Jump to content
I Forge Iron

55 forge tuyere diameter

John Kelley

Recommended Posts


I'm building a bottom draft 55 forge this weekend...gonna give this forging a go.

Judging from the pictures and comparing to the 2" bung...I'd guess about 1.5".

My question is what Diameter of tuyere is recommended?

Thank you for any help you'd be willing to give.




Link to comment
Share on other sites

Thank you Stash.

I should have included that I do plan on using an old hairdryer for the air.

I have read that there is something to having enough air velocity..not just volume.

Would you think that a 2" would still work well with a hairdryer?

I understand...I can always change the size if I feel it will help.

...I'm just trying to do this on a shoestring and I'd rather not have to buy two pipes...lol

...On the other hand...I do have a squirrel cage fan that I could use...but it pushes WWAAAYYY more air than a hairdryer (which seems the cheap standard), even when intake and exhaust are basically plugged and the motor is struggling. Can't read any specs on it...but the intake is 3" and the fan is about 7" in dia and about 6" long. This fan is like all the air flow of a good sized box fan going thru a 2.5x8" hole....seems a bit much

I would think that there is a max air as well.


Thank you very much for the help.



Link to comment
Share on other sites

I made my blower from a fan similar to the one you are talking about. Using it electrically is going to be WAY too much air, but making it a hand crank works a treat. Some 2x4s for a frame, a few pulleys, and some round stock to act as axles is all you really need. Oh, and a welder. Its worth considering anyway. Gives you way more control than a hair dryer. 

Link to comment
Share on other sites

Most 3rd world countries have a 55 gallon drum somewhere. Those drums were delivered by a vehicle so the air pipe that was used was from the exhaust pipe of the vehicles. 

In application 2 to 2-1/2 inch diameter works. The larger the better only because it allows for a larger ash tube which does not clog with ash nearly as quickly. Use a ash tube length of 12 to 16 inches below the T in order to hold a quantity of ash. You can plug the bottom of the ash tube with what ever is available to stop the air flow down and out the ash tube.  That said, I prefer a 3 inch ash tube because it was available (pipe) and does not clog up with ash. 

I would suggest a side blast forge configuration as it is very simple and much easier to make. Just put a house brick on edge against the wall of the drum and make a slot down the side of the drum to the top of the brick. Fold the tab across the top of the brick and out of the way. Lay a piece of 3/4 inch or 1 inch pipe into the slot, across the top of the house brick and 8-10 or so inches into the forge. Add fuel, add air and be happy.

Most any air source can work if you use a 3 inch expandable aluminum dryer vent pipe. Crush the aluminum to match the steel air pipe. Aim your air source at the open end of the aluminum pipe with a 3 inch or so air gap between the two. If you want more air, aim closer, for less air, aim not so close. This way you can vent any amount of unwanted or unneeded air.  Fully adjustable air flow that way.

This was designed and written for use with bituminous coal, but with a deeper side wall on the pan I have used raw wood such as sticks, and pallets as fuel. 

You can make the fire smaller by adding bricks to form the size circle you want to use as a fire pot.  This also saves on the fuel as you only burn what is needed.

The 55 forge has undergone many modifications and can be used for many different type fires, from a 4 inch diameter fire pot to a 24 inch diameter fire pot. It depends on your next project and the type fire you need for that project. Those modifications include the 55 forge with the Supercharger, or chimney. This gets the smoke out of the work place and is easy to build and use. 

It is the joy of tinkering with what you have to make it better and to better suit your needs. No one ever said you could have only one forge. Currently I have 3 forges that almost touch each other. Choose the type fire you want, light that forge, and you do not have to move the anvil as all the forges are just a step away from the anvil. And yes, many times two of the forges were going at the same time. LOL


Link to comment
Share on other sites

Thank you Glen.

Lots of good thoughts and info in your post.

I hadn't thought of positioning the blower like that.

I might try that.

If I find it's not quite enough air that way, makes me think about possibly fixing my tube to one side of the blower vent and leaving the rest of the vent open.

...then maybe have a slide gate on the remaining vent opening for adjustment.

Thanks for getting my mind looking at it in a different way!

Link to comment
Share on other sites

The only issue would be if the blower is not powerful to move enough air for the forge. 

You can use any style or size blower using the aim and miss technique. It is infinitely variable without a air gate or slide gate. I suggested an 3 inch diameter expandable aluminum dryer vent. Any type piping would work. The aim and miss technique can be used with a solid metal air pipe such as auto exhaust pipe. 

The original air pipe was a 4 inch diameter plastic dryer vent that did not survive the flashback from the forge. The flashback was a loud noise followed by fire that melted and destroyed 5 feet of the plastic dryer vent pipe and  ended the forge session.  Replaced it with 3 inch diameter expandable aluminum dryer vent that has survived a couple of flashbacks from the forge.

The expandable aluminum pipe allows you to easily position the air source on the ground, a table or where ever it is handy. I like the ground position as the aim and miss air adjustment technique is foot operated.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...