I bought out a retiring cabinet shop's nordfab. Its great stuff when your installation environment is interesting (up super high in my case).
I bought out a retiring cabinet shop's nordfab. Its great stuff when your installation environment is interesting (up super high in my case).
Glad its my shop I am responsible for - I only have to make me happy.
Static pressure is good but you also need enough air volume to allow for adequate air speed to keep dust and chips moving, not dropping out of the airstream and sitting on the bottom of the pipe. When I first installed stationary D.C. lines I'd use a 2.5" hose for something and the dust and chips would get sucked up. When I'd open a blast gate upstream from the 2.5" hose, there'd be a slug go into the blower. There wasn't enough airflow in the main line with just the 2.5" hose open. Since I've cracked an upstream blast gate no more slugs going into the blower.
I uset metal and am very happy with it. Largely driven by the availability of Y's with all combinations of diameters and large radius elbows that I couldn't find in PVC. Sched 40 is also darn heavy to hoist up into the air in 6-8" diameters when working alone.
Little known (apparently) is the availability of duct tape back in the plumbing section that is ASTM rated for use on ducts. Works great-- when I disassembled my last system for a move after 10 years it was still like new. $12 a roll rather than $2, but makes for a nice tight system.
I choose metal for the following reasons:
- PVC has tight elbows, bad for flow
- PVC is heavy and larger outside for the same inside diameter
- PVC comes in 6" and 4" but no 5"
- blast gates, etc readily available for steel.
- For 6" the cost wasn't that different
I used 26 ga. steel pipe (not spiral) and sealed all the joints and seams with a brush on sealer made for for camper tops or metal roofs. Easy to use and the pipe can easily be taken apart if necessary.
No PHD, but I have a DD 214
My dust system is all PVC, even the parts that I made for it, except for the rubber couplings between the pipe and separator.
Charley
Metal all the way IMO.
If at first you don't succeed, redefine success!
I used 26ga spiral steel with long sweep fittings. Easy to install. I choose not to spend the money on Nordfab though, that stuff's crazy expensive.
If you go spiral, make sure it's externally seamed with no corrugations (smoother interior). The corrugations give more strength, but at the expense of more pressure loss.
thanks to all for the great information. I went with metal for the small run from the DC to the cyclone and I have a new respect for tin-bangers. only had 3 elbows and 3x30" ducts 26g but lots of frustration, clearly there are tricks to assembling the duct. The elbows fitted together nicely on the bench but again gave me trouble on the final assembly, I had to add additional crimping, more frustration... in the end it all came together but with more screws then I wanted. The very good news is Prelim ft/m meter tests indicate suction will not be an issue and I have not even applied tape yet. Once I apply tape I may remove the screws.
Next challenge, mount the cyclone platform on wheels and join it to the DC (already on wheels) and then support duct to the cyclone platform so I have one unit on wheels for cleaning and maintenance.
Pictures ad meter readings to follow.
So the metal pipe was the best solution for me as I had to adjust, adjust, adjust and adjust some more but in the end it works. It did not turn out as pretty and perfect as I envisioned, but the great part is it squeezed into its allocated space bulling with my router table for floor space, albeit with some rough cutting of the new base. The DC, cyclone and connecting duct are now one full unit so they can roll together as a unit when maintenance is needed. I still need to add a bridle rope pulley to lift the cyclone to empty the container. Then I will seal the duct with tape
Note the Plexiglas view-port on the cyclone may be a waste, already getting too foggy.
DC setup1.jpgDC-base-extended.jpgDC-base-extension-2.jpgDC-tight-space.jpgviewport.jpg
Alan thin 6" and 8" S&D PVC etc., isn't readily available outside the few large urban centres we have in Canada, and if it is, it is horrendously expensive. Here in Saskatoon, largest city in the province with a population of 1/4 million, 6" was quoted to me at $10.00 to $16.00 per foot and 8" at $16.00 to $24.00. You don't even want to ask about fittings. Borg stores don't even stock 6" of any kind so it is only available from plumbing or irrigation companies. Heavier PVC or metal are the only options.