HVLP problem...

[Jim Kappel]

I'm using a Graco 3800 HVLP. I've got a #2 tip and I'm spraying DNA with TT Dye. There seems to be a small dripping from the tip that is causing it to splatter a little bit when I first activate the gun. I've double checked the tip for tightness and the needle. Both seem to be fine....

What else am I missing?

Jim

[Jim Kappel]

I just took the #2 off and tried the #3. It works. However, I don't want to use #3. Or can I???

[Frederick Rowe]

The Rule of Thumb I've used with HVLP spraying is to first get the viscosity where the finish levels properly, then find the right tip/volume of air to spray. As your dye isn't a "leveling finish" I would use whatever tip works. The #3 tip should give good results, although, like you, I would have started with the #2. Did you inspect he needle/cap for defects that would cause the drips?

[Carroll Courtney]

If it is dripping from the tip alittle then the needle is not seating right in the fluid tip,or the spring that pushes the needle into the fluid tip may be the problem.I'm not familiar with that type of spray gun,so these ideals may not apply----Carroll

[John Lucas]

I think Carroll is on the right track. I ahve had more than my fair swhare of air brushing and varied units. They all sharewd and suffered from same problems. Needles that didnt seat properly. If turning yur needel solves the problem, then that might do it. When you clean your components, put a light dab of oil on the needle before re-seating it. Use the finish oil you can find. I use to use oil from nosew or bald head on finger tips and then spread to needle. Finally, on real thin stuff to spray,lower the pressure. If it a gravity feed cup, you should be able to lower it quite a bit

[Jim Kappel]

Thanks for the tips. I ended up using the #3 with pretty good success. I definitely would have rather gone with #2.

I checked out the 5 tips and needles I have. All needles seated themselves perfectly to the end of the nozzle end. The #2 did not. Looks like either the nozzle is not perfect or the needle. Sad thing is they have NEVER been used!

I'll guess I'll have to replace them right off the bat.