What 6" PVC pipe is best for ducting

[Dick Howard]

Am trying to figure out what type/grade pvc is best for dust collecting. Also what radius 90 works best. 30 or 45 degree wyes? How hard is it to weld pvc? Lots of questions , Know the answers are in this group somewhere. Many thanks for your help.
Dick from Emmett, Idaho

[Terry Hatfield]

Dick,

Welcome to the Creek!!!

I use 6" S&D (sewer and drain) it is also called PVC 2729. It is lightweight and much cheaper than the Sch. 40. I use 45 deg. wyes...honestly I have never seen anything else in S&D. Put 2 45's together to make a 90 deg. turn to get a longer radius than the stock 90's have.

I don't ever glue anything. I just seal the seams with adhesive bathroom caulk. Works great and if you need to take it apart to move something you can just cut the caulk and pull the fittings apart.

I use a couple of 1/2" screws at each connection until the caulk dries and them remove the screws and caulk up the holes.

If you want to see my system you can click on the "www" button on the bottom of this post and go to the shop tour. Also much good information on Bill Pentz' site about PVC and dust collection in general.

http://cnets.net/~eclectic/woodworking/cyclone/Index.html

Check the new releases and the ducting page.

Let me know if I can answer any questions or help you in any way.

Thanks,

Terry

[Dick Howard]

Thanks for the answers Terry, Ive been lurking around for a week or two. Have been to your site. Nice. I just got a jet DC1200C for my bday. Want to plumb it in right. Thinking about trying to bend my own 90s. Have bent a lot of conduit, but nothing as big as 6in. Hope to eventually upgrade to a dust eleminator but that is down the road a ways. Will use blower for the cyclone if it will work good. Anyway, thanks for the information. Its a good thing you and Bill Pentz are doing.
Dick

[Bill Pentz]

Dick,

Here is my dust collection site and I've shared out quite a bit on ducting in its own web page. Terry followed my designs and then of course improved on them! Good work Terry! You can get to that ducting section by clicking on the "ducting" blower on the Cyclone and Dust Collection Information (http://cnets.net/~eclectic/woodworking/cyclone/) page.

I've played a touch with some of the larger PVC and have picked up a few pointers that I shared out way back. Other than lots of cautions as the off-gasses from PVC are deadly, take a look at my notes: Tips & Tricks in working with PVC (http://cnets.net/~eclectic/woodworking/pvc.html)

It takes me either an oil or glycerne bath (or a big vacuform) to work on the bigger pieces. To bend the bigger pipe, the theory is the same as the conduit, but the practical required me to buy a second big heat gun. Just too much surface area to work with my one gun.

Here are a few of the pieces of magic I did a year or so ago. All were from 18" and 20" round stock, all schedule 40 which is much harder to work than the 2729 S&D that Terry recommends and uses.

http://cnets.net/~eclectic/woodworking/DustFilterManifold.gif
bill

[Dick Howard]

Thanks Bill, I printed out the info you refered me to. Don't know how soon I'll get to try it but ideas keep poping up. Have a propane torpedo heater I might try for a heat source. Should be enough if I can control it. Want to make a jig like a conduit bender to keep from kinking or deforming. From your notes it looks like a 30" CLR for 6" pipe is best. Will try that. Thanks again. Dick

[Mac McAtee]

I agree that the S&D is the better PVC to use. You can get long radius 90° elbows from McMaster Carr, not too expensive. I wouldn't weld, glue or caluk anything. Plug your system together, the pipe seals fairly tight and if there is an air leak at a fitting it will be so small that dust will seal it up naturally as time goes by. Use 3/8" self drilling, pan head sheet metal screws, one or two at each joint to hold the pipe in place, just drill them in at the fitting hubs and they'll hold the system together. No one, that I know of, after they have their system plumbed ever is satisfied with their orignial concept. If you haven't glued, welded or caluked all you have to do is pull out a few screws and make the changes that you want. Quick simple and easy.

[Hal Flynt]

I also like the S&D. I did find 90 deg. wyes and slope them towards the collector. I ran a couple of laps of masking tape around the pipe to snug fit to the wyes etc. while I refined the system. When I got it the way I wanted it, I put a sheet metal screw in the fittings and ran a lap of duct tape aroung that. (I never know when I'll want to change it.)

I did go ahead an glue the wyes and blast gates as I figured they will stay as a unit.

To fit the black blast gates, I heated a short 4 inch length of S&D (follow all safety precautions as fumes are toxic) with a propane torch until soft. Slid the cutoff section on the flare, that comes on the end of the S&D, over the blast gate and inserted the softened pipe into space between the flare and the blast gate very quickly pushed down on the flare to reduce the softened S&D to a custom fit on the blast gate. When cool, pull the blast gate and flare off, then run a bead of RTV and reinsert and let dry. A screw here helps hold too.

[Dick Howard]

Thanks for the input guys. Hope to try a few things soon. LOML has me busy with yard work right now. She can't stop the thought process tho.

what kind of blast gates are you refering to Hal? Tried to go to your web site but could'nt. Maybe you were working on it at the time. Will try later
Dick