Newbie dust collection question

[Mike Gager]

Mike, wouldn't the diameter of the opening in the pipe simply reduce to the size that would allow the passage of air ata speed and volume that's still capable of moving dust?

Because the air is pulled rather than pushed, I don't think it'd be possible to "clog" a DC system. In other words, how would the last bit of dust get into the pipe to cause a closure if not moved with a moving air stream? And if the air is moving, how would it not keep itself scoured open as if the piping itself was a producer of dust?

Physics problem: Anyone ever see a DC system clog shut?
.

yeah its pretty simple, if the chips fall out of the moving airstream, they will collect on the bottom of the piping. eventually there will be enough of these chips that collect on a joint or transition that the line will clog

mike, the harbor freight inlet is 5". its also pretty common knowledge that HF over rates the DC and its actual rating would be more like 1 1/2 horsepower with a cfm rating of around 1100

[Wayne Jolly]

Here is a question that I have not heard (seen?) yet. What tools are you going to be collecting dust from? If your tools are all small then you may be ok with a shop vac. But other tools BEG for dust collection.

Having asked that now, I would have to say also that the dc bags will make a big difference too. If you have the 30 micron bags, you will still get a lot of fine dust in your shop. Perhaps not as much as you are getting now, but you will still get it. Add a 1 micron bag, or better yet, a cannister, along with plastic bottom bags and you will see even more improvement. Then later you could add an air filtration system and reduce the dust even further. But you will never get rid of all of it. To help with that, I have added another specialized "tool" called a GBO (Garage-Blower-Outer). If you can't find a GBO, then you can substitute a leaf blower. GBO's look EXACTLY like leaf blowers anyway.

xeddog

[keith ouellette]

john, according to bill pentz (internet dust collection guru) the harbor freight machine isnt powerful enough to keep chips in suspension with 6" pipe, thus a condition would be present that would allow for the chips to become clogged. whether or not in the real world this actually happens i dont know, its just what he recommends. if you can find 5" pipe of the same type that would be great

ken, you wouldnt want to use the dc as a house vacuum because the ducting would likely need to be smaller then what a dust collector requires. house vacuums likely use pipes that are less then 2". however if you could run large ducting throughtout your house (sized according to the dc needs) it may be an idea worth looking into

I can run two 4" gates at a time with my 2hp HF dust collector. I Bet its powerful enough for 6" duct. Its plenty powerful.

If you take apart the fan housing you will find the fan is the same type and pitch as jet dust collectors of a comparable size and the housing is the same. . That leaves the motor and it may or may not be a full 2hp but its more than 1 and 1/2 to be sure.

I know the older HF collectors weren't very good and were completely miss rated as to hp. The only place the HF dc will clog up is at the fan entrance where they have a screen to keep large particles from passing. It is easily cut out.


It will pull enough for 6" pipe but you would have to make an alteration.

[keith ouellette]

yeah its pretty simple, if the chips fall out of the moving airstream, they will collect on the bottom of the piping. eventually there will be enough of these chips that collect on a joint or transition that the line will clog

mike, the harbor freight inlet is 5". its also pretty common knowledge that HF over rates the DC and its actual rating would be more like 1 1/2 horsepower with a cfm rating of around 1100

Experience has shown me its more than 1100cfm but I agree its probably less than rated also.

[keith ouellette]

Why couldn't I use 6" single wall snap together metal duct work to hook up the dust collector. This is the 8" version of what I'm talking about http://www.theductshop.com/uploads/c...s/reg/BL-M.jpg
I can buy it for 3.00 per 5 foot section, It has a seam but I figured I could put the seam at the top and use metal tape to seal the seam and connections.

Thanks
John

If you can get that for that price then I don't see why not unless it is so thin that the pressure from the dc would crush it, which is a possibility.

Remember if you get the HF 2hp dc you would have to modify it (very simple) to except the 6" duct

[Cliff Holmes]

Why couldn't I use 6" single wall snap together metal duct work ... I can buy it for 3.00 per 5 foot section

At that price, it's probably 30ga metal, with a good chance the DC will suck it flat. 26ga is what you're shooting for.

[Wade Lippman]

It will do a good job on a jointer, planer, or router table; poor job on table saw or miter saw.
Unless they have improved the bag, a significant amount of the fines will just pour though it and probably be a worse problem than nothing.

At the very least, get a canister; better yet a cyclone. I wish I had done it right the first time...

[Dave Schreib]

I work in a small garage shop and don't actually produce all that much, just have fun. To justify the cost of the DC system, I am wondering if I couldn't pipe the house for a built in vacuum system. Is this possible?

Disguise the purchase of a new tool as a gift for your wife? Brilliant!