|Project by klipper||posted 05-03-2011 11:22 AM||3215 views||7 times favorited||19 comments|
There are lots of beautiful projects on this site, but this isn’t one of them. However, it is a very useful solution to a problem.
In 2010, I installed a ClearVue Max Dust Collection System in my workshop. It is a great system. It can handle two six inch runs simultaneously. It has an 8” diameter inlet and you need to install a 8-6-6 Wye to convert the 8” diameter pipe into two 6” diameter pipes. I decided to use 6” “sewer and drain” PVC pipe for my ducts as it is thin walled, light weight, easier to handle and the least expensive option for smooth walled ducts, which is critical for keeping the air flow up over long runs. Finding the PVC pipe turned into a real challenge, but finding a Wye with the right dimension turned out to be impossible. I spent a lot of time looking for one that would work. I did buy a metal pant wye at McMaster-Carr but the diameters were off enough to make it unusuable.
I finally had a novel idea. Why not make it out of wood. So I set out and drew up some full scale plans, keeping in mind the need to have the 6” legs at 90 degrees, a large radius curve to reduce drag, a smooth inner surface and lands on the inside of the adapter against which the PVC could seat. I decided the easiest way would be to make it from a series of segments glued together, instead of carving it out of a single block. Some decisoins are easy!!! I realized that, except for the very top and very bottom piece, I only needed to design 1/4 of the project. The other sections would be either identical or mirror images. I made patterns for each of the pieces. There are 50 pieces to this puzzle but due to symmetry, there are only 13 unique shapes.
I chose cedar for most of the pieces due to its light weight. I used oak on a bias for the top and bottom pieces for extra strength across the seam. Using the full scale pattern I had made as a gluing template, I glued up each quarter section, one piece at a time to ensure alignment. I didn’t want to use brads to hold the pieces in place, as I was going to have to smooth the inside and outside surfaces. When the quarter sections grew up to the point of mating, I glued two quarters together, to assure a good fit along the top and bottom seams. Establishing a good fit in the crotch was important as well.
When I had the two halves in place it was time to smooth the inside surfaces with gouges, rasps and a small rotory sander. I then used West Systems Epoxy to coat the inside of the halves to give the surface some protection against abrasion. Cedar is light but it is soft. With that done, I glued the two halves together, smoothed the outside and applied epoxy to the outside as well, using fiberglass reinforcement on the openings, where the most of the stress would be. And finally, I made a circular pattern as a guide and used a router to cut the correct inside diameters of the openings.
It was a lot of work, especially the hand smoothing of the inside, but it does the job I needed and makes a great conversation piece when I have new visitors to the shop.
-- Best Regards, Dennis