has any one had any success in the suppresion of sanding dust with out sacrificing airflow? im looking into high pressure water fogging systems etc. id like to know if anyone else has had any successfull ways of getting great airflow without poluting our earth! http://www.feraldave.com
The funny thing is you think its polluting the earth to sand a surfboard??? The sanding dust that comes from sanding a board is totally a nusance dust, according to the EPA. No different from dust off a dusty dirt road or the dust that is in your house. Read the Hazmat for silmar resins. If your shop is in a residentual area you will have problems if you blow the dust on someones house, but if you are out in the boonies dont worry about it. If you do need to control the dust somewhat you can build a box over the outside of your fan and line it with owens corning insulation. The insulation will trap the dust and let it fall to the ground then you can scoop it up and put it in the trash. Also hardened silmar is safe to take to a land fill.
Herb has a cheap system using box fans to blow dust towards a misting system across the garage opening. You can get PVC misting nozzles for about $15 for 4. This is probably for shaping foam. Herb? Look online for “dust supression.” There are a few good sites with home-made dust filters for fine particles (sanding glass). The link below is a good place to start. Amazine how important this seems to garage woodworkers and doesn’t get much mention by shapers. Rob Olliges http://www.jimthompson.net/boating/Maintenance/dustcollection.htm
Ah yes - dust. I have and use a Grizzly G8027 in my mostly woodworking shop, which is good for woodworking with larger machines ( point sources, as it were) and what have you, though a couple of friends who do more along those lines like the box-type electrostatic collectors that work wth a fan to get airborne aggravating dust like you’d get from sanding. For the volume of dust, chips and whatever that I produce, I have an inline cyclone arrangement- a plastic lid that sits on a heavy metal trash can with a bag liner and kinda preciptates the majority of the dust into that rather than having it travel on to the bags on the machine itself, which are a pain to remove and put back. Worth having if you have to bag your dust and such besides which the bags are a helluva sight easier to deal with than the heavy and awkward metal trash can. Neither one, though, would be all that great for sanding and shaping. The small box filters won’t take up enough dust and the bag types like I have work far better for stationary tools that have dust collection ports on 'em. The way a planer or a big disc sander throw dust around, they just won’t work, though it’s light dust that usually doesn’t fly that far. All is not lost, though. There’s something called a ‘sanding table’ or ‘downdraft table’ , a grid-topped box with a blower and collection system below it ( see the link below for some big 'uns that could perhaps be modified for surfboard shaping and sanding ). It wouldn’t be that tough to make one, either, with a fairly healthy bag-type dust collector, some plywood, some heavy plastic mesh and a few inexpensive fittings. A couple of crosspieces on it, voila, you have a shaping and sanding stand with built-in dust collection. A little clever design and a surplus blower capable of 750 CFM or better ( squirrel cage blowers, as my late father called 'em) and you could dispense with the external dust collector. hope that’s of use doc… http://www.grizzly.com/products/items-list.cfm?key=570010&sort=price
I suppress my dust with 4 boxes fams at the end of my room stacked 2 high and both sets tilted inward this gous int an insulation lined box that angles down into a 6 inch hole, underneath this is a trash can 36 gallon with 2.5 feet of water there are 2 canvas tubes that come from the hole a big one that goes around the rim of the can and drawstrings tight and a nother thats narrower that drops into the water. FINALLY there is a air inlet for the compressor that runs into the bottom of the trash can it causes a jaccuzi affect that traps the dust into the bubbling water, I have to dump it everyday it gets to the consistancy of gravy and works pretty good http://www.surfboardglassing.com
I haven’t read the resin MSDS, but the Clark foam MSDS says it is a “fully reacted polymer” and only creates “nuisance dust”. Okay, the first means that it isn’t chemically reactive, but neither is asbestos. The second seems to imply that the dust has no particular health effects. Do you believe that “nuisance dust” isn’t bad for you? I don’t. Dust isn’t good for your lungs, period. Some of it will, in any environment, get into your lungs and that’s why we evolved with hair in our noses, mucus in our lungs, cilia and all - to intercept, encapsulate, render harmless, and expel trapped dust. What’s the point? I don’t belive that “nuisance dust” is harmless, whatever the composition. I shape and sand in my large back yard - dilution is one solution to pollution. Accomodating neighbors are another. On a commercial basis, dilution is strictly prohibited by federal law at 40 CFR 261 or so. Note also that a homeowner is largely exempt from hazardous materials regulation under RCRA. This means (without State laws or County ordinances to the contrary) that I can dump anything out of my garage in the trash can.
We built a cyclone separator in our factory. Surprisingly it did not cost that much for how well the thing works. Basically it is a large can we had built by a local vent/duct company with a cone section below. The “can” is about 4ft across and 6ft tall including the conical part. I built a “blast gate” at the bottom of the cone out of plywood to gain access. Air flow enters the top edge so the air spirals downward, inside of the can. There is a 16 inch pick up tube which enters from the top of the can down the center INSIDE the can and stops about 1ft short of the bottom. The 16" tube sucks up the flow via our 15inch squirrel cage blower (1800cfm) that’s mounted on top of the can, and out the ceiling. I was stoked to see that there was no residue on the roof even when our sander would do 15 boards at a time. Every couple of weeks, I hit the can and the dust all falls off the insides of the can down to the blast gate at the bottom. I slide the gate open and the fine debris falls into a trash bag. Another note, if your sander can adapt to it, a “one sided” sanding approach seems to be very effective. We exploit how moving air “hugs” along a wall. To do this, we have a 2ftX2ft hole in the door and the air flows along the sanding room wall, then at the other end of the room we have the inlet to the separator. The board/rack is along the wall and the sander works just out of the airstream. The board is in the airstream. The hole in the door is at working height and the outlet hole is at eye level. Air moves over the board and pulls surrounding dust into the stream. The stream hits the wall at the end of the room, depositing the heavy particles on the floor and then the stream bends up into the inlet to the separator. The sander stays pretty clean, except for his hands during hand sanding. We’re pretty stoked on the results. Hope this helps.
Slick! Very slick! And I’ll bet it would scale down some too. If you were to do it all over again, say the Mark II version, would you put the separator inlet closer to the floor to get more of the heavier particles? Thanks
You know doc, that’s a good question. When I first did the drawing, I was concerned that the separator would not work so I kind of used the far end of the sanding room as a separator of sorts. So now we’ve got a TWO STAGE separator: the end of the room and the cyclone can itself. We’ve been placing the trash can for the sandpaper scraps a couple of feet past the end of the board and it’s funny, the trash can (and adjacent floor area) collects more dust than the separator. When the door is shut and everything is going very little debris gets on the sander, so I must have got the velocity right (I actually had to reduce the pulley ratio because the blower motor was getting a bit warm)(so my CFM is a bit less than the original). Initially the airflow was too fast and some dust would recirculate and get on our sander, Chris. The theoretical mass flow rate could be calculated and then matched for a down-sized version. (CFM/Inlet Area,sq.ft.)= stream velocity. Actual velocity is lower due to static pressure losses and I also hung the sanding room door with a 2inch gap at the bottom to keep the doorway clear and reduce tracking crud around the rest of my shop (it works!). I think a good Mark II would be have a hole in the door about 6inches x 20inches wide. That’s a little less than 1/4th the original area so to get the same velocity about 1/4th the CFM should do it (with a lot of assumptions, of course). A pick up horn close to the floor might be nice(but more static pressure loss), as this would have to be routed upward to the top of the separator. This horn would act as a plenum chamber and if baffled a bit could separate large particulates. I also think some kind of air horn/velocity stack mounted on the inlet hole in the door would get a more deliberate laminar(ish) flow to increase efficiency, but my door/room won’t allow for this. I should note that large debris such as fin box grindings end up right on the floor under Chris, as well as some hand sanding residue that does not get whipped up into the stream as with the disc sander. Lastly, I designed but never built the room to neck down very small where Chris works, so the velocity would stay up and turbulence/recirc would be reduced; maybe a 6’6" ceiling and only 48" inches wide. Chris probably would get claustrophobic and panic, so I never pursued…
Damn - you have seriously thought this through. I’m impressed. I keep thinking that something with a little static electricity involved would be useful, but then static around fine dusts does have that problem of going boom if they’re even a little flammable. Probably not a serious worry but why bother anyhow. Rather than necking down the room height a lot, would a wide, solid shelf over the sanding area have a similar effect - or at least to some extent?? Say 12" wide, running the length of the room and perhaps you could hang some flourescents from it for task lighting? Use an adjustable shelving system so you can play with it some for fine tuning. Something like this might work as a benchtop system, much smaller with a much smaller vac, though I think it’d still be beyond the capacity of, say, a shop vac. I see what you mean concerning the lower pickup/inlet. Plus, more particulates in the air column means air the column itself is heavier - dunno how that’d work out. There was a similar problem, though much different in degree, in the setup they used with water columns when they were sending down the Brooklyn Bridge cassions - particulates in the water column increased the specific gravity of it such that they had some major problems with it. Much heavier than plain water. This may not be a real consideration - it’d depend on how heavy the dust was plus how high the lift was and so on. The diverter/velocity stack rig on the door- yes, it’d be very much in the way or else a kinda complex folding rig that’d be forever breaking down, and diverting the air imposes some load/slows down the airflow besides. About the only addition to this I might suggest is something, perhaps with soft foam at one edge, that you could set against the wall at the end of the day which acted to give you a pickup right on the floor. Then your sander could just sweep the floor towards it and save some dustpan work and have all your dust going to one place. On the other hand, if there were future waste disposal requrements for separating, say, fin box debris from resin/glass dust, you’re set with what you have now. Again, I’m really impressed. It’s mighty rare that somebody takes the trouble to think something like this through. doc…
I see it but I dont, Plus one needs to post a diagram I feel, you know to better assist the bredrin http://www.surfboardglassing.com
dunno if this will help - and please chime in if I’ve misunderstood something. This is kinda like those bits in school- ‘this is left as an exercise for the student’… I’ve left out a few things in the incredibly crude sketch, notably the happy and relatively dust-free sander, but I hope this makes sense. 
thats pretty good. http://www.surfboardglassing.com
Wow! that’s weird! that looks exactly like my sanding room!!! (air outlet is about 24inches higher). That is amazing, usually something would get lost in the translation… …you mentioned an extended light shelf, well we’ve got one! It is at about eye level and it has a fold-down adjustable leading edge about 8inches wide. The shelf seems to work. At first, Chris wanted to tear it down, 'cause he kept hitting himself in the head (he’d say the shelf kept hitting HIM in the head). He’s since adapted. I get in there from time-to-time and I sort of adapted… About the dust pick-up, we use those in the shaping rooms, they are connected to the planer vac set ups by “Y’s” and blastgates and work very well. I’d like to get something like that going for the sanding room. I have a digital camera. If I could learn how to post I could show photos. I’ll check the archives tonight. Back to the grind; so to speak.
Well, you described it pretty well. As for a sweeper’s gizmo for the sanding room - something like this below might work out pretty well and it’d be quite cheap to make - so if it doesn’t work you can toss it with no regrets. Storing the thing would just be lying it on it’s side and putting it up against the wall in a corner - about as out of the way as it’s gonna get. The small inlet is gonna increase the speed of the airflow in so a little shove with a push broom should whip it right in there. The partial vaccum the smaller inlet makes will, given a little cheap foam hardware store weatherstripping, hold it to the wall as well as it needs to be held. hope that’s of use doc… 
Ingenious. I will take this project on as my work starts to lighten up. Thanks for the idea… …I dig the sketches.
Well, you have such a nice setup already, this kinda complimented it. The sketches- well, just Windows Paint. It’d probably be nice to have something, some sort of 3D CAD program that would do jpgs, but at the moment I haven’t got one. Have to see what Tucows has for freeware, I guess. You might get a kick out of the way my shop’s set up. I do a lot of woodworking and all there, but the small metal bits ( especially drill bits, adjustment screws, that sort of thing) or small wood bits can sometimes get loose or get dropped. So, the setup I have will pick up wood dust, sawdust, plastic dust - but not metal or anything fairly dense . Saves me a lot of time and trouble.
Making a fast pass here because I’d rather be here than working… Used to work in aerospace and went through MSDS for aluminum dust from spinning, trimming, grinding, machining, and polishing that material…amazingly the only thing required for aluminum dust was a basic dust/particle mask available anywhere. Supposedly breathing that dust was ok. On my second tour with that one company there was a whole department for grinding large parts, and the company on it’s own upped the protection level for full respirators. I was in an office on the production floor and would walk through areas as required, and I would go home at night and use some kind of skin cleaner on cotton over my face and the thing came out looking like I wiped it on the shop floor. The human body was designed/evolved to cover much more natural substances; yes, asbestos and aluminum occur naturally in the environment, but not at the levels industry creates. Use protection if you are exposed frequently, heh heh. As for dust collection systems, there are many commercially available. That place I worked at had an incredible one for aluminum which even scaled down should suck the air clean of ambient floaters in a shaping booth, bot not of course the floors. Granger and McMaster Carr might have stuff like that, plus regular companies who do nothing but. A trick on that is to look for auctions or companies either going under or retooling. You can sometimes buys stuff for pennies on the dollar or in some cases just haul it away for them. I’d go down and take a couple of photos but I’m not sure if I’m “grata” or “non-grata” anymore after my last escape…