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4 hours ago, habu2 said:

While a bigger fan will help it will only magnify your airflow distribution problem. You may need to "chamber" your airflow paths so that the fans only pull from the periphery of the base.

What more could I do to "chamber" it ? Everything going thru the filter holders gets drawn up the booth back thru a chamber which narrows near the top where the fan is.

Steve

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Airflow is proportional to pressure drop.  Your design doesn't have a constant pressure drop across the filtered area, the pressure drop is greatest at the rear and goes to near zero at the front of the filter.  This is demonstrated by the airflow results you observed.  (this is not a criticism of your design)  To equalize airflow across the filter you need to increase flow resistance where pressure drop is greatest and have less flow resistance where pressure drop is low.  Your filter has an airflow resistance that is rated in pressure drop per unit area, so by having less filtered area at the back and more area at the front you can equalize flow rate. (electrical analogy: think of pressure drop as voltage, airflow as current, and filter area as a resistor)

 

In English: Make a mask to control airflow rates.  Take a piece of cardboard the size of your filter(s) and cut holes in it, a small one at the back and a larger one at the front. If you want airflow in the middle of the filter cut a medium size hole there.  You can have several different size holes from front to back.  The idea is that filtered area of each hole gets proportionally larger as they are farther from the back. Get some stick incense, light it and hold it near the different sized holes while the fan is running to judge the airflow rate through that hole.  This will be an iterative process, and you may go through several pieces of cardboard (and incense).  If you need more airflow cut a larger hole.  If you need less airflow use tape to block off the hole.  Start with a single row of holes until you figure this out, then you can cut more holes by repeating the pattern left/right across the filter.  The holes can be circles or slots (or stars or octagons or....) what is important is the size (area) of the hole.  And remember, the area of a circle is proportional to the square of the diameter of the hole. For a given pressure drop a 2" dia hole will flow 4x as much as a 1" dia hole.  Once you finalize your design you can cut a clean "master" mask for your booth.

 

Try this before you buy a bigger fan.  You may find that, with reduced filter area, your current fan will be adequate. Hope this helps.

 

.

 

 

Edited by habu2
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I was on my phone last night so I had no graphics capability.  Whipped this up quickly on the PC this morning just to kinda put words into pictures.  This is just conceptual, not dimensional.

 

MASK2.jpg.69f7f17f4850c14d87bb545b67a38144.jpg

 

edit: with some clever placement you can offset the pattern such that by flipping the mask over you can double your filter life.  :thumbsup:

 

MASK3.jpg.18c8fd632b098d7988bb5cb3f4de3a63.jpg

Edited by habu2
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I've been using a similar design for a while now. My design has the fan directly underneath the filters (automotive HEPA filters) and there really isn't as much suction as I believe there should be, so I'm gonna look into a similar pattern as well. Thanks for the explanation habu2!

 

On another note for the actual inside where the painting will take place. Think about painting the inside a medium gray (or even dark gray) instead of leaving it white. It is tough to see the paint coming out of an airbrush with that white background. Seems like the correct color for light all around but it really makes it tough to see regardless how much light is there. I've experimented with different shades of gray surrounding and darker is better.  

 

Cheers

Larry

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Thanks habu, those pics helped.

Did as you suggested by making two cardboard pieces for the filter holders, one for the left and one for the right. I came in 1" off of all four sides of the cardboard and started at the booth front. I made a row of 3/4" holes ( largest hole punch I had ) across the front edge. Then using the anemometer, I took readings. Then I measured 1 1/2" up from the tops of the first row of holes and added a second row and, so on, checking each row with the meter as I went. I then turned my attention to the LH side filter holder and started adding holes just like the RH side piece. By this time it was dinner and tomorrow is another day to get back on it, will see where we end up.

 

Steve

 

(edited)_IMG_7461.JPG?width=1920&height=1080&fit=bounds

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The new fan arrived late yesterday so, today I was able to get it fitted to the booth. Luckily there wasn't a lot to do to get the new one to fit the space where the old one sat. I needed to make a new spacer block, the part that mimics the fan shape, because the bolt pattern to attach it to the fan was different. I also made a new gasket to go between the fan and the spacer block, I was able to reuse the gasket that goes between the spacer and the booth back. Now I can get back to working on getting the baffles figured out.

Steve

 

(edited)_IMG_7466.JPG?width=1920&height=1080&fit=bounds

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I've reached a stopping point on the booth until I can get the bench built and, the exhausting details finished. Once that is completed I can see how the booth performs and see if any additional work needs to be done with the baffles before I make the permanent ones. The numbers we recorded were almost perfectly symmetrical side to side so that's good news. I also got a roll of filter material ( MERV 5 ) instead of actual filters, much cheaper.

Steve

 

(edited)_IMG_7467.JPG?width=1920&height=1080&fit=bounds

 

(edited)_IMG_7468.JPG?width=1920&height=1080&fit=bounds

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  • 1 month later...

We are certainly in some strange times these days. I never thought I'd have a issue procuring some 2 x 4's but, it seems they are tough to get. Hopefully I'll be able to find some soon so I can get the bench built for the booth.

Steve

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Article in my local paper about a builder who will no longer build 2-story homes in his housing development due to a shortage of building supplies, specifically lumber. 

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It’s bad. Really bad and only going to get worse.  I just finished my bench/booth yesterday. I started out with two sheets of MDF and one sheet of 3/4 ply.  I went back a week later for more lumber and the stack of MDF was sold out. Who the heck is using that much MDF?
But here’s my final project.

 

I9fNUp.jpg

Edited by Scott Smith
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For all of you that airbrush inside the home, how well does your booth vent fumes outside?  Any complaints from the family?

I use a Peace Maker booth in my garage, but I also typically spray acrylic lacquers, which produce strong/harmful fumes.  The only bad thing about the garage is that it is very hot in the summer and freezing in the winter, so airbrush sessions are not always comfortable. 

 

Regards,

John

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5 hours ago, vonjhn68 said:

For all of you that airbrush inside the home, how well does your booth vent fumes outside?  Any complaints from the family?

I use a Peace Maker booth in my garage, but I also typically spray acrylic lacquers, which produce strong/harmful fumes.  The only bad thing about the garage is that it is very hot in the summer and freezing in the winter, so airbrush sessions are not always comfortable. 

 

Regards,

John

 

I have a Peace Maker as well that I use in my basement.  I have it vented to the outside.  I typically spray acrylics, but occasionally shoot Alclad.  I also prime with Gunze or Tamiya primer.  I run the Peace Keeper a minute or two before I start spraying, and let it run 5-10 minutes after I'm done.  I've not had any complaints about odors or fumes since I started using it.

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See that window to the left of my bench?  I’m going to cut a piece of wood about 10” tall and install a dryer vent in it.  Simply raise the window and close it on the board. 
 

when I was at my last home there was no way to vent to the outside and it was very annoying. Overspray dust settled on everything, winter painting was worse since I could not open the garage doors outside my shop.  I’d spray something and leave the room.  Never really had a problem with fumes getting upstairs. 

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14 hours ago, Scott Smith said:

It’s bad. Really bad and only going to get worse.  I just finished my bench/booth yesterday. I started out with two sheets of MDF and one sheet of 3/4 ply.  I went back a week later for more lumber and the stack of MDF was sold out. Who the heck is using that much MDF?
But here’s my final project.

 

I9fNUp.jpg

That’s a very nice and organised looking workplace 

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16 hours ago, BastianD said:

That’s a very nice and organised looking workplace 

Thanks.  But give me time.  I’ll turn it into a natural disaster if I’m not careful.  Just pulling all my tools out of the boxes have me wondering how and where I’m going to put them all.  

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On 4/12/2022 at 1:43 PM, RichB63 said:

Steve, that’s quite an impressive project. Thanks for sharing your work here.

Thank you, it's a long overdue project that's for sure. I just wish I could get materials to get it finished.

Steve

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  • 2 weeks later...
On 4/8/2022 at 11:33 AM, vonjhn68 said:

For all of you that airbrush inside the home, how well does your booth vent fumes outside?  Any complaints from the family?

I use a Peace Maker booth in my garage, but I also typically spray acrylic lacquers, which produce strong/harmful fumes.  The only bad thing about the garage is that it is very hot in the summer and freezing in the winter, so airbrush sessions are not always comfortable. 

 

Regards,

John

😬 Been airbrushing in a 10x11 room at a desk near a window for about a year.  no ventilation. just open the window and set up some cardboard for the overspray.  Maybe I should get a little fan to bring in some fresh air hahaha

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  • 3 weeks later...

Not a criticism but is the base stable?  A few well placed diagonals (or shear plates) would stiffen it up without much effort.  

 

.

Edited by habu2
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4 hours ago, habu2 said:

Not a criticism but is the base stable?  A few well placed diagonals (or shear plates) would stiffen it up without much effort.  

 

.

 

Very stable.

Steve

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