Building open fronted spray booth. What filters?

[Roger440]

As per title, im going to put one together.

Loose plan is, i have a large extractor fan. Designed for use on roof of industrial building. Fan is circa 2 ft diamter with a serous motor attached. I used to use it at my old place mounted in the wall when spraying. It moves some serios air!

I intend to mount it on a pallet and build a box effectively, so i can spray components (bits of car), with the air being pulled through from the front, through the fan and out through a filter.

Or may be with filter in front of the fan. Not sure?

Something like this, but for £50, not £1500! https://www.ebay.co.uk/itm/Alloy-wh...117580?hash=item2f3c89a90c:g:rKoAAOSwh0BeIEKd

My main unknown, given 2K will be involved and it wont be exhausting to outside all the time (sometimes it will) is what filters. Clealy i need a primary spray booth filter, but not clear what charcoal/carbon filter i should be using behind this?

Thoughts?

 

[Parm]

If your not exhausting externally 100% of the time it’s not worth doing

filters don’t knock out 2K

 

[mtt.tr]

Just buy a premade booth. Im happy to try to make things, but a spray booth and extraction aint one of them

 

[Parm]

Just buy a premade booth. Im happy to try to make things, but a spray booth and extraction aint one of them

nothing wrong with making your own, it’s not that complicated. But all exhaust Air must be vented externally.

put the dirty air back into the building and you may as well not bother with the booth

see this mistake all the time. We call them recirculating LEV. Complete waste of time, effort and money

 

[mtt.tr]

nothing wrong with making your own, it’s not that complicated. But all exhaust Air must be vented externally.

put the dirty air back into the building and you may as well not bother with the booth

see this mistake all the time. We call them recirculating LEV. Complete waste of time, effort and money

My concerns have always been pumping paint fumes out to my neighbors.

 

[Parm]

My concerns have always been pumping paint fumes out to my neighbors.

and this is the problem. To do it properly you have to do a D1 stack height calculation taking into account local topography to ensure adequate dispersion

the simple becomes complex when you do it properly

even the likes of the big car plants with massive production spray booths don’t have any exhaust filters

 

[mtt.tr]

and this is the problem. To do it properly you have to do a D1 stack height calculation taking into account local topography to ensure adequate dispersion

the simple becomes complex when you do it properly

even the likes of the big car plants with massive production spray booths don’t have any exhaust filters

Friend has a booth in his barn, paid to have it all set up. When hes painting youd have no idea he has an exhaust filter was serviced few weeks ago

Went past a proper spray shop few weeks could smell it from a good 200yards away

 

[pedrobedro]

The ones at the boiler factory where I worked years ago had a recycling water curtain where the overspray was drawn through and used to settle it in clumps to be cleaned out every so often.

 

[Parm]

The ones at the boiler factory where I worked years ago had a recycling water curtain where the overspray was drawn through and used to settle it in clumps to be cleaned out every so often.

yep, a wet back laminar flow booth. Common in production painting. Way better than using pre filters

 

[mtt.tr]

What happens with the water @Parm

 

[Parm]

What happens with the water @Parm

It recirculates in the system, dosed with biocide to control legionella. SHOULD be disposed as contaminated waste

 

[Roger440]

If your not exhausting externally 100% of the time it’s not worth doing

filters don’t knock out 2K

Hmmm. I thought the whole idea oif the charcoal/carbon filters is that they DID remove the 2K. Why are they used at all?

 

[Roger440]

Friend has a booth in his barn, paid to have it all set up. When hes painting youd have no idea he has an exhaust filter was serviced few weeks ago

Went past a proper spray shop few weeks could smell it from a good 200yards away

I assume this still exhausts outside though?

 

[mtt.tr]

I assume this still exhausts outside though?

yes buts its prefiltered

 

[Parm]

Hmmm. I thought the whole idea oif the charcoal/carbon filters is that they DID remove the 2K. Why are they used at all?

I’ve never seen any type of filter used to knock out 2k

 

[mtt.tr]

I’ve never seen any type of filter used to knock out 2k

im sure 3m lit offers filters that work against 2k

But thenis unlikely to be spraying more likely foam and glue

 

[Parm]

im sure 3m lit offers filters that work against 2k

But thenis unlikely to be spraying more likely foam and glue

This is what 3m have to say about filters for isocyanates

https://multimedia.3m.com/mws/media/777847O/isocyanates-3m-techupdate.pdf

 

[Roger440]

I’ve never seen any type of filter used to knock out 2k

Thanks. I think my take might differ from yours in as much as, the right filter (activated carbon) will stop 2K, but, there is no way of knowing when its "overloaded" or reached the end of its useful life. ie, the exact same problem with the disposable catridge masks that almost every painter in the land is fond of. I guess you could work out the life with the right gear etc, but thats simply not practical in the real world.

So, if we accept that as a given, i have out my thinking cap on.

Knocking a hole in the wall of someone else's building isnt going to happen. Nor do i want this thing permanetly parked somewhere (hence on a pallet).

So, ive modified the design such that the exhaust will now be the full widith of the pallet, but only about a foot high. That way, i can plonk it in front of the roller shuitter, bring the door down to the top of the exhaust, and knock uo a couple of plywood infill panels either side to block off the gaps each side of the spray booth.

Everything exhausted to outside, no need for anything other than a regular paint booth filter to capture the overspray.

Job jobbed i reckon. Will post pics when done.

 

[RichardM]

Will your exhaust be to a public thoroughfare?

 

[Ali]

recirculating LEV. Complete waste of time, effort and money

just in the case of 2K, or other fume?