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RB211
12-14-2016, 10:51 PM
Finally got my sandblaster working, and discovered that the built in paper cartridge filter and foam pre-filter is woefully inadequate. Suction stays but a dust cloud inside the cabinet gets to a point that it is hard to see.
http://uploads.tapatalk-cdn.com/20161215/c8a6933d415ba14e6e970b8b159639fe.jpg

So my question is this... Do I ditch the paper filter and get one of those 5 gallon bucket cyclone separators?


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10KPete
12-14-2016, 11:19 PM
A cyclone will cut about 90% of the stuff. But you need a good filter to get the rest. For wood dust I use the little cyclone from Onida and my shop vac for the suction. The shop vac has the really fine sheet rock filter bag in it. But..... after 4 years of fairly steady use, the vac bag was just showing some little indication that there was anything in it!!!

Your usage should be about the same...

Pete

wierdscience
12-15-2016, 12:24 AM
+1 for the Oneida cyclone,I would ditch the in cabinet filter and add the cyclone.In a cabinet you have negative pressure,until you pull the trigger and add air to the system.You need volume to make up the difference.If the shop vac ends up having enough volume you may need to add a vacuum brake to the box so it doesn't suck the window out in between trigger pulls.Just a hole in the cabinet,maybe 1-1/2" in diameter with a flap of rubber fastened at the top on the inside of the cabinet so it acts as a one way valve.

The cabinet will also most likely work better since the fines will be removed and the reusable abrasive that gets through will end up in the bottom of the cyclone bucket.

RB211
12-15-2016, 10:31 AM
The cabinet has a built in filtered inlet, so it won't implode, but the suction is still great enough that I can't open the top up. Cyclone looks good but is way more than what I want to pay. What about bubbler systems? Or I could just make my own out of sheet metal, hmm?


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RB211
12-15-2016, 11:39 AM
Well doing more research... Yep, looks like that Oneida Cyclone is the way to go!

mikegt4
12-15-2016, 10:13 PM
I use a Oneida cyclone filter with my TP tools Scat Blaster cabinet. I works great and helps keep my shop vac clean. There are plenty of DIY cyclone plans on the net but I found that the materials cost is not that much less than the Oneida, especially if you can find it on sale.

Out of curiosity, you said that the filter shown in the OP is the make up air inlet?

That filter may be restricting the air flow into the cabinet so that there isn't much flow across the inside of the cabinet reducing the "scrubbing" action of the vacuum. My cabinet does not have a filter on the inlet, just an open hole with clamshell "scoop" on the outside with the opening facing downward. The outlet to the cyclone/shop vac is at the opposite end of the cabinet. The airflow across the cabinet needs to be more than the airflow produced by the gun or the dust will just swirl around and cloud your vision.

J Tiers
12-15-2016, 10:24 PM
Yeesh..... I think my 6HP shredder has a bigger air filter than that, the one on it is very similar in shape.

Rich Carlstedt
12-15-2016, 10:29 PM
That filter looks like a nightmare to clean, and there is no where for the sand particles to go.
Ditch that filter and take some 1/2 wire mesh ( garden variety ) and wrap it around a 3 pound coffee can for shape. Then put a ordinary paper filter ( just a bag- used in shop vacs ) over the form and attach it. The sand/dust falls off the bag with a nudge when you stop the vaccum .

Rich

RB211
12-15-2016, 11:19 PM
That cone filter is the suction inlet going to vacuum. It worked great for the first 20 seconds, haha. I removed it, will go directly to cyclone. The inlet filter for fresh air going into cabinet is a fine cotton looking thing that I beleive is restricting the airflow too much. Will address that as well. Right now I need to make or modify the current motor mount on the air compressor to have more adjustability.

JRouche
12-16-2016, 01:23 AM
Huh. Well it sounds like you got it figured out. Thats nice.

I have had a few inexpensive blast cabinets, cant afford the real deal. Have used some top notch cabinets though. It is all about the air no doubt. The big industrial units I have used we were more about making sure the operator didnt spray the face glass.

You can suck as much air out of the box as you want, but if you dont have enough pre-fillters before the intake you will be fighting dust the entire time.

The cabinet HAS to have some prefilters in place. Meaning the abrasive media filter before the fine filter.

You dont want a dusty cabinet where you cant see the item you are abrading? Lighting yes, and a good triple filter before the intake from the box. JR

chipmaker4130
12-16-2016, 10:02 AM
I don't know which Oneida product you looked at, but I went with the (much) cheaper plastic Dust Deputy. It was $45 from ACE hardware. The plastic is quite thick, and the thing is overall well constructed. I did use a top and bottom aluminum plate on the mounting flange to flatten it out. I am astounded at how well it works. Their ads sound too good to be true, but they are! I did make my own adapter fittings from ABS solids for my Shop-Vac. I don't know about the metal 'pro' version, but you can pop the top off the plastic one for cleaning (mine gets an oily film after a few weeks since I use it all around the shop and machines).

mikegt4
12-16-2016, 09:22 PM
Oneida Dust Deputy is what I have. It was about $45-$50 at Menards.

I still don't see why you need filters at all. My cabinet fresh air intake has no filter. The cabinet outlet is just a shop vac hose adapter screwed to the side of the cabinet. The hose goes to the Dust Deputy which captures the dust and deposits it into the 5 gal. bucket. The hose from the DD outlet goes to the shop vac itself. The filter in it finishes the job although there is very little filtering that it needs to be done. The Dust Deputy cleans the air pretty well.

The dust captured in the bucket under the DD is usually very fine powder, the leftover of fractured media which is no longer of any use. The larger media particles (still of abrasive value) tend to fall down into the hopper rather than circulate around in the air. If I inadvertently point the gun in the direction of the air outlet in the side of the cabinet I do get "good" media sucked away but once you adjust your technique so as not to do that then the loss of good media is minimal.

Mcgyver
12-16-2016, 11:28 PM
cleaning air from blast processes is a big issue. We make a line of wet air scrubbers, up to 80,000 cfm (yes its big) for commercial shot blast units. The problem is without expensive equipment the fine particles, micron stuff, just isn't cleaned out of the air and for some blast media (ie silica) its a very real health risk. Obviously no one wants to spend magnitudes more on dust collection than they do the blast unit, but imo its a bad idea to exhaust the air back into room. Better if can to to vent outside after the vac, or suffer with the little filter which I believe puts a lot less dirty into the room than sucking with a vacuum would

J Tiers
12-17-2016, 02:06 AM
cleaning air from blast processes is a big issue. We make a line of wet air scrubbers, up to 80,000 cfm (yes its big) for commercial shot blast units. The problem is without expensive equipment the fine particles, micron stuff, just isn't cleaned out of the air and for some blast media (ie silica) its a very real health risk. Obviously no one wants to spend magnitudes more on dust collection than they do the blast unit, but imo its a bad idea to exhaust the air back into room. Better if can to to vent outside after the vac, or suffer with the little filter which I believe puts a lot less dirty into the room than sucking with a vacuum would

A lot of truth to that, although it probably depends on how much time is spent in the environment. Shot blasting makes a lot of dust, as does sand blasting. But the typical sand blaster cabinet is not used that much, and probably is less of a hazard by far than an all day industrial process.

That works both ways, though, if not used a lot, the loss of heated air in winter is not so serious. So if you CAN lead it outdoors, that's better.

Thing about the cyclones, they depend on "mass separation".... they throw out heavy stuff that is denser than air. But there is a class of smaller particles that are carried in air at least for a time, and the cyclone separators just are not very effective on those. The particles are not different enough from air to be thrown out unless you have a number of stages, and even then some will come through.

The "wet" scrubbers, spray types, or wet surface impingement, etc, can do a lot better, but are just not home equipment.

wierdscience
12-17-2016, 08:50 AM
One of the biggest problems with air filtration in the HS,is the lack of small,affordable centrifugal fans that have decent static pressure and volume.A shop vac,even the expensive ones are not very efficient and wood working dust collectors are biased towards high volume.What's needed is a blower with a 2" wide x 14 or 16" diameter impeller with a reasonably tight fitted scroll.Those do exist,but cost $$$$.

IF a decent fan is available,then more types of filtration become possible. I've been wanting to build a water bath air filter based on the same principals as an oil bath unit used on an IC engine.

http://www.instructables.com/id/Make-an-Oil-Bath-Air-Filter-for-your-Motorcycle-or/

RB211
12-17-2016, 08:53 AM
I put wheels on my blaster cabinet stand and will only do it outside, while wearing a respirator. The vacuum is also outside. I'm a bit paranoid about abrasive dust in the workshop, and lungs. While I was at it, I bolted my grinder to the stand as well, so all grinding is done outside as well. Yes, talking about the dust deputy.
http://uploads.tapatalk-cdn.com/20161217/21f78e57a834ee418e577ec411f52e3e.jpg

ncjeeper
12-17-2016, 04:11 PM
I made a baffle and put it over the hole. That helped a lot with reducing the amount of media getting sucked out of my cabinet.
http://i978.photobucket.com/albums/ae266/ncjeeper-1/DSCF1179_zpsjf6e0tic.jpg (http://s978.photobucket.com/user/ncjeeper-1/media/DSCF1179_zpsjf6e0tic.jpg.html)

RB211
12-18-2016, 03:40 PM
I made a baffle and put it over the hole. That helped a lot with reducing the amount of media getting sucked out of my cabinet.
http://i978.photobucket.com/albums/ae266/ncjeeper-1/DSCF1179_zpsjf6e0tic.jpg (http://s978.photobucket.com/user/ncjeeper-1/media/DSCF1179_zpsjf6e0tic.jpg.html)

Nice idea!


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RB211
12-21-2016, 01:40 PM
Heres the adapter I made. Never wanted it to be this fancy, just using the materials I had on hand. Wish I could weld Aluminum.
http://uploads.tapatalk-cdn.com/20161221/f432e5ff511693226f2c3cfd02d96b95.jpg


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