Good to know. I’m still getting pieces together for a grinder.
The DOM tubing is 2.625" OD and 1.875" ID by 48 inches long. Plenty to work with.
While I’m waiting to get that tubing I’m going ahead and making the grate, I’m probably going to use some small angle iron I have laying around and have it facing upwards to hold ash for self insulation.
I’m also cutting the ceramic wool to size and forming the tube. I forgot how irritating that stuff is to work with, in more ways than one.
After realizing i don’t have enough angle iron to make a good grate I think I might go with perforated diamond plate. I’ll weld tabs to the interior of the drum to hold up the diamond plate, which will also hold up the insulation. I’m trying to design the insulation as such that it will be a very close fit that I then seal up by smearing refractory around the edge. I want to leave the flutes a friction fit then a bead of muffler repair sealant which resists very high temps. Better than blowing holes in the drum with my welder.
Dont worry about insulation sealing. If you put cheramic wool in in tightly so that it hold its self up thats more thain good enaugh. The gasifier seals its self after a few runs with ash and dust.
Oh, and the pipe diameter looks perfect!
I wish I had more free time to go to the scrap yards. I have a few in my area but all of them close when I get off of work and are closed on weekends. I know for a fact I could get piping and large diameter tubes for a lot cheaper there.
First step to completing the build! Already blew one small hole in the barrel but thems the ropes with flux core welding. Patched it up a bit but I’ll probably just smear muffler sealant on it to be safe. The grate seems thin so I bought enough to double up in a cross hatch pattern. I welded two bits of angle iron on the edge to hold the grate up. In the centermost part it’s actually 8 layers thick so I think it will last long enough.
What I’d give to have a 22" diameter disc about 1/4" thick with holes already made!
Cody, I love this project! Just in case you haven’t discovered it, use a serrated bread knife for cutting ceramic batt insulation. Smooth, fast, accurate cuts.
Perhaps this should be under Tools Tips and Tricks.
One more update before I make any progress. With my welding setup and skills I am going to abandon using an ammo can as an ash cleanout.
I’m instead going to use 2 inch pipe welded to a flange bent to the contour of the drum and bolt it in place with sealant, not unlike what Gary Gilmore has done in his Simple Fires.
I’ll probably use a T fitting for the Gas output and have a plug so I can inspect with a light and get a skinny vacuum cleaner end in there for cleaning out. For grate inspection I’ll just scoop out any charcoal in there and look at it from the top.
Pipe size might change to a 3 inch if I can find it, to be determined.
The rest of the tubing for gas travel will most likely be conduit steel pipe or exhaust tubing. After the cyclone I’ll see if the metal is cool enough for simple hose clamping connections.
If you go to your local hardware supplies store and buy a 3 inch pipe coupling that is male one end and female other end you all you do is drill a hole to suit in your drum/container and bolt it direct in to the drum , then on what ever end is on the outside you can always fit a reducer down to what ever size your gas outlet pipe will be , that way there is only the one fitting to worry about and its still large enough to use as a clean out .
Dave
Do you have a picture of one of those couplings or the name of it? I’m trying to google a 3" npt male to female coupler and not finding much. Closest i found to your description is a reducer bushing, and that might work as long as I can find a nut that will jam the face of the bushing against the drum.
I will go outside and see if i can find something to show you
Ok i have male too male fitting that will do just the same job as i mentioned , the fitting in the photo is a 1inch but they do all sizes in galv fittings , if you cant find them in the cheap galv then you might have to look at black steam pipe fittings .
I use 1 inch and then if i need to go bigger i use the fittings in the photo to take it up to 1" 1/4 or to inch and a half i dont go bigger as i don’t need too yet .
Jesus Almighty this tubing looks more like it belongs on a Swivel Gun than on a gasifier. The whole 48" length weighs 50 pounds!
Dave, Brian, and Cody,
I think the pipe fitting you were referring to with male and female threads is called an extension.
Bombs away! 
+20
I perused my local Lowes and found the only large diameter pipes were the Rigid Conduit type, 2" bore galvanized steel. I found a few fittings and pipes, as soon as I can get a hole saw that makes a close enough cut to put some sealant on I’ll take some photos of how I plan to assemble it. I’ve been doing dry runs on a junked drum I use as the afterburner on my TLUD.
If I can also find a clamp on fitting for the rigid conduit nipple I’ll hook it up to the cooling pipes that will run along the length of my truck’s bed. Maybe I’ll get lucky and find something at an auto parts store that can get me an air tight seal.
I’m still undecided on what material I want to make the cooling pipes out of, either thin conduit or aluminum tubing.
Running into some hole cutting issues.
I suck at using hole saws, and while practicing my cuts I can’t really get a good angle in on the barrel. A square attack angle is really the best that I can do with this jumbo hole saw.
@KristijanL what if I were to use only one pipe but with two rows of jets coming out? Since this is very thick tubing I think with water drip it will be fine. Here’s a drawing for example.
Worst case scenario for jet angle I can just weld over the holes and drill new ones.
What type of hole saw are you using and what size ?
I only use the tct hole saws off Ebay very cheap and long lasting and fantastic in stainless steel , compared to the bimetal saw blades you pay a fortune for .
Dave
Oh your nozzle idea of a double angled row sounds like a winner remember double the holes might mean altering the dia of each hole maybe smaller to keep the velocity right .
It’ll be open ended on both sides. I really like the idea of a single flute mostly to keep the weight down. Plus I’d like to use the rest of this tubing on an updraft perhaps.
Hole saw size is 2-5/8", and others in the 2" range for exit pipe.
All the cheapo blades I’ve gotten like to snag on the barrel that I’m practicing on, throwing the drill out of my hand. Tried going nice and easy and tried just a bit faster, I know with larger diameters you dont want to go too fast. Tried a Lenox brand one and the one that I really like is a Starrett diamond grit hole saw, the Starrett hasn’t snagged yet and leaves a smooth hole with no burrs. Dad worked at Freightliner and said they used those all the time when building trucks.
It’s just really hard drilling at any angle other than square to the surface when the teeth like to snag on the new made edges it just cut. Maybe the teeth are too aggressive not sure.
I think for my other holes I’ll drill with a smaller bit and cut to the final hole diameter in slits with my dremel or jigsaw and file it to fit. I’m nervous around power tools ever since my fingers got chewed up by a table router.
