Building a spray booth - extractor fans

[HammerUK9]

Hi guys,

I've been putting together a homemade spray booth, and have finally reached that awkward point where I have to sort out an extractor fan. Now, I've pretty much decided to use high-flow computer fans as they tend to have brushless motors, and as an almost exclusive 'proper' acrylic user, I feel the system should be safe enough.

Now, do I use a single fan of 120mm diameter in the middle of the booth (510x380mm), or two side by side to even out the airflow? And if I use two, then can I exhaust them into a single duct?

Opinions welcome (in fact, required!)

Tim

[Black Knight]

I would put one each side of the rear panel, towards the edges, so not in direct path of paint as it were. Then use flexible tubing from each to a Y joint, then a single tube to your exit area. Perhaps your main particle filter in the fork of the Y. I would also put a smaller tube joining the two arms of Y, to even out the pressure.

F

[Jens]

You'd need a very, very high concentration of thinner even without a brushless motor to make it dangerous.

Jens

[HammerUK9]

Thanks Black Knight - I can visualise what you're saying and will give it a go

Tak Jens - that's reassuring

[BrianI]

Looking forward to seeing the finished article, Tim. I've often considered fettling together a spray booth.

Does yours extract outside via ducting?

[Rick Brown]

Hi guys,

I've been putting together a homemade spray booth, and have finally reached that awkward point where I have to sort out an extractor fan. Now, I've pretty much decided to use high-flow computer fans as they tend to have brushless motors, and as an almost exclusive 'proper' acrylic user, I feel the system should be safe enough.

Now, do I use a single fan of 120mm diameter in the middle of the booth (510x380mm), or two side by side to even out the airflow? And if I use two, then can I exhaust them into a single duct?

Opinions welcome (in fact, required!)

Tim

I need to make one chap, any chance you can show us how you did it and where the idea came from?

How about a "WIP" then a "Ready for inspection"?

Rick the engineer..

[Abacus]

I have a 4" xpelair with ducting, flange and exhaust for the window if you want. Will post a pic later. Aidan

[jettnett2003]

I need to make one chap, any chance you can show us how you did it and where the idea came from?

How about a "WIP" then a "Ready for inspection"?

Rick the engineer..

Look here http://www.britmodeller.com/forums/index.php?/topic/53785-diy-spray-booth/

And here http://www.militarymodelling.com/news/article/homemade-spray-booth/3661/

Edited November 27, 2013 by jettnett2003

[Rick Brown]

Look here http://www.britmodeller.com/forums/index.php?/topic/53785-diy-spray-booth/

And here http://www.militarymodelling.com/news/article/homemade-spray-booth/3661/

Cheers!

Rick.

[Mike]

I found the extractor fans to be a bit weak, and eventually went with an extractor hood (from a kitchen) mounted on my bench upside down, with a rough furniture board booth built around it and a strip-light mounted in the cut-back roof. The hood is vented outdoors, and works bloody well

The hood was £30 from Wickes, and the board was only a couple of quid. I didn't have the energy to do a tidy job of the cutting, so just left it rough. Doesn't look lovely, but it does the job

P.S.Despite what some people might tell you, I've not managed to blow myself up yet by the fumes being lit by an "unshielded" motor. How much trouble would the manufacturers be in if their hood ignited gas from a hob?

[mollythedog]

Yep, like Mike, I have been using a cheap extractor mounted in a white melamine box,connected to the outside using normal 100mm plastic drain pipe,the bends and angles are pre shaped,simple. Gaffer tape over any joints you want to keep loose for cleaning,or just glue using the pvc glue.Works great, change the cheap foamy paper filter every 3 months. I didn't have the clever idea of mounting mine at the bottom,which would really suck up all the paint and fumes,but will do that next time.

Been using it for more than 10 years,will cellulose, enamel, acrylic without any issues. I added an old record platter from an abandoned hi-fi for extra chic and it spins beautifully with a nudge,allowing around coverage.

Cheapskates rule!

Cheers

mtd

[HammerUK9]

Golly, this thread's really taken off!

OK guys, I'll treat you to a WIP of the booth

Like some others here, I've also used Klaus Raddatz's webpage as the basis for designing my own booth, and here it is in it's current state:

Using a cardboard/paper mockup and some guesstimation, I decided that a 20 x 15 x 15" (508 x 381 x 381mm) booth would be sufficient for my needs. I got a bit lazy, so I set these as the external dimensions rather than the internal ones. Using a tip from Klaus' design, I built a 2 inch plenum chamber into the base to help even the flow out. I also wanted to include a grid that I could rest the booth's filter elements on top of.

Materials used:

6mm plywood (bought from Wickes, £8.something for an 8' x 2' sheet - not bad)

11mm plywood (had some hanging around, used as battening in place of 10mm strip wood)

Panel pins (& appropriate hammer )

Bondloc contact adhesive

Front corner:

All joins were first glued with the contact adhesive and then reinforced with panel pins. I'll fill them in in due course.

Rear corner:

The rear vertical battens were made from 10mm strips of 11mm plywood.

And here's the grid:

The plywood around the edge was used to simultaneously batten the sides and support the grid. The edging strips are 30mm high, so that the top edge sits 15mm below the 2-inch mark - there's a reason for that....

You can see in the back corner, there's a gap between the vertical batten and the edging strips. This gap is....you guessed it, 15mm. This is so that I can lay the filter elements across the grid, and then fit a wooden square (which is tight to the booth edges) on top to pin them down tightly.

Here the grid is from some more angles: it simply consists of 10mm plywood strips connected by halved joints. Each strip fits into a slot cut into the edging plywood.

From below:

And again:

And here's the booth with a couple of 1/32 aircraft sitting on a makeshift floor to give some idea of working area

Can you tell what it is yet?

Hope that's interesting enough so far

Tim