Hot Nipples (side blast forges, ceramics )

[Bob JS]

I need to 'build' (read as sling some mud in a tin box) myself a new forge, and I think a side blast is the best option for me.

Have read through some old IFI threads, main issue seems to be burning the blast pipe - cast iron water cooled is out of my league atm.


I was wondering, how does terracotta clay hold up in the heat of the fire??

Could I use a flower pot as blast nipple?

They look pretty similar to me


Thanks
Bob

[Glenn]

Contact Vaughn who sells water cooled twyeres or you could fabricate one easily enough.

If this is a new forge on the cheap, then get a longer than needed piece of pipe and as the end of the pipe burns off, advance it into the fire. I used a piece of schedule 40 pipe for a long time with little or no loss to the end of the pipe. In the original 55 forge (bottom blast) I used auto exhaust for the air tube and in heavy use at welding temperatures lost about 3/4 to 1 inch of the end per year. Auto exhaust is thin wall stuff and I thought the loss was acceptable for the amount of use I got from the forge.

You may want to search for a *hearth stone* (or what ever it is called), basically a rock shield to protect the air pipe used in some forges.

[Bentiron1946]

You could try but it will most likely crack on the first fire. You need some real hard fired ceramics for what you want to do.

[Bob JS]

Thats interesting Glenn, I just didn't think pipe would last that long in the middle of the fire.

Sacraficial pipe it is then!

its just another on the cheap, temporary forge.

thanks for the advice

[Fe-Wood]

I love that forge picture!!!!

[Charlotte]

If I may suggest, I have used fireplace brick in a couple of situations similar to this.

Buy a couple of fire place brick.
Using a concrete drill of say 1/4" or 3/8
Drill a series of holes the size to a diamater of the size you need in one brick.
Drill a series of holes the size of what ever your inlet pipe is.

Using one of the round carbide grit hacksaw blades, worry out between the holes and around the sides to the taper you need.

Glue the two brick together with fireplace mortar.

Shorten the brick to a size that is convient to placement you have selected.

I know it sounds a litte crafty but it's only defect is that you will need to scrape of any clinker before its is cool.

I've done this with bottom blast forges and not had any particular problems that I didn't have with iron fire grates.

[John B]

Hi Bob,make your own water cooled tue iron and tank. The attached pics show a small portable forge set up that will give a general idea of the principle.

At Westpoint we use home made units that have served well in production and competition scenarios for many years, with little signs of the front plate burning away and we use coke.

The outer tube is approx 4" diameter x 10" long, the inner one is 1.125" diameter, passing through the tank and welded to the back of a 1/2" thick mild steel disc with a 3/4" dia hole through which works well. (You could have anywhere from 5/8" diameter to a 1.250" diameter hole, all will work)

This plate is then welded to the outer tube and the other end of the smaller pipe welded at the rear of the tank, and a slide valve positioned over this to regulate the air flow.

Make the tank a good size 24"x12"x18" or bigger will be adequate.

This will cost a lot less than a cast iron one.

Alternatively convert to a bottom blast forge and it won't take as much space up in the workshop. (PM me and I can send you detailed plans for bottom blast forge)

We have a used cast iron firepot for sale at Westpoint. Complete with clinker breaker but it will need the old bolts removing and new ones fitting.

[MLMartin]

you could always take your schedule 40 pipe and coat it with what ever clay you can get, down here in GA you can dig up red clay anywhere, ive seen clay dug from the ground used to make many forges with pretty good success. and i know many old Celtic forges had clay used to make the air inlets, so why dont you just use a heavy wall piece of pipe, then cover it will clay, sounds good to me, if it dosent work your not out much time or steel

[Bob JS]

Thanks John for that great info, Im going to bookmark it for future use.
Only problem is I cant weld, yet - Its high on my list of skills to learn.

The reason I thinking about a side blast is mainly because I intend to put the forge inside my existing BBQ - which is enclosed on 3 sides with a roof and a chimney. It will be sitting on a table of 6'' concrete, so I simply wont have room for a bottom blast with ash dump - without making the forge very high, and getting the wrong type of nipples hot.

I think Mlmartin's suggestion is probably what I going to settle on.

Bob

[David Einhorn]

Perhaps I am oversimplifying things but I posted some information on a Civil War era side-blast forge over here:

http://www.iforgeiron.com/forum/f7/hot-cold-air-11199/

[Bob JS]

Simple is good! I had this idea that I would have a pipe sticking into the fire - but it looks like a 'hole in the wall' is all thats required.

Right, Im off to go and dig up some clay.

Ps. Thanks Charlotte, I think I missed your post earlier.

Bob

[grimcat27]

id say use a clay to line the outside pipe and take it about half to one inch past the end of the pipe

[MattBower]

I'd expect the clay to crack and fall apart as i dries. It'll shrink considerably as it dries; the pipe won't. Wrapping in some wire might help hold the pieces together when that happens.

[Charlotte]

I'd expect the clay to crack and fall apart as i dries. It'll shrink considerably as it dries; the pipe won't. Wrapping in some wire might help hold the pieces together when that happens.

If you come on the heating wire from an electrical heating element, such as from a clothing dryer, or old fashioned room heater, you can use that as an embeded reinforcing element or as a backup in a clay arch or brick ceiling.

If not exposed to direct welding heat it will so a supporting job for quite a long time. The material is typically nickle chromium wire.