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View Full Version : Blast Cabinet Vacuum Help needed- Thanks


my58
03-28-2007, 11:06 AM
I have searched but find very little about Blast Cabinet vacuum options. I destroyed the budget on the huge compressor and blast cabinet. The shop vac I was using (shuts down from overheating) and I read on the forum regular shop vacs die easily from the dust. What are others using. Is there a economical solution? (my budget is shot) I saw HF has a pneumatic vacuum for sandblasters but I hate to waste my air running it. Has anyone used it? Any thoughts on it?

All input is greatly appreciated.

Thanks

MXtras
03-28-2007, 11:35 AM
I strongly recommend only using compressed air when you absolutely have no other option. It is an expensive way to power tools/equipment.

A cyclone with an exhaust filter or duct would be the best method. Google the net - there are several guys thet have built their own and there are plans on the web.

Scott

the dude
03-28-2007, 04:31 PM
I wrecked a shop vac by using it on my blast cabinet. I like the cyclone idea mentioned above. I was also told (and bought) special prefilters that fit over the main filter to get out all the small stuff.

I now pressurize my cabinet with my shop vac and collect the dust in a 5 gallon pail... I don't know if it works as well, but the vac has lasted.

Charles (in GA)
03-28-2007, 04:57 PM
It isn't cheap, but it IS designed for blast cabinets and will hold up. If you buy a cabinet from TP Tools, the vac comes with it. What you saved on some other brand, you will spend to get the vac.

http://www.tptools.com/dg/15_Vacuum-Dust-Collector.html

Charles

PAToyota
03-28-2007, 06:00 PM
I got one of the VAC-35 units with my TP cabinet. Added the direct mount reclaimer and the "exhaust to outside" kits. Figured I'd upgrade to one of the DC176 units when I killed the little VAC-35, but that hasn't happened yet...

Aceman
03-28-2007, 06:33 PM
Another option I've heard of is using a 5 gallon bucket partially filled with water. Drawing the suction through the water keeps the dust from getting to the vaccum.

Mikeyworks
03-28-2007, 07:49 PM
Another option I've heard of is using a 5 gallon bucket partially filled with water. Drawing the suction through the water keeps the dust from getting to the vaccum.

A water trap...that's exactly what I was going to recommend.

http://i2.photobucket.com/albums/y38/Mikeyworks/garage/waterfilter.jpg

toms73novass
03-28-2007, 07:59 PM
I tried a water trap idea and because of the bubbling of the water the tube that went to the shop vac carried water and ended up putting a gallon of water into the shop vac after about 30 min.

toms73novass
03-28-2007, 08:01 PM
What I have used and has worked well is to use a Gore-Tex Clean Stream filter for my shop vac. It blocks the finest dust and I have used the same shop vac on my blast cabinet for at least 3 years and its still going.

mike944
03-29-2007, 07:23 AM
I tried a water trap idea and because of the bubbling of the water the tube that went to the shop vac carried water and ended up putting a gallon of water into the shop vac after about 30 min.


I was planning on building one of these, but i came up with a design variant, that might solve the problem of water in the vaccum. I haven't tried it yet, so i can't guarantee it will work.

Instead of having the inlet tube stick down into the water, drill a large hole in the side of the bucket, right near the top. Drill the hole angled so the inlet air comes in against the side of the bucket. (tangent to the diameter) Point it slightly downward as well, and glue it in place. The exit hose to the vaccum should be in the center of the lid.

When you turn on the vaccum, the air rushing in should cause the water in the bucket to start rotating, and the centrifugal force of the rotating water will eventually cause it to ride up on the walls of the bucket in a thin layer, right where the air (and dust) is entering. the centrifugal force will mix the dust and water, and this force will also keep the water away from the exit hose in the center of the bucket.

This is the principle of how an industrial cyclone separator works (and those new fancy expensive bagless vaccum cleaners), except with the addition of water

If someone gets around to building one of these before i do, let me know how it works.

bmwpower
03-29-2007, 08:45 AM
Or just make the dip tube and the bucket longer and deeper, respectively. Do you really need that much water in the bucket?

Jononon
03-29-2007, 08:54 AM
I tried a water trap idea and because of the bubbling of the water the tube that went to the shop vac carried water and ended up putting a gallon of water into the shop vac after about 30 min.

This worked to solve that problem in a professionally manufactured, but useless, water trap:

http://img113.imageshack.us/img113/23/baffledly5.jpg

The passages have far more cross section than the vacuum tubes, so it doesn't kill the airflow, and next to no water reaches the shop vac. As most of the bubbles rise straight up from the inlet tube, the lower baffle catches them. Simply hacked together from acrylic sheet and glued in place with aquarium silicone.

Apologies for pinching Mikeyworks's diagram, Microsoft Paint isn't exactly ideal for drafting !

-lecroix-
03-29-2007, 02:53 PM
I did something similiar ... but diffferent too. I have my vacuum port flush with the top of the bucket. The port from the blaster exits just ABOVE the water line. As the vacuum pulls, the tramp dust flows to the end of the tube and then "stick" to the surface of the water due to the velocity the vacuum is pulling. It then settles to the bottom. No tubes are under water.

my58
03-29-2007, 03:28 PM
Thanks for the great information.

I am amazed how little info is available on the web about this. The cyclone style dust collectors seem to be best, however none of theses solutions are inexpensive.

With as many of the blast cabinets being sold (HF alone sells a ton) I would think more people would have solutions. It seems crazy that people are paying more for the vacuum then they are for the blast cabinet. What are all these people using?

Piper
03-29-2007, 05:53 PM
I use this same set up for drywall sanding and I've done a ton of it. I use a drywall mud pail, the one that is about 16 inches round by about 16 inches deep. I put maybe 1.5 inches of water in the bottom. I used 2 shop vac attachments machine screwed into the lid that came with the drywall compound. Very fortunately someone put about 30 feet of central vacuum hose in my dumpster at work the weekend I made this contraption and it fit perfectly with the whole set up. (horseshoes or what eh:thumbup: ). I didn't do anything to the shop vac filter and just use a normal shopvac bag. As drywall dust is finer than blast cab dust I'm sure my situation would be dustier but it works fine. After sanding I empty the drywall mud pail and it's usually filled with about 3 inches of sludge. You just need to make sure that there is water to catch the dust. If it gets too dry the dust will make it into the vacuum. When I use 1.5 inches of water I can usually sand for 2 or 3 hours. I guess it depends on how long you want to sand blast.

Good luck and YMMV

Piper

toms73novass
03-29-2007, 07:07 PM
lecroix,

Is this the type of setup you have?



I have tried baffles etc, and no matter what I get moisture in my shop vac. Plus there is a pressure drop due to having to go thru the water.

-lecroix-
03-29-2007, 08:32 PM
Close ... but both my hoses come in from the top ... the blast cabinet hose goes to just above water line and the vacuum hose is exactly as yours.

Not sure if my setup is the "proper" setup ... but it works for me and I haven't lost a ShopVac yet ... going on two years with same unit.

my58
03-30-2007, 10:30 AM
I found this bucket lid 7.99
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=9586

It looks like all I would need is to ad some extra lenth of plastic pipe inside to make the water filter discussed above.

Any Thoughts?

Thanks again

KCHOTBOAT
03-30-2007, 01:34 PM
I saw HF has a pneumatic vacuum for sandblasters but I hate to waste my air running it. Has anyone used it? Any thoughts on it?

Thanks
I had one and it worked fine as long as your compressor can keep up.

toms73novass
04-02-2007, 04:33 PM
Close ... but both my hoses come in from the top ... the blast cabinet hose goes to just above water line and the vacuum hose is exactly as yours.

Not sure if my setup is the "proper" setup ... but it works for me and I haven't lost a ShopVac yet ... going on two years with same unit.

I tried it and it works like a champ!!! I would say that it catches 90% of the powder. My gortext filter stopped the rest. I can probably blast for 10 hours now before I would even have to think about cleaning out the shop vac.

Thanks for the tip:thumbup: .

It also does not cause moisture to get into the hose going to the vac.