Holding Blades in Heat Treating Oven?

Tom Militano

Tom Militano

BANNED
Joined
Feb 27, 1999
Messages
1,160
I have a new Evenheat oven and I was wondering what makers are using to hold their blades during heat treating? Stainless pipe has been recommended or slotted firebrick. I have a couple of pieces of carbon steel square tubing laying in the shop. Any problem using it? Any other suggestions? Thanks.
 
Tom, When I had my Paragon oven it came with a few cerramic bars with holes for some type of steel rod's and the blades woud go inbetween the bars. For regular tempering cycles I just used angle iron with slots.
 
Do you think the slotted angle iron would work to hold the blades during heat treating? I have some in the shop, someplace.
 
Carbon steel won't survive heat treat cycles, once you break 1000 degrees F it's going to scale and flake off fast. I made a record rack by taking a 3/8" X 3/4" 303 stainless bar, drilling 1/8" holes every 1/2" or less and inserting stainless steel pins about 2" long, then welded a stabilizing bar on each end. One of these lasts me for about 15-20 heat treat and double that in tempering cycles. The secret to making stainless last longer and will make your element last longer is to not leave your door gapping open to cool down, but cool down slow with the door closed.
Jim
 
I have been using slotted soft fire bricks for years with no problems. They heat up as fast as the interior oven walls-they the same stuff.
 
Ceramic blade racks from Jantz,or othe suppliers.About $10/pair.Last forever.
 
I use regular ol angle iron with slots cut with a chop saw. I have used the same one for I don't know how many heat treats and its just fine. If and when its burned up I'll just cut another short piece, slot it and it will be good for a bunch more. I would be afraid that fire brick be a heat sink and keep that part of the blade from coming up to heat, but that wouldn't be a problem as long as you place the far end of the handle section in the brick. I know the angle iron comes up to and maintains the same heat as the enterior of the oven a lot quicker then fire brick will.

Good luck,

Bill
 
I use the soft firebricks, laid down the center of the kiln. I lay the packet of multiple blades down on the firebrick, so the blades are laying on their side.
I cut two slots in the firebrick to accept the tines of my fork.

The porous firebrick heats very quickly to the temperature of the kiln, and, there is no burning metal to affect your heating elements, or your lungs.

If you try this method, you will find it is much better than dealing with individual blades in individual packets. You only have to open the furnace door one time, and, you get all of your blades to the quench plates at once.

The blades in a packet must all be the same thickness. I get zero warpage using this heating method.

Stay Sharp,

RJ Martin
 
Tom, I got my two ceramic racks from the Evenheat company I think. It's been a while.
 
Martinsite said:
I use the soft firebricks, laid down the center of the kiln. I lay the packet of multiple blades down on the firebrick, so the blades are laying on their side.
I cut two slots in the firebrick to accept the tines of my fork.

The porous firebrick heats very quickly to the temperature of the kiln, and, there is no burning metal to affect your heating elements, or your lungs.

If you try this method, you will find it is much better than dealing with individual blades in individual packets. You only have to open the furnace door one time, and, you get all of your blades to the quench plates at once.

The blades in a packet must all be the same thickness. I get zero warpage using this heating method.

Stay Sharp,

RJ Martin
Click to expand...
well now so i dont have to keep all the blade edges up in the kiln this will save me some real pain
and now that i have my quench plates i should be good right
butch
 
Are you sure both blade's sides will get the same heating if blade laying on it's side on a brick? After all air and soft brick is a different substance with their own characteristics.
 
Yes, they heat evenly. Firebricks heat and cool very quickly. Once the furnace temperature reaches about 1200F, the heat being radiated from the furnace walls really comes into play. Ask yourself what effect opening and closing the kiln door 5 times has on that 6th blade sitting in your rack, waiting to be taken out and quenched!
I have used this method for over 5 years now, it is the simplest and best way, and yields outstanding results.

RJ Martin
 
great so i can foil my 2 kabars in the same pack and use my quench plates with not a worry
thanks mr martin
 
anyway you can sketch this set up RJ? I am having trouble visualizing it...........I know.. I am slow :)
 
Take 1,2 3 or 4 firebricks, depending on the size of your furnace. Put them down the center of your furnace. Lay your fork on the bricks. Sketch the outline on the bricks. Gouge out the troughs in the bricks until they are deep enough so you can insert the fork under the foil package. An old file is great for this. Even the handle of an eating spoon. Whatever works.
Voila! You are done.

It all depends on the geometry of your furnace. I have several combinations of bricks that I use, depending on what blades I am heat treating. That's the beauty part. Folder blades require one brick wide. Smaller fixed blades get 2 bricks wide, etc.
You can saw the bricks easily to custom fit to your knives, so that you get support under the whole blade. That is important. If you hang blade tips and tangs off your bricks, well, they're going to sag.
 
RJ, when you're doing multiple blades in a single pack, are these blades beveled or blanked flatstock? Room temp quench plates? Thx.
 
What about carbon steels? It seems easiest to me to just cut a few grooves in a slice of firebrick the exact width of the chamber, and jus slide it front/back relative to the blade size.....i may make a more drable one out of angle iron after reading this, though.
 
I cut six grooves in a firebrick yesterday and I'm going to try the furnace out tomorrow.
 
Tom: Good luck, and have fun.
fitzo: Yes, fully ground. Quench plates at RT is fine.
tiktock: Leave some space along the sides of the furnace. I don't recommend putting metal inside the furnace, other than your blades.
What do you mean by "What about carbon steels"?
 
You must log in or register to reply here.
Back
Top