Hopefully someone could steer me in the right direction.I tried spraying some 2k primer the otherday and I was getting alot of yellow dust on the panel like some of the primer was drying as it comes out of the gun.I'm using a conventional siphon feed gun with the air pressure at 45psi and the fluid needle was two and one half turns out.Thanks for looking.

I dont know about 2k,about I was using gray and that happened and I did'nt have enough reducer(thinner).So you might try to add some more.I was told 1to1 if you had a lot of pits to fill,if not you can use a little mor reducer.

I always mix my stuff 4:1:1. I spray the 2k primer, and have never had a prob. Maybe you have too much hardner in it?

What primer you using, PPG dupont? Also what primer, PPG makes a hundred of them?

Did you follow the mixing guide lines as they were listed on the can? I know not all products have the ratio listed on the label.

What gun are you using and whats the fluid needle size? If you remove the needle it should be etched on the needle and many times is labeled on the outside of the air cap. Its the funny looking thing with the two pointy ends on it where the paint comes out.

how far back is the gun to the surface? It should be around 6-8 in. Too far away will yield a dry spray.


Simply adding more reducer is NOT the answer in fact that can be more deadly.

YOU NEED TO GET ALL THE PAINT TECH SHEETS FOR EACH PRODUCT YOU PLAN ON SPRAYING THEN FOLLOW THEM

I'd like to find out the answer to this myself,because its happened to me a couple of times with the gray primer that you just add reducer too,and i added mor reducer and it sprayed fine,but Im far from being a pro though so dont listen to me I just figured it worked for me maybe it would work for you but now I see that I done wrong graemlins/clonk.gif so it has me wandering what is wrong so If you find out let me know.

That happened to me and I found out I was too far away from the surface while spraying.It was drying before it got to the body.I have to agree,don't just add more reducer.If you are adding more reducer to get it to "work", isn't that the same as being too far away from the surface to be sprayed?Just asking for my own information.

The primer I'm using is Limco 700k 2k primer filler.I have the tech sheet and the mixing ratio is 4 parts primer to 1 part hardener.My gun is a mechanics brand with a 1.8mm tip.As for gun distance I don't believe I'm more than 8 inches from the panel.

If the dry area is at the edge of the spray fan, one of the problems that causes that is your gun isn't atomizing the material. Also, the material control screw should be all the way out when sparying primer. You can narrow up the fan by adjusting the top screw on the gun (turn clockwise)but the material will be heavier as it goes on the surface you are painting (I don't recommend this).

I know nothing about the Limco primer. Since you have the tech sheets look and see what size tip they recommend for their product. Most will be a range of tips. For ex PPG K36 has a range of 1.4-1.8 I believe.

We use K36 at work with a 1.4 tip. I have the same gun at home as we do at work but mine is the 1.7 tip. When spraying k36 out of that 1.7 gun the pattern is much drier and coarser because the paint is not getting atomized right. the reason I have that 1.7 tip is because I prefer the K38 which is a heavier bodied primer and shooting it out of 1.4 is tough.

If your Limco primer is comparable to PPG k36 then I would have to say that the 1.8 tip you are using is a bit of overkill.

Toby,sorry but I really dont agree with the statement of "turn out the material screw all the way out when shooting primer".
You only turn it out enough to get proper atomization.
We use a Sata LM2000 HVLP gun, you turn the screw all the out on that thing and you will have stuff running all over the place. On a flat surface just think of that extra reducer just sitting there getting trapped cause its covered with tons of primer.

I know I cant even come close on trying to explain the proper gun setup in words so theres a link to a post from Martinsr graemlins/thumbsup.gif He does one hell of a fine job...Eric
http://www.chevelles.com/cgi-bin/forum/ultimatebb.cgi?ubb=get_topic;f=3;t=005189

700k is what I have used and I had that same problem till I shortened my distance to the surface.Did you ask the guys you bought it from for any advice?They mayu be able to help you a lot witht he setup.Where I buy mine at,they spray this themselves so they know what to set it at by experience.

I use 700k alot, its a nice product, and your mixing it correctly, don't add any reducer. IMO your problem is the fluid adjustment, should be wide open, may want to bump the pressure up a bit too.45-55psi. Stir the can well before mixing every batch, its thick stuff.

I was at my local paint store today and asked them about the problem and he also said it did'nt have enough reducer if it is doing that.

Thanks everyone for your replys.I have read the tech sheet and it suggests a 1.7mm - 1.9mm tip for a siphon gun,it also says film build is 2 to 3 mils per coat.I do have a gravity feed gun with a 1.4mm tip that I may try.I'm gonna spray some this weekend and try some of your suggestions I will post back with my results.Thanks again to everyone for your help.

This is really simple guys, Think of your paint gun as a carburator. The key to proper atomization is air to fluid ratio. You can spray with as little as 10psi or as much as 60psi but the amount of fluid must match the amount of air and keep the same ratio. Fill type primers are very heavy and thick and need to be applied with lower air pressures, high air pressures tend to atomize the primer too much causing the fuzzy haze/overspray you describe. Many paint companies are now marketing roll on and brushable fill type 2K primers. Use a large fluid tip gravity feed gun with lower air pressure and your material transfer will be much better.

Well problem solved.I was at the autobody supply store yesterday and got to talking to the counter person about my problem,turns out my primer was bad.I sprayed some fresh primer today and it when on smooth.Thanks to everyone who was quick to offer help.