Ady1

Please could you give details of the furnace – make and model. I have always believed a furnace is a better option than a propane torch for silver soldering and heat treatment.

JA

I have a smaller oven which was and still is sold for enamelling jewellery. cost around £ 80.00 some 20 years ago. from Walsh and sons in Hatton Garden , London. I use it for heating tools for my fly press to harden etc. handy item just plug into the mains and it gets to around 850' C in about 45 mins.

I had a few goes at bidding for similar furnaces to the one ADY1 shows. I ended up buying one of these.

This one has the advantage of digital temperature control, just set the temp on the electronic display and it stays there to within +/- 1C ( I've checked it , settles down very well once set point has stabilised). Temperature controllers for the ADY1 type are a rather expensive extra. I'm very pleased with mine – I have successfully annealed some hard spots in cast iron – it would have been nice to have been able to set a cooling ramp but that is not possible with the built in temperature controller. I just manually dropped the temp by 100C every hour. Great for hardening, tempering steel and for heat treating copper beryllium springs.

Cheers,

Rod

Andy, I have one used for some 30 years now for various ethnic heat treatment jobs, just one point when considering it for case hardening, be sure you consider the size of the pot or box you will use not the component.

You need room around your component for the carburising compound and then room around the box of say 1.5" min and bit more if possible.

Regards John

Ady that's OK if it's a through hardening steel but if it does not have enough carbon then you will need to case harden. Don't forget to temper after hardening to suit the job in hand

Edited By JohnF on 23/04/2015 22:14:55

Edited By JohnF on 23/04/2015 22:26:02

Some useful notes here, Ady

… and here, using a tube packed with Carbon Black.

MichaelG.

Edited By Michael Gilligan on 24/04/2015 06:06:15

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Clive,

I have not used it myself, but the gentleman that recommended it to me is a tutor at the British School of Watchmaking.

MichaelG.

Edited By Michael Gilligan on 24/04/2015 09:35:27

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Not specifically, Clive

This was just general purpose technique

…. have a look at the second link on my early-morning post.

MichaelG.

I needed to case harden the tiny ratchet pawls for the oiler on my Minnie Traction engine. I used bone-meal (from the local garden centre) packed around the components in a short length of thin walled tube and heated the package for about 10 minutes, before quenching.

Did it work, I think so… a week or so later, I needed a bit of 1/16th mild steel for something else, so found a bit in odd's and sods tin and put in the mill. The 3/8 end-mill would not touch it – I had previously done a test with some bits of MS and somehow consigned them to the odd's and sods tin!

Phil