Want to build a new forge.

Discussion in 'Shop Talk - BladeSmith Questions and Answers' started by Southclaw, Mar 19, 2011.

  1. Southclaw

    Southclaw

    157
    Nov 30, 2009
    I think I am ready to upgrade my forge. I have a naturally aspirated forge that I built a few years back, and I want to build a blown forge that I can setup with a PID.
    I would like suggestions on the design. Please give me your opinions on what you think is the best or even a good design for a blown forge. I have seen photos of vertical round forges, horizontal round forges, and square or rectangle forges.
    Your advice would be greatly appreciated.

    Thank you in advance. And any photos you could post would be of great help.

    Zech
     
  2. Stacy E. Apelt - Bladesmith

    Stacy E. Apelt - Bladesmith ilmarinen - MODERATOR Moderator Knifemaker / Craftsman / Service Provider

    Aug 20, 2004
    Round 16" long, 12" OD. Horizontal setup.
    5" interior chamber diameter.
    2" High-Z Kaowool with 1.5" thick cast refractory liner and ITC-100 coating.
    Two 1" blown burner ports. Positioned at 1/3 distance from ends, aimed at the tangent. Cashen style mixing chambers on the burners.
    100CFM fan with variable speed control
    PID two-stage controller setup
    Separate PID/TC just to read temperature. Overlimit alarm on its output (audible backup and double check on the controller)
    Master shut off solenoid for safety.

    This won't be the cheapest forge you can build, but it will be the best one you ever use.
     
  3. Southclaw

    Southclaw

    157
    Nov 30, 2009
    Stacy if you had a photo of it that would be great! I can build most things, if I can see it. I am a very visual person.
     
  4. Stacy E. Apelt - Bladesmith

    Stacy E. Apelt - Bladesmith ilmarinen - MODERATOR Moderator Knifemaker / Craftsman / Service Provider

    Aug 20, 2004
    I don't have a photo of one like this, but most of the basic info can be found on Darren Ellis and Kevin Cashens' sites. I still have a "project in a crate" to make an extremely overbuilt forge, after the new shop is done. I will be documenting that, and may turn it into a Build-it book/DVD. Of course I will share the progress here first.

    I will say that, while building a forge like I described is not extremely complex, you will have to know what you are doing to get it made right. Just looking won't help much.

    The build is done in several steps. Building the burners, building the two-stage controller, pouring and curing the liner, wrapping it with insulation and installing it in the tube , fitting the burners and TC, attaching the end plates, tuning, celebrating the project's completion with a beer.
     
  5. Fred.Rowe

    Fred.Rowe Dealer / Materials Provider Dealer / Materials Provider

    May 2, 2004
    I built this two stage blown forge with Stacys information. The dual control system is the way to go. Perfect accuracy at set temperature along with a wide heat range. It is easy to control the forge atmosphere also.
    This build was a little extreme; but hey, I'm an old hot rodder.:)

    Fred
    [​IMG]
    [​IMG]

    [​IMG]

    [​IMG]
     
  6. Southclaw

    Southclaw

    157
    Nov 30, 2009
    This will have to be one of the few occasions that I disagree with you Stacy. Like I said I am a very visual person. If I want to build something, most of the time I just need to look at it. :D
    I thank you much for your advice. I would like to know where to place a hole for the thermometer, and how large of a hole to make for it. I plane on making the blown forge first and upgrading it with the PID later.

    Fred that does look like over kill. Why do you have 5 burners? I don't think I have seen one with that many before.

    Zech

    Edit: I would like to know where I could get a 100CFM fan with variable speed control. How much would that run?
     
  7. Fred.Rowe

    Fred.Rowe Dealer / Materials Provider Dealer / Materials Provider

    May 2, 2004
    Hi Zech,

    Its similar to knives; one mans extravagance is the next man's EDC.:)

    The five burners give options; each one has its own needle valve and can be brought on line or shut down as needed.

    I would suggest a 150 cfm pole blower; which can be had at most motor supply houses. Buy one that can be used with a rheostat. You control the fan speed with it.
    Use a K-thermocouple to monitor temperature and to connect to the pid controller to operate the air/gas mixture.

    When building a blown gas forge many of the concepts cannot be understood by just viewing the forge after it is built; it is important to understand the science behind the concepts.

    I learn best kinetically also, but after building a few forges I find reading up on what I am about to build has made the building itself more enjoyable and the result more predictable.

    Best of luck to you, Fred
     
  8. indian george

    indian george

    Feb 15, 1999
    I have a tutorial on my too.;)
     
  9. Stacy E. Apelt - Bladesmith

    Stacy E. Apelt - Bladesmith ilmarinen - MODERATOR Moderator Knifemaker / Craftsman / Service Provider

    Aug 20, 2004
    As Fred stated, some things won't tell you much by looking at them. Seeing a poured refractory liner won't tell you much about pouring refractory liners. Seeing a system with parallel circuits won't tell you how to balance resistance loads in a parallel circuit. I understand what you mean by - See it/build it - as I do a lot of that,too.

    The TC should be in an area that is where the blade is. One simple method is to add a "burner port" in the center of the forge. Use it to run the TC into the chamber. This will place the end of the TC at the roof of the forge above where the blade is most of the time. Make the port size to fit your TC sheath, and seal it with satanite.

    BTW, a poured refractory liner is not a necessity, good old satanite on the inside of the forge works fine,too.
     
  10. Southclaw

    Southclaw

    157
    Nov 30, 2009
    Let me start by thanking you guys for the info.
    I think I need to clarify what I said earlier. The reason I wanted to see photos was because I wanted to know the best physical design for a forge. I do do my share of research on subjects before just jumping in. For instance I have not researched PIDÂ’s enough to start working on that part yet.
    Stacy. Is poured refractory a better insulator?

    Now that I think about it maybe I should get to work on the PID right along with the forge. Looks like I have LOTS of old threads to read through.
    Thanks again guys. This place ROCKS! :thumbup:
     
  11. Mike Davis

    Mike Davis

    Feb 7, 2006
    Not trying to be a thread hijacker, just saying..Stacy, thanks for the info, Fred...That thing is beast!!! Stealing ideas for my new one :)
     
  12. Fred.Rowe

    Fred.Rowe Dealer / Materials Provider Dealer / Materials Provider

    May 2, 2004
    You are most welcome Sir and I know I can speak for Stacy in this instance.

    Building forges is a heck of a lot of fun. There is under a thousand dollars in the Vulcan's Chariot forge. Quite a bit of time involved.

    Good luck to you, Fred
     

Share This Page