HomeBrew Fluid Bed (Pics)

[Brandon Jennings]

A simple project to build really I used a 4" to 3" reducing coupling for the base, I sealed the bottom of the base with a 4" plug (actually not intended to be used with the coupling but it worked great...because the plug was re-cessed in the bottom of the base after I siliconed it in place). To serve as the "cup" I used a 4" to 3" sewer and drain reducer, which fits snugly into the Coupling opening. Between these two is where you place a filter ( most use coffee filters or paper cut outs from a brown bag) then secure the two fitting back together.

It works!..but I got them dang ole Volcanos ya'll talk about..even with the brown bag material. I only tried it for a short time..I will work on it more tomorrow. Maybe I can regulate the air flow and find the right combination to work with the filter.

I would appreciate any tips or if you have any information that may help me. I want to say thanks to all who posted the great idea on the homebrew versions of this thing. Here are the pics:

[Uncle Grump]

Tree

Volcanos are a fact of life w/ some powder paints, as I am learning.

I did my first bed w/ 2" dia. cups, w/ Fl Yellow powder and brown shopping bag paper, it was picture perfect - the paint looked like boiling water. It went down hill from that point - using white and black paint. I am told that "heavy" paints like black are a problem no matter what you do.

I've since tryed a smaller pump - my original was for 30 to 60 gal. aquariums, have dropped down to one for 10-30 gal tanks.

Other things to try/look at:

1) Multiple valves - I've got a cheapy turn button valve that came w/ the pump ahead of the refrig ice maker valve on the bed - allows for course and then finer air flow adjustment - this has helped alot w/ the white paint.

2) All papers are not alike - I've heard of others using coffee filters - it didn't work for me, they seemed more coarse (porus) than the shopping bag I was using. Have also tryed:
- office paper
- other shopping bags (one shopping bag I found had a "polished" finish) - others
were tighter (less porus)
- the photo reprint envelopes from Sams Club

I have tryed stacking sheets of paper one on top of the other - this has helped along w/ other varieties of paper.

Some shopping bags are "tighter" - less porus. On a another forum, a poster suggested bags for vacumn cleaners. Not had a chance to try that.

3) You might try changing your bed to a wider base. I started at 2", have one under construction that is 3" - this will double the space which the air pump has to put pressure against, thus reducing the overall air pressure on the powder.


Using the formula: area = radius squared X pi (3.1416)
2" dia pipe = 1" radius. (1 x 1 = 1) x 3.14.16 = 3.1416 sq in.

3" dia pipe = 1.5" radius. (1.5 x 1.5 = 2.25) x 3.1416 = 7.06 sq in.

This is the reverse of the venturi principle used in the carburators of gas engines, where air is drawn thru a smaller opening to increase the pressure.

4) Try using just enough paint in your cups to cover the paper, and then ajusting the air flow - so that you can see easier when it wants to volcano. Adjust the air up just enough that you see the powder start to move, then add more powder and re-adjust. I did this w/ white and using two valves, I got a picutre perfect boil. But it is alot of futzing. Sadly, the white setting didn't work with the black.

The last time I played with black, I ended up w/ the air set to produce a minimum volcano, then shook the cup as I dipped my jigs - these turned out fairly.

Last - after investing a fair amount of $ and time to make one (now 2) of these, I've actually done more jigs just dipping the jig straight in to the paint container, not even using the bed.

Pumps vary, valves vary, papers vary - even the humidity in one house to the next will vary. Keep playing - all you can do.

UG

[Fatman]

I've researched making these through 5 different fishing boards and I may just stay with dipping in the bottle the paint came in and use the money I'd spend on the PVC and pump to buy more paint and hooks.

I get a few paint bumps and that's only in black.

Fatman

[wardsmit]

I have made several of these for myself and others with the pvc...i also have had better luck with the 2" but have a large one for larger items like bigger jigs slabs etc. I also use air brush. Prior posts are correct in that all paints are not the same. Especially the ones with glitter. I have the best luck with the diffusion of air into the cup but also a "t" set up that I can bleed off pressure if i need or close for full pressure. Have it working satisfactorily and on some it looks like a pool of flowing water. It takes a bit of practice and I am always trying to do more than I should or I would make notes as to which colors need which pressure and diffusion. Bottom line is that i usually end up with some great painted items