My Spray Booth Construction

[thibaultron]

Started a new thread about the construction of my spray booth. I started detailing it on the “What have you done today” thread, but figured that that was to much info to clutter it with.

 

I’m going to put the earlier postings in with the date I posted them, then continue in this thread. So the beginning may be somewhat choppy, stick with me.

[thibaultron]

2/15

Today I had an epiphany. I've been shopping around for a fan to use in a spray paint booth. I'm going to be using acrylic, so "explosion proof" is not a neccessity, even if I could find one. The internet sites say 500 CFM.  Seems a bit high, but start there So, I've been looking at the squirrel cage type with the motor outside the case. Non explosion ones on Ebay with ~150 CFM go for about $60 US. I next thought of using an old dryer blower and motor. Used driers are about $100. I stopped and asked about broken ones at the local places, $35 or more.

 

 

Then I remembered the old electric leaf blower that has been dragging around my shop for 6 years, that my wife bought at a yard sale. Squirrel cage, motor  outside the blower housing, and lots of CFM. I think I have a volunteer!! I'll probably end up building an outside box to house it, to cut down on the noise, but for now construction can begin.

 

After some discussion, about 500 or 600 CFM being way too much flow,  I found a 250 CFM blower on Ebay, and bought that. The leaf blower idea, though, did get me moving on construction.

 

2/15

 

The trouble with the regular hood and bath fans is that the motor is in the air stream, and the vapors (if solvent type) can deteriorate the insulation. The squirrel cage hood fans run about 30 to 50 CFM, too low.

 

You can get new SC fans with about 130 CFM for $60, but if that is not enough, I've wasted the money. The leaf blower is rated 600 CFM. If that is too much I can ramp it down, to find the right value. A 500 CFM new fan runs about $150.

 

A drier runs about 130 also, if I can find a free one, I can try that later.

[thibaultron]

2/16

 

After looking at a few spray booths, and plans, here is what I'm planning on building. The top has a cutout for a light, I'll put plexiglass in the opening. The top hinges up so I can have more access to the top of the model, or to clear masts, if needed.

 

 

The front lip will also be a plexi piece. I think I'll use plastic wrap as an inside cover to both clear parts. I can strip it off and replace it, when it gets coated.

[kurtvd19]

Ron:

The photo below is of the Badger Air Brush spray booth - the fan is 165 cfm.  It is more than adequate for the 13" x 18" size of this unit.  There are times I do not turn on the fan because the air movement draws the paint away from the object being painted.  Using only acrylics, so turning it off isn't a big deal. 

 

I think you may be overpowering the spray booth with the 250 cfm unit but with the depth of your unit being so deep, moving the object out and away from the rear of the box might be the answer to too much air movement.

 

I used 4" metal duct off the fan to go up from the fan, over to the center of the unit - past the motor - and then down.  I secure a nylon stocking over the end of the metal duct to catch any over-spray that isn't caught by the filter in the unit - and some does get by.  Being acrylic, the stuff that gets by the filter is dry particulate and is caught in the piece of stocking.  Also, the Badger paints are virtually odorless so I have never been encouraged by the ADMIRAL to exhaust to the exterior.

 

I like the design you are using and the plexi panes are a nice addition.  Look for a 2' led type light for the top - the more light the better.  I added a light to the top of the Badger unit that is just outside of the front of the box.  This is OK as most of the time my work sits just outside the front of the box anyway to have access to the part being painted, but your location is the optimal location.  The 165 cfm fan in the Badger unit is entirely adequate to catch the over-spray and pull it to the filter so you won't have any problems if you bring the object forward.

 

You will probably want to get a turntable of some sort.  I use the one by Tamiya and every so often I drop it into the paint remover to clean up the top turntable surface.  I have a larger turntable but it's finished wood so I cover it with a piece of newspaper so it stays clean - when it's not being used in the spray booth it sits on the table where club members use it to access the snacks during meetings.

 

Following with interest.  Be sure to let us know how the unit works.

 

Kurt

[thibaultron]

2/17

 

After going over my drawings one last time, and finding a few errors, I started construction on my Spray Booth.

 

 

I've cut out all the plywood, and ripped a 1 X 6 into 3/4" strips. The strips are for the corners, to strengthen the joints.

 

Here is a picture of the sides, with the strips glued and nailed on. The ply is warped a little, so all the clamps are to hold the glue strips on solid, until the glue dries. I'll let them sit overnight, and do the rest tomorrow, when I the clamps are free.

 

 

The glue strips are sitting over at the left of the ramp. The rectangular arrangement of strips are for the filter mount and blower bulkheads. Most of the case is 3/8" ply (I would have preferred 1/2", but I had the 3/8"). The blower bulkhead is 3/4", as I felt the 3/8" was too thin for this. The notch on the larger end of the one side is a lap joint in the plywood. The ply is 3/8" exterior siding.

[thibaultron]

2/18

 

Today I glued the corner strips to the bottom of the spray booth.

 

The booth will ultimately reside on a table with casters, so I can move it around. I have an old table top, that will be used for this.

 

As I mentioned before the plywood is warped. I don't have deep enough clamps to get to one of the internal corners. So I decided to screw the bottom to the table top, in the position it will be at. This flattened the ply.  In addition I temperarily screwed the corner pieces down also. I'll remove all the screws when I go to assemble the booth.

 

Here is the bottom screwed to the table. I'm left handed, thus the offset to the right. The left hand area will be for storage of the airbrush equipment.

 

 

Next I laid down the sides in alignment with the bottom, so I could position the internal corner pieces correctly.

 

 

Then I glued and screwed the pieces in place. I found that even with the bottom piece screwed to the table, the screws in the corner pieces were needed to get them to lay down without a gap.

 

Here's the bottom finished as far as I want to go for now.

 

 

I still have to put in the piece for the bottom of the blower bulkhead, but I'm going to do that after the sides and bottom are assembled. Less chance of having it in the wrong spot, if the sides are not perfectly aligned. A good seal here is essential.

 

I stopped here to let the glue dry overnight.

[thibaultron]

2/19

 

Today I glued the sides onto the bottom of my spray booth.

 

Before I start, for my mother should she ever read this. Yes, shop horrible mess, you raised me better, suitably ashamed. Sorry. :-)

 

I started out dry fitting them. The filter frame will not be glued in today, but it is being used as a jig to keep the sides square, and correctly oriented front to back. It is tight against it's glue strips which are already attached to the sides.

 

 

I disassembled the parts and marked the bottom of the sides for where the long strips mated to it. Then I drilled 1/16th pilot screws through the ply. The purple paint was put on by the lumberyard. The panels were damaged, so I got them for 70% off. The paint is how they indicate to the cashier that this is the case. The damage was to the lap joint notches, so didn't affect this use.

 

 

After putting the side and frame mount back in I installed the screws. Starting in the middle, due to warp in the plywood, I drilled the pilot holes through the glue strips and ran in the screws. Then, naturally I installed the other side.

 

 

I found that both sides bowed in, so I had to clamp the filter mount in firmly, and put a screw in to hold it in place.

 

 

I mistakenly installed the glue strips at the back of the booth to the side pieces, so I couldn't put screws in from the bottom, with everything screwed to the table. I used my two long clamps to hold those two joints tight to the bottom. Tomorrow, I'll remove it from the table, put in screws, and reattach it.

 

 

One side at the back was twisted in, so I clamped it from the side, another reason the two glue strips should have been attached to the bottom first.

 

 

The strips and ply come out to 1 1/8" thick, and my screws are 1 1/4" long. When I'm done, I'll go back with a motor tool and cut the ends flush.

 

 

 

[thibaultron]

Kurt;

 

If I find that the suction is too great, I'll either sell that blower, and buy a smaller one, or build a new booth the full 39" width of the table. The construction has not been too bad thus far, other than lugging my heavy 10" miter saw in and out of the shop.

 

This booth was built with mostly stuff I had around the shop, but a bigger one should not cost more than $50, with the ply and 1 X 6 board for the glue strips.

 

One thing that I am going to add, after viewing another booth build on YouTube, is a cover for the front, when I'm not using the booth. It will keep the dust out between uses.

[thibaultron]

I just did a little more drawing, and a 36" wide booth, for a 14X30 filter, could be made from a single 4X8 plywood sheet. I think a 1/2" thick sheet would be required, not the 3/8" one I used.

[Jaager]

From a strictly theoretical OP and no background reading:

 

When using water based solvent -

you need air flow to pull the over spray to the back - but not so much 

that the actual spray is affected?

Would one or more DC computer cooling fans produce enough negative air flow?

 

How about using used corrugated cardboard boxes as raw material for the structure?

Three layers glued up with PVA is fairly strong and 1/4" - 1/2" sticks can re-enforce 

the corners.  LED lights do not weigh much, so a strong structure is not needed to

hold them up.  The joins could be duct tape so that it could be stored flat and not

take up much room.

[kurtvd19]

The airflow works for any spraying media - if the airflow is too strong the paint doesn't get to the object because it's drawn to the fan.  I have no idea if the cooling fans would work or not.  As I related before the 165 cfm unit I have sometimes is too strong when doing fine detail work and I turn the fan off.  The size of the booth matters as 165 cfm might well be totally inadequate for a larger booth.  I have been in automotive spray booths that made my hair stand up - but they also use a lot more pressure to the spray gun.  As I seldom use over 20 psi the airflow easily disrupts the paint spray.  If one routinely sprays with higher pressures I am sure a higher cfm exhaust fan would be needed so the spray doesn't escape the booth.

 

With the work involved I wouldn't try to use cardboard.  What you describe could work but if being able to fold it up is the important part why not use ply and piano hinges instead of duct tape?  I once used foam core to make an overhead soft box for photography - light weight, duct tape to hold it together.  Wound up remaking it with light ply when the duct tape kept coming apart - the adhesive doesn't last forever.  The foam core version proved the size worked and I used the pieces as patterns for the plywood version but for the effort I would have been ahead of the game just using the plywood to start.

 

LED lights are sure the way to go today. 

 

Ron - I think regular 3/8 plywood would work for the bigger booth.   Maybe the outdoor version you used has more flexibility than regular 3/8 ply because of the thinner areas between the "planks"?  The difference in weight between 3/8 and 1/2 inch is considerable.  Using the corner bracing/gluing strips really beefs things up.

 

Kurt

[thibaultron]

Today I worked on the filter frame and the sloped back piece.

 

When I was assembling the sides, the filter frame broke along one of the "plank" joints. To fix this and reinforce the other joints, I glued two glue strips on each side at the back of the frame. I also didn't notice when I was cutting it out that the siding lap joint was along one side. Rather than cut a new one, I cut a section of the matching lap off the other side of the ply. Unfortunately, it fell into several pieces! I went ahead and glued the large pieces to the frame. The red circle is the break. There was enough of them to supply a firm seat for the glue strip along that side. Here is a picture of all the parts clamped together.

 

 

Because the filter will be sitting against the front of the frame, I countersunk for the screw heads, before I installed it. I'll go back when I'm done and countersink the screws along the bottom, so that they don't damage the table surface.

 

 

I glued and screwed the frame into place. I drilled the pilot holes into the glue strips, after it was in place. This allowed me to fine tune the position.

 

 

 

I marked and trimmed the 45 degree angles at the top and bottom of the sloped back. I found that my cutting of the parts was not as symmetrical as I thought, but I got it all to fit.

 

 

The warp of the sides is causing the top tips to close in toward the inside. To get the correct measurements for the back I had to brace them apart. One of the glue strips for the blower well cap and a square came out to the right length for this brace.

 

 

I clamped one side down flat and screwed in that side of the back, then I flipped it over and did the same for the other side. With the holes ready for the gluing, I removed the screws, clamped the first side back down, applied glue and screwed it back together. The other side followed. Then I cleaned up all the glue that got squeezed onto the table top while I was installing the screws.

 

 

 

When marking up the back, I found that the blower housing cap, is 1/4" too short, to match the sides.

 

 

 

The blower wall is 3/4" thick, so I'm going to go with the present cap. I keep repeating to myself, "It's a spray booth, not a piece of cabinetry."

 

The cap will not be glued to the booth. I'm going to make it removable so I can work in that area, if I have to, in the future.

 

This is all the permanent assembly I can do right now, I've run out of screws and glue! The blower should be here by the end of the week, so I'll work on mounting it to the 3/4" ply wall.

[thibaultron]

Kurt;

Your right 3/8" should work, it doesn't have to carry more than it's own weight.

 

I see what air flow I get with the blower. It should be here by the end of the week.

 

I've figured out how to  mount, and plumb it. I'm planning on using 6" duct work, for the output end. Metal not flex hose. It will only have to run about 6' when in it's final place.

[thibaultron]

I found a manufacturer spec. sheet for the blower I bought, and have determined my initial design for mounting and venting it. Here is the drawing I made from it.

 

 

The blue washer I’ll explain later.

 

The inlet diameter of the blower is ~4.8”. I didn’t want to just have the mounting bolts sitting directly on the blower wall wood, I’d like to have a metal ring, to spread the weight, and keep the bolt heads from working down through the wood.

 

There is an inlet ring that has a funnel shape that comes down close to the blades. My initial thought was to simply use this inside the booth as the metal support, but then I realized that this makes a seal to prevent backflow.

 

Looking on the net, I found a 5” duct bulkhead like fitting. So I plan on having the flange of this as the metal support ring. I’ll trim the duct portion to fit so that it stops just short of the inlet ring.

 

 

Have been watching a video series where the guy did use the inlet ring inside the booth, and he had major blowback problems.

 

For the outlet plumbing, I’m going to use 6” duct. The blower outlet is about 3 1/4” X 4 1/4”, so this should give me a low restriction flow.

 

I’m not sure which of the two ways below, I’m going to use to adapt the outlet to the duct.

 

1. Fashion a round wood plug that bolts to the outlet. The duct will fit over, that then be secured with screws.
2. Use a metal end cap, and cut out the center to match the outlet.

 

 

I was leaning toward the wood plug, but the cap would be stronger, and not much, if any,  more effort to make.

 

I also found a 6” duct wall vent. Like a drier vent on steroids.

 

 

Back to the blower mount. The blower can’t just be bolted directly to the booth wall. The outlet flange would hit the wall. So it has to be held away from the wall. I plan to use a ¾” wooden flat donut, for the spacer. This will get the outlet flange just clear of the booth wall, and provide a good seal between them.

 

So the mount will consist of: The 5” bulkhead mount,(trimmed), the wall, the donut, and the inlet ring, where it is supposed to go. I was thinking of using all 8 of the available inlet ring screw holes, but just the four actually used by the manuf., should be enough. The other four are provided so that the blower can be rotated 45 deg., if needed from the holes in whatever equipment it attached to.

 

Here is a drawing of the blower mounted to the booth.

 

 

When the blower actually gets here, I’ll double check the measurements.

[thibaultron]

The blower arrived today! It was close to the drawing I had, but not exact. I'm redoing the drawings, then this weekend, I'll get it attached.

[James H]

Is the extraction unit rated for operation in explosive atmospheres?

[Canute]

Ron, is the exhaust vent going to be permanently installed in a wall? If it will, put some screen in the vent to keep squirrels and other critters out of your building. Don't ask how I know this...

[thibaultron]

James; The booth is not explosion proof, just resistant. The blower motor is on the ouside of the blower housing, not in the air stream.

 

Canute; The vent I'm going to use has the screen built in, and a flapper, like a drier vent.

[thibaultron]

For an explosion proof blower look at marine engine housing blowers, rated "Ignition Proof". There is a Coast Guard standard for them. They will need a 12V 5AMP or more power supply.

[thibaultron]

The blower came in the mail, and I compared it to the drawing I had made from the manual. Except for a few minor details they were close. The only important difference was in the position of the screws holding the inlet ring on. In the manual, there were 8 holes set square with the body. On the blower I got, there were only 4, offset by 72 deg. from square.

 

 

I waited for the blower to arrive, before cutting anything, so this wasn’t a problem.

 

I wired on a plug, and tested the blower. Kurt has a point. The blower may be too powerful for this size booth, but I’m going to finish it, and see how it performs, with this blower.

 

As I mentioned before I am going to mount it with longer screws through the blower wall, into the holes normally used to mount the inlet ring.

 

As you can see the blower cannot be mounted flush with the wall, as the flange on the outlet protrudes past that surface of the housing (lower right). To overcome this I am placing a ¾” thick plywood ring between the housing and the wall.

 

I had originally thought that I would have to have some sort of metal ring on the inside of the wall, so that the screws would have a stronger seat. After mounting the blower though, I found that there was more than enough wood surrounding the screws, to prevent them pulling through, using just washers.

 

I cut the hole for the opening in the wall, and the wooden ring out with a saber saw. I would like to give a nod to a very nice saw that I borrowed from my neighbor. It is made by Bosch. That is the smoothest running saber saw I’ve ever used.

 

Here are two shots of the pieces, and another is of them arranged as they will be when assembled.

 

 

 

 

Note that at this point, I’ve already drilled the mounting holes. I took some care in getting the cuts smooth, but I didn’t go back and sand everything to a furniture grade finish.

 

I printed out my drawing, and attached it to the wall, at the marked center of the board. I then drilled the first hole per the drawing. Then I placed the inlet ring with one hole aligned with a drill bit in the hole, and the other holes aligned with the ones on the drawing. Using the ring as a guide I drilled the other three holes.

 

I then cut out the opening, and the ring. I clamped the wood ring in place and drilled the holes through it. Luckily I managed to get them all straight through both pieces, and the screws matched the holes in the housing. I drilled them by hand, as my drill press is buried at the moment, so I was quite pleased that they all came out correctly.

 

I then mounted the blower using 2” #8 sheet metal screws, and a #8 and #10 washer under each screw head.

 

 

 

I thought I was careful in getting the blower on correctly, but notice the arrow drawn on the blower wall in the first picture. It should be pointing up. Yes, I mounted the blower upside down! I then disassembled it all and remounted the blower correctly. Normally this wouldn’t matter, but the spray booth is not entirely square, and the wall will fit only one way, and I need the blower outlet to point toward one specific side of the booth. As I’m facing the front, the outlet has to go toward the right hand side (the left as seen from these pictures looking at the back of the booth).

 

I then temporarily mounted the blower and wall to the back of the booth. I will not be gluing this wall to the booth, but attaching it just with screws. I may have to remove it in the future for maintenance. I put it in place so that I could attach the glue strip along the bottom. I waited for this until now, to make sure everything would line up.

 

Here are three shots of the blower and wall put into place, while I was doing this. These shots are with the wall just wedged in place. I used clamps to hold everything tight while I was putting in the glue strip.

 

 

 

 

You can see in the pictures that the wall is sticking out a little at the top, before I clamped it tight.

 

The next two pictures are of the installed glue strip. The first is from the front with the wall still clamped in place. The second is from the back with the wall removed.

 

 

 

In the first picture you might notice that there are only three screws installed. When I went to the hardware store I asked for 4 #8 screws and 4 #10 screws. The #10s were in case I needed a larger screw than I thought. What they gave me was 3 #8s, 3 #10s, and 2 #12s! I went back later and they gave me another #8 free.

 

One thing I forgot to do was wipe the glue where it had squeezed out! I got called out to do something else and forgot to do that. I may have to do some cleaning up of that area.

 

I initially attached the strip with a few small brads in predrilled holes (as seem in the photo). After this shot I clamped the piece in place, and screwed it in from the bottom.

 

The inlet ring is mounted against the housing (the way it comes from the manf.), not on the inside of the wood pieces. I have seen some booths where this was done. The inlet ring seals off the larger housing opening, and extends down close to the blades. This keeps the air from blowing back out this area. If you mount it on the inside of the wood, this pulls it way from the blades, and allows a large amount of blow back, into the booth, like leaving the end of the balloon open after blowing it up.

 

Next time I’m going to work on the top cover of the blower box, and install mounts for the filter.

[thibaultron]

I caulked the booth today, and re-cut the top to make the light opening larger. I also used the Dremel to cut off the tips of the screws that protruded into the interior.

 

I limited the caulking to the filter mounts, and the blower chamber. Any air that may leak in around the joints of the spray area will not have much of any effect on the performance.

 

I had planned to make the cover of the blower chamber removable, but decided that it should be permanently attached. I can access the whole thing from the blower end, as the blower wall is removable.

 

 

I caulked as much of the chamber as I could get to. I caulked both joints each glue strip made with the inside, and along the outside of the chamber cover.

 

 

With everything glued, the caulk may not have been necessary, but it won’t hurt.

 

I installed strips to hold the filter in place. I cut them so that the filter is a light press fit. If needed in the future, I will add some kind of tabs to hold it.

 

I caulked around the outside edges of the filter wall, and the outside of the filter strips.

 

 

The joint at the top of the filter wall, blower chamber cover, and sloped back, got special treatment. I filled the joint from the top, then added more along the top of the filter wall. Next I added an angled strip to fill the gap at the cover / sloped back joint. This was not glued, but set in a bed of caulk.

 

 

 

I then turned my attention to the booth top piece. I decided that I needed to make the light “hole” larger. I trimmed it so that the back and sides were 1 ½” wide, and the front 1”.

 

 

This piece will be hinged  to the sloped back using a piano hinge. The top is ¾” plywood and the sloped back 3/8” ply. I needed to cut a rabbet in the back of the piece, so that the hinge will sit properly. This is shown to the bottom of the picture, above.

 

I attached another piece of the angled glue strip along the booth top / sloped back joint. It provided stiffening to the plywood edge of the back, a seat for the top, until I install the hinge, and a slightly better seal to the joint.

 

 

The plywood used for the booth was warped, and the tips at the top front turned in. So that the top would fit correctly I added a removable brace to the front. The top is hinged so that I can get better access to the top of a model, and a permanent brace would interfere with this. I simply screwed a couple of short pieces of glue strip to the front of the booth, and the brace sits in the gap between these and the strips along the top of the side walls.

 

 

It pushes the tips apart about an inch, as can be seen when I just sit the brace on top, without forcing it in place.

 

 

This is a photo of the top and brace in place.

 

 

With just the overhead shop light shining through the top, you can see that the interior is well lit.

 

[thibaultron]

I “finished” construction on the spray booth today!!. The finished is in quotes, because it is still in the experimental stage.

 

I temporarily used closed cell weather stripping to seal the blower wall, that is why it is sticking so far out from the rear edges of the booth.

 

 

Here is a shot of the filter in place.

 

 

The filter is 10” X 20”. The top filter frame piece is screwed in from the back.

 

I’ll paint it after I test paint a model, and see how it works. Just feeling the airflow by hand, indicates that the blower may, indeed, be too strong for this size booth.

 

It may be a week or so before I can paint something, as family and work needs may interfere.

[kurtvd19]

Ron:

You might consider an extension of the booth's base out from the front of the box.  The photo is the Badger booth before I added the light.  I do all the actual spraying on the base area outside the enclosure.  The filter to front of enclosure is 5" and the enclosure to outer edge of the base is 8".  The airflow is higher the closer you get to the filter, so moving out from the filter will decrease the airflow so your blower might be just fine.  Spray water from the brush to observe the airflow at different distances.

Kurt

[thibaultron]

Kurt;

Thanks I'll try that when I can do some tests. It may be a week or so before I can do the testing.

[thibaultron]

I tested the booth today, it seems to work OK, at least with me spraying water. The water was not highly visible though.

 

Feeling the flow with just my hand, the area directly over the fan inlet seemed to have the most flow, not surprisingly.

 

I decided that I needed to spread the flow over more of the back of the booth. So I’ve added two angled baffles just behind the center of the filter. I calculated the area of the openings left between the baffle edge and the blower wall. The total area is over 3 times the area of the blower inlet, so I should not be overly loading the fan.

 

I’ll do more testing tomorrow, after the glue dries, and I reassemble the booth. I think I’ll go down to the discount store and buy some cheap incense to do a smoke test.

 

Here is a shot of the drawing, I’ll add pictures tomorrow, or when I find the camera! The green bar is the filter, and the red bars are the baffles I added.

 

[thibaultron]

I cut the baffles from some of the left over ply siding the rest of the booth was built from. They are ~4” wide, set at a 17  deg. angle toward the back.  I cut 4 short lengths of the ¾” square glue strips to add surface area for the glue. I figured that if I tried to glue just the baffles in, they would end up inside the fan. I used small brads to hold it together while the glue set.

 

Here are pictures of the baffle I added. It will probably be next week before I can test the booth again. Once again work and family needs.

 

Baffles from the back.

 

 

 

And another from the front.

 

 

There is about 1 3/8” gap between the rear of the baffles, and the front of the blower wall. This gives 35 ½ sq. inches of area in the gaps between both baffles and the wall. With about 18 sq. inches of area for the blower inlet, I think this is enough so that there will be little added restriction from the baffle addition.

 

I bought some incense today, to use as a smoke source for testing, when the time comes, then a paint test.

[thibaultron]

Was finally able to do some testing of the booth today. Unfortunately neither my camera, nor my phone give good enough video to show the testing.

 

However, here are the results:

 

1.      The 250 CFM blower is too big for this size booth, 2' X 2' X 2', but it does not suck the paint stream when I paint, so, for now, I will use it as is. If I was to do it again, I'd get the 130 CFM blower.

 

2.         The blower is also, I'm sure loader than a 130 CFM unit, but it is not objectionable. My cheap Harbor Freight compressor, on the other hand, is objectionably loud though! I need to get a long hose at put it in another room.

 

3.         The baffle I added, helped in distributing the air flow evenly across the filter.

 

4.         When I did a smoke test, with incense, there were no blowback areas anywhere in the booth. The smoke was drawn directly back in a straight stream.

 

5.         During the summer I will have a nice breeze blowing past me! In the winter, maybe not so nice!

 

6.         I think I will simply direct the output into a covered bucket, with relief holes drilled in it, for acrylic paints. There was nothing coming out the outlet, nor any smell. If I use solvent paints, then I will vent it outside. The blower would exchange the air in the shop, much faster than either my heating, or air conditioner could keep up with, if vented outside all the time. Another reason for a smaller blower.

 

7.         This size booth is a better fit for my space than a 3’ wide one would be. I have another sheet of 3/8” plywood, though, so I may build the bigger one, just to see if I like it better.

 

I have to build the table/desk next, and paint the booth. I have some aluminum flashing, white on one side, I may line the bottom with it, just to make paint cleanup easier. I also have to find a light to install in the top.

2 Like this

 

[thibaultron]

Booth Table

 

I built the base for the table today. I didn’t attach the table to it. I want to attach the casters first, and I haven’t bought them, yet.

 

I designed it for the larger 3’ wide booth, just in case. The wider booth is 28” deep plus 5” for the blower. So, I made the base 33” deep, so that the whole assembly would not be back heavy, with the blower hanging in mid air. The smaller booth comes to 29” deep. Maybe later, I’ll cut the base down, if I stick with the smaller booth.

 

Here are a couple pictures of the drawing.

 

The first is the lumber frame, without the casters. The table top is only 24” deep, therefore I made the main section of the base this deep. Happily, there was just enough of the 3/8” plywood sheet left to skin the back and sides. The bottom of the base extends past the main section to give me the 33” deep footprint I wanted. The width of the base was determined by the 35” width of the top of the remaining plywood.

 

 

In my normal frugal mode, I found a 74” long piece of 2 X 6 and a length of 2 x 4, that I ripped down to make the frame pieces. Note that the 2 X 4 also supplied the second piece “E”.

 

Here are the cuts for the plywood.

 

 

This is the resulting assembly. I ran out of long screws, and reused the pieces cut from the booth sides to attach the “E” parts. The angle was not quite the same, but it doesn’t look too bad.

 

 

I used a couple of pieces of ¾” plywood to reinforce the back corners. These were recycled from an earlier project. Waste not, want not.

 

[thibaultron]

Here are some pictures of the finished spray booth:

 

 

 

These are a couple of pictures of the airbrush mount, and the regulator mount. The short length of glue strip is there as the regulator mount screws were longer than the ply was thick.

 

 

 

 

 

I made a temporary dust cover for the booth out of a couple boxes, that I used as drop “cloths” while painting the booth.

 

 

[thibaultron]

Yesterday I modified my spray booth. When I built it I used a 36" wide table for the base. The booth itself is 24" wide. in the new section of the shop, the base is too wide, so I cut it down to 24' to match the booth. Once I get the shop arranged, I'll hinge the other 12" of the table to the booth, with a support, so I will have that surface, when I am using the booth, but it will be out of the way otherwise.