JHCC

Homemade gate valve

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I made this gate valve for my new JABOD forge and thought folks might like to see how the insides work. It was pretty easy to put together, and all the materials were screws and pallet wood that I had on hand already.

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Starting with the back board of the forge, I drilled a 2" diameter hole in the middle. I used a big Forstner bit for all the holes, but since the pallet wood was so hard (red oak), I had to hog most of the material from the middle of each hole with a twist bit.

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The middle layer has two holes spaced 2" apart: one that directs the blast into the tuyere and one that exhausts the excess air. 

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The sliding gate has a 2" x 4" oval. When the gate is all the way in, the oval connects the blower with the tuyere. When it's pulled out, the oval connects the blower with the exhaust vent.

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Another piece of wood covers the outside and holds the whole thing together. The 2" hole is centered between the tuyere and the exhaust vent.

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The little metal clip keeps the gate from pulling out, and there's a little block of wood at the end (see top photo) that keeps it from pushing in too far.

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It's pretty rough and ready and leaks a lot, but it does a great job of adjusting the blast.

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Kind of fancy for a box of dirt isn't it? Pretty slick John, the blower inlet is the round hole visible on the outside in the pics. Yes?

Frosty The Lucky.

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Wow, my air gate was a slot cut in the tue pipe with a scrap of sheet metal shoved in, way more rough and ready than yours lol. OTOH, you won't lose the gate as many time as I did.

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47 minutes ago, Frosty said:

Kind of fancy for a box of dirt isn't it? Pretty slick John, the blower inlet is the round hole visible on the outside in the pics. Yes?

Frosty The Lucky.

Yes, that's the inlet. I haven't yet figured out how to attach the blower, but then again, I'm not yet sure what the blower actually will be. I'll probably start off with the same shop vac I was using before, but Lisa just got a new vacuum and I'm all set to modify the old one.

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Wanna go old timey blacksmitherly? Find a tin can about the right dia to fit whatever blower hose you have. Then find a larger tin can and cut an end out. trace the ID of the small can in the center of the larger lid. When you cut it out with tin snips or a SHARP chisel leave about 1/8" overlap on the inside. AND leave a couple tabs to you can pin, rivet, screw, etc. it all together.

With the lid cut it's easy to pein the extra in to make a lip for reasonable air tightness. If you forgot the tabs solder the assembly together, other wise punch a couple holes and wire, pin, whatever the sophisticated mounting flange to the equally sophisticated custom air connection. Screw or pin it to the air valve.

Everything stays in character.

Frosty The Lucky.

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What is this "air tightness" of which you speak?

By the way, the great oven disassembly of 2016 left me with a ton of hex head sheet metal screws, which are coming in very handy. 

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Here's the fitting to attach the shop-vac hose, made from a soup can, a section of shop-vac extension wand, and a gasket of motorcycle inner tube. 

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And here's a video of a kindling fire going from "no blast" to "full blast" and back. 

 

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Cool. Looks like you are ready to heat some steel in that guy. With charcoal I doubt you are going to need much of a blast with that. 

I'll have to make one of those one day. 

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4 minutes ago, Daswulf said:

Looks like you are ready to heat some steel in that guy.

Just as soon as the temperature gets up a bit closer to freezing.

4 minutes ago, Daswulf said:

With charcoal I doubt you are going to need much of a blast with that. 

I've been burning rice coal (anthracite) mostly, but if I do go back to charcoal at any point, it will be easier to regulate the low blast.

4 minutes ago, Daswulf said:

I'll have to make one of those one day. 

Yeah, but you can make one out of metal, with that sweet new welder of yours!

 

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Haven't done a coal fire yet, but I was using it to good effect in the rivet forge (which was clayed to have a very similarly sized firebowl). My daughter has a project she wants to make before the end of spring break, so I'm expecting to fire it up within the next few days.

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On 3/15/2017 at 11:31 AM, Daswulf said:

So you are getting good results with the rice coal in the jabod?

Resurrecting the thread: Yes, hot enough to burn a piece of 5/16" x 1-1/4" into a corn chip. 

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:lol:

better then not hot enough! You can always turn the air blast down so it's good to be able to crank it up for large stock. 

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2 minutes ago, Daswulf said:

You can always turn the air blast down so it's good to be able to crank it up for large stock. 

I'm actually not using the gate valve at all (just leaving it wide open) since I just picked up an old variac that I can use to vary the speed of the blower. I posted about it earlier today on the new Jabod thread.

 

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That's what I meant. I saw that. That is a cool old " potentiometer "? Not sure exactly how it works but I know basically what they do. Love the look of that old thing :)  same basically as the router speed controller I use isn't it?

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The technical term is "variable transformer", and I (not being an electrical guy) have no clue how it works. I've just been told (A) that it works best with "universal motors"/"motors with brushes" and (B) that vacuum cleaners have universal motors. It certainly functions just like your speed controller.

One nice thing about it is that it's basically spliced into the middle of a heavy duty extension cord, so all I have to do is plug it into the wall, plug the blower into it, and we're good to go. I'm thinking of getting a Grizzly 2x72 grinder, and I'm wondering if I might be able to use it as a speed control on that....

6 minutes ago, JHCC said:

I'm thinking of getting a Grizzly 2x72 grinder, and I'm wondering if I might be able to use it as a speed control on that....

Addendum: did some research, and the answer is NOPE. Oh, well.

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Ingenious JHCC. Like the valve of an old steam engine. It looks as it can be much better in controlling air than the usual valves. It also means that a blower that relies on its own air for cooling the motor does not get overheated. I will keep the principle in my mind should I need to rebuild my forge. Thank you for posting.

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