Frank's Wrkshop: Dust Collection Plans

[Kelly C. Hanna]

Great score Frank! I think you chose well on the DC.

Don't belive everything you read about the PVC DC explosions theory Bob...I have yet to meet or talk to anyone who catually had that happen.

[Jim Becker]

Here are some thoughts and discussions on using PVC. You may find some of the responses interesting.

Along the lines of Kelly's comments, you might want to puruse Dr. Rod Cole's article on the same... http://mywebpages.comcast.net/rodec/.../DC_myths.html

PVC is definitely not appropriate for a commercial shop, but for the hobbyest, no issue in my mind. That said, I also prefer metal duct for the flexibility it gives in duct design that you cannot get with PVC, primarily due to non-availability of the necessary duct sizes and components.

[Chris Padilla]

Jim,

True, there is no 5" PVC...the best you can get is from 6" to 4" or if you want, 8" is available but no odd numbers there. For example, a wye only comes in all 6" or 6" x 4". But, HEY!, it might force you to stay all 6" which while possibly painful, is the best thing for DC!

If you want to go the PVC route, I chatted with an extremely helpful guy at a local irrigation warehouse (this is the place you should go to for DC PVC stuff) and we found 3-4 kinds of plastic he stocked. There is the Schedule 40 stuff but it is VERY expensive for the fittings for Sch 40...twice that for S&D fittings. No doubt that Sch 40 is very heavy-duty for DC but I think it is overkill.

There is also SDR21 and SDR35. I forget the reasons agains SDR21 but I think you cannot use the same fittings for SDR35 and SDR21. SDR21 requires the use of Sch 40 fittings I think. Don't blast me if I'm wrong here.

Anyway, in the end, we decided that the SDR35 pipe (S & D, sewer and drain) and its associated fittings would do the job and be the most cost-effective over anything related to Sch 40.

Prices I got from Horizon, my irrigation warehouse:

SDR35, 6", 20' lengths, $57.20 ($2.86/ft.)
6" wye S&D, $30.98
6" 90 deg S&D, $14.65 (you shouldn't use these...too tight a radius)
6" 45 deg S&D, $15.76 (2 needed to make a 90)
6" coupling S&D, $9.67
6" x 4" wye S&D, $27.00

Sch 40 fittings...just double what you see above...roughly. Also, you won't find a 6" wye in Sch 40...only tees. Now the SDR35 they have was gasketed and hubbed strangely at one end (kind of double-hubbed, probably for the gasket) so I will probably lose about 6" of each 20' pipe and I am probably paying a bit more for the gasket.

I think PVC might be easier to work. I also think PVC might be easier to seal air tight. PVC won't dent if you drop it or accidentally step on it or bump it. There should be less cut hands from PVC vs. sheetmetal. I wonder, too, if PVC might outlast metal? Water and PVC go well together but even galavanized steel won't last forever against water. When I built my cyclone, it was recommended to spread some polyurethane caulk along the inside of the cyclone at the intake where chips will hit the cylinder wall.

Also, with Terry's method of a friction fit and a bit of caulk at the edge, it should be easy to change the piping as needs change in the shop.

So those are my arguments for PVC over metal but I an anxious to hear more reasons against PVC. I will try and find some local sheetmetal place and see what they have, get prices, and then sit down and figure out the $$s to compare PVC and metal. Should be an interesting exercise.

[Bob Dodge]

Hi Kelly, You gotta ask yourself this question regarding PVC and fires, Why would you ever hear about a homeshop fire????ANY home fire??????

If a forest-fire is about to wipe out a community, you'll hear about it, but a home fire??? Of course, you never will.

I think sometimes we "assume" a little too much on these chats, then take it as gospel.

If you ever did have a fire, is there a possibility that an insurance company could balk at dishing out the dough??

There's more ways to start a fire with dc's, than just static electricity. One way would be to pick up a nail with a floor-sweep. When that hits a steel impeller, you'll get a spark. A spark, sitting on a pile of dust in the dc, being fanned by incoming air, could cause a fire quite easily.

While chances of that happening are remote, and that could happen using metal pipe as well as PVC, could the insurance company use it as an excuse to not pay out.??

PVC is combustible, and in industrial applications, you are not permitted to use combustible plastic pipe, to convey combustible materials.

As Jim says, the fittings are also more appropriate with metal spiral pipe. Static becomes a non-issue, and the insurance claim concern, is eliminated.

Most people use PVC because they think metal spiral pipe is too expensive, and that they're saving money. It just isn't so. You have to look around a bit to find it, 'cause it's less common, but any heating and ventilation contractor can point you to a source. As I mentioned in an earlier post, I bought from a small local pipe manufacturer, and paid about $1.20/ft for 6" pipe. That's cheaper than PVC.

These pipe manufacturers are everywhere, just not very visible to the average hobbyist. Look in the Yellow Pages, under "pipng".

All the best, Bob

[Chris Padilla]

Hi Kelly, You gotta ask yourself this question regarding PVC and fires, Why would you ever hear about a homeshop fire????ANY home fire??????

If a forest-fire is about to wipe out a community, you'll hear about it, but a home fire??? Of course, you never will.

I think sometimes we "assume" a little too much on these chats, then take it as gospel.

True, Bob, but assuming that it does cause fires is the same thing. All I can say is that Terry has had his up for many years (I'll let him correct me) and his personal belief is that it is simply not a concern.

Most people use PVC because they think metal spiral pipe is too expensive, and that they're saving money. It just isn't so. You have to look around a bit to find it, 'cause it's less common, but any heating and ventilation contractor can point you to a source. As I mentioned in an earlier post, I bought from a small local pipe manufacturer, and paid about $1.20/ft for 6" pipe. That's cheaper than PVC.

These pipe manufacturers are everywhere, just not very visible to the average hobbyist. Look in the Yellow Pages, under "pipng".

I think this may be true, Bob, and I'll certainly report back what I find out. Shipping busts the budget for the spiral stuff so if I can find it locally, it will definately go back to being a consideration. Right now, PVC is looking good to me.

[JOHN HANCOCK]

Chris,

I bought my pipe from Air Ducts West in Hayward. I got their name from Bill Pentz's website. There was a price increase right after I bought due to steel prices but I paid:
$16.75 26 Ga 6" sprial 10'
$28.00 24 Ga 6X6X6 wyes
$11.75 24 Ga Die stamp 90's
$10.50 24 Ga " " 45's
$ 3.50 6" couplings

I decided to buy the blast gates there when I went to pick up the order and can't find the receipt but I think they were $21.00 for 6".
Of course, since I picked up, no freight.

The price on the pipe went up to $22, I think. Not sure of new prices on others.

[Chris Padilla]

Sweet, John!! Thanks so much for the pointer...metal is suddenly looking good again and Hayward is darn LOCAL! I hadn't read Bill's site in a while and I probably should have.

So the pipe prices are a bit cheaper for metal (2.20/ft vs. 2.86/ft) but the fittings seem to be A LOT cheaper. I assume these are bonfide dust collection fittings or are they still HVAC-type of fittings? It would about seal the deal if they were for dust-collection (pointed the right direction).

Are the 90s and 45s consider the long-radius style? Do they have gentle tapers from 6" on down? Are they open on weekends? I suppose I could Google 'em and find out everything for myself!

[JayStPeter]

I used a combo of Sch35 PVC and metal. I bought 10' sections, 45s and wyes in PVC from the local borg. I seem to remember the prices being signifncantly cheaper than Chris' list ... along the lines of $18 for a wye.
When I needed adjustable elbows and adapters, I used the cheapo $5 HVAC stuff. These fittings have plenty of bends, so are strong enough. Then made my own blast gates. I can't remember exactly how much I spent on DC piping, but I think around $600. A significant number there ~$230 was my order from Oneida that included some 7" stuff and adapters to 6" to get out of the Cyclone plus the flex tube.

Jay

[Chris Padilla]

Thanks for the reminder, Jay. I need to visit the borg and see what they have, too, but I just don't recall seeing 6" fittings there to be honest. Still, worth another look...I practically live there on the weekends anyway.... ...no wonder my shop is taking forever!!

[Terry Hatfield]

Chris,

Sorry to be so tardy in my response. A little hospital stay this week kinda got in the way. Not to worry, I'm OK now..or rather will be pretty soon.

I used S&D , sewer and drain. Lighter and cheaper than sch 35 or 40. I have talked with many people across the country about this pipe and everyone has been able to find it eventually but it took some doing for some folks. It just all depends on what is used in your area. Try plumbing and irrigation supply houses.The pipe should not be more than $1 or so per foot. If fittings are not available or not economical in your area they can be purchased from McMaster and Carr.

www.mcmaster.com

I see the 6X6X6 wyes for example are $10.53 each acording to their site. I doubt that anyone would have much more footage or fittings than Dennis Peacock's shop. I bought all the necessary parts and pieces and helped Dennis with his install. Total for everything was about $400 if I remember correctly.

Is the spiral pipe and fittings better for dust collection??? Maybe, but you got some first hand experience with my system and I seriously doubt that spiral pipe and "real" DC fittings would make any measurable difference except the cost. Bob has an extensive knowledge of dust collecdtion and I agree with him on every point except the economics of PVC. I simply do not see any way that one can construct a 6" system for less or even equal to what S&D PVC is with spiral metal.

I personally would not ever use anything except PVC. But that's just my opinion. I could be wrong.

t

[Bob Dodge]

Hiya Terry,

Good to see you again. Been a while, it seems. Hope you're feeling well, and getting better by the day.

Well, if anyone ever was in a position to comment about PVC, it most certainly is you, Terry. That's quite the set-up you have. Always puts a grin on my face, when I take the "Shop tour". That's flat out, the nicest shop I've ever seen, lol. I'd kill for HALF that space, ;-))

I mentioned PVC, primarily as an insurance consideration. I'm just not certain what they might do, in the event of a fire. I do know, that in industrial applications, it is strictly "verbotten".(forbidden) I'd certainly not have any issues with airflow, especially if one takes the time to provide adequate relief in the elbows, wyes, etc. Two 45's end to end, certainly is preferable to a single tight 90.

I was easily able to find a small manufacturer of metal spiral pipe, about two years ago. Paid $17. Canadian, for 10 ft lengths, of 22 guage pipe. That's about $12.50 US, per 10 feet.= $1.25 a foot.

I found my supplier by starting with a heating and ventilation supplier. They had none, but were able to recommend a place, which was right down the street. In that situation, I found that the metal was MUCH cheaper, than any PVC I had previously looked at.

I picked up a few long radius elbows, but even at half price, I found them expensive. I used HVAC elbows in some situations, ensuring nice long-radius turns. Two 45's, end to end, to make a single 90. Was dirt cheap, too. Works fine.

For my pre-separator, I use strictly OVERSIZED elbows, especially if I have a tight 90 degree turn. I merely add a reducer, after the oversized elbow, to neck back down to the appropriate duct size. The oversized elbows at the pre-separator, really reduce resistance dramatically in some cases. Depends on how resistive that particular branch is.

Just as a point of interest, some industrial cyclones, are now required to have an explosion vent. Not certain exactly, what that translates too. I'll be going to a large industrial trade show, at the end of October, and try to get more details.

Take care Terry, and all the best, Bob

[Chris Padilla]

Terry,

Can you be more specific about the kind of pipe you use? I guess I should have read off your pipe exactly what you have. Darn it!!

The irrigation house did show me some really thin 6" pipe but I could squeeze it pretty easily with my hand and so thought it might be too flimsy and I passed on it pretty quickly. The 6" fittings the irrigation house had were the cheapest ones they had and were S&D so perhaps McMaster-Carr, even with shipping and possibly tax, might be cheaper.

[Terry Hatfield]

Terry,

Can you be more specific about the kind of pipe you use? I guess I should have read off your pipe exactly what you have. Darn it!!

The irrigation house did show me some really thin 6" pipe but I could squeeze it pretty easily with my hand and so thought it might be too flimsy and I passed on it pretty quickly. The 6" fittings the irrigation house had were the cheapest ones they had and were S&D so perhaps McMaster-Carr, even with shipping and possibly tax, might be cheaper.

c,

Most likely I have what they guy at the irrigation supply showed you. It should be stamped ASTM 2729. That is the sewer and drain pipe. It is fine for DC. I have helped a few guy's that bought the pipe locally and ordered the fittings from McMaster. Sometimes that is the most economical way.

t

[Frank Pellow]

I picked up my Oneida 2hp commercial dust control system about a month ago from Welbeck Sawmill. Welbeck Sawmill is in the bush about a three hour drive from Toronto and it is well worth the trip (http://www.welbecksawmill.com/). I had a very very full trailer coming home. It is a good thing that Oneida pack their equipment so well. In fact their packing is made better than a lot of manufacturer's products.

Since then, everything has been sitting in my garage waiting for me to prepare the shop. This morning, I moved the unit into the shop and the ductwork just outside the shop. I am attaching a couple of photos.

Aside: With a couple more hours work, we will be able to get the car into the garage again (for the first time since last March). Margaret (my wife) has been on my case about this for some time and it is none too soon because winter is on its way.

I have no idea whether getting the unit put together and operational is going to be easy or difficult nor how long it will take. I am about to find out.

[Ken Fitzgerald]

Go Frank Go! Let me know how you like that Oneida system! That's the numer dc I've got in mind for my shop!