Latticino

I am not familiar with that particular castable refractory mixture (hopefully it is a castable insulating refractory like Kastolite 30, not just a castable refractory like Mizzou), but it shouldn't be necessary to mortar the bricks together before casting.  You may want to include a sacrificial layer of wax paper on top of the bricks to keep the castable drying evenly, if you are planning on casting the crown in place.  Most castables like to be kept fairly moist while they are setting.

Rebar hangers or wire shouldn't be required in the castable floor either.  The arched crown may benefit from some form of reinforcement, though any part of it that gets exposed to the forge atmosphere will scale away pretty quickly.  I have used stainless needles available from refractory suppliers for this purpose in the past, which can certainly help with the fairly common cracking that you can experience as the forge goes through repeated thermal cycling.  They are absolutely NO fun whatsoever to mix into the dry material.  

The other recommendation I have for you is to modify your frame so you have some kind of compression member holding the bricks in place.  Angle with threaded rod is popular.  The lightweight bricks are pretty friable and become more brittle over time.  As I understand it, with your current design you don't have to worry much about the brick cracking, but you certainly don't want pieces falling off the perimeter.

As I've stated in the past, I have a theory that a burner block with long refractory outlets is more likely to suffer from preignition than one with shorter tubes, but I haven't had a chance to really study it.

That should do it.  Nice job pulling down the heel as well.  Look forward to the finished product.

Certainly looks like wrought to me.  You did a fine job keeping the HC centered, at least in the photos.  Can be more difficult once forged to shape.  I've done a handful of blades with this kind of combination, and the wrought moves so much faster than the HC it can be a challenge to forge accurately.  If you forged close to final shape and thickness with forged bevels you should have enough cladding to show up.  Can be a real test of your forging skills.  Check out Nick Rossi's videos on forging San Mai wrought knives for good info.

I don't do a full perimeter weld prior to the initial forge weld, but if you have clean surfaces it can't hurt and will eliminate the need for flux.

Be careful when quenching.  The different thermal expansion between the hardened steel and wrought can rip your billet apart right down the spine.  Careful normalizing and stress relief before hardening and a slight bevel at the spine to reduce the thickness of the cladding seems to help.  Also make sure you get the blade into tempering as soon as it cools to a point where you have martensite conversion.

Not to be "that guy", but you really might want to consider encouraging safety glasses while in the shop.  After all, he won't be 8' away from the business end of the stock during the entire process.  It really sucks getting a flake of scale dremeled out of your cornea.  

I wouldn't use that type of fan for a forge blower unless I had no other choice.  That fan is optimized for high airflow at relatively low external static pressure (probably on the order of 0.1 inch WG).  You want the opposite for a forced air burner fan.

If I had to use it I would construct a shroud on the fan outlet that transitions from the 1' x 1' size down to 2" diameter at a maximum of a 30 degree angle from horizontal (something like below, but much longer).  I would minimize the duct length at the 2" size and no use elbows unless absolutely necessary.

Honestly, for the effort involved, you are better off finding a better option.

Assuming you already have a hardy hole you plan on using the bick in, you source a piece of medium carbon steel (I used 4140 for one and an old jackhammer bit for another.  The latter comes with an already forged swell that can work as a seat - see below) that either has a large enough crossection to forge down to fit your hardy (or can be upset to be large enough first).  Isolate the mass for the tennon and forge it to fit that square opening.  Then reheat that area and forge on top of the stock to create a seat for the bick on top of the receiver.  You can also arc or forge weld a collar at that point to build up some mass for a more secure shelf.  Then it is just a matter of forging a long taper of the crossection you want and bending it over to the final configuration.

Well, at least the interior of the tuyere...  The external surface can get hotter, but since metal is such a great conductor of heat, not all that much hotter unless a steam jacket gets formed at the interior interface of the tuyere and cooling fluid.  Looks like a good size tank.  Keep it filled with water, and raise up the bed of your forge fill (as others have suggested) and you should be OK.  Hopefully the tuyere was fabricated from at least 1/2" thick stock and the exterior pitches down slightly towards the outlet to allow the proper circulation of cooling fluid (my theoretical optimal design for a sideblast tuyere would have the exterior designed as an offset reducer with the flat side down and set horizontal.  The inner tube would be parallel to that horizontal bottom "skin", and the whole thing made from wrought iron to stand up better to both the potential rust and heat from the forge).

The water is supposed to get hot.  How large is your bosh tank?  How is it configured?

On 9/2/2022 at 4:57 PM, Drunken Dwarf said:

why a side draft is beneficial over a top hood

As JHCC noted, a high speed inlet very close to the source of the fumes will capture the adjacent fumes.  The larger size hood above the source of hot fumes will both capture the fumes and the environmental air from the sides of the hood.  If the fumes happen to be rising at a higher velocity than at the capture zone at the face of the hood, they can "hit" that lower velocity section and create turbulence which can lead to the fumes spilling out past the hood.  If you look at it from a fluid dynamics standpoint, there is a characteristic flue velocity that will be created by the buoyancy of the lighter hot gasses inside the flue.  The hotter the gasses, the potentially higher the velocity (Note: as previously mentioned in other threads, a typical capture velocity for the face of an overhead hood is on the order of 100 ft/min).  If you induce significant room air into the flue, you cool those gasses by mixing.  The volume flowrate is directly related to this "chimney effect".  If the flue stack geometry is the same for an overhead hood and a sidedraft hood the hotter gasses from the latter will pull in more of the fumes you want to extract, and the proximity ensures that.  It is not at all uncommon to see the fire at the top of your coal pile to get sucked horizontally by the induced draft.

Yes, I have a HVAC Engineering background, and yes Steve, Goods and JHCC are giving good advise (as usual).  Note that after the reduced size entry opening the flue duct should be full size for the entire length to attempt to minimize duct friction which will reduce your flow velocity.  Also:

• The height of the stack is the driver for the exhaust.  Within practical limits the taller the better
• Try to minimize the number of elbows in the line.  If you must have them use 45 degree elbows if possible, or at worst long sweep elbows with smooth interiors (pleated elbows of flexible material are the worst option)
• Check your building code for details on penetration of structure and required height above adjacent roof pitches as well as termination proximity to operable doors and windows.
• Make sure you have adequate make up air for your exhaust.  If the air can't enter your forge the combustion gasses can't be exhausted.

Think carefully about how you are going to support this (including from wind loads).  Also keep the duct at least 18" from any combustible structural elements.

You may have issues with the fumes spilling past the 12" opening.  That is one of the advantages of the side draft hood.  A smaller opening can be set very close to the fire, so capture is very effective.  

If your wife also has some grog left over from her ceramics efforts I would mix a very generous amount into the clay as well.  This will help with the inevitable shrinkage you are going to see when the clay dries.   As Frosty noted, try to put the clay in as dry as possible, then let it dry completely before firing your forge.

Nice clean bevels.  Very impressive, I still struggle with those on double edged blades.  Draw filing is tedious, but the only way I've been able to get it to work.  I know some folks who can do it all on a belt grinder, and that is real skill.  Good luck with the heat treatment.  As I'm sure you know, lawnmower blades can be a mixed bag, and long thin blades are prone to warpage.

Any concerns about laws concerning sword canes?  I believe that some states prohibit them.

Sand, flux, heat sounds like a recipe for creating a glassy surface.  I would be looking at other alternatives if you plan on doing any forge welding...

I reiterate, it is a bad idea to depend on temper colors to properly temper knives IMHO.  These colors can be affected by a lot of different things (traces of oil on the surface, ambient light, fingerprints...) and are unreliable.  It isn't as big an issue for struck tools where a hardness range is acceptable (and I use a very similar technique to JHCC), but ideally not to be used for blades. 

For blades I would temper in an oven.  If I had to torch temper (or use tempering tongs) I would completely abrasively clean off the thinnest sections of each portion of the blade and carefully heat from the spine down to the edge.  You should let the blade go down to room temperature to maximize martensitic transformation anyway, so no reason to not fully clean the edges.  Definitely safer if you give it a quick "snap temper" first if possible.  

Note: if you are torch tempering, you need to work your process so you heat both sides of the blade equally.  Not a big deal for a thin kitchen knife, but significant for an axe...

I assume you have already thoroughly read through this post: 

It appears to address a lot of your questions.

Good size Trenton in good shape on a nicely made stand.  From the measurements might be in the 200+ pound range.  In that condition I wouldn't be surprised if you could get 5 or 6 $/LB, especially if you include the stand.  I'd get some friends and an old bathroom scale and weigh it before selling.

Like I said, if I were in the market and this one was only 2 hr drive away, I'd already be on the road.  Hope you get lucky.

Note: a few weeks of looking is nothing.  Some people look for months or even years.

Unfortunately your question is unclear.  It isn't obvious whether you are looking to determine temperature before hardening, or during tempering.

For Hardening:  Temperature needing to be reached is just when the particular steel enters into the austentitic range.  Best way to tell this is looking for decalescence.  

I wouldn't use tempering colors to gauge temperature for tempering after the hardening cycle on blades.  Works OK for chisels, but I want to be more accurate for blades.  I would strongly recommend you temper in an electric oven.  You only need to go somewhere between 350 and 550 deg. F (depending on the hardness desired).

Old Peddinghaus are arguably better than the new ones.  The one I used at NESM had the hardest face of any anvil I have used before or since.  This one looks like it is in great condition.  I would jump on it as fast as possible if the price were anywhere near reasonable. If it was closer I'd be tempted, and I certainly don't need another anvil.  At under $4 per pound this won't last long.

Don't know anything about fake Peddinghaus anvils.

Real nice one Jennifer.  The on bias punch and drift is impressive, and the wrought iron is so knarly it looks like petrified wood.  Looking forward to seeing what you make with it.

Might want to consider something like this:

Frosty and Mike are the experts, and there is certainly a possibility that the refractory is still outgassing.  However, if time at elevated temperature doesn't take care of that, I would look into reducing the size of the orifice in the  mig tip used (though the flame picture looks pretty good to me).  You should also confirm that the orifice has no distortion or burrs from getting cut or sanded back.

Check James Austin's Blog: http://forgedaxes.com/blog/  and don't miss out on the links.  He doesn't specifically note the stock he uses, but the details on the process are invaluable.  Note that James is a world class traditional axe forger, and even he indicates that this is a difficult project.  Also, he usually works with a team of, at minimum, a striker and director...

I believe that James Austin has been experimenting with forging these axes for a while.  If I remember correctly he has a visual storyboard online somewhere that goes through the process.  Hopefully you already have experience forging axes and forge welding, as this is by no means an easy project.