what is the best plastic pipe to use

4” rain gutter PVC. It is a lot cheaper than sch 40 or 80 and is much lighter and easier to work with. Plus it works well with 4” rain gutter hose.

-- Rob McCune

I used 4” drain pipe. No need to spend more money than you need to. All the fittings are inexpensive also.

Don’t know if I’m using the correct name for it, but it’s the stuff you get at Home Depot or Lowes. It has
a thin wall and it the most inexpensive 4” stuff they sell.

-- Gary, East TX -- The longest journey begins with a single step.

do blast gates and 4” flex hose fit

-- Do it right the first time. Becuase fixing it is a wast of time.

Actually they don’t. The blast gates are too small. I solve that by cutting a 2” piece of pipe and then cut a slot
in it. Making it look like the letter “C” if you were to spread it open. I trim it enough so that it fits in the
end of the pipe. Then the blase gate fill fit snugly.

The flex hose is just a little bit bigger than the pipe, but you can get it into the 4” fitting. I usually use a
coupling.

The pipe does have a expanded end so that another piece of pipe will fit into it. I just cut that part off.

I usually hold everything together with a couple of 1/2” #8 screws.

The trouble is well worth the cost savings. You only have to do it once.

-- Gary, East TX -- The longest journey begins with a single step.

thanks garyk
I have a 21/2 horse grizzly on 220v. do you think I should run a 6” main and drop 4” from ceiling

-- Do it right the first time. Becuase fixing it is a wast of time.

To tell you the truth, I don’t have a clue.

I ran 4” for everything and I have a 2 1/2HP DC also. I ran mine under the concrete slab so I don’t have to
suck everything up the ceiling.

-- Gary, East TX -- The longest journey begins with a single step.

I’m no expert but I did quite a bit of research online before designing my system…and I can share you some links to some of the articles I’ve read…

This guy did some calculations re: 6” vs. 4” and convinced me to use 6” mains (along with reading Sandor’s book)
http://unkis17.googlepages.com/dc.htm

Here are some other links I saved that you may find of value:
http://www.woodcentral.com/articles/shop/articles_221.shtml
http://www.woodcentral.com/articles/shop/articles_221.shtml
http://harderwoods.com/pipedocs.html
http://home.comcast.net/~rodec/woodworking/articles/DC_myths.html
http://www.benchmark.20m.com/articles/BlastGate/blastgatebuilding.html

-- Patrick, Chicago, IL http://www.TenonAndSpline.com/blog

Basically, the air flow in the pipe must be at least 3500 cfm in order to suspend the dust particles. To get this in a 4” pipe you need a lot of HP. A “6 pipe requires a whole lot more power. This is fine is you are designing a system for the free standing shop of 1000 sq ft or more where you have room for the bulky pipes and the need for rather long runs. However, it is overkill for the guy who works in his basement or garage. Also, high HP translates in high noise level. For that reason larger shops often put the dust collector in it’s own enclosure outside the shop. If you were to put a 2 1/2 HP unit in your basement, you will quickly get the attention of the entire family.

If you are looking for a smaller system for the home, lower HP and a 3” piping system with 2 1/2 inch flexible hoses to your tools works just fine. Veteran woodworking author Nick Engler describes this type of system and gives technical details; http://www.shopsmithacademy.com/SS_Archives/SS109/SS109_Dust_Collection.htm

-- "Heaven is North of the Bridge"