Another first time ribbon burner forge build thread

[Bull Bison]

Got my forge completed finally. Over the last two nights been slowly bringing it up to temp. First night let it run at low temp for about ten minutes, last night for roughly thirty minutes at half mass. Gonna crank it up a little more tonight over some drinks. No cracks yet, holding up well. 

Made out of an thirteen gallon compressor tank, 12" OD and 24" long. Lined with 2" of Kao Wool and 1-2" of Mizzou. I figure I'm setting at about 500 cu in.

Ribbon burner is 9" x 3" with twenty five ~1/4" orifices (I used drinking straws). I cast it using Mizzou which seems like a good robust product. 

Had it running at 1 PSI last night which seemed like I could potentially drop it a little more once up to temp (forging temp not welding temp). We'll see, I'm still learning, fun times. 

[Latticino]

Looking pretty good, though a little long.  I made my current forge out of a similar tank, but cut around 5" of length off and wish I had removed more.  Keep us posted on how it works for you.

[Bull Bison]

Thanks, I'm sure your right on it being too long. The more research I keep doing, albeit a little late, the more it's becoming apparent that is probably the situation. 

I wonder if I could cast a removable "plug" out of Mizzou to take up some cu in. 

In my previous life I would hit BBQ cook offs and ended up building a rather big trailer smoker. The fellers on the BBQ forums had, through years of trial and error, created a formula that would kick out the size of your firebox, air intake, exhaust flue, etc. based off the size of cooking area you needed. I'm sure a similar formula could be created, or probably already has been and I just haven't ran across it yet, for these forges based on the size / cu inches you need. 

 

 

[Frosty]

When you describe the liner you say it has 1-2" of Missou, did you mean to type 1/2"?  One to TWO inches of hard refractory inner liner / flame face is way more than necessary to the point of being detrimental.

Looks good, how does it work for you? 

Everybody who makes their own propane forge has several old models gathering dust in a corner somewhere. As soon as you start using your new and improved forge you start noticing things that need improvement. 

Frosty The Lucky.

 

[Bull Bison]

No typo there, I've got 1-2" of refractory on top of my ceramic wool. 

Unfortunately I don't have anything to compare it to, as this is my first forge and my first forge to work on. I put about 4-5 hrs on it Saturday and it seemed to work just fine. Again, I just don't have a good point of reference. 

 

[Frosty]

That's close to the same mistakes I made building my first forge, at least yours isn't way too large. Good job, problems and all.

Next time I highly recommend you pick ONE of the proven forge designs in the "Forges 101" section of Iforge and follow it closely. Mixing and matching requires a deeper understanding of how they work and the probable effects of the changes you make than a beginner usually has. Make sense?

In general, the outer insulating liner should be 2 layers of 1" 8lb. ceramic wool refractory, I'll call Kaowool for ease of typing, there are lots of equivalents. Rigidize each layer as you install it, do NOT buy commercial rigidizer, even though it does a GREAT job it's really expensive and has a very short shelf life as in dead in a few weeks after opening. We use fumed silica mixed with clean fresh water. It's commonly available at plastics or fiberglass suppliers, it's used to thicken resins. Be SURE to buy the "Hydrophilic" fumed silica. The other type is a REAL BEAR to mix with water. That's why it's called phobic.

To rigidize the blanket you first wet it with a spray bottle, this is called buttering and helps ensure a proper bond between the silica and blanket. The water causes the rigidizer to flow along the fibers and concentrate at junctions. Once buttered spritz on the rigidizer, it's hard to over do the rigidizer so have at it. a good trick is to put a couple drops of food coloring in the mix so you can see how it's covering. 

Let it dry and cure it to a dull red with the forge burner or take your time and use a Bernzomatic soldering torch. This vitrifies the silica making the blanket stiffer but more importantly it it makes vitrified ceramic fibers from breaking off and floating around your breathable air. Think mesotheleoma hazard. Yes?

Once rigidized and cured trowel the hard refractory onto the blanket. Missou is a good product but if you need more I'm a huge fan of Kasto Lite 30, li. It's a 2,600ff. water setting high alumina castable bubble refractory. About the same as Missou except the "bubbles" which are evacuated silica spheres. (I can NOT bring myself to type vacuum "FILLED") What they do in the refractory is two fold, first they provide insulation where missou has about the same insulating properties as en equal thickness of limestone. The second property and less important in a forge is make it physically lighter. Bubbles are commonly available at concrete batch plants where they fill cement trucks it's used to make light weight concrete. If you want to experiment or make light concrete just replace some of the fines in the mix.

Anyway, plaster the floor of the forge with maybe 1/2" max and when it sets, mix up more and plaster the sides and roof with maybe 3/8" max. Lots of guys are using 1/4" all round. Being a water setting refractory it NEEDS to cure in a 100% humidity environment. As soon as it's set place it in a sealed container with a couple inches of water on the bottom or a WET towel and leave it at least 24 hours. 

Do NOT try drying it, this is a B A D thing to do to it. It REQUIRES water to properly form crystal lattice that make it hard. Do NOT try rushing the stuff, your patience will be rewarded.

Whatever hard refractory you buy FOLLOW THE DIRECTIONS!

Make sense?

Frosty The Lucky.

[MrMedieval]

That's a nice clean looking forge well done mate.