shop vac exhausted to DC

[eddy merckx]

Hi everybody.

I'm thinking of how I can improve the suction on my shark guard. I currently have it Y-d off of the 4" main hose which connects the the TS. I am making a bunch of cabinets. This project has around 50 pieces of 3/4" birch ply. Everything is cut out now, but I really noticed a lot of airborne dust after all that cutting.

Some research revealed that the 2 2/2" hose which goes to the Shark Guard pretty much restricts the airflow to the point of letting lots of dust escape. The options are either to somehow upgrade to a 4" port or hook up a shop vac to the Shark Guard.

The shop vac solution would be the easiest and cheapest, however I am concerned about how much dust will escape from the vac. I was thinking that I could vent the vac into the DC hose.

I was wondering if anybody can think of a reason why this won't work or will harm the vac. What do you think?

Thanks in advance,
Eddy

[jziegler]

Why not just get a HEPA filter for the shop vac? That and a drywall type bag in the shop vac will take care of the dust very well.

Jim

[eddy merckx]

Hi Jim

I do have a hepa filter already, but it gets clogged so fast that I'm sure some fines are blowing through it. I've heard about using a drywall bag, although I'm pretty sure it won't fit in my Ridgid vac--at least the bags at HD are labelled for other vacs. I guess I could buy some and see.

Thanks for the advice,
Eddy

[Stytooner]

If you have the original type with 2" port, then the best would be from a shop vac. The 2.5" works pretty good off a 4" main. Ultimately the 4" works so well on a DC that you need a blast gate to keep from picking up small parts.

If you have the Ryobi version, keeping it as low as possible will also help.

To answer your question. There is no reason at all that exhausting back into the 4" main on the DC won't work. In this case, you would not even need any filter in the vac. This is provided that you turn the DC on of course.
Let us know how it goes.
Thanks.

[cgallery]

In this case, you would not even need any filter in the vac.

Thanks.

But won't that send all the sawdust through the motor on its way to the DC?

[cgallery]

Hi Jim

I do have a hepa filter already, but it gets clogged so fast that I'm sure some fines are blowing through it. I've heard about using a drywall bag, although I'm pretty sure it won't fit in my Ridgid vac--at least the bags at HD are labelled for other vacs. I guess I could buy some and see.

Thanks for the advice,
Eddy

If your vac is the type where the inlet is on the barrel then bags should be available for it (Ridgid makes some, but I use the Shop-Vac brand bags on my Ridgid cause they're cheaper).

If your shop vac inlet is in the lid of the vac, then you're right, bags won't work.

If you can use bags, they will eliminate the plugging you're experiencing on your filter.

[Stytooner]

But won't that send all the sawdust through the motor on its way to the DC?

I think it may depend on the brand, but wet vacs should be able to exaust without fear of getting water in the motor. The motor is sealed off from the blower portion.

[eddy merckx]

To answer your question. There is no reason at all that exhausting back into the 4" main on the DC won't work. In this case, you would not even need any filter in the vac. This is provided that you turn the DC on of course.

That's a great idea Lee. Even better is that it won't cost anything to try.

If your shop vac inlet is in the lid of the vac, then you're right, bags won't work.

Yup, I have the one with inlet in the top. Next time.........

Thanks for the ideas guys. I will let you know how it goes. I'm trying to hotrod my dust collector in the hope of squeezing every drop of efficiency from it. I have a Jet 1100 DC, Wynn filter and the plywood dust separator disc. Now I want to run 6" pvc to my tablesaw. Luckily I found a sand and gravel place on my daily commute which carries the inexpensive stuff. If anybody is interested, I will post the results after I finish.

Eddy

[poolhound]

I use a shop vac on the SG as I dont seem to get that much suction when connected to my main DC setup. I have a 4" hose Y'd off, one half goes to the 4 to 2.5 reducer and fits into the back of the BT. The other half goes to the belly pan. The connector at the belly pan also has a 2.5" port which I had intended to run to the SG but most of the "suck" seems to end up going into the belly pan.

[Bob Bassett]

Had the same problem. Solved with the problem with the Onieda Dust Deputy. For $99 you get their little cyclone collector that fits on a 5 gallon pail.

I have a pail that is half full, now, and the VAC filter is pristine.

[LCHIEN]

here's a wild theoretical idea, all half-baked...

Use the Shop vac exhaust air to BLOW into the top of the shark guard.
you've got the DC pullling (hopefully) several hundred CFM from the shop air in the close vicinity of the saw, and the vac will push maybe 50 CFM into the shark guard. which will add to the makeup air flow going to the DC direction thru the saw. As an additional bonus, you'll not have to clean the SV filter except for what air cleaning function it provides.

OK, well, obviously not tried, who knows if it will work. Maybe instead of ending up in the DC, the extra air flow will end up shooting dust out the sides of the shark guard....

[eddy merckx]

Hmm, that's an interesting idea Loring. My instincts tell me that a lot of dust would spray out, but you never know.

I read about a guy who mounted a compressed air nozzle below the table, at 90 degrees to the blade. The compressed air blows all the dust off of the blade before it rolls back to the top of the saw. He said that it worked pretty well. That would be a fun project to try some day........

Eddy

[LCHIEN]

That "blow the dust off the blade" air thing probably works well for conventional cuts where the blade is buried in the wood and the only exit is down.

i find that the worst case dust out the top of the saw experience comes when I do an edge cleanup rip, cutting 1/8th to 1/16th off the edge of a board, then the sawdust literally comes off the side of the board and spews across the table top.

[Stytooner]

It will lift the shark, I think. Especially with our saws where the RK is lowered so that the clamp is on top of the stock. This also is dependant on the type of cut. Cleaning up an edge might leave enough room for the exhaust pressure to escape.

[JR]

Eddy,

I'd be a little concerned about your original problem. That DC should be able to handle both ports very well, even given the restriction of the 2-1/2" hose.

In my setup, using the HF 2Hp DC, I have a 4" main line running overhead down the length of my shop. I drop down via 4" flex to the back of the BT with a Wye serving a belly pan. I have a seprate drop-down serving the SG. It requires about 4'-5' of hose to reach the SG. I get pretty good suck out of that configuration.

Just a thought.

JR