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I Forge Iron

New to site. Just finished gas forge


Ijimmyzw22

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Yes I did, tried a few friends forges and put together what I thought I would like. The only thing left to do is coat the wool with refractory cement and am awaiting the fire bricks. Fired it last night for the first time and it heated steel real quick. I have a few friends that now want one just like it. The only thing is I might want to try some different burner types but overall I am real happy with it. allowed me to practice my welding too.

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Welcome aboard, glad to have you. If you'll put your general location in the header you might be surprised how many of the Iforge gang live within visiting distance.

That's a beautiful looking forge. Along with agreeing with Thomas about top mounted burners. The burners on my shop forge are vertically top mounted and heat is drawn up any that aren't running even though I can partition the inside of my shop forge. That's a different thread though.

The biggest problem I have with vertical top mounts is the fuel supply. It appears your forge is plumbed to receive propane through a rubber hose connected almost directly above the front opening. :o

My recommendation in those cases is copper tubing for the final connections.

What are you going to use fire brick for? NOTHING in the forge I hope, there are MANY better alternatives. Hard fire brick is a major heat sink and has only slightly better insulating properties than an equal thickness of lime stone. And NO, having a large heat sink isn't beneficial unless you're cycling a LOT of steel through the forge rapidly say in a production shop.

Soft fire brick is decent insulation, not close to ceramic blanket but not bad. Unfortunately soft fire brick isn't rated for the temps a decent propane forge generates. Higher rated soft brick is available but is darned expensive and still a little short of temp. The stuff tends to break down in a couple few thermal cycles or one long session.

The only place I like fire brick is for the front porch just outside the forge opening. The porch tends to take a good beating, folk are always bumping and scraping it. 3,000f split hard fire brick is tough as nails and relatively cheap. Other than that I wouldn't use any kind of fire brick in a forge no matter how you coat it. Maybe, MAYBE is it's in a spring shop with a bunch of ham handed knuckleheads using hard brick for the outside shell as armor is a good idea but that's about it for me.

Oh, what about the box of soft firebrick I have under my gas forge? I also have about a dozen hard full and half a dozen split hard bricks too. I use them to test chamber size and shape when I'm testing a new burner and I use them to make brick pile forges at Demos. Folk who might be interested in giving blacksmithing a try rarely want to spend a few hundred bucks on a commercially made gas forge or have the tools and shop skills to build their own. NOT for a test drive. However a dozen fire bricks, $15 in plumbing parts, hose and a few fittings lets a person  give smithing a try for say $100+/-. Folk in the audience can wrap their heads around this kind of investment/gamble.

I connect the fuel lines to the burner with rubber at demos as I lay the burner on it's side so convection is no danger to the hose.

Anyway, I much prefer either a kiln shelf or spread hard refractory floor in a gas forge. High alumina water set castable refractories will withstand fluxes well and they're tough as concrete at rated operating temps. You'll see the name Kast-O-Lite 30 come up frequently here, it's nearly perfect it's rated operating temp is 3,000f. it's a bubble alumina meaning not only is it immune to welding fluxes the "bubbles" are little ceramic spheres with vacuum centers  so it's a much better insulator than regular castable refractories.

A 1/2" or so hard refractory inner liner or "flame face" is rapidly becoming the preferred stuff in gas forges. Lots of guys have been making gas forges and tinkering around for what works best and so far this seems to be the recipe. Two layers of 1" ceramic blanket refractory rigidized with sodium silicate or colloidal silica rigidizer for the insulating outer liner or backer. Then the inner liner or flame face about 1/2" of a hard castable refractory, high alumina is preferred. The floor seeing the heaviest use needs this much to resist mechanical erosion, you can get away with a LITTLE less on the sides and roof but not a LOT less. Then the last ingredient is a IR reflective or re-radiating kiln wash. ITC-100 has the most name recognition in this role but the stuff is expensive and not terribly resistant to being rubbed. There are other products that work as well maybe better and cost much less.

About the hard liner there are a number of ways to apply the stuff. Most popular seems to be mixing it like stiff plaster and troweling it on and it's an effective method. If you "butter" the ceramic outer liner first it will stay in place much better applying it to a dry surface is a bad technique as the surface will absorb the water out of the castable and it can't set leaving a layer of dry powder between the hard and soft liner. Buttering is a mason's term meaning to wet the surface getting mortared, plastered, etc. I butter with rigidizer, it's stickier and works a treat.

Again, nice looking forge, really nice. Gonna give it a nifty paint job? Header paint works nicely and comes in lots of cool colors you know. ;)

Frosty The Lucky.

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