Njaak

Oh, and yes, was keeping it at 1925 or so. HOT indeed

It's actually currently on standoffs the threaded rod has acorn nuts on the bottoms, and raises the base of the forge about 2 inches off of the sheet metal. So far so good

Mikey, I have digital calipers they're essential to custom bicycle work... the only builder hobby I actually got really good at (so far). The pile of bricks forge works like a charm. Here it is with some A33 in the process of becoming a drift. Burner doesn't overheat, and kept the temp super stable. I'm happy Thanks so much Frosty for the picture of that build. It was worth a thousand YouTube videos.

I finished the pile of bricks! Flame is stable, thermocouple installed! Ramped up heating slowly over a couple of days. Tonight I'll test it out for real if all goes well

Great, thanks!

Frosty, I think now I'm going to build up a pile of bricks like the one in the picture you sent, then sort out if and how to convert the current mess into something for heat treating. To that end, are the bricks forges your club builds using 23 or 26 series bricks? I've read some varying suggestions (insulation value vs strength). My plan is to coat the inside of the chamber with 1/4" of Satanite. I was thinking all 2300 series except the brick opposite the burner which is do with 2600. Thanks.

All sounds good. I've got time set aside for mid August for the rebuild attempt. I'll post questions when they arise and pictures as the Frankemforge progresses.

Ok, to recap: 1 - feel free to tease, I'm used to it, my kids and wife are pros. 2 - Correct, I only spent about 18 months in a shop as an engineer, mostly on CAD drawings and particle physics for electrostatic precipitation. Then moved to audit functions and then policy... etc. Mostly my diy skills are limited to bicycle mechanics, and home renovation. 3 - I'm starting with few tools. Drill press, 2x42 belt grinder, 8" bench grinder, hand held angle grinder, Dremel rotary tool, tap and die set, and hand tools. Zero machinist tools, nor any real experience with them. 4 - Reason for current length was twofold: (1) I had the tank, and (2) I wanted to heat treat longer pieces... and didn't really know how to do that at home without a kiln or forge of sufficient length. I still don't know how I'd do that... I have a kiln I use for HT in stock removal knife making but it can only handle pieces up to 10" total length. 5 - point taken re: not a precision build and tangential flames. Direct impingement on side wall is fine by me.. but how that induces swirl is hard to sort out. Turbulence, yes. 6 - Frosty, that picture shows a clever use of thread and l angle. I love it! Lots of material I don't have in that build but I'll start accumulating. 7 - I've got 2x1" kaowool already, and plenty of Satanite to work with... So that's what I hope to use rather than scrapping and starting with all new everything :/ Fixes to the current project: 1 - shorten the chamber to 9"? 10"?.. I'd like to keep the cylinder rather than going with bricks, since I have it and have some kaowool, but don't have any bricks. 2 - move to 1 burner, with side direct burner mount (not tangential). 4 - taper starting from OD of mixing tube, not ID of burner. Without tangential placement the amount of flare is even less. Those thread protectors are looking better and better.

Appreciate the advice and I do have a stepson who's an electrician so I will get him to sort that out for me.

Grinding an offset ellipse onto 2" pipe to within 0.005". That sounds... hard. I might be able to pull it off with my bench grinder (8" wheels) but the OD of the chamber is 9" so much fidgeting. It's a fun challenge and would save a pile of $ though.

Mikey that sounds harder than picking up a MIG welder and learning how to use it LOL

Ok, did some 101 reading and rethinking. My basic cylinder is 5" ID and 19" long. 373 cubic inches. Frosty, I'd used diameter instead of radius in my previous calculation... urgh. Hence the factor of 4 error. Most embarrassing, as some 15 years ago I earned a mechanical engineering degree (that was used for nearly 3 years, before turning my brain to other useful things). I'm flattening the bottom out a bit which will reduce the volume no more than about 1/10 to 1/8. Roughly resulting in say 340 cubic inches. My understanding is the rule of thumb is one 3/4" burner per 250-300 cubic inches. Given I doubt I'm in the highest efficiency build category, I believe 2 burners should work well. They may even be a bit much. My previous design with even less volume (door constrictions) and 3 burners was unfortunately.. really really bad. The pipe reducers on my burners appear to be the worst flares ever. I will remove them and cast my reducers into the build. The 1/12 rule suggests that for my 0.75" ID burners, the entrance diameter at the forge hot face is only marginally bigger. A 1" increase in diameter per 12" length, means that with 2" wool thickness and a 30 degree angle of incidence, I'll build my mold about 6" long with one end at 0.75" diameter and the other at 1.25" diameter and cast around it. I'm also reconsidering my use of a threaded burner support bar. I did so because I don't yet weld, but do plenty of threading. However, the extra steel adds weight and fuss. I may either pay someone to weld it up, or knuckle down, take a step back, and learn to weld. Some pics of my rough sketches and math for critique. Thanks all!

Thanks SO much Frosty. I'll put some sketches together in the coming days for a rebuild and post for critique.

Hey Frosty I did that re: location. Not sure why it doesn't show... I'll put up a sketch, but I'm already disassembling it. Volume calculation is just pi*(r*r)*L. Don't and back "openings / doors" have depth to them so I included that in the total. The objective is to be able to forge pieces up to 12" long in a hot zone. The rebuild will allow up to 4" wide. I'd like to be able to do knives, drifts, axe heads, and basic tools. I'll go to the 101 page again. My build was based on one I going in instructables. I did add the constricted openings and third burner, clearly mistakes I think. Thanks again.

Many thanks I'm in Ottawa Ontario Canada. Yes, 3/4" ID pipe as burner tubes. Two with bell reducers, One with a 1 1/8 ID tube instead of any flare. I would be very interested in thread protectors and will look into getting some. Also thought I could remove the flares entirely and instead cast them into the chamber with Satanite or something like that. Main chamber is approximately 5" ID, 13" long (1021 cubic inches). Front and back ports are approximately 3.5" ID and 3" deep (231 cubic inces between the two). Total roughly 1250 cubic inches plus a little more for the burner port holes. I was worried I had one burner too many, but went with the advice of a local guy down the road from me that does a lot of metalworking... But he's not a blacksmith. If I need to go down to 2, I'll likely just rework the entire thing. Might a ribbon burner sort out my problems? I chose propane burners because my area is windy and I only work outdoors (hence forge on a cart). Thanks again good sir!