use the 26GA...
tape the seams...
use rubber cement as gasket material... thin layer on one part and assemble after dry...
use saddles instead of fittings... hose clamp them on..
use these style of reducers..
see if a wholesaler will give you a break...
Sounds like sound advice! Thanx for the .pdf!
I've gotten others (on another forum) who have stated they didn't go the route you mentioned, rather they reduced to 6" PVC immediately out of the DC and reduced to 4" lines fairly quickly. Then there are yet others who have recommended a mixture of the two (metal vs PVC, reduction "out of the DC"). My thinking is that I wouldn't want to reduce to 6" lines until after the first branch, and reduce for 4" lines for the down-drops.
Maybe I'm being too picky about "leaky" systems and the aesthetic of the spiral pipe vs. snap-steel vs pvc (thin wall or schedule 40).
My set up will basically be:
1) 15-18' run across the "back wall" of the shop which will service:
A) a small line to my bench (against a wall)
B) router table (Triton TRB001 2" dust collection hose)
C) radial arm saw,
D) 18" band saw.
-[The "small line" will be a sweep-type opening for brushing stuff into
and a 2" line for small cleanup]
-B and C will likely be a "Y" where both are either open or closed for air movement purposes.
2) a 10-15' run to the center of the shop which will service the Robland X31.
3) Somewhere in there I need to put in a floor vent for cleanup.
So I would think the following would be the starting point:
.....................Robland, 4" drop
. ....................6" |----|
..............| |DC |---7"----Y-----6"------T---------T---------X |----|
The periods are to be ignored -- they are there for spacing purposes only.
Where the "T"s are each 4" 45 degree angles into flex hose. The flex hose runs will be about 6-8' each, coming from roughly rafter-height where the 6" line is. The "A" is a 4" Y 'splitter' that will either be both-open or both-closed (via a gate) to feed the Radial Arm saw and router table. I have these both open due to the restricted air flow from the router table and its expected decrease in efficiency. The "X" at the end of the run will be a "gradual 90" to 4" line to feed the bench sweep, and I'll put a 2" "Y" near the "bottom" of the run for the vacuum hose line.
Theoretically I could switch to PVC at the 6" runs. Savings would be measurable, but I'm blessed with a good budget. Is there an advantage (other than price) by switching to PVC?
I just read the Bill Pentz site article on Ducting (Thanx, Stick!) https://www.billpentz.com/Woodworkin...ne/ducting.cfm
and it covers ALL of this stuff.
Stick, your initial advice is SPOT ON with that article in mind. I think my design idea (made before reading that article), with the thought of using the 26g spiral ducting, is correct.
I'm sure I'll come up with more stuff to dither about...