Building my first forge, some questions.

[Liam Ryan]

I found a supplier with some Kaowool, and have a basic design figured out. I am thinking an 12'' horizontal pipe, 8" across, forced air design. ( I like the way this one looks, by the end I mean.)
[youtube]4SZNkJ0KevM[/youtube]
Now I have a few questions, first is, is that forced air design worth the trouble? it seems like it would be an efficient way to get high heat with little gas.

Next, you will notice at the end of the video his blanket is getting scorched, and anvilfire recommends a layer of ITC-100 over the blanket to extend life and make a more efficient setup. This stuff is pretty expensive though, is there a cheap alternative? Or could I get away with using nothing? The forge won't be used very much, a few knives and maybe a longer piece.

That brings up my final question, what are some tricks for getting a longer piece, like 20", up to critical for quenching in a smaller forge? Maybe slots cut in a firebrick in the front and back (if the back were open) and the long piece could be moved in and out through the slots, would that work?
Hope that's not too confusing.

Anyway, thanks in advance!

 

[HomeBru]

I used Plistix 900F from Zoeller http://zoellerforge.com/flare.html instead of ITC-100 and it's holding up nicely. You want to put something on the wool to keep microfragments from breaking off and creating an inhalation hazard.

Drawing a longer piece back and forth through the heat is how the old-timers did it. Takes some skill from what I've seen

 

[Stacy E. Apelt - Bladesmith]

Read the forge building tutorials in the stickies. there is a lot of info there. Blown burners are the way to go if at all possible. Adding a PID to either read the forge temp, or control it will make your forge a top notch device ( assuming it is well built).

The kaowool blanket needs a coating of about 1/4" (6mm) of satanite or similar refractory, and when that is cured, give it a final coat of ITC-100 or similar product. Don't try and save money in the forge lining. Made right it will last years....made without the proper coatings it won't last six months. Also, the fibers blown out from an uncoated lining can be a serious health risk.

A blown burner, with an expansion chamber, will be very efficient. It also can be turned down much lower for HT, than a venturi burner.

Make the back have an open port about the same size as the front port. No need for either to be more than 3" wide and 2" tall for most makers. You can block the back port with firebrick when not needed.

I regularly do the HT on 24-30" swords by slowly and evenly "pumping" them in and out through the front/back ports. It takes practice and you have to do it at night ( or on a very cloudy day), but with some skill you can evenly heat a blade much longer than your forge.

 

[Liam Ryan]

This is great info, thanks. The forge will be seeing very little use, as I do plan on building something bigger and investing more money down the road, but right now I am just learning as all my knowledge is theory at this point, I need to actually go and do it finally.
So I may just start out building a firebrick forge and troubleshooting on that.

 

[A.McPherson]

I second Stacey's advice... Definitely use forced air. I started out with a venturi type burner and now that I have my forge built, I'm considering making it a forced air type. The control available with a forced air type is far greater, and it is "scale-able". By that I mean you can add to it as you need/want to, adding a PID, extra burners etc.
With a venturi type you are kinda stuck with whatcha build/buy...