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It's what the forum is for. Please let us know how you get on and post some pics when it's done.

Why are you mortaring them together? I have built 5 or 6 HT ovens to date and gave up on mortaring them after about the third failed attempt to stick a couple of bricks together. They work fine with dry joints. If you need to prevent movement, a very useful cheat that I have found is to pin...

For O1, an HT oven does not really seem necessary. There's no particular ramp requirement so all you really need is to be able to soak at the Austenitizing temperature you choose. With a good burner that incorporates progressive air:fuel ratio adjustment, a gas forge is able to provide the...

You don't really want to know. I think it's all related to the way 2-flute drills have a tendency to drill somewhat triangular holes. I can vaguely remember covering it at college 30-odd years ago and the math was horrible. The fluteless ones that look like they have a hole drilled through them...

There are 2 things you need. One is a readout. If you can cope with degC, search on ebay for a TM902C and buy at least one. It's not pretty, it's not particularly rugged, it's not American. It is accurate. It only takes a Type K input and reads to 1368 degC or so (2495 degF or so). It is under...

A big disadvantage of shaded pole motors in dirty environments, particularly those with airborne metal dust, is that they are not sealed. The fact that electric motors work by interacting magnetic fields means that they will attract steel particles. Shaded pole motors also tend to run hot, so...

I missed this thread the first time around. As per post #3, the cos Phi setting is the power factor. From the manual, it looks like the SMTech is a Sensorless Vector drive. As far as I can tell, there are some differences between “Vector” and “Sensorless Vector” drives, with the main...

There are several reasons to embed the elements in the wall: safety (the operator cannot touch them), to protect them from harsh atmospheres (we normally have an Oxidising atmosphere, which is pretty aggressive. Some of the things the pottery guys do with glazes are even nastier), to reduce...

I thought so. I am hugely impressed by the TM902C. I have had a few, some marked for different maximum temperatures. All have worked to 1370 degC (with a suitable thermocouple). I've had them on a calibrator and accuracy is as good as anything I've had from any of the big names at twenty times...

Basics: A thermocouple is just 2 different metals joined together. When the junction is heated, it produces a voltage which depends on the temperature and the metal compositions used. Any metal combination can be a thermocouple. A number of particularly useful compositions have been...

Ramp is useful when the HT recipe calls for it, but also has a role to play when tempering. Using a slow ramp can dramatically redice temperature overshoot as a result of direct radiative heating. When heating to a setpoint, the controller runs the elements at full power until the...

As the guys have said, filling it with bricks will just increase the thermal mass and slow things down. I can't make out the markings on the control knob from the photos, but assume they are power increments. These are unlikely to relate in any meaningful way to actual temperature. To get...

I have built several unsealed VFDs into IP66/NEMA 4x panels and used homebuilt remote control boxes for them. Diagram: I have found this works with most VFDs that can be configured for 3-wire control, but not all. Check the manual for your drive carefully. The switch and...

Search ebay for "TM902C". It should bring up a thermocouple and handheld readout for around 5 bucks delivered. The thermocouple supplied is a glass-fiber insulated bead type K. It is about 3' long, good to around 400 degC (750 degF) and will work with the junction immersed (though once soaked...

I am pretty sure the plans you'll have seen were Andy Gascoigne's, as they were also on the BCS site for a time. His original thread on British Blades was back in 2004, so it's a fairly old document. It can be found at: http://www.freewebs.com/knifemaking/HT%20FURNACE.pdf It used an...

I can't help on the wiring, as the mains supply is different here , but you mention "240 VAC Kanthal heating element" Are you using 2 of them in series? I don't know your situation, but if you are following Andy Gascoigne's HT Furnace plans from way back, he used 2 of the 115 VAC...

I understand that, because indenting them causes some work-hardening, there is a limit to how close you can go to an existing impression and still get a true reading. Effectively they can get used-up when there is no longer enough space between the test marks to get any more in...

That link takes me to Don Foggs vertical forge design. The one I was looking for is his HT forge design: basically a horizontal 55-gallon drum lined with one layer of 1" inswool, with a small burner low down at one end and a rectangular exhaust port high up on the other end. On the two I've seen...

With all due respect to Larry Zoeller, I am fairly certain he is wrong on this one. Here is a forge I built specifically for HT. I was trying to scale down a Don Fogg-style horizontal 55-gallon drum HT forge to a size more suited to the space available to the average UK knifemaker. It is...

300 cu in in a firebrick forge to 2300 deg from a 20 lb cylinder seems to be asking quite a lot of the design. How much wriggle room is there on these numbers? Where are you? This is likely to make a difference in terms of the available gas take-off rate and burner rating available without...