[TheForge] Portable Forge rebuild

Thu Jul 17 01:28:04 2003

Dianne;
Nobody addressed the flywheel problem directly...but before I do, please 
note that a wise few contributing smiths
were able to make the distinction between what one *can* fix and what 
*one should* fix. The rest of us  are generally unable to make that 
distinction.
You were on the right track with a general preheat...at least 400*. 
Hotter would be better. The cracks and joints all need to be ground out 
so you can  get good weld penetration.
Brazing  is  a good method, High nickle welding rod or even cast iron 
welding rod all work.  If you use Nickle rod, peening  each short 
section of weld as it cools helps.
As you weld, the weld area will first expand, then shrink...the molten 
weld contracts a lot , building up stress.  If you look at the wheel, 
you can anticipate where  the stress will first push then pull  when you 
weld. The trick is to pour on additional heat at the points  where the 
stress will occur so that the wheel moves in and out  in parallel.. If 
you are welding up a spoke, you will probably have to add extra heat to 
 other spokes and at least a couple of places  on the rim.
The  above is why you recieved advice to find another one....but some of 
us are more stubborn than sensible...It may well be part of "the 
syndrome".....Pete

Best, Dianne wrote:

>(Fer them what also visit the Blacksmith's Junkyard, I apologize - this'll
>be a duplicate)
>Good mornin fellers! 
>I'm rebuilding a portable forge that was in a fire and I have a few
>questions: 
>#1 - Cracked pan. 
>The pan has a crack 3/4 of the way across the bottom. Since I am planning on
>lining the pan with clay, I don't think the crack will be a problem. Am I
>wrong? 
>#2 - Broken drive wheel 
>A segment (between two spokes) fell out of the large flywheel that drives
>the blower. The ends are rusty, so it has been broken for a long time. 
>I know how cast iron is SUPPOSED to be brazed (by evenly preheating,
>brazing, and the slowly and evenly allowing to cool) but I haven't had much
>luck with that process - I have had new cracks form during cooling. 
>I am thinking about repairing the flywheel segment by using epoxy and
>putting in a couple of small steel pins. Is there an easier way? 
>#3 - Flywheel weight 
>This is a lever-operated blower and, looking at the flywheel, which is
>relatively light, I was wondering if adding some weight would give longer
>blower action (momentum) - would this be an advantage? I could put steel
>"tire" around the flywheel and just about double its weight. 
>#4 - Blower drive belt 
>I am wondering what to use for a blower drive belt. Obviously the thinner
>and more flexible the belt, the longer the blower will spin for each pump of
>the lever. I have some rubber (conveyor belting), but that has lots of drag.
>The only canvas belting I have is too heavy to turn easily on the small
>blower pulley. Any suggestions? 
>Thanks fer yer ideas fellers! 
>Calamity Jane 
>
>
>
>--- StripMime Report -- processed MIME parts ---
>multipart/alternative
>  text/plain (text body -- kept)
>  text/html
>The reason this message is shown is because the post was in HTML
>or had an attachment.  Attachments are not allowed.  To learn how
>to post in Plain-Text go to: http://www.expita.com/nomime.html  ---
>_______________________________________________
>http://mailman.qth.net/mailman/listinfo/theforge
>theforge mail list group photo site is
>http://www.photoaccess.com
>Login:  [email protected]
>password:  anvil
>___________
>
>
>
>  
>

--- StripMime Report -- processed MIME parts ---
multipart/alternative
  text/plain (text body -- kept)
  text/html
The reason this message is shown is because the post was in HTML
or had an attachment.  Attachments are not allowed.  To learn how
to post in Plain-Text go to: http://www.expita.com/nomime.html  ---