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We have a dust problem in our finished surfaces. As soon as the finish is applied and even during the spraying process, dust particles settle on the surface. It is approximately 1 particle per square foot. So far, we have blown off the entire spray room and let the dust settle. Then the spray booth where scraped and coated with booth liner. New booth filters where installed. The floor was well cleaned. However there is no improvement. We have an air makeup with wire mesh filters. There is always positive air pressure in the finishing room. All the sanding and rag tagging is done outside the finishing room. All carts and materials are blown off before entering the finishing room. The workers believe that there may be too much air movement caused by the air make up unit blowing into the room. Any suggestions? Thank you for your input.
Try spraying water on the floor.
We replaced our three air make up units filters feeding our spray room with Merv 10 pleated filters outside ... and also put a layer of spray booth media wired to the bottom to catch big stuff...and had our ducting into the room redesigned to hold Merv 8 filters... it's a pain to replace the filters outside ... requires changing every 6-8 weeks but the feed air is clean! we also have drives on the spray booth motors to turn the fans down to make sure we have plenty of positive air in the room.... any dust we have is just from being unclean elsewhere... you guys wearing tyvek? amazing how much lint comes off your clothes... we also buy plastic sleeving on a roll from Uline and replace it very often carrying our paint hoses.... you can really get a lot of trash just from handling your hose while spraying
Are you sure that the problem it ins't from the paint, gun or fluid tube?
I am not sure that there is no problem from the spray system. However, we have it whether we spray from a cup gun or airless/airassist. All spray material is filtered before being used. We will install a new fluid line, fluid filters 100 mesh for the pump filter and 200 mesh for the gun filter.
We found out also, that we have a lot less particles in the finished parts if they are hung instead of flat finished.
Does anybody have experience with blowing pieces of with de-ionized air. Does it make a difference?
Thank you for all the feedback and food for thought. I will keep you posted.
Did you try to wet the floor with water before spray?
I did not try water on the floor. How much do I put on it? Can it cause blushing due to higher humidity? Thank you for your input.
Just a light coat with a regular spray bottle
One of those garden sprayers used to apply fertilizer works quite well. I was intrigued by the comment from one of your finishers that their might be to much air movement.
It looks like you have quite a large finishing area. With all the "surface areas " where dust can accumulate, its possible that when everything is up and running...the dust that's sitting on that surface area is being kicked up and making its way onto what you are spraying.
If that duct line with the 3 grills up by the ceiling in your second photo is the air make up unit then take a look at the inside. Even if there is a filter on the intake end there is probably still dust on the floor of the duct. I'd suggest pulling a grill off and swiping the duct floor with a rag to see what you get.
Could be a waste of time but shouldn't take long to find out.
I think that Robert has keyed into something important, the size of the finishing room. You have at least two open face spray booths. There's overspray and not 100% of it is going to land in the booth filters.
Air currents and vortices, you are still likely to have airborne dust from your atomized spray and also from the lint on everyone's clothes.
I think, also, that your workers who say maybe there is too much movement of air are also on to something.
You might explore the possibility that a positive pressure room has it's own problems and instead try some strategies to have a more dust free environment by having access points that are more air tight with stricter controls over who enters and leaves and how they ingress/egress your spray room.
Wetting the floor helps. While 90% humidity might be too much, 45% humidity might be way too dry for purposes of dust. Try 75% humidity and hopefully that's enough moisture in the air to weigh down the dust that forms and prevent other dust from forming, a byproduct of static electricity.
Thank you all for your feedback so far. We had our finishing material supplier come in and he pointed out air movement against his neck and the fact that the walls where likely not cleaned for a long time. Therefore, we will shut down the finishing room for a day and clean down from top to bottom. We are going to brush off all the walls, cabinets and all surfaces. We are in process of getting filters installed in the air make up and get Tyvec suits. I hope this will get results. Thank you for all the feedback so far. I will keep you posted on the progress.
noticed in 2nd picture the insulation on ceiling.
get yourself a good magnifying glass sometimes help identify dust.
Get a really high intensity light, shut off the shop lights, and fire everything up. You should be able to move the high intensity light around and see the dust particles in the air and possibly where there are coming from.
The first thing that I noticed is all of the horizontal piping and scaffolding hanging from the ceiling directly in your airstream. Its got chain, 2x framing lumber, pipe.
All of these surfaces will collect tons of dust. When you turn on your system it will aerosolize all of those super fine particles.
It looks like it might swing? Everytime you place something on it or bump it, you will knock more dust into the air.
Stand up there and blow on it. If you can move it with your breath, then the system will definitely move it.
I would rethink that whole setup. Only vertical wire no chain. Try to get all of the piping above the airstream.
Figuring out contamination problems in a spray booth is the bane of most shops at some point. Good luck.
from what I understand the only way to completely solve the problem is with an enclosed down draft booth. Otherwise you have too large of an area to try to sterilize
jonathan, do you think there is an option of fitting factory filtered doors on the face of their existing booths ?
there would be no room to operate
Hi everybody. First of all thanks a lot for all the responses. On our Graco airless/airassist system, we installed a new fluid line that was not changed for 1-1/8 years. We also changed filters to 100 mesh at the pump and 200 mesh on the gun. On the old fluid line, we constantly changed from white paint to conversion varnish to precat to sealer to primer. This system is now dedicated to clear finish material only. These changes alone removed most of the particles.
We received the Tyvec suits and will shut down the finishing room for at least a day to clean. What is the best method for cleaning the walls and ceiling. I was told that vacuuming is not an option due to the explosion hazard so for the moment we think of brushing them off. I just wonder if we not just moving the dust and it will settle elsewhere?
I liked the idea with shining a strong light in the room to see how much dust is floating around.
Thanks again and I will keep you posted.
wipe the walls with damp rags or a mop
Take the filters off of the out take. Use a compressor hose to blow the dust off of everything. Let the fan suck it out of the spray room. Do it a twice so you don't miss any spots.
The less air you move, the less dust you'll have.
Is there a paint out there that I can use on the wall that will attract less dust? Thank you!
We had a similar problem on a much smaller scale. What we discovered was the air was so dry (10-20%) that static electricity was causing the dust to attract to product. Our solution was spraying water on floor and walls and intake filters. We don't seem to have as much as problem when the humidity is higher. (20-40%)
Hi Martin, check with your coating suppliers for a peel-able booth coating. It's used for coating the inside of the booth. When the need arises,just peel it off and re-apply another coat.
I suppose you could apply it to the walls as well, one Company I worked for used to coat the P-Lam counter tops and cabinet ends prior to shipping. These were projects that were shipped overseas.
It may have been overkill but, the preventive measure worked at the time.