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Uncle Grump

Another volcano question :(

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All

I put the fluid bed together using Cadman's tutorial. Used 2" PVC, a 10-30 gallon aquarium pump (Wal-mart), the refrig water valve, brown paper bag as the membrane material. Cups are just shy of 3" tall. Made 3....

Am using Janns Netcraft paint (so far), white, black, and fl. green.

Cup 1 - Fl green - worked perfect - boils nicely - cool I thought!

Cup 2 - White - major volcanos - adjusting valve doesn't seem to help.

Cup 3 - black - volcano - 1 spot - but really shoots the powder. thing.

I searched the forums using 'volcano' and 'volcanos fluid' - read those posts.

Added some balled up TP to air chamber - not alot of differance. Am now in the process of adding a second layer of bag material to these cups - using Elmers woodworker glue as adhesive on these.

I cut my pipe on my table saw - using a 32T carbide blade. If I may ask - how did you guys cut your pipe? At least on the black cup, I am wondering if I have a nick on on the edge of cup.....will see what the second layer does. Blade may have been a touch low when I cut them....

Any other suggestions?

Many thanks

UG

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UG,

Your second layer may help, but sometimes just changing the paper will solve your problem. Paper bags are not made to the highest standards. If the volcanos are not shooting paint all over the room I don't worry about them. Paints are different consistancies and react differently. On some colors like white I give the whole bed a shake just before I dip. Hope this helps.

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UG,

Volcanos are usually caused by a weakness in the membrane. For the paperbags, it could be a thin part in the bag or a little tear. For the plastic membranes, it could be a pin hole in the seal around the bottom. Like Basseducer also stated, different colors/brands of powder paint will act differently in the fluid beds. Black, white, brown, and some of the darker colors are heavier than the lighter colors. In your case with the black and the white, the air is not being difused and evenly distributed through the bottom of the cup so the air is looking for the easiest way through the paper bag (thinnest part) and causing your volcanoes. Hope this helps.

Thanks,

Benjamin

www.tjstackle.com

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Thanks for the responses.....

The 2nd layer of paper helped w/ the white cup - but I have to crank the air down to next to nothing - as a result - only the center 'boils'. The black still flys all over the place....and still in one spot - so I am leaning toward having a slight nick on the edge of that cup.

I mis-posted this morning w/ regard to my pump size- the pump I have is for 30-60 gallon tanks. It has two outlets - I was using one, had the other plugged. Even when I remove the plug and let it run un-impeded - the black paint flys.....To to much pump/air?

Dayooper - You mention plastic membranes - could you explain further?

Thanks again

UG

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UG,

The commercial fluid beds use a hard plastic membrane specifically designed for powder paint applications. It is designed to diffuse the air to get an even flow and it is very expensive. I believe the black paint is flying because the air is traveling through the paper without much resistance. How is the chartreuse green working for you? The lighter colors especially the Pro-Tec candy colors work wonders in the fluid beds.

Thanks,

Benjamin

www.tjstackle.com

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Fatman:

I have tryed coffee filter material - if any thing, its more porous than the brown paper bag I was using. We don't drink coffee at home, so I snitched one from the coffee club at work - don't know if the brand of filter would make a differance.

All:

I spent some more time on this over the weekend. I did the following:

1) Went to a smaller pump - this one for 10-30 gallon aquariums vs the 30-60 I had. Smallest I could find.

2) Put a second control valve on the line from the pump to the bed. This is a cheapie (plastic) that came w/ the pump.

3) More experiments w/ paper and the cups. I took a file, and made sure the edge of the cup was smooth and flat - no burrs from cutting the pipe etc.

a) Made a new bottom for the cups using 20# printer paper vs the brown shopping bag - paper is much finer.

B) Added additional layers under the printer paper - held in place by friction between the cup and base. Tryed coffee filters - as Fatman had asked - no go.

c) Had a Sams Club photo reprint envelope - paper is fine grain and dense / heavy - this did make a differance.

d) Had a shopping bag from a local store. Brown paper, but lighter and smoother grain - not coarse like original shopping (grocery store type) bag.

4) Using the printer paper (glued), the fine brown paper bag, and the Sams Club envelope helped the most w/ the white and black.

I don't know why I thought of it, but using the paper stack in 4), I added just enough white powder to the cup to cover the printer paper, then turned on the air, and started fiddling w/ both valves - used the plastic valve as the coarse control, the brass valve as a fine control. The valve adjustment was to try to reduce the volcano's to the point were I could no longer see movement (spurting powder), I then would add powder, and slowly opened the brass valve until I would see movement. Repeating this process, I enventually had an entire bottle of white powder in cup at nice rolling boil - and no volcanos. It was rising a inch in height easily - from air off to air on.

Sadly, this same combination of pump, valve settings and paper stack did not work w/ black. The best I have been able to do is about a 1/8-3/16" rise in the powder (regardless of amount of paint in the cup) and "fine" / low height volcanos - they spray powder, but it's not flying all over the bench top. Have also found that shaking the bed/cup (as Basseducer suggested) helps - but its not going to be easy to shake and dip jigs at the same time.

Am also in the process of re-creating the bed using 3" PVC vs the 2" I started with. The 3" PVC will increase the surface area the air has to push on, and should decrease the air pressure / velocity against the paper layers.

Did not have time to test the Fl Green w/ the air settings that worked for the white.

UG

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I have had great results using cut up vaccum cleaner bags. They are designed for air to pass through, but prevent dust to pass. I glue them on with yellow carpenters glue and trim flush with the O.D. of the cup.

You don't need the expensive ones, you can by the cheap-o's and they work great. They are more sturdy than coffee filters, or paper bags, and distribute the air evenly across the cup, very few, if any volcanoes, air adjustment is one of the keys to a good finish, but with the vaccum filters, it seems that it takes far less air to get the powder rolling.

Hope this is helpful

Dan Wadsworth Sr.

Old Hippy Brand Jigs

wadsword@live.com

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