This place really gets me in trouble :D

toms73novass · Feb 18, 2014

Well, I bet you can guess my influences in this post :bounce:

.

I am not a huge poster, but read this section every day, because fabrication of all types is my hobby.

About a month ago I made this paring knife with a cocobolo handle made from an old file.

After making it I realized how much easier it would be to form a more complex knife with a anvil: late 1800's Peter Wright 183 lbs

Then I realized my heat treating oven was WAYYY to small to anything larger than a paring knife. So this is what I am into now.

Can anyone say Solid Rivits! Of course the trigger valve disintegrated on me just before I was about to finish and I had to use my impact gun (ewww..) (ordered a new valve and I should be back in business)

It has a workable area of 6.5x6.5x22. Should be able to make short swords if I want to. :wtf:

Next is to cut the grooves from the Kanthal wire, wind the wire on my lathe and install the temp controller.

Will update soon.....

softailgarage · Feb 18, 2014

Now, would you consider that an oven or kiln?

Amitygravel · Feb 18, 2014

Yup ,
You sealed your fate with the anvil.
Definitely post up the progress on the oven.
And of course more knives too.

nmcqueen469 · Feb 18, 2014

Awesome! GJ has has done it job and served you well.

toms73novass · Feb 18, 2014

softailgarage said:
Now, would you consider that an oven or kiln?

My controller will do 1200 C which is 2192 F. Which is more than is needed for heat treating. Will it actually hit that temp? not sure yet. The old smaller one would, but this one will have more wire which will reduce the heat that is generated in the coils.

Really there is no difference between a kiln and heat treating oven except its orientation and the temperatures that are reachable.

I had nichrome wire in the old heat treating oven. I went with a 16g Kanthal hopefully for longevity.

DoghouseForge · Feb 18, 2014

First - the knife looks good! I like the larger handle...not to many cooking knives take into account a working mans hands.

Second - I must admit extreme jealousy over your heat treat oven...

do you have a ball park of the materials cost? controller/thermostat included?

Im trying to decide if its worth it to build one or to just pony up and buy a darn "evenheat"... :headscrat

Looking forward to more knives!

JP

22george · Feb 18, 2014

we're proud of you.
lt never ends

toms73novass · Feb 18, 2014

DoghouseForge said:
First - the knife looks good! I like the larger handle...not to many cooking knives take into account a working mans hands.

Second - I must admit extreme jealousy over your heat treat oven...

do you have a ball park of the materials cost? controller/thermostat included?

Im trying to decide if its worth it to build one or to just pony up and buy a darn "evenheat"...

Looking forward to more knives!

JP

The oven costs:

IFB 2300f Bricks $62.88
Kanthal 50ft 16g $25
Controller w/k thermocouple (ebay) $26
Solid state relay $20
Sheet metal $25

I think with hinges and other odds and ends I should easily be able to keep this under $200.

Amitygravel · Feb 18, 2014

Tom
Where did you get the firebrick and Kanthal ?

toms73novass · Feb 19, 2014

Kanthal was temco on ebay
Firebrick was a local refractory supplier

toms73novass · Feb 19, 2014

Here is the latest update:

Wound the wire around a .375 rod in my lathe.

50' gave me 27" coiled.

I did some research on coil spacing and found 3-6x the wire diameter worked out to about .25" Stretched out to about 138".

Next I had to determine a pattern that would use it up and start and terminate in the same location. Laid it out and then used my mill to cut the slots .5" wide .6 deep.

I actually cut 2 patterns in it, incase I need to replace the wire, I could get more and run 4 parallel coils next time.

However, this pattern used up exactly the wire.

Now to paint, mount controller and work out door mounting.....

NASTYZEN · Feb 19, 2014

Cool project! Thanks for posting the step by step. I'm already in trouble with this place dammit!! Now I can't unsee what you've done. I think I'll be in trouble for a while longer..

toms73novass · Feb 19, 2014

Well I have too much wire in the system, coils don't even turn red.

Need to search up a bit more info to determine how much I need to shorten it.

Not a big deal, I just may have cut all the extra dado's, we will see.

Lhorn · Feb 19, 2014

Knife looks great. Some talented mofos in this place.

JonBoehman · Feb 19, 2014

Yeah I know what you mean about this place getting you in trouble. I've copied several tidbit off this forum and even final started my own build thread. My wife tells me I spend too much time on this site also. But, it doesn't stop her from asking me to do some of her Pintrest project either. Lol!

Kevin54 · Feb 20, 2014

toms73novass said:
Well I have too much wire in the system, coils don't even turn red.

Need to search up a bit more info to determine how much I need to shorten it.

Not a big deal, I just may have cut all the extra dado's, we will see.

Instead of shortening your wire, can you split the wire length in half and instead of running two wires off of your controller, run four wires off of your controller? That way you would still have the same amount of wire for your heat, but you are only heating 2 halves instead of one continuous length. If that make sense.

toms73novass · Feb 20, 2014

Kevin,

That is what I think I am going to do, still researching.

That will double the amount of watts in the oven. Just have to make sure that it won't be too much before I cut the wire in half and have it melt on me.

toms73novass · Feb 20, 2014

Well I did some calculations Kanthal has about .34 ohms/ft If I do two loops at 25' that would be 8.5ohms. v=I*R gives me I=28.23A P=I*V P=6776w Per loop !!! Which provide about 1960 deg F

More thinking to do.....

kazlx · Feb 20, 2014

When you get it figured out, write it out for the rest of us idiots! I've always wanted to build one.

toms73novass · Feb 20, 2014

Well I'll post pics in a bit. But I removed the wavy part of the pattern and just went with two rows. This brings the amount of wire down to about 40' of Kanthal. I had it up to 920C which is above 1600F . Plenty of heat for a heat treating oven. It draws 34 amps ,17 per leg of the 240 line. Now to finish the door.

MFolks · Feb 20, 2014

Nice to see the use of "Cleeco's" in the fab of the oven. I've used many sizes over the years in aircraft and missile assembly.

toms73novass · Feb 20, 2014

Ok, Pictures as promised. Also, on my initial try when the coils never turned red, it was partly due to a bad connection I had on the relay. However, even with the correct connection it was not hot enough.

Rerouting of wires:

Control panel: (I think I am going to put a small computer fan on it to help move the air since it is right against the cabinet and at 1600F it was about 140F.

Temporary "door" to keep heat in. Took it to 920C (1688F) and it was still slowly climbing (20 minutes). I will see how hot it will get once I have a proper fitting door.

Lhorn · Feb 20, 2014

Wow, that thing looks like it was made in a factory. Nice work!!

Amitygravel · Feb 20, 2014

Tom ,
Very nice indeed.
Thanks for taking the time to post the progress

toms73novass · Feb 21, 2014

Ok here it is:

I used the door arrangement similar to the small original one. It uses gravity to keep it closed, and works well. It drops open and is limited by the bottom metal lip. Also, the inner brick is tapered into the opening to add a bit of overlap to reduce heat loss.

There was less heat leaking than just having it flush with the front like in the initial testing. Heated up faster also.

Made some small plastic "feet" out of some red plastic rod I had by putting 1 cut half way through the rod and slipped over the edge of the sheet metal.

e30bradley · Feb 21, 2014

that oven is awesome!

DoghouseForge · Feb 21, 2014

That turned out great!

Im gonna have to make a go at one myself. We have "Superior Brick and refractory" locally so the resourses are available... Im not sure how I will cut the bricks for the wire though...

Thanks for posting and showing your work! I needed something like this to push me over the edge...

JP

toms73novass · Feb 22, 2014

Since the crazy zig zag pattern is not needed, they are all straight cuts. Do you have a router? That will do the job nicely. You could also had cut them with a hand saw down each side of the groove and then snap the excess off (doable, but not as astatically pleasing.)

If you do have a router, or can borrow one, a nice jig of plywood with a guide edge will make the job fairly easy. (I can provide a sketch if needed).

dr_clyde · Feb 23, 2014

That's really cool. I've been needing an oven for awhile for doing pre and post heat, and some minor heat treating. I think I might make one...

Edit: removed price question. I should read more carefully.

JeffDM · Feb 23, 2014

You suggested a router, what kind of bit would you recommend for slotting the brick? I've never worked with brick in any any way like this.

toms73novass · Feb 23, 2014

Just a regular straight cut 2 flute bit will work fine. This stuff is so soft you can practically cut it with your finger nail. Make sure you use Insulating Fire Brick not Hard Fire Brick.

Make sure you do it outside with a mask. It will make LOTS of dust. On the mill it was not an issue because I could control speed and rate of cut and had the shop vac in my other hand sucking up all the dust.

toms73novass · Mar 21, 2014

Made a new control panel box, this one is larger so that there is better flow of air and allows everything to be a bit further from the oven. The fan is a computer high flow cpu fan and it really moves lots of air. I put in an old wall wart transformer I had and had to put a rectifier on it to make it dc because it was as 12v to run the fan.

I think that this will work out much better to keep things cooler inside the box.

BellyUpFish · Mar 22, 2014

Wow... Nice work.

efncrx · Mar 23, 2014

Very very nice!

toms73novass · Apr 5, 2014

Here is the newest installment:

I now have a forge done and can start beating on stuff....

I chose to go with a tangential entry of the flame so that it was not blasting on a particular spot, particularly after reading about JP's issues and him using a baffle to protect the knife blades.

It gets up to heat fast, I used 3 layers of ceramic wool with a coating and with a hard firebrick on the bottom. I also created a door on the back to keep heat in if needed and a front door for using just thinner items and it opens for larger/odd shaped pieces. I also made the front end open if I have to replace the insulation.

I still need to make the slide out support for the front to keep bar stock level.

It is roughly based off this build:

Here are pics of the build:

toms73novass · Apr 6, 2014

Well I tried to make a leaf as a thing in the forge out of some old rebar. Turned out ok. Still have a lot to learn.

DoghouseForge · Apr 6, 2014

FORCED AIR!!! so freaking cool !

The leaf is not bad! The vien lines could be a little deeper the the gard stuff looks great. I see a thriving key chain business budding. Lol

JP

DoghouseForge · Jun 23, 2014

so... you build a forge that could double as a jet engine and then only made one leaf?

Im expecting big things from this thread over the summer :thumbup:

jp

bulletpruf · Jun 24, 2014

Very nice work. Please keep posting pics and details.

toms73novass · Jun 24, 2014

JP, you got a jeep and it isn't done yet? :lol_hitti

During the summer I usually work on my car projects and when the cooler weather arrives I do stuff that makes heat.

My real addiction is cars, usually with turbos:
73 Novass w/454
63 Corvair turbo spyder (on rotisserie for way too long)
86 BMW with big turbo
98 Dodge Ram Cummings with compound twin turbos
01 Audi Biturbo allroad

So I will get back to doing more in the fall

Have a good one bud.

This place really gets me in trouble :D

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