High build primer question

S

ssanto

I'm shooting SPI high build 2k with a Harbor Freight purple gun tomorrow. I'm using an extra tip that I enlarged from 1.4 to 1.8 in the gun. I'm playing around with gun settings today so that things will be ready to go tomorrow.

I find that even with the enlarged 1.8 tip, I still don't get a whole lot of material out of it. I've got the fluid adjustment turned all the way out, the fan all the way up, and inlet pressure at 43. It makes a nice cigar shape with good atomization (small droplets around the outside). But the cigar shape isn't as big as when I shoot SPI epoxy. I made a really slow pass on a test panel and it didn't run. Then I slowed way down, like 2 inches per second, and I finally got it to build enough to the point of running.

So I suppose I can still paint tomorrow but it will take a while. I have a Devilbiss PLUS gun and it looks like the biggest tip I can get for it is a 1.8. But I hear that gun puts out a lot of paint so I wouldn't be surprised if I got better coverage with it than the HF gun (even though they have the same tip size).

Thoughts?


Thanks,
Sal
 
A couple things I have learned. First, make sure its mixed properly, both the straight 2k in the can, and then the 2k and activator in the mixing cup. When you mix the 4:1 mix in the cup mix around a minute, this is very important. I usually have to reduce a small amount, 5%, have you tried reducing at all?
 
I usually use as much reducer as activator.
Reducing really helps with primers for flow and smoothness.
I usually use a 1.6 tip and it's more than big enough.
 
all i have sprayed for years is the hb primer. i run it through a sata 100b with a 1.9. that almost hammers out too much material at times. no reducer added. i dont really find the hb primer to be excessively thick so it probably has more to do with your gun.
 
all i have sprayed for years is the hb primer. i run it through a sata 100b with a 1.9. that almost hammers out too much material at times. no reducer added. i dont really find the hb primer to be excessively thick so it probably has more to do with your gun.

It looks like I'll be in the market for a new primer gun soon... My $10 HF purple special is already leaking from where the needle goes through the seal. :(
 
It looks like I'll be in the market for a new primer gun soon... My $10 HF purple special is already leaking from where the needle goes through the seal. :(

That leak is caused by the packing nut being loose. Not always but more often than not, you can tighten the packing nut and fix that leak. If you don't, not only will it leak, it will spit as you paint.

John
 
Good point! I tightened it up and the needle is a lot more secure through the bushing. I'll bet that will fix it.
 
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