Exhaust set -up for spraying -Advice please

[Peter36]

When I moved into my basement workshop I set up a canopy with a 12" exhaust fan - the biggest I could fit and I set up corflute sheets around it to form a spray booth . works reasonably well but still leaves a dusting of dried lacquer over everything . I was thinking of spraying facing the open garage door with a couple of fans behind me . Has anybody tried this ?

Peter

[Harry72]

Probably need to build(sealed)in three sides and install a lazy susan to rotate the object to paint all sides.
Or if you can shift the hood to a corner of your workshop, then make a 2 peice wall that hinges in the middle and then hinge 1 edge off a wall, that way while its not being used you can just fold it out of the way!
Should make it to be totaly enclosed and have a filtered inlet, on one of the movable partition walls you could install a door for your access. This will allow you to still use your workshop while the paint is drying... nothing worse than having to pack up for the day because of wet paint!
You'll need some form of lighting that is fume proof, some peices of perspex as windows for external lights to shine thru cut into your hood, may work.(fume proof lights are worth mega $$$)

Has that 12" exhaust fan got a completely sealed motor, if not your flirting with fire(pun intended).

[journeyman Mick]

If that fan motor isn't totally sealed and sparkless then a fire isn't your greatest worry, an explosion is. :eek: Imagine a room full of solvent fumes at the right fuel/air ratio and a little spark inside the fan motor. A large instant "flashover" which may burn you and sear your lungs, if you don't die from the burns you'll die from your lungs being toasted.

Mick

[echnidna]

The fan motor can be isolated from the fumes and also separated from the airflow path by using a anti flashback mesh which will prevent flashbacks. Sorry but I don't recall the size of mesh needed to do the job.

The other failing with your current setup is that the exhaust outlet is above your workspace. It should be as low as possible and behind the workspace. The reason being is that the droplets are heavier than air and tend to fall.
Lifting them with a fan will increase the overspray mist landing on your work.

[Peter36]

Thanks all for the comments and advice . I will have to extend the duct intake down to floor level and devise an easily demountable enclosure . The canopy also serves to remove floating dust particles which was the reason for mounting it at ceiling height .

Bob. Any ideas on where to start enquiring about that mesh

Harry . What's Port Pirie like these days. I remember it as an 8 yr old when I lived with my Grandparents in Broadway Road ??? and used to walk across the salt flats to Pirie West Primary . But then Grandpa died and the war finished and my father came home and we left Pirie .

Peter

[Sprog]

The fan should be on the inlet side giving a slight positive pressure to the spray booth. Exhaust to outside atmosphere. No fumes will find their way into the motor. The outlet should also be filtered.

[Harry72]

There was salt flats?
No salt flats there anymore its all old house's, gee you have been away for a while havent you!
Yeah not a bad little town, until you go shopping for woodwork stuff... I guess your lead(Pb)in blood level would have dropped by now?

[echnidna]

Peter, you could try worksafe for info.
I recall the mesh was much finer than flywire.

[DarrylF]

Peter,

What about just hanging poly tarp from 3 edges of the hood to form a 3-sided room when needed? Easy to pack up, cheap, adjustable and the hood would still do the dust extraction thing when it's not a spray booth.

[Peter36]

There was salt flats?
No salt flats there anymore its all old house's, gee you have been away for a while havent you!
Yeah not a bad little town, until you go shopping for woodwork stuff... I guess your lead(Pb)in blood level would have dropped by now?

And I always thought I was a naturally slow learner .... now I can blame the lead .