Spray booth (Greatdane) - Page 2 - Scroll Saw Woodworking & Crafts Message Board

Ben · 08-06-2008, 03:44 PM

Quote:

Originally Posted by greatdane2

Ben how long are you going to spend cleaning the sides and top of that booth. And are you using a bathroom fan?

Alan.

I don't spray paint much. I use it for the lacquer fumes and such so it stays pretty clean. The fan is an in-line 6" vent fan.

Ben

greatdane2 · 08-06-2008, 03:50 PM

Thanks for the reply Ben. The government auctioned off a Level 2 Bio-Containment work station last week. Would of made a killer spraybooth, it went for around $120. The only problem was it weighed over 800 lbs. Tad bit much to get off the truck on this end.

Alan.

greatdane2 · 09-17-2008, 06:16 AM

Ok, I'm a bit confused.(be nice) I worry that just using an exhaust fan to pull the paint and fumes out of the spray booth will also draw in more dust. Would it not be better to make a room and forcing air in though a filter and then putting another filter to clean the exhaust.

Alan.

Jim McDonald · 09-17-2008, 11:35 AM

Alan,
If the fan is properly sized for the environment (size of booth) it probably will not pull any material off the floor into the material. Provided, or course, that you allow the dust in the air to settle a bit prior to spraying.

A fan will be much more efficient in the pulling mode than pushing. You can better control the air flow with an exhaust set up. If you really wanted to do it to totally minimize potential for contaminants, a enclosed box similar to Ben's with an inlet high on the box filtered and the outlet low in the box would seems to minimize the potential for stuff getting into the cavity. Just be careful not to overload the fan by putting too dense a filter in the inlet and choking the airflow.

My opinion--for what it's worth.

Pajaro · 09-17-2008, 11:49 AM

My paint booth.

greatdane2 · 09-17-2008, 06:46 PM

Thanks Jim, Pete play nice.

Alan.

merlin7 · 09-17-2008, 08:31 PM

Pete, are you too close to Okalahoma?

JohnB · 09-17-2008, 10:36 PM

G'day Alan,
I don't seem to have much of a problem regarding dust on the sprayed items.

As Jim has pointed out, the fan is to shift volume, and so wont stir up dust.

The ideal way is to have the fan in the roof of the booth and ducted outside.

BTW, put a shield over the outlet, you don't want to blast over spray all over the neighbours car LOL

I just fixed a tin box over the outlet on the outside wall with the open end facing down

greatdane2 · 09-17-2008, 10:59 PM

OK, thanks. I allways seem to get dust on my finish and thought the forced clean air will help. Your way seems a lot easier John, so will do that.

Alan.

jim_mex · 09-27-2008, 05:00 AM

Hi Alan - At last a chance to give you some advice! As I'm a ceramic engineer, spray booths and spray booth problems are part of my bread and butter !

Without going into loads of suggestions - many the other guys have already made make lots of sense- I can at least confirm that the design of any booth is critical in that it should pull air in at a healthy rate, this might sound obvious but you would be surprised how many booth don't!

You can easily check if a booth is working with a smoking oily rag or similar so you can see the exhaust pulling the smoke into the booth. this should always be done with a mock up of a piece to be sprayed and you standing in a spraying position and actually spraying air or paint into the booth - remember that the fan not only has to pull new air into the booth but also remove that you put in when spraying.

If it looks like you arent getting enough smoke pulled into the booth try restricting the size of the front of the booth - for example a you could fit an adjustable sash or guillotine window type shutter on the top of the booth which can be lower a little to improve the suction. Similarly, wings fitted to the sides can help to better channel the flow into the booth.

If you cant improve the flow this way then you probably need to a) increase the exhaust fan speed . If its pulley driven this is not to difficult to do. or b) install a bigger fan.

Its also important when selecting a fan to check its an exhaust fan and not a normal ventilation fan as the blade pitchs are different which affects the pull

I'd also look to having the fan in the back wall of the booth and not in the roof. so you are extracting closer to the piece you are spraying

Regarding the idea of a pressurised clean room - this is actually not such a daft idea. I know of one local carpenter who does french finishing in what is basically a plastic tent kept under pressure from a filtered air ceiling fan. The entrance is a plastic strip curtain door for easy access and since using this system his dust problems have disappeared - or at least are kept outside. Similary, this system is common in decorating and screen printing rooms in ceramic factories

I lot more can be said on this matter but I reckon best is for you to shout if you need specific help/advice

Cheers
jim

09-17-2008, 11:35 AM	#14
Jim McDonald Sawdust Maker Join Date: Jun 2008 Location: Muncie, IN USA Posts: 1,127 Blog Entries: 9	Alan, If the fan is properly sized for the environment (size of booth) it probably will not pull any material off the floor into the material. Provided, or course, that you allow the dust in the air to settle a bit prior to spraying. A fan will be much more efficient in the pulling mode than pushing. You can better control the air flow with an exhaust set up. If you really wanted to do it to totally minimize potential for contaminants, a enclosed box similar to Ben's with an inlet high on the box filtered and the outlet low in the box would seems to minimize the potential for stuff getting into the cavity. Just be careful not to overload the fan by putting too dense a filter in the inlet and choking the airflow. My opinion--for what it's worth. __________________ Jim If it cannot be fixed with a hammer--must be an electrical problem. "Political Correctness is a doctrine, fostered by a delusional, illogical minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end." Last edited by Jim McDonald; 09-17-2008 at 11:36 AM. Reason: spelling error

09-17-2008, 11:49 AM	#15
Pajaro Going back to who I am. Join Date: Jul 2007 Location: How can you have fun in a place where dogs aren't allowed. Posts: 2,129 Blog Entries: 1	my booth My paint booth. __________________ Pájaro Pete Hombre del pájaro www.pajarostudiowns.com Member " Scrollsaw Association of the world " Excalibur EX-21 fanatic One of the Chosen few "If you play with things that can eat you, you're going to get eaten" (Tarzan) . "

09-17-2008, 08:31 PM	#17
merlin7 Member Join Date: Jul 2008 Location: Graham, Wa Posts: 55	Pete, are you too close to Okalahoma? __________________ Merle

09-17-2008, 10:36 PM	#18
JohnB 1 Tin Soldier Rides Away Join Date: Sep 2007 Location: Kalgoorlie, Western Australia Posts: 5,198	G'day Alan, I don't seem to have much of a problem regarding dust on the sprayed items. As Jim has pointed out, the fan is to shift volume, and so wont stir up dust. The ideal way is to have the fan in the roof of the booth and ducted outside. BTW, put a shield over the outlet, you don't want to blast over spray all over the neighbours car LOL I just fixed a tin box over the outlet on the outside wall with the open end facing down __________________ Regards John "The Golden Mile" Clowns to the left of me, Jokers to the right, here I am, Stuck in the middle with you. Some of my Stuff Retired Medically Unfit WA Police Officers

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08-06-2008, 03:50 PM	#12
greatdane2 Senior Member Join Date: May 2008 Location: Vancouver Island, BC. Canada Posts: 2,298	Thanks for the reply Ben. The government auctioned off a Level 2 Bio-Containment work station last week. Would of made a killer spraybooth, it went for around $120. The only problem was it weighed over 800 lbs. Tad bit much to get off the truck on this end. Alan.

09-17-2008, 06:16 AM	#13
greatdane2 Senior Member Join Date: May 2008 Location: Vancouver Island, BC. Canada Posts: 2,298	Ok, I'm a bit confused.(be nice) I worry that just using an exhaust fan to pull the paint and fumes out of the spray booth will also draw in more dust. Would it not be better to make a room and forcing air in though a filter and then putting another filter to clean the exhaust. Alan.

09-17-2008, 06:46 PM	#16
greatdane2 Senior Member Join Date: May 2008 Location: Vancouver Island, BC. Canada Posts: 2,298	Thanks Jim, Pete play nice. Alan.

09-17-2008, 10:59 PM	#19
greatdane2 Senior Member Join Date: May 2008 Location: Vancouver Island, BC. Canada Posts: 2,298	OK, thanks. I allways seem to get dust on my finish and thought the forced clean air will help. Your way seems a lot easier John, so will do that. Alan.

09-27-2008, 05:00 AM	#20
jim_mex 'Senior' member - no way! Join Date: Sep 2008 Location: Pachuca, Mexico Posts: 2,393	Hi Alan - At last a chance to give you some advice! As I'm a ceramic engineer, spray booths and spray booth problems are part of my bread and butter ! Without going into loads of suggestions - many the other guys have already made make lots of sense- I can at least confirm that the design of any booth is critical in that it should pull air in at a healthy rate, this might sound obvious but you would be surprised how many booth don't! You can easily check if a booth is working with a smoking oily rag or similar so you can see the exhaust pulling the smoke into the booth. this should always be done with a mock up of a piece to be sprayed and you standing in a spraying position and actually spraying air or paint into the booth - remember that the fan not only has to pull new air into the booth but also remove that you put in when spraying. If it looks like you arent getting enough smoke pulled into the booth try restricting the size of the front of the booth - for example a you could fit an adjustable sash or guillotine window type shutter on the top of the booth which can be lower a little to improve the suction. Similarly, wings fitted to the sides can help to better channel the flow into the booth. If you cant improve the flow this way then you probably need to a) increase the exhaust fan speed . If its pulley driven this is not to difficult to do. or b) install a bigger fan. Its also important when selecting a fan to check its an exhaust fan and not a normal ventilation fan as the blade pitchs are different which affects the pull I'd also look to having the fan in the back wall of the booth and not in the roof. so you are extracting closer to the piece you are spraying Regarding the idea of a pressurised clean room - this is actually not such a daft idea. I know of one local carpenter who does french finishing in what is basically a plastic tent kept under pressure from a filtered air ceiling fan. The entrance is a plastic strip curtain door for easy access and since using this system his dust problems have disappeared - or at least are kept outside. Similary, this system is common in decorating and screen printing rooms in ceramic factories I lot more can be said on this matter but I reckon best is for you to shout if you need specific help/advice Cheers jim