# 28 ga duct for dust collection - any good?



## gtbuzz (Sep 19, 2011)

I know the recommendation for galvanized ducting for dust collection is min 26 ga. My local big box stores all have 30 ga and that does seem very likely to collapse. I was all set to go the S&D PVC route when I checked a local plumbing supply store and found that they have 28 ga snap lock duct for very cheap. A 5 foot length of 6" duct was only $4 (about $0.80/ft). I had priced out 6" ASTM2729 at about $3.50 / ft.

The fittings were significantly cheaper too than the corresponding S&D fittings.

I've got a small shop, so I don't need all that much stuff. About 30 lf of ducting and a handful of 45s and wyes. Difference in price is about $125 for 28ga vs $250 for the S&D. Question is will the 28 ga suffice? A difference of $125 isn't that much in the long run, but I'd like to save the money if I could.


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## b2rtch (Jan 20, 2010)

I bought my 6" duct at HD. 
I am not sure what the gauge is. 
To prevent it from collapsing, I made a vacuum safety valve that let air in the system when the vacuum become to great.

http://lumberjocks.com/topics/46764




























You can use the idea, it works well.


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## gtbuzz (Sep 19, 2011)

Wow, that's a fantastic idea; thanks for that! I've got a 3hp motor from a Shop Fox DC, so I'm sure if that's good enough for you, it's more than enough for me.

Did you just use any available spring, or did you figure out some sort of spring rate required?


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## b2rtch (Jan 20, 2010)

I just got a spring not too soft, not to hard.
As you can see, I use a CD.
With all the port closed, it opens, with one port opened it closes.


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## Finn (May 26, 2010)

I used 24 guage 6" round snap lock pipe that I got here: http://www.globalindustrial.com/g/hvac/ventilation/Duct-Pipes-Plenums/speedi-products-round-pipe-84073


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## Grandpa (Jan 28, 2011)

I bought 26 ga. spiral wrap from my local Locke Supply Centre'. It is a heat and air/plumbing/electric supply supply place aimed mostly at professionals. I bought 3-10 ft stick, 6" in diameter for $130. That comes to $4.30 per foot but I should never have to worry about it. It was cheaper than 6" plastic in that place. I bought wye's from the same place. These are 6×6x6. I bought the remaining couplers from ACE hardware. These are stove pipe quality. These have ribs etc so they won't collapse like long straight runs of pipe. I was in a shop with 6 inch A/C grade pipe that collapsed. An experience I didn't want in my personal shop. just what I did.

BTW b2rtch, I like your safety valve design. Should work well. That could save a lot of misery.


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## fge (Sep 8, 2008)

I get the same duct Jim gets from the same place. It is a great product for a great price. I get my WYES there also.


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## Finn (May 26, 2010)

I made my own Wye's and blast gates. I am a retired sheet metal worker. I have installed miles of spiral pipe and have seen it smoke tested with leaks all along the spiral seam. I painted my snap lock pipe seams with a duct sealer. That would be a chore on spiral pipe so I did not go that route.


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## AlanBienlein (Jan 29, 2011)

Bought all of my snap lock duct work at Lowe's and Home Depot. Couldn't tell you what gauge it is. I also made all of my own wyes and blast gates. Did my duct work for my shop for about $120 total. I can also close all of my blast gates with no fear of collapsing them. I was going to do spiral originally but got a quote from a local company for $500. That changed my mind very quickly.

Just a side note I use a 16" impeller with a 5 hp motor driving it on my system.


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## shawnmasterson (Jan 24, 2013)

AlanBienlein I take it you never had a plugged pipe. 5HP and a 16" impeller that's a monster. I have 3HP and a 13" impeller and had a collapse of 25' of 7" pipe. I was vacing planer curls with a 4" hose and it pulled a ball of shavings to the end of the 4". It collapsed the pipe before I could hit the remote. I just started plumbing with 6" pvc


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## AlanBienlein (Jan 29, 2011)

Shawn Masterson said "AlanBienlein I take it you never had a plugged pipe. 5HP and a 16" impeller that's a monster. I have 3HP and a 13" impeller and had a collapse of 25' of 7" pipe. I was vacing planer curls with a 4" hose and it pulled a ball of shavings to the end of the 4". It collapsed the pipe before I could hit the remote. I just started plumbing with 6" pvc."

Never had a plug in the line from shavings but I have run my cyclone with all blast gates closed whenever I empty the collection drum to make sure I get the ring tightened all the way.

If you look closely at the pictures I posted all of my ducting is hung with brackets that the duct work slides thru and therefore is supported on all sides to prevent collapse. I have a 8" main with 6" branch lines with all machines converted to 6". The only 4" I use is for the router table portion of the table saw and that has 4" connections above and below the table.


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## shawnmasterson (Jan 24, 2013)

I never thought that would help. sweet Idea.


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## b2rtch (Jan 20, 2010)

AlanBienlein,is your cyclone a "E-bay" one? 
Looking at the picture again, it looks like it is home made
How does it work?
I almost bought one
I just installed a Clear View 5hp.


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## AlanBienlein (Jan 29, 2011)

That is my second cyclone I built. The first was an 18" dia just like the clearview. I modified that one to the same specs as the cvmax but just wasn't happy with the suction from it. I gave that one away to a local fellow wood worker and built a 20" diameter cyclone.

It work great but I do need to make sure another blast gate is at least partially open otherwise it will collapse the flex connecting the machines to the system.


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## b2rtch (Jan 20, 2010)

Then use my vacuum safety valve idea, it works great.
Look at the top of this post


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## gtbuzz (Sep 19, 2011)

Thanks for all the replies. I think I'd actually be comfortable going with 30ga using Bert's safety valve idea but ironically, I was able to find a local supplies for 28ga that's cheaper than the 30ga at my local HD/Lowes. FWIW, it's a Fergueson. Those seem to be located throughout the country in case anyone wants to check on local pricing.

Bert - I've got the eBay cyclone that you're talking about. It seems to work okay, but honestly I've got no other metric to measure against. I'll be documenting my build over the next week or so as I get everything set up.


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