Finishing Booth

[John Reeves]

LOML wants high gloss black finish. I tried a brush and proved that that was a poor choice. I built this booth and I have a HVLP gravity feed spray gun.

:eusa_clap

As you can see on the left side I tried to learn to spray. I mixed lated with latex paint conditioner, Flowtrol, and the dilution was 50%. I still got a lot of splatter. How do I get rid of the splatter?

Any suggestions?

Also, if any one wants to use the booth, come on over.

John

 

[Gofor]

From the pictures, it appears your gun is not capable of spraying as heavy a coating as latex, or your air pressure is too low. Latex paint by its nature is high viscosity and hard to atomize. Takes a lot of air pressure and a large spray head/fluid tip assembly. That's why most house painters use an airless system (paint compressed to 1500 - 3000 psi), and then many still backroll with a regular paint roller to even it out.

For a high gloss black finish, you will probably have better luck with a lacquer. Another option would be to spray with a flat or low sheen black lacquer or spray bomb paint, and then overcoat it after it dries with a high gloss clear finish of your choice. Using the flat or low sheen coating will eliminate any need for sanding which would probably be visible through the clear overcoat. Try a test sample first.

Question: is the black paint you are planning to use a latex? If not, you will find that different types of coatings spray differently and require a different set adjustment on the gun.

On a positive note, it looks like you are getting a good straight stroke as you spray. Because of the lousy spray pattern of the latex, it is hard to tell if you are overlapping your strokes about 50%. For a consistent thickness, you want to start on the top or bottom edge with only half the fan pattern hitting the surface, and the progress down or up the piece overlapping the strokes approximately by 1/2. This will give the best uniform thickness of coating over the entire surface.

JMTCW
Go

 

[Jim M.]

Nice booth John, what are you using to move your air? Jim

 

[DaveO]

:5badair:


Sorry, I couldn't resist, I've been wanting to use that smilie for a long time :lol: :lol: :lol:

Dave

 

[John Reeves]

I am learning how to do this. I turned up the air and got comgortable adjusting the air and marerial flow to get a good coverage. The panel on the left has two coats of Kils. The other ones only have one coat.

 

[John Reeves]

The fan is a HVAC fan that I salvaged. The booth is collapsible and I can use the fan for shop ventilation during the warmer months.

I will put a switch for the fan and soon to be added lights so I left the high speed connection short. Currently, I just use an extension cord. The switch is for low and medium speeds that I use for moving air in the summer months.

 

[Jim M.]

Nice job John, at some point I'm going to have to make a booth myself. I've been using an old EZ-up tent next to my shop with home-made tarp for sides and a box fan stuck under one side to move air. Thanks for giving me some ideas, Jim

 

[NCPete]

psst, hey, John, I know where you can get some more lights! :lol:

 

[McRabbet]

John,

Nice looking rig, but DO NOT spray any solvent-based products into this booth -- the HVAC fan motor is in the airstream and could easily ignite flammable vapor in a heartbeat! It's motor is an open frame, continuous duty motor that has exposed brushes -- it is NOT explosion proof, which is required for spray booths. The filters you normally install in the rear frames will not stop the flammable vapors, so be cautioned: PLEASE ONLY USE WITH WATER-SOLUBLE, NON-FLAMMABLE FINISHES!

Rob

 

[woodguy1975]

John,

Sweet spray booth dude!

 

[sapwood]

Cool setup up John :icon_thum
And a good job on improving your work environment . . . first air filtration unit and now paint/fume exhaust.

Roger

 

[John Reeves]

Thanks Guys!! Rob, I am aware that this is for water based only. I know it is NOT set up for solvent based material. That will have to be an upgrade using a fan that is belt driven among other things.

It does a pretty good job of keeping what little over spray that have out of the shop. (I have the exhaust blowing through a window that I open.) I even use a respirator.

My test of how well it is working is how much paint I get on my glasses. For you spectial wearers, you might be able to identify with this. So far I have not gotten any spots on my glasses. I have only had two drips/runs (and my glasses work fine so I can see!)

If any one needs it, feel free to come and use it.

 

[chris99z71]

My test of how well it is working is how much paint I get on my glasses. For you spectial wearers, you might be able to identify with this. So far I have not gotten any spots on my glasses. I have only had two drips/runs (and my glasses work fine so I can see!)

FWIW, did you see Bruce's thread about the dryer sheets?

 

[John Reeves]

I did not see that thread. Thanks Chris

 

[McRabbet]

John, My caution was aimed at anyone that reads the thread so they don't build one and use solvent-based sprays in it -- I was sure you wouldn't have mis-used it, but it needed to be said in the interest of safety... BTW, it's a great looking booth!

Rob

 

[John Reeves]

No prob. Rob. I need all the help I can get all the time.

 

[Jim M.]

Thanks for looking out for us Rob, sometimes it's what goes unsaid that can hurt the most. I'm enjoying all the new low VOC, water-borne formulas on the market now, especially Defts clear finish. Just completed a remodel of the 1/2 bath outside of our master BR and zero smell from the paint - wife was overjoyed. Thanks again, Jim

 

[woodydiver]

Hello all,
i have to agree and disagreee with a couple of things said about the fan used on the spray booth.

I agree that an explosion proof motor would be best but dont stop at the motor. The fan would also have to be made of something other than steel to keep from rubbing together and causing sparks. Typically the fan blade would be aluminum to keep from sparks. dont forget also that any light switch or other switches can cause sparks and ignite the solvent.

Also, from what i have read and have been told, dont some water based products have alcohol ?

You could put the fan outside the wall, pipe the vapors into the inlet of the fan and directly vent the output outside. This would isolate the motor more from the vapors, but still would not be explosion proof.

I disagree about the comment that the motor had brushes. If the fan and motor came out of a house hvac unit, the motor should be a Permanant split phase motor. you can tell if it is by looking for the Oil can capacitor, oval or round silver can. These motors have no brushes, or mechanical switches to cause sparkes.

You also have to be careful in using these types of fans because the need a certian amount of back pressure. If you dont load the fan enough, the motor and overheat and burn up. It would be a good idea to check the current draw after it is running , and compare it to the motor nameplate.

A standard single phase motor has a black round capacitor and an internal mechanical switch that kicks in and out at about 2/3 speed. (larger motors may have a black capacitor and an oil can capacitor) I would not recomend using these motors because of the big spark emitted during switching of the cap's.

Typically the only motors with brushes should be power tools, vacuums, routers drill and etc. (called universal motors because they can run on single phase ac or dc).

Thanks,
curt

 

[John Reeves]

Curt,

This fan has an oval capacitor mounted to the metal fan shroud. Now, what does that tell me?

John

 

[woodydiver]

hello john and all,
If the motor has an oval capacitor it just means it doesnt have brushes. i cant tell by the picture if the motor is direct drive or belt driven, which would determine if you could completly isolate the motor from the fan intake and exhaust by redirecting the air flow through the fan only. If the airflow did not go through the motor, there would be less of a chance that the motor would be a problem and all you would have to worry about is the fan blade material and any other source of ignition.

As far as the overall safety, it is better than the other types of motors i mentioned eariler, but we all know explosion proof is the best choice.

I have read a couple of articles in some wood working magazines talking about the issue of fans and spraying finish. ill have to find the one and post it.

i didnt want to cause any confusion,
curt