Questions about Critter Sprayer

[cgallery]

So my Critter Sprayer has sat in its original box for almost a year. This evening I was finishing a small project and thought it would be near to try it. I was spraying Polycrylic (unthinned). I had to take the air compressor up to about 35-PSI or 40-PSI to get it to spray.

What I noticed almost immediately was a cloud forming in my basement. It seems the gun atomizes the stuff pretty thoroughly. So I stopped and thought I'd research this a little.

This is normal? You guys use these in your workshops without any sort of consequences (like finish settling on your tools?). After trying it for just a minute or two I'd be fearful or using it inside.

[cabinetman]

Using that sprayer, or any spray technique that atomizes chemicals in an enclosed or semi-enclosed area will produce an unsafe and mist filled area. I call that "hazardous confinement". If you don't have a spray booth, and only a garage door open, you will have an inadequate ventilation problem. You will need a regulated air flow in and out of the spray area. Technically, clean filtered air "in", and a proportionate evacuation. In addition to that, figure a dust free area to boot.

If your conditions won't allow that, you could go to wipe on, or brush on finishes. Spraying outside will eliminate the "confined area" problem, but also presents other obstacles which could affect your finish, like airborne dust/particles, bird poo, or moisture (if the project can't be moved). I can't emphasize the use of effective respirators. In a confined area, what is sprayed stays airborne for quite some time, meaning the headgear should be on longer than desired, or that you should remove yourself while it settles on anything in the area.
.

[cgallery]

Thanks Cabinetman. New to spraying, I had no idea what to expect. I was only using a water-based finish but I stopped because I was uncomfortable with the prospect of breathing the finish.

I've had much better luck with rattle cans. They don't seem to produce the cloud atmosphere that the Critter did.

[wbsettle]

That sounds like a lot of PSI for such a thin liquid. Did you adjust the height of the liquid nozzle in front of the air outlet? The more the liquid nozzle sticks into the air stream, the better the siphon and more material drawn.

I've only run Rustoleum Hammered paint and Xylol thinner for cleanup through my Critter so far. Finally settled on a PSI around 37 with the liquid nozzle tip in the middle of the air outlet for the unthinned paint. I didn't notice the atomization you describe...I actually had much less particulate bouncing back and landing on the floor than when I used a rattle can version of the same Hammered paint...now that was a nasty cloud. It took quite a bit of experimenting to find the combination of PSI, liquid nozzle height, and distance to target to get the Rustoleum to behave like I wanted. The nozzle height seemed to be the most critical variable. At my paint settings, the Xylol cleaner, which seems thinner than Polycrylic to me, still didn't atomize.

-Brent

[cgallery]

That sounds like a lot of PSI for such a thin liquid. Did you adjust the height of the liquid nozzle in front of the air outlet? The more the liquid nozzle sticks into the air stream, the better the siphon and more material drawn.

The nozzle seemed set dead-center right out of the box. The manual said that would give me maximum flow.

One thing I should mention was that I didn't have much finish left and perhaps that was a contributing factor. I would say I only had enough to cover the bottom 1/4" of the siphon tube.

I will experiment a little more with water and see if I generate the same sort of cloud. At least I don't mind breathing some water (this time of year it isn't a bad idea, my house is pretty dry from the forced-air heat).

I will say that I did finish the project this morning w/ a rattle can and it didn't produce hardly any overspray. I am hoping I can get the Critter to work as well.

[Jeffrey Schronce]

We have to remember that the Critter is not a HVLP sprayer, thus over spray and the cloud is to be expected. Even with water based product you need to get proper venting going on. Also an upgrade to a better spraying waterbourne finish wouldnt hurt either.

[cgallery]

We have to remember that the Critter is not a HVLP sprayer, thus over spray and the cloud is to be expected. Even with water based product you need to get proper venting going on. Also an upgrade to a better spraying waterbourne finish wouldnt hurt either.

Stupid question, but why do rattle cans work so well? Does the propellant allow them to work like a HVLP sprayer?

[dkhoward]

Um, I dont want to be alarmist here, but if you are working with any kind of aerosalized material (even spray can paint) and you aren't wearing the best breathing protection you can afford, you are taking your life in your own hands.