Forge Assembly WIP

[silver_pilate]

Ok, so I've got a good coat of cured satanite, and today I layed down the mizzou floor as a protection against flux and to build the floor up a bit where my stock will be resting. I mixed the mizzou with water to a troweling consistency (it takes quite a bit less water than the satanite)...



...and spread it on the forge floor. I spread the mizzou following the countour of the forge and thinning it out up the sides until I had about 1/2" of mizzou on the floor and coming up the body sides about 1/3 of the height of the floor. I used a paint stir stick as my trowel:







After I had the floor down, I closed the forge, and I patched the seam around the door with satanite. I also installed the TC sheath and sealed it with satanite and patched a few areas around the burner tube that were a bit thin. This will set up for a day or two, and then I'll fire the forge a few times, gradually brining the chamber to temp to get rid of any remaining water. Then I'm good to go!

--nathan

[indian george]

Hey!!! Where did you get that TC sheath?????

[silver_pilate]

IG, I got it at www.auberins.com. Look on their thermocouple link, and it's on the second page I think. It fits the TC with the little cermic TC blocks installed like a glove. The specs are listed and it's a reasonable price.

--nathan

[Fletch Helical]

Very well done WIP.

Question about the gas and air side. Assuming one wanted to build a dumbed down version can you just pipe the propane in through a simple line above the blower?

[silver_pilate]

Sure. Just basically eliminate all of the pipe fitting stuff I did and have the gas come in at that small red elbow just behind the ball valve. Make sure your pipe is big enough for a good mixing chamber before narrowing down to the burner tube. The black burner tube is considered a consumable as it will very slowly and gradually wear down form the heat of the forge.

--nathan

[Fletch Helical]

So essentially you would want a fairly big pipe after the ball valve for the air and gas to mix then you can reduce that down to a smaller pipe that will pipe right into the forge then correct?

That black pipe is just standard black gas pipe right? That will wear down??

[silver_pilate]

Fletch, that's my understanding. I'm no expert on building burners as I didn't build this one, and this is my first forge. Check out Indian George's tutorial on his website or any of the other discussions on forge burners that are out there to be sure. As for the burner tube, yes, I understand that is wears (VERY slowly) with use. Depending on how much you use your forge, it would take years for it to wear significantly.

--nathan

[69_knives]

You don't have a flare on your burner in the video; is there a specific reason for that?

[silver_pilate]

Cause it didn't come with one.

My understanding is that blown burners don't use flares where venturi burners do. Someone correct me if I'm wrong.

--natha

[Phil Dwyer]

Good going Nathan. Thanks for taking the time to post all this for us.

Quick question: I've heard it said that it's a good idea to have the blower above the gas, instead of coming in from the bottom. I too would rather do it like yours, but I understand there is a higher explosive risk factor should gas settle in the blower (when it's off) and get ignited when it powers up. Whereas if the blower's above the gas line it can't do that. The problem with that though is the heat rising from the forge after shutting everything down, and having to leave the blower on for a while to keep it from getting to hot.

What are your, or any of you other good folks, thoughts on that?

[69_knives]

I see. I wasn't aware of that.

[DrThunder88]

Speaking of flares, I've noticed some blown burner designs have a reducer bell before the final tube, as in the Ellis burners, whereas others, like Indian George's, are a single diameter . Is the reduction so the burner fits into a specific forge opening or does it affect the burner's properties somehow?

[bladsmth]

Here is Kevin Cashen's excellent page on burner design and opperation :
http://www.cashenblades.com/info/gas_forges.html

Stacy

[armourer2]

Great post! I feel like I've just gotten another walk thru of our gas fire low pressure steam boilers at work.

Patrick

[indian george]

IG, I got it at www.auberins.com. Look on their thermocouple link, and it's on the second page I think. It fits the TC with the little cermic TC blocks installed like a glove. The specs are listed and it's a reasonable price.

--nathan

Thanks Bro

[silver_pilate]

Well, I have the forge running, and I even pounded a little steel tonight (all thread...going from round to square and back).

A couple of things. First, if you use a ceramic sheath, make sure that it is out of the way. I barely tapped the end of it with the all-thread, and the end of it broke off exposing the TC tip. Actually, I found the sheath was really smoothing out the temperature swings and the TC was much more responsive when exposed. Not sure if I'm going to replace the sheath. Probably I will run it until the TC fails someday and then get a new TC/sheath.

Next, I'm having a little trouble getting this forge to settle down at lower temps. It likes to run, and it likes to run HOT. I was able to get the two stages fairly well balanced at 1750F +/- 30-40F (the PID is learning still), and I could probably cut that range down with some very fine tuning. However, at the lower ends, say 1500F, it is very difficult to get this thing to stop from raising in temp. The gate valve is almost closed and the needle valves for the propane are barely open with between 1-2 psi through the regulator (2 is the lower reading on the guage, and I have it sitting right there). I'm not going to have any trouble at all reaching welding temps.

Here's a pic of the forge running:



FYI, I stuffed some bits of kaowool around the burner tube inlet to prevent any extra air in.

Anyway, thanks for following along with this build. Now I really have to learn to control a hammer and learn what the heck I'm doing when forging .

I will gladly accept free lessons .

--nathan