Hello all,
I have a CAT 14:1 pump that was set up with a 411 nozzle
I also picked up a 511(it was a return and got a discount)
It works great for most solvent I use
The only time I'm running into a small problem is when I'm using a post-cat such as MLC Turino, the nozzle gets a little clog when I set the gun down for short time/break time
So I started to take the air cap/nozzle off the gun and drop it in a cup of thinner until I'm ready to spray again
I also use a small brush to clean it,it works but I still get some clogs
I'm wondering if I were to get a larger nozzle, would it help with clogs?
What size nozzle do you guys/gals use for post cat CV?

Depends on what kind of a clog. Is it internal to the nozzle or external as in build up?

I do something different. I have a cup of thinner that I can take the gun and put the tip into the thinner. I don't remove the cap, just submerge it in the thinner still attached to the gun.

I have a setup where it balances properly and I don't have to worry, simple to do. The only thing I have to do is spray air out of the gun to clear any thinner that gets behind the cap. Takes 10 seconds or so.

As for internal clogs, I also run a micro screen O-ring in all of my tips. Instead of the hard white O-ring I use the screen in place of it. Stops almost all debris from reaching the tip.

Thanks Leo

Not exactly sure if it's internal or external
I do see build up,not much but I guess enough to cause a clog
I do keep a nylon brush and clean it with solvent

"As for internal clogs, I also run a micro screen O-ring in all of my tips. Instead of the hard white O-ring I use the screen in place of it. Stops almost all debris from reaching the tip."

Interesting,you are talking about that little white O ring that is inside the nozzle tip?
If so where do you get that screen O ring from?
Maybe I should try it and see if it does any better

The number for the screens is 129-609-901

They run about $5 each and are sold in 10 packs.

They last a long time for me. I remove and clean them when necessary. It can be tough, but I use a sharpened pair of tweezers that I use for pulling debris out of the finish when it happens.

I've always used these screens, even in the bigger 12-174 tip, why take the chance?

Thanks Leo
Looks like a Kremlin product

I will get some and try them out!

It's the Turino and nopt the tip. Turino wants to set up quickly on the end of the tip. Easy fix, sort of:

After every door dunk the face of the gun (the air cap part) into a tiny cup filled with lacquer thinner). Partially trigger the gun to get air through the cap to blow out the lacquer thinner. Now, you're ready for another door.

For Turino, 10% catalyst and 10% reducer (Standard Lacquer thinner or Care Reducer), I prefer a 509 tip. Or a 609 tip. I'll sometimes use a 409 tip if there's no large doors or panels.

Daniel

I think you're right
I have been cleaning the nozzle with a nylon brush and thinner
After a few spraying a few doors
Seems to work ok
Thanks for the advice

Sorry to piggyback off this, but I'm fairly new to the AAA system. I have been spraying with the .411 tip exclusively. Regardless of what I'm spraying. From klearvars, to turino, to clawlock, and even coda.

In order to make the different viscosities work through the tip, I'd reduce more or less and then play with the pressure to make the spray come out better.

I have used a .413 tip, however that just dumps the material on and then I end up with unnecessary build up, leading to bridging on 5 piece cabinet doors.

I see the mention in this thread about using .5xx tips. What is the difference with the .4xx sizes vs .5xx sizes? I know the difference between the .409 - .411 - .413 as that's what I've used but I'm not sure what the designation of the 5 means?

My only guess is that the first number references a different spray pattern width, whereas the second number references the orifice width leading to different amounts to be sprayed?

Sorry for the ignorant questions.

Yes
The first number is the size of the fan
So if you have a 4 it means half of the fan
=8" fan
5 = 10" fan and so on
The next set of numbers is the size of the orifice of the nozzle
I have a 411 and 511
I think the 11 is pretty standard for CV/pre-cat etc...

A 509 versus the 409:

The 509 can give you a 10" fan. The 409 can yield an 8" fan. You double the first number, and that's your potential fan size.

The 09 is the sizing of the orifice and that orifice size determines your material flow through the tip.

409, 509, and 609 tips all have the same amount of fluid material flow. So with larger fans and the same material flow rates, that translates to a slightly "finer" fan as you up the fan size. You're getting more coverage with the same material and so you get a thinner dispersion of the atomized fan, and that's what I mean by finer.

The jury is out with regard to plain tip seals or screened (150 mesh) tip seals. My experience is that the screened tip seals don't help me. If the finish wants to clump as it's being atomized, then it's going to, and that means yet another door that gets earmarked for resanding and reshooting. Thus, having a fluid line that has no "cholesterol buildup" to line its "arterial walls" is important.

My settings for Turino, reduced 10%, and catalyzed 10%, are 23 psi for air, and 600 - 900 psi for fluid.