New Forge Build (and a few questions at the bottom)

[Salterclan]

Hey all, long time reader first time poster out of Charleston SC.  I have owned a forge before but it is falling apart and really was more of a farrier style forge from 10 years ago anyway.  I have done some forge welding (not like Damascus.  Just putting Mild or junk steel together to make cool decorative trivets etc.)  

So, I am attempting to build a forge from what I purchased a few years back and while I have tried to read a good bit and catch up, some things appear to have changed or maybe I'm just looking in the wrong place.  The hope is to build something better insulated and a good first forge for small items again like knives small hammers and all of the other trivets I used to build.  Later, I'll do a larger oval forge after I learn from this one.  I might even try my hand at a ribbon burner in the future. 

Pretty sure a lot of what I bought was from Larry Zoeller a few years back when I thought I was going to have time to do Blacksmithing, and then life got in the way.  So I'm back and ready to go.  I'll include pictures of everything I have found.  Hopefully I can get some feed back as to whether these steps are still good options or if things have changed.   I've attached a photo of the burner he produces which I am assuming is still great for a Freon Tank size forge. 

 

I also have the Rigidizer and what looks like some cheap parts to do the plumbing.  I don't know if I can find the original hoses I purchased so I'll need to get those.  

 

Can anyone confirm which type of coating this is? I think I used this to coat my original furnace in the areas I replaced firebrick with the ceramic fiber insulation.  I can't remember what it is or if it's a good choice for the one I am making now.  

This is obviously Plistix.  I was planningg to use this instead of the other coating to cover the rigidized insulation.  However, that part leaves me with a few questions.   

 

1.  Is Plistix the only thing needed?  I think I got it because the thought at the time was you wanted something reflecting back the heat so a relatively thin layer of Plistix versus a thick layer of something else means quicker heating and less propane etc.  

2.  If I do this should I be putting in a Firebrick on the bottom?  If not should I just flatten the bottom with more Plistix?  I'm not sure if I have enough either way.

3.  When I am putting the ceramic fiber in should I be using some type of high temp glue to hold it to the metal?  My last forge had quite a lot of distortion at the mouth on both sides so whatever I can do to help with that.  I know over time there isn't much you can do about metal warping.  I do have a lot of 1/4 inch plate so I could make a large flat plate on the front to leave metal a place to hang out.  Maybe that would help where the tank, and ceramic fiber meet.  

I know there isn't a perfect answer and everyone has opinions, but I'm open to whatever the respected voices suggest.  

If you guys think building a circle is a waste of time and I should just go ahead and make an oval I can do that as well.  I just assumed that with only one burner it's not like I will have a lot of room either way to heat up, so I'd just make the hole whatever the size is with 2" of ceramic in it.  

thanks for any help and I'll put some progress photos as soon as I know I'm not wasting my time with the freon tank and how I attach the insulation.

-Salterclan

 

 

 

 

 

[George N. M.]

Welcome aboard from 7500' in SE Wyoming.  Glad to have you.

Can't help you on your forge construction questions.  Just a welcome to the forum.

"By hammer and hand all arts do stand."

[Frosty]

Welcome aboard Salterclan, glad to have you. If you got your forge kit from Larry, it'll make a fine forge. Sure things have changed, they change all the time but it's not a race. We can work with what you have.

Larry makes good burners. You might want to make a different style at some point but his modified side arm is a solid proven burner.

The ins-stuff is a rigidizer and is used to make the ceramic blanket refractory stiffer and more structurally strong. It's important role though is encapsulating ceramic fibers that can break loose and float around in your breathable air. It's important to use it for safety and performance.

Plistex CAN be used alone over the blanket as the flame face but being so thin doesn't shield the blanket sufficiently.

The current consensus choice for a flame face refractory is Kastolite-30 li. It's a 3,000f, water setting, high alumina, castable bubble refractory. The bubble part of the description means part of the fine aggregate in the refractory are evacuated silica spherules which lighten it physically and increase it's insulating properties.

The insulation factor is very attractive for making the ceramic blanket last longer, it's another shield against the forge environment.

The plistex is then painted on the interior surface of the castable refractory liner as a final layer or armor, Plistex fires hard like a ceramic coffee mug and is much higher % alumina and laughs at molten borax welding fluxes. 

I don't know what is in the bucket, do you know the product name?

Frosty The Lucky.

[Salterclan]

Ok sounds good.   I thought I bought Kastolite in the past so I’ll look around.  No need to use a high heat adhesive to hold the ceramic blanket to the steel surface? I know the rigidizer is good for the encapsulation part so should I put it on both sides near the ends where over time the metal may pull away or just fill any spaces that might open up with Kastolite / plistix?  
 

Thanks again!!

[Latticino]

Stuff in bucket looks like Satanite to me.  Was formerly thought of as a good coating for refractory blanket, applied in multiple thin coats, but most users report that it is quite fragile, cracks and breaks down pretty quickly with use.  I would substitute a 1/2-3/4" thickness of Kastolite 30 instead.

[Salterclan]

I found it.  Bought it on Ebay quite a while ago. link removed Morgan K Bond 3000 deg fahrenheit.  I would say that it is relatively fragile based on how it has worked with my older forge.  It did eventually crack in some places and flake off of the insulation, requiring more coats just to stay safe.  However, I have no idea if that is similar to Satanite.   I'll stick with the Kastolite and Plistix.  Now I just need to see if I have Kastolite around here somewhere.  The reason I'm years behind on this is I built an addition to the house for my parents.   The good side of that is I now have a larger garage, but I also have a big mess to clean up as all of the work to build the house was either constructed or stored in the garage.  

 

[Frosty]

Morgan K-Bond 3,000 is refractory CEMENT it is NOT a flame face refractory and will be short lived as a forge liner.

No need to cement the blanket to the forge shell, just cut it a little too large and compress it in place, it'll stay fine. Alternate the seams between layers so they don't line up. Then the rigidizer will stiffen it up and the layer of Kastolite will set and cure like concrete. It won't go anywhere.

If you have enough blanket it's easy to make a cylindrical forge into one with a flat floor, sort of D like. Just cut a strip of blanket the width you want for the floor and feather the edges where it meets the cylindrical walls for a smooth transition rigidize and plaster it in place with the Kastolite. You'll use a little less kastolite and plistex.

Boy your story sure sounds familiar. I don't despair by reminding myself that real life is that thing that disrupts or cancels my plans.

Frosty The Lucky.

[Salterclan]

Makes sense about the k bond.  I think I originally bought it to put together fire bricks but the ones I got that were for 2500 deg F totally didn’t handle anything above around 1500 degrees and fell apart.  I’ll keep it around honestly because I’m making a regular fire pit outside where the first layer is that weak firebrick.  It will be fine for a firepit.  
 

Also, my past self was being nice to my present self.  Just found a box that I never opened.  It says Kastolite 30 LI Plus 55 lb.   So really the only thing I need to find now is whether I have that original hose or if I need to pick one up.  I would hope some store around here would have it since it’s for Propane.  Looks like I’m making a forge this week after all.   

[Mikey98118]

11 hours ago, Frosty said:

elcome aboard Salterclan, glad to have you. If you got your forge kit from Larry, it'll make a fine forge. Sure things have changed, they change all the time but it's not a race. We can work with what you have.

Larry makes good burners. You might want to make a different style at some point but his modified side arm is a solid proven burner.

Frosty's first point bears repeating. I would put it that "anything you buy from Larry, you can trust."

Secondly, Larry does make good burners, and that model happens to be his improved burner design. Larry is well known for his first burner design, which are modified side-arm burners. I think he called this second series his "Z burner". While his original series worked just fine, I remember that he was quite pleased with how improved these are other the old design.

[Salterclan]

Do I do two layers of 1” insulation on the ends as well?  
 

-Saltee

[Salterclan]

I moved the seam over after this picture was taken so they are clocked about 90 degrees which was a pain (ruined a piece of insulation) and added in a bit of insulation on the bottom for the shelf.  As far as the Kastolite is concerned is best to paint it in or just make an interior mold from cardboard or metal or plastic the size you need and pour it in?   I read a few places that a 1/2 inch all around is good but I also read other thicknesses.  From 1/4 to 1” depending on who was talking.  I would assume thick enough to be solid but not so thick that it takes longer to get it up to heat.  Just not sure what that amount is.  

[Latticino]

My preference is a cast inner liner.  It is a bit tough to paint it on in layers, the material really isn't made for that.  Even troweling can be a challenge.  I like 3/4" thickness, but each to their own.  I find it pretty hard to cast anything any thinner.

[Mikey98118]

Also, how much difference there is between a semi-insulating refractory's hot (flame) face and its cold face (against the insulation) has everything to do with how thick the cast refractory layer is. The hotter the "cold face" gets the shorter the insulation's lifespan will be.

We tend to want as thin a cast refractory layer as we can manage, but this is probably over-kill with a refractory like Kast-O-lite 30; especially with today's hotter burners.

[Salterclan]

So one person said 3/4 inch and one said also, as thin as possible.  What is that?  1/4 inch?  

[Salterclan]

I’ll be doing it later today.  I’ll shoot for 3/4 inch ish.  

[Mikey98118]

No; what that second person wrote was that such thin layers are probably a mistake. A 3/4" layer should be an improvement.

[Salterclan]

Right and you wrote we want as thin a layer as possible.  That was the part that was unclear.    

On 12/6/2022 at 11:06 PM, Mikey98118 said:

We tend to want as thin a cast refractory layer as we can manage, but this is probably over-kill with a refractory like Kast-O-lite 30; especially with today's hotter burners.

Either way you both seem to be saying that 3/4 inch is good so I’ll shoot for close to that.  Thanks again for advice.  

[Mikey98118]

What I,m saying is that most of us prefer to make the forge super-efficient, and so we go for thin flame layers. I'm also saying that this is not really your best move. "Thinner is better" was wise when hard cast refractory was little better at insulating than clay ceramics.

Kast-O-lite 30 changed all that. Nowadays, a 3/4" hard refractory flame layer should be just fine, and your ceramic fiber will last a whole lot longer.

[Salterclan]

Ah ok got it.  Yes that makes more sense and thanks for the clarification.  I finished casting the Kastolite yesterday and I’ll start doing the low temp burns tomorrow so hopefully it was successful.  Multiple mistakes in the order of how you do it, but it’s good practice.  I am hoping to make a large kiln for melting aluminum and copper etc. in a crucible as well as a larger forge for those rarer big projects.    

[Latticino]

Make sure your casting is completely dry before firing.  Cure time is pretty long.  Can accelerate a little by putting an incandescent light inside forge body and letting run for a day or so (first with the door full open then mostly closed).  Watch for moisture boil off during initial firing, and go slow at first.