Building my first forge...

[hogworthy]

Sorry if there is already a post about this sort of thing...

I will be building my new gas forge soon and I wanted to get everyone's opinions and comments before I make a mistake that could be avoided.

I have a tank from an old air compressor and will be lining it with Kaowool. I planned on a few layers of satinite followed by Rex's HYB-UV. I will be using a T-rex with a needle valve idle/bypass setup.

Should I run the burner into the side of the forge perpendicular to the cylinder like this??
http://www.google.com/imgres?imgurl=http%3A%2F%2Fwww.zoellerforge.com%2Fcoffee5.jpg&imgrefurl=http%3A%2F%2Fwww.zoellerforge.com%2Fcoffee.html&h=395&w=360&tbnid=DDtKKGmjgGKu0M%3A&zoom=1&docid=RIPudbvLZVF1bM&ei=puiRU62BOs2PqgavmIH4Ag&tbm=isch&ved=0CD0QMygSMBI&iact=rc&uact=3&dur=1791&page=1&start=0&ndsp=30


Or come into the side like this to (I guess) make the flame rotate around the inside of the forge?
http://www.google.com/imgres?imgurl=http%3A%2F%2Fwww.zoellerforge.com%2Fssforge.jpg&imgrefurl=http%3A%2F%2Fwww.zoellerforge.com%2Fminiforge.html&h=199&w=288&tbnid=BSmca_89weWmmM%3A&zoom=1&docid=fYvYdU57dGme7M&ei=puiRU62BOs2PqgavmIH4Ag&tbm=isch&ved=0CEkQMygVMBU&iact=rc&uact=3&dur=3792&page=1&start=0&ndsp=30


Lastly, where is the best place to buy high carbon steel between 1075 and 1095?

Is 5160 too hard to work with if you don't have a power hammer??

 

[Stacy E. Apelt - Bladesmith]

Well, both aren't really what you want for a full size forge.
The burner guide tube should be placed about 15-20% forward of the back, and at a chord/tangent to the top of the chamber. The burner tube should be angled slightly forward ...... about 15-25 degrees.
There are several older forge build threads with diagrams. I think most are in the stickys.

 

[hogworthy]

This is going to make me look stupid...but, where do I find these stickys??

 

[NC Biker]

This burner entry as suggested by Stacy works very well for me:

 

[hogworthy]

Thank you so much.

That was what I was thinking when I read his post, but the diagram makes it totally understandable. I was a land surveyor for a decade, so seeing prints always makes more sense than those word things.

Just joking, but seriously thanks guys. I can already see that I will be returning here often for information and tips. Great community!!

 

[Stacy E. Apelt - Bladesmith]

Thanks NC. I couldn't find a link with a clear drawing.

 

[hogworthy]

One more question if you guys don't mind.
I saw some videos online that recommended securing the layer of ceramic blanket with high heat glue. One guy used this stuff called liquid glass. Is this step either required or recommended in your opinion?
I was thinking it might be overkill, but I'm putting a lot of time and money into a forge I hope will last many years. If this small (and relatively cheap) step will prolong the life of the finished product, then it wouldn't be that big of a deal.

 

[Stacy E. Apelt - Bladesmith]

Not needed, unless you are building a barrel size forge. On a regular size forge, the satanite coating will keep everything nice and snug.

 

[hogworthy]

Awesome... thanks. I will be using part of a tank from an old air compressor. Should be under 400 cubic inches if my calculations are correct.

I'll be cutting and grinding tonight and should be going on the first heat by next week.

Thanks for all of the help guys.

 

[hogworthy]

Do I have to fire satanite to cure it? Or can I just let it dry for 24 hours and apply the next coat??

 

[NC Biker]

I let mine air dry for a few hours and then fired the burner up for a few minutes between each coat. This worked well. After building the satanite up to about a 3/8" thickness I applied a couple thin coast of ITC-100 firing it between coats. Here is the first firing after all the refractory was done:

[video=youtube;Z509xrH4Lzk]https://www.youtube.com/watch?v=Z509xrH4Lzk&list=UUCKK4BKTL4e623xaoZ9PDaw[/video]

 

[Stacy E. Apelt - Bladesmith]

I let dry 24 hours, fire on low briefly, and add the next coat.

 

[NC Biker]

Here are the directions for applying Satanite from High Temperature Tools & Refractory's web site:

Apply the Satanite to the wool using a paintbrush, covering all exposed wool surfaces. To cure it, you want to dry it slowly. First, let the forge sit for a few hours minimum to air dry a little, then fire up the forge just briefly and shut it down. Do this several times, allowing it to cool down in between and increasing the on-time with each subsequent cycle. You'll see water vapor evaporating the first few times you do this. Finally, fire it up and bring it up to full temp to fully cure it. You will probably want to apply at least two coats of Satanite in this manner...it's a little time consuming (do it over a couple of day period) but makes for a more robust coating. a 1/4" layer is a good thickness to shoot for. If you are going to apply ITC-100 over top of the Satanite, be sure to fully cure the Satanite first.​

Hope this helps!

 

[hogworthy]

I am almost done... when I figure out how to post pics to this forum I'll put up the whole series.

 

[hogworthy]

Flare for the burner mounting tube is also flared to, hopefully, continue the expansion of gas as it enters the chamber. My goal from the beginning was to most efficient with the fuel.

Old air compressor tank cut and etched to reduce corrosion.

Back door cut and shelf welded on for fire brick door "plug". My welds are horrible, but the hold... I'm learning as I go.

 

[hogworthy]

Burner hole cut and mounting bracket for control and needle valves welded in place.

Forge floor "base" in place.

Full base mixed and poured over the brick and blanket. The mixture is 1 part concrete (with stones removed) to 2 parts pearlite and 2 parts satanite.

Second burn while "curing" the satanite. This was at 3-4 psi for about 30 seconds.

 

[hogworthy]

The whole setup completed...

Three layers of satanite and 2 layers of HYB-UV from Rex... might add another layer of HYB as I still have over half left.

 

[hogworthy]

Thanks for all the input from everyone... I could have tried to do it without you, but I doubt it would've turned out this nice and burn this well.

Thank you Rex, for those if too lazy or time-strapped to build our own burner, you provide one hell of a product.

Thank you blade forums for all of the info and help.

Now I need to learn how to forge a blade... no more stock removal!

Expect more questions soon! You guys rock.

 

[Atlas Knife Company]

Now that you've finished it, could you measure and tell us how many cubic inches it is? If it's as big as it looks, your burner might not be big enough. The rule of thumb is 400 BTU per cubic inch. Your original estimate of 400 cubic inches would put it at around 250 BTU.

 

[hogworthy]

That was originally a thought that bothered me, but due to the mass and quality of refractory that I used (3 layer kaowool - 4 layer satanite - 3 layers HYB-UV) it burns like crazy.

I was messing with it yesterday - once up to temp and running hot it will almost BURN carbon steel at below 5 psi (not sure of exact reading because my gauge sort of has a space between 0 and 10).

At this same pressure I was only replacing the work piece for between 15-25 seconds before it came out red hot between forgings.


Note the pressure gauge at the top of the pic - this is the heat at that pressure.

The fire bricks are also painted with satanite and HYB-UV, not that they needed it, but what the hell why not?