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Heat Treat Furnace Build
- Thread starter jbolt
- Start date
- Joined
- Dec 3, 2013
- Messages
- 1,848
For the PID I got the SYL-2352P from Auberins on the recommendation from others. I don't know much about these yet.
- Joined
- Oct 13, 2014
- Messages
- 10,613
Awesome Build!
I have some experience around pottery kilns that are constructed similarly, fire brick with a metal skin. They get blazing hot on the outside, you may want to consider adding a couple of inches of mineral wool insulation between the brick and casing, if excessive radiant heat is a concern.
I have some experience around pottery kilns that are constructed similarly, fire brick with a metal skin. They get blazing hot on the outside, you may want to consider adding a couple of inches of mineral wool insulation between the brick and casing, if excessive radiant heat is a concern.
- Joined
- May 7, 2014
- Messages
- 776
Here was a post by Ray C (hope all is well w/ him btw if anyone's heard from him of late). I learned quite a bit from Ray and some of the textbooks he notes. Passing the info. CG
http://www.hobby-machinist.com/threads/heat-treat-oven.9929/
http://www.hobby-machinist.com/threads/heat-treat-oven.9929/
- Joined
- Dec 3, 2013
- Messages
- 1,848
A little more progress on the build.
After much reflection I decided to do a redesign on the frame to accommodate a 1" layer of ceramic blanket. I would prefer to be able to use the oven inside my shop and with the limited space I have I'm hopeful it will keep the outer shell temps acceptable.
In addition I added a sub frame to the firebrick assembly. I had some concerns about braking the joints of the firebrick when handling and the way I assembled the bricks I wanted additional support on the bottom row.
The sub-frame is made form some surplus 1 x 1 angle I had. The sub-frame is held together with 3/16" rods that I single point threaded on each end for a 10-32 nut. I could have used all-thread but what is the fun in that.
Between the sub-frame and firebrick is a single layer of ceramic paper and a layer of steel mesh on the sides and top to provide some support. A piece of 22 ga. sheet metal on the bottom. I used the mesh to help with the break-in to let moisture out.
After much reflection I decided to do a redesign on the frame to accommodate a 1" layer of ceramic blanket. I would prefer to be able to use the oven inside my shop and with the limited space I have I'm hopeful it will keep the outer shell temps acceptable.
In addition I added a sub frame to the firebrick assembly. I had some concerns about braking the joints of the firebrick when handling and the way I assembled the bricks I wanted additional support on the bottom row.
The sub-frame is made form some surplus 1 x 1 angle I had. The sub-frame is held together with 3/16" rods that I single point threaded on each end for a 10-32 nut. I could have used all-thread but what is the fun in that.
Between the sub-frame and firebrick is a single layer of ceramic paper and a layer of steel mesh on the sides and top to provide some support. A piece of 22 ga. sheet metal on the bottom. I used the mesh to help with the break-in to let moisture out.
I notice the heating elements are too long in the picture once they were stretched. Can you cut the excess off or do you have to use the full length? ( I would think the length must be kept original). Also, how did you terminate the ends of the elements for connection? My questions are because this is on my short list of things to build.
- Joined
- Dec 3, 2013
- Messages
- 1,848
The coils of the elements are not supposed to be cut, the pigtails can be trimmed. The extra length you see will turn along the back wall before the pigtails are run out the rear.
The pig tail will be run out a small hole and then terminated on a stainless steel bolt. It is recommended to make the termination on the outside. Repeated heat cycles can loosen the connection if made on the interior side. I have also heard it is recommended to double back and twist the pigtail to reduce the amount of heat at the element termination.
- Joined
- Dec 3, 2013
- Messages
- 1,848
A little more progress this weekend.
I'll start by saying I really dislike flux core wire welding. I can stick weld, tig weld and gas weld but for some reason I have a hard time seeing the weld joint with flux core wire. Nor does it help to not have a proper welding space and table. Working on a HF folding table out in the driveway stinks. I long for the day when I have a decent shop.
I got the frame mostly welded up and the door partially made and hinged. I also test the fit of the heat chamber to the frame. So far so good. My local metal supplier gave me some aluminum diamond plate cutoffs to use for the frame sides. Can't argue with free.
I'll start by saying I really dislike flux core wire welding. I can stick weld, tig weld and gas weld but for some reason I have a hard time seeing the weld joint with flux core wire. Nor does it help to not have a proper welding space and table. Working on a HF folding table out in the driveway stinks. I long for the day when I have a decent shop.
I got the frame mostly welded up and the door partially made and hinged. I also test the fit of the heat chamber to the frame. So far so good. My local metal supplier gave me some aluminum diamond plate cutoffs to use for the frame sides. Can't argue with free.
- Joined
- Dec 3, 2013
- Messages
- 1,848
Slowly but surely progress is being made.
I have the heat chamber installed in the frame. The heat chamber is centered in the outer frame with jacking screws on the sub frame. I installed the diamond plate top and bottom and the 1" layer of Inswool ceramic blanket first and then used the jacking screws which are accessible through the open sides to center and lock the heat chamber in place. Once that was done the side insulation and panels were slid in place. The door was a little more complicated since I wanted to be able to service the innards if necessary so I didn't want to weld everything permanently inside. A smaller frame made from 1-1/2" angle slips inside the outer door fame from the front and is held in with screws from the side. Two jacking screws through the bottom of the door frame center and adjust the height of the door firebrick in the opening. It took a little more work but everything is adjustable so it fits together very well.
Next is getting the rear closure done and the control box wired and installed.
I have the heat chamber installed in the frame. The heat chamber is centered in the outer frame with jacking screws on the sub frame. I installed the diamond plate top and bottom and the 1" layer of Inswool ceramic blanket first and then used the jacking screws which are accessible through the open sides to center and lock the heat chamber in place. Once that was done the side insulation and panels were slid in place. The door was a little more complicated since I wanted to be able to service the innards if necessary so I didn't want to weld everything permanently inside. A smaller frame made from 1-1/2" angle slips inside the outer door fame from the front and is held in with screws from the side. Two jacking screws through the bottom of the door frame center and adjust the height of the door firebrick in the opening. It took a little more work but everything is adjustable so it fits together very well.
Next is getting the rear closure done and the control box wired and installed.
