ARTICLES & REVIEWS

I actually took out a metal system to put in my PVC. I had used 26 gauge snaplock pipe for the old system with regular HVAC fittings. The HVAC fittings are all made backward. They are designed for the air to be moving away from the blower not towards the blower as we need it to do. I simply could not spend the amount of money required to buy the "real" metal. If you feel better about metal then by all means use it, but if you want to save some money and get a perfectly good system, PVC is a good choice. My entire system cost around $300!!!

I used 6" S&D (sewer and drain) PVC. It is also called PVC 2729. It is much thinner, lighter and cheaper than regular schedule 40. Most likely it will not be available from the big box stores so you will need to check plumbing or irrigation suppliers in your area.

The pipe comes in white or green so check the color before you buy. All the fittings are white as far as I know.

I used 2-45's together instead of a 90 deg fitting. I could not find long radius S&D 90's in my area but if you can find them they would be fine.

Keep the runs as short and straight as possible. Limit the use of flex. Flex hose is a huge performance robber. Run 6" right to the machines. If you must reduce to 4", do so as close to the machine as possible, but change your machine hoods to 6" if you can. This makes an incredible difference. 6" flows almost twice as much as 4". I have used many HVAC register boots to make new machine hoods. They work great and are dirt cheap.

Don't glue anything. Simply use some short screws to hold them together for the initial installation and then seal everything up with white adhesive bathroom caulk then you can remove the screws so nothing is protruding into the air stream that might start snagging shavings. I washed the entire system with a rag and some thinner to remove any scuffs and get the green writing off the pipe. Makes everything look much better.

I also built my own blast gates using scrap plywood and hardboard. They are really simple to build and they seal up very well.

After the system is installed and sealed, run the collector/cyclone with all the gates closed. Use your hands to feel around the connections for leaks. Many times you can just hear the leak. The tighter the system is sealed up the better the efficiency will be.

A word about static...

I have made no attempt to ground my ducts at all. The wire reinforced flex hose that I used does act as a bleed off conductor which helps, and it is humid most all the time where I live which is also a factor. I have not gotten even one zap!! If you do get static in your system, a bleed wire wrapped around the ducts - or a length of aluminum tape on the ducts - connected to the machine and the collector will bleed off any charge.

Check Rod Cole's excellent article about static electricity also in the Articles&Reviews Department.

Cyclone and ducting info will take you to my shop tour and provide more information on ducting and building your own gates, building a sanding/routing downdraft box etc....

^© 2003 by Terry Hatfield . All rights reserved.
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