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APG1961
02-09-04, 08:32 PM
Well, I'm almost there :) :) The HT furnace has proved to be a GREAT success. Fired it up for the first time on Monday and got a piece of O1 tool steel up to hardening temp in less than 20 mins and that was with me keep opening the door to check for hot spots on the element.

The insulation firebricks are doing there stuff as the outside of the furnace gets warm but you can still touch it with bare hands without much pain!.

At the moment I am waiting for a digital temperature control to arrive, that will measure and maintaine a set temp.

When I get more time I'l write up some info on how it was designed and built. But for now heres a couple of photo's of the allmost finished project.

http://img.photobucket.com/albums/v447/spireknife/ovenclosed.jpg

The second photo shows the furnace warming up..the elements get a LOT brighter and hotter than this.

http://img.photobucket.com/albums/v447/spireknife/ovenopen.jpg
Kevin
02-09-04, 08:38 PM
Fabulous.
PS_Bond
02-09-04, 09:01 PM
Nice.... Are those Kanthal elements then?
APG1961
02-09-04, 10:04 PM
Nice.... Are those Kanthal elements then?
yes thats right..kanthal for up to 1200oC. 13amp 3.1Kw
one_rod
02-09-04, 10:14 PM
Neat job Andy.

Do the write up, please!

Mick.
PS_Bond
02-09-04, 10:16 PM
Oooh.... I have a controller knocking about , but it only goes to 999C. A HT oven is on my to-do list, and I've been vacillating over gas or electric. Out of sheer (impossible to justify) laziness on my part, would you be so kind as to do a more complete breakdown of dims, parts & suppliers? :biggthump
APG1961
02-09-04, 10:24 PM
Oooh.... I have a controller knocking about , but it only goes to 999C. A HT oven is on my to-do list, and I've been vacillating over gas or electric. Out of sheer (impossible to justify) laziness on my part, would you be so kind as to do a more complete breakdown of dims, parts & suppliers? :biggthump

No problem!! I've lots of photo's and will put up all the dimensions and list of suppliers. Also a write up in MS WORD could be a possible for emailing out to anyone interested.

If you want to be able to HT stainless you will need a 4 digit control and K type thermocouple for temps over 1000 oC

Andy..
PS_Bond
03-09-04, 09:47 AM
Inconel sheathed, mineral insulated K types are what I use to check the forge temperatures...

If I ask Martyn nicely, he might host the doc here (although I'd probably be inclined to pdf it?)
dtalbot
03-09-04, 09:50 PM
No problem!! I've lots of photo's and will put up all the dimensions and list of suppliers. Also a write up in MS WORD could be a possible for emailing out to anyone interested.

If you want to be able to HT stainless you will need a 4 digit control and K type thermocouple for temps over 1000 oC

Andy..
Put me on the list for the doc when done!
Nice job :biggthump :biggthump
David
Kevin
04-09-04, 01:08 AM
How stable is it at holding tempering temperatures...like 400 F?.....Some of the production models tend to fluctuate a bit that low.
APG1961
04-09-04, 10:34 AM
How stable is it at holding tempering temperatures...like 400 F?.....Some of the production models tend to fluctuate a bit that low.

At the moment I'm still waiting for a digital control to measure and maintain temp. :zx11pisse

I have another smaller furnace that I've fitted with a Eurotherm 807 microprocessor digital control and this can hold a perfect set temperature by use of logic control.

Andy..
MushiSushi
04-09-04, 11:10 AM
How stable is it at holding tempering temperatures...like 400 F?.....Some of the production models tend to fluctuate a bit that low.
that might be down to having a different thermocouple, type Ks are quite accurate at that level but they don't like continuous use over 1000C, type N are better for use over 1000C, but, I believe, aren't as sensitive at the lower temperatures.
Tvividr
07-09-04, 10:57 AM
No problem!! I've lots of photo's and will put up all the dimensions and list of suppliers. Also a write up in MS WORD could be a possible for emailing out to anyone interested....
Andy..

Please put me on the list for the doc as well :biggthump
APG1961
07-09-04, 09:45 PM
Please put me on the list for the doc as well :biggthump


You have email with pdf attachment

Andy..
APG1961
07-09-04, 09:51 PM
If anyone wants the information please send me your email address to :-

andrew.gascoigne(remove spam)@bbuk.net

please remove the words and brackets remove spam ;) ;)

Please let me know if you want pdf or Word Doc pdf is a lot smaller file ;) :thanks:
Tvividr
07-09-04, 10:28 PM
You have email with pdf attachment

Andy..
Thanks :biggthump
APG1961
16-09-04, 07:02 PM
If anyone wants the PDF file for the information, I have just put it onto a web page for easy downloading or viewing.

HT FURNACE (http://www.freewebs.com/knifemaking/heattreatmentfurnace.htm)


At the moment there is nothing else on the web site as I've just not had the time :( :( Too much work and not enough play :( :(


All the best,

Andy.
Gunmen
17-09-04, 08:04 AM
Thanks, that is a GREAT tutorial !

I got a kiln at the moment, that is made for ceramics... it takes up to 3 hours to reach the desired temperature !!!

So 30 minutes sounds just great to me !


Sander
PS_Bond
17-09-04, 09:20 AM
Here's some related gubbins, BTW:

http://www.pyrouniverse.com/reswire.htm
http://www.morrigancraftpottery.co.uk/ewind.html
Trond
17-09-04, 09:28 AM
Great stuff,
e-mail sendt :)
shing
17-09-04, 09:30 AM
Great tutorial, what size fire bricks did you use Andy?
APG1961
17-09-04, 05:55 PM
Great tutorial, what size fire bricks did you use Andy?

The fire bricks are 230mm x 112mm 75mm type 23 insulation bricks from Anchor refractories in Dronfield Nr Chesterfield.

They charged me £10 per dozen for cash ;) ;) Very nice people to deal with and don't mind small orders as long as you collect.

Andy..
APG1961
17-09-04, 06:06 PM
Thanks, that is a GREAT tutorial !

I got a kiln at the moment, that is made for ceramics... it takes up to 3 hours to reach the desired temperature !!!

So 30 minutes sounds just great to me !


Sander

The secret is in the type of bricks. Type 23, insullation!!!!
APG1961
17-09-04, 09:15 PM
Here's some related gubbins, BTW:

http://www.pyrouniverse.com/reswire.htm
http://www.morrigancraftpottery.co.uk/ewind.html

Thanks Peter

The morrigancraftpottery site is VERY interesting..Might have a go at making my own elements for future projects..Need a source of Kanthal wire on the roll now.
shing
17-09-04, 10:05 PM
You got a number for Anchor Andy? I used to work in Chesterfield.
APG1961
18-09-04, 09:11 AM
You got a number for Anchor Andy? I used to work in Chesterfield.
Here it is Shing :-

Anchor Refractories
Callywhite La
Dronfield
DERBYSHIRE
01246 292422

You can find them next to the Cafe' it's only a small unit on the right as you enter the compound.