Real tired of punching out these holes in the large masonry forge. It will get plenty hot to weld when the holes are free, but they seldom are. Lots of punching. Time and again. The fellow prior to me build this for the historical society and I thought it was a mathematical science to design a tuyere. CFM and size of fire pot, the size of the bellows and the counter weight etc. etc.all had to coincide with one another.

I have used this large forge for years and had enough.

The bottom of the fire pot is 8.5 inches and is eight inches deep. About 18 inches across at the top. There are four 3/8 inch holes in original tuyere. 1/4" steel plate and very badly warped. Inlet to tuyere from bellows is 3 inch pipe.

New fire pot base is 1/2 inch steel plate with 1/2 inch steel stock welded inside the 3 inch hole

Not thew way I would do it but hay, it should work 

I didn't attend college to study forge design and function but I can tell you the old tuyere don't function well. The worst aspect of the old is the 2.5 inch pipe fits inside a 3 inch pipe. Thusly,  as the four holes plug the air is now routed AROUND the firepot.

My small rivet forges won't plug up like that as they have much larger holes. Enter my new designed tuyere for the large masonry forge. It will initially be experimental. if it works as well as I hope; it remains.

I have an old french portable forge, the tue was a cast sphere with slots in it.  Held up quite well until I attached a powered blower and then it didn't take long for it to burn out, now it's just a hole in the bottom lol. I have fixed it by using a cast drainpipe cover so that should hold up for temporary use. 

yes. Anything to allow air in and fire from dropping through. Although some drop-out would be permitted as you need to pass some of the clinker/ash,. thus the clean out. If nothing ever passed though, why do we all have the clean out cavity below the air inlet?

iI too much passes though ,I weld in a couple of 3/8th inch nuts to fill the gap a bit....... between the gaps.

have you seen the bottom blast tuyere on an alldays and onions forge, it's one slot that swivels, hard to explain. brilliant design.

Yes. Wikipedia has a pic.

Report on this new tuyere design.

It's like this. The last smith who was quite obviously experienced, designed the tuyere I have used for the past six full years after he left the organization.

I figured this is how a forge works; crappy. No or little air. Fight to aquire heat.  Frustration.  Agrivation. But yet tuyere assemblies I have designed for two rivet forges works well. Tons of air. Loads of heat. Satisfaction.

So I have to wonder what this other smith was smoking. 6" deep fire pot. 9" across the bottom. 18" across the top and he makes a tuyere with four 3/8 holes.

This newly designed tuyere is so fantastic. .....so user friendly. ...so efficient. ....so effective I am worn out from smiling all day. I had to put my free hand in my coat pocket to keep from waving at the visitors.

I used it for 7 hours today. I think I'm going to patent this application.

I need a nap.

Congratulations.

What you experienced is what a lot of folks go through.  They see an old-timer doing something and think that's they way it's supposed to be because, surely, the old-timer must know something after having been doing it for ages on end.  It's a logical fallacy that applies to a lot of things in life.

You struggled and cussed for years, and when you finally got fed up and changed things around a bit.... you saw that the old-timer didn't know diddly.  Like the saying goes, just because you've been doing it for decades doesn't mean you're doing it right, only that you've been doing it for decades.

Enjoy your new forge, friend.

V

That is what I was trying to say. Thank you. I didnt have the literary tongue to do so. I won't find a better explanation than yours.