Melted tuyere

[Quench.]

We've been having Seattle weather in NC, so I haven't gotten to use the forge that much. This weekend was perfect.  I ran it for about a two hour stretch yesterday.  When I cleaned it out, I saw my cast iron tuyere had melted.  Now this is a made in China floor flange from a big box, but I didn't think it would last only a couple forgings.  And it was fine at the end of the last forging.  I turn down (not off) the air between heats.  It's an electric blower.  The forge is a new build this winter.  Any idea what's wrong?  (Second picture is before; just shows how the coal piles in.)  -Q

 

[Glenn]

Check to see if ash has built up in the air pipe.

If so you get a fire below the twyere and the grate can get incredibly hot.

[Quench.]

Ohhhhh...  Glenn, I think it did.  When I was cleaning it out, I was having trouble sweeping the small pieces down.  They clogged up right away.  I took a piece of rebar and really had to mash on it to clear the tube.  I'll bet it was partly clogged.

Well, shoot, how does one deal with that situation when the forge is running?  Can't very well poke through the grate.  Can't really remove the grate with the coals in there and have any possibility of getting it back in place.

Is this something common?  Any way to prevent?  Was a bit of a pain, cutting the holes in that flange.

Just checked inside the forge body with a flashlight. The down tube didn't get hot enough to burn the high temp paint on the outside surface of the tube.

-Q

[Glenn]

The ash tube is just that, a collection area for ash. You clean it early and often to keep the ash below the level of the T and the air inlet. If the ash builds up to the T or air inlet the forge fire starts RIGHT THERE. If additional ash builds up it can block the incoming air and the forge will choke and suffer.

Usually anything less than 2 inch ash tube can cause problems. A long ash tube works better than a short one, long being 12-18 inches in length. It holds more ash before you have to dump the ash. 2 inch usually does not clog nearly as quickly or as easily as smaller tubes. I prefer a 3 inch ash tube if I can build it that way.

One suggestion is to leave the ash tube open (no flapper valve etc). Place a bucket under the ash tube and fill the bucket with water until the water touches the ash tube and a bit more. You can tell just how much more when it quits bubbling when you give the forge air. Any ash that falls through the twyere will fall down into the ash tube and into the water. On yes, the bucket full of wet ash can be very heavy (do not ask how I know this).

This is a 2 inch ash pipe with one 3/8 bolt for a grate. The 3 inch needs 2 each 3/8 bolts. Yes that is a lot of air and that air is what makes the fire hot. Both fire pots have been used with coal fines or coal dust.

You can see the cone that occurs naturally in THIS forge. The grate is 2 pieces of 1/4 inch bar stock in the atuo exhaust pipe I used for a twyere and ash tube.

The bricks were added to the 55 Forge to better shape the fire. They made the fire smaller and deeper for the project at hand.

[Daswulf]

big/deep enough down pipe might help. flapper on the down pipe and just kill the air and open the flapper.poke if you have to, then resume air again.

[Quench.]

Great advice, thank you guys.  I see what I need to do now.  Tube is all 2".  Down tube below the T is only a 6" nipple.  Design error there, oh well.  My ash dump is welded to that 6" pipe, so I'm kind of stuck with it. Maybe I could extend it with a connector.  Better option is to dump the ash every 30 min or so, probably.

So much trouble to drill out that flange.  I think I'll look into the bolt idea.  Way easier to replace, too.  I've seen those pictures before, too--should have just  started with that.  Will get that done right away.

That's a cool idea, with the water.  Hard to get it through the doorway, though.

Thanks again!

-Q

[arkie]

I find that a lot of folks like to try out their welding skills on a "T" pipe arrangement.  Really hard to change anything.  If one simply uses black threaded pipe on the "T's" and bolts on the firepot (if any are needed...some are heavy enough that weight alone holds them in place), then problems with plumbing can easily be corrected.

To aid in clearing out the down-pipe and ash dump, just make a long, pointed rod about 1/4" diameter and poke it through your tuyere.  Some pots with the cylinder clinker breaker might not permit that.

[Glenn]

10 minutes ago, Quench. said:

That's a cool idea, with the water.  Hard to get it through the doorway, though.

I use a 5 gallon bucket and to get the rim of the bucket say 2 inches above the bottom of the ash tube. I put the bucket on a couple of bricks if needed.  THEN I fill it with water. 5 gallon buckets fit through a door way just fine when you only fill them half full (grin) I can make 2 trips rather than mop the floor that way.

 

[Charles R. Stevens]

Quick and dirty, buy a 2" exhaust flapper, weld a handle on the flapper extending to the honeys side, clamp it on your ash dump and walla, easy counter weighted ash dump...