Building a steel blower housing

[Wes Billups]

Many years ago I purchased a 16" impeller with the intention of replacing the existing 12" impeller on my cyclone dust collector. I'm finally getting around to building the blower housing. I've gone back and forth on buy vs. build. Ultimately I've decided to build in order to save a little bit of money, hopefully end up with better quality, and most importantly because I want to give it a try.

I'm going to use the design from Bill Pentz's website (pictures are all from his site).
350609 350610

My question is, has anyone made one of these themselves out of steel? My plan is to use 11 gauge steel instead of the MDF in the plans. I've got someone with a plasma cutter that will cut the pieces to shape and I've got a wire welder. The steel is going to cost me less than $50 so I should end up with a pretty good unit if all goes well. Just need to practice my welding skills as this will be the first time welding on something that has to hold air.

Anyone have any tips, suggestions, pictures from their builds. I plan on taking many pictures and posting the process here. I've never documented a project like that before so it may be pretty crude. Plus I'm hoping you guys/gals will help push me along.

Any feedback would be appreciated.

Thanks,
Wes

[Matt Mattingley]

I've built the blower, fan, the cyclone...

http://www.sawmillcreek.org/showthread.php?220526-Bill-Pentz-cyclone-build&highlight=

[John K Jordan]

I've built the blower, fan, the cyclone...

http://www.sawmillcreek.org/showthread.php?220526-Bill-Pentz-cyclone-build&highlight=

I just glanced through your build thread and although I want to go back and read it in detail all I can say now is wow! What a good looking build!! How has it worked out over last couple of years?

I put in the 5hp ClearVue and it is incredible.

JKJ

[Wes Billups]

Wow Matt. That is exactly what I was looking for. I was positive someone on here had made a housing out of metal. While my metal working skills aren't anywhere near what yours are I hope to have something that looks and functions similar to yours when I'm all done.

One of my concerns has been what thickness of steel to use for the housing. I was planning on 11 gauge (1/8") but see you used 1/4". Do you think there will be any issues with me using 1/8" steel for the housing? My concern is that my motor will be supported by a 20" diameter disc of 1/8" steel and I don't want it flexing too much causing interference issues with the fan wheel. I can always add some square tubing to the backside after the fact but if it'll only be $20 more to go with the thicker steel I might do that.

I believe I'm stuck with using the same gauge for the flat sections as the curved sides. I was under the assumption I would have to buy an entire sheet. I'll call tomorrow when they are open to see if they'll sell smaller quantities at the same price. I'd probably use 1/4" for the flats and 1/8" for the curves if I can order just what's required. Plus I feel more confident with my ability to weld thicker steel and not distort it.

[Matt Mattingley]

I just used hot rolled plate. It's been a long time but I think it is only 0.236". I went that thickness because the motor weighs 50 pounds. I went with stainless steel on the sides and I tig welded it. The outer diameter where the exhaust gets pinched into a sharp corner I drew a line with a square and used a cut off wheel to half cut through the stainless steel and I bent that corner. I started welding there and worked around and around tacking. There was about 6 inches extra on the other side of the exhaust and half inch on the sharp corner side. So I with a cut off wheel left half inch on the other side. This gave me something to attach my exhaust duck work to.

[John K Jordan]

...
My question is, has anyone made one of these themselves out of steel? My plan is to use 11 gauge steel instead of the MDF in the plans. I've got someone with a plasma cutter that will cut the pieces to shape and I've got a wire welder. The steel is going to cost me less than $50 so I should end up with a pretty good unit if all goes well. Just need to practice my welding skills as this will be the first time welding on something that has to hold air.


Wes, I haven't built one and I am certainly no welding expert but I have welded a bit of sheet metal. 11 ga is pretty darn thick and should not be much trouble.

I learned to weld sheet metal with a torch. I would use TIG now but I have welded some pretty thin stuff with both flux core and MIG (MIG is a LOT cleaner). One problem is to prevent the metal from warping as you weld. Clamping the work down to something solid (I sometimes use plywood) helps but tacking it all over is a real help. Another issue is to get sufficient penetration without burning through the back side from too much heat. The way I learned was to make a series of very small tack welds, each just a short blip with the wire on the ends then the center, then more tacks between those until the weld is finally continuous. That's the way I repaired an old farm truck door, generator housing, wheel barrows, etc. Once the thing is tacked you might be able run a series of short beads on steel that thick but you can still blow through 1/8" steel with too much heat. I've welded 18 and 20 gauge with a wire welder using the successive tack method.

I'd practice on strips of the same steel you will be using to get the current and wire speed right and to get the feel for the perfect tack weld.

There is a lot of info on the web. This one might be a fun read: http://www.speedhunters.com/2014/03/the-101-how-to-weld/

A plasma cutter is great. Unless he has a computer controlled cutting bed you will get a lot better edges if you use a template. For straight lines I just clamp a piece of wood, for short curves I have used thick bent wire. For the housing you show a template made from some kind of sheet stock to guide the edge would be great. But with mild steel that thin, you can also get pretty good cuts with a hand-held jig/saber saw will also work - it's pretty quick with a good blade. I do use the plasma cutter for most things since it is here, especially on thicker steel. I can cut up to 1/2" on mine.

If you have pinhole leaks can you use a silicone caulk seal? That's what ClearVue instructs for all components of their cyclone.

I did just now see your question about thicker steel and I can't answer that, except to say thicker is easier to weld than thinner (up to a point!). With 1/4" steel I would definitely cut out the parts with the plasma cutter. The same issues about warping from too much heat in one place apply, though. Bending 1/4" steel into curves for the side of the housing will be challenging unless you have access to the equipment, such as a heavy duty plate roller.

JKJ