed as base coat.

John