Fine mist sprayers
 

Need some ideas on spraying a liquid material onto an object with fine mist. because of trade secrets, I really can't say what I'm spraying, but I can say that it's an acid type material.
The pray bottles I've been using are leaving a splattered pattern...the droplets are too big.
So, I'm looking for a fine mist spray bottle with a trigger action or something similar.
I've considered using an airbrush to be able to control the spray fineness, but am pretty sure that anything made of metal would be destroyed pretty quickly...

What's the acid?

Kinda need to know what it will/won't eat to offer advice.

Check PM...

There are plenty of acid resistant plastics available. Teflon coated plastics are the first thing that comes to mind but I also thing Polyimides could also resist acid. If you need some life on it that is one thing but if you only need a temporary solution than that is a snap.

Can you use a fume hood and apply by vapor instead of by spray?

Not really having a problem with acid resistance here...the bottles I have seem to hold up pretty well and not deteriorate at all. It's just that, in many cases, the spray patterns are too blochy and not very consistent.

Here's an example of something reasonably consitent with a decent spray pattern...



http://forums.pelicanparts.com/uploa...1291751487.jpg

Think these types of units are mostly plastic. Cheap enough to be a disposable cost if you plan your production runs properly.

Amazon.com: Spra-Tool Aerosol Spray Paint Gun: Automotive

Amazon.com: Preval Complete Spray Gun: Home Improvement

Spra-Tool Power Pack Aerosol Spray Pain Gun

Used to use Muradic acid. Got away from that becasue it rusted everything, and I wasn't able to apply the specific wear patterns you see above.

We have a bunch of experience in spray and atomization - we have a aerosol filling line and have product in aerosol cans ranging from solvents to heavy grease. The things that influence patterns are pressure, orifice size/shape, viscosity, base material, delivery gas (propane, butane, heptane, CO2...) and carrier solvent/diluent for starters. Thats a several dependent variables to monkey with. That actually provides a bunch of opportunity to get it done. I think you may have to go with a very smal orifice(s) and use higher pressure.

Right... I thought you were going for uniformity, but I see what you did there.
So, +1 to what Lube said. For best atomization, small orifice at high pressure.

ultrasonic nebulizer

If you are doing small parts you might try fuming instead of spraying the parts. I used this method to age some guitar parts and it turned out pretty well.

Again, I used to fume using Muriadic acid, but with the fuming I could not "direct" where the fumes went. It covered the entire part. I you look at the picture above, there are some portions of the part that are less aged than other...the spray is dispersed so it blends somewhat

One consideration is a flat spray tip used for spraying agricultural chemicals. You need the tip, spray body, hose, and small pump. Several websites detail chemical/product compatibility. It all depends on how much you want to spend and how meticulous you wish to be.

mcmaster.com would be a great place to browse.
jurgen

I get what you're saying. Maybe you could spray on some sort of masking material to the areas you don't want aged. It might be easier to to spray varnish or laquer in the fine spray pattern than acid. I have never done that but its just a thought. Maybe get hold of Vince Cunetto at Vinetto guitars. He has done tons of these kinds of ageing processes. He might share with you.
JMPRO