Latticino

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

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.

I feel your pain, as I also attempt to make knives and struggle with grinding (particularly double edged pieces and recurves). In addition to use of new belts I do have the following, culled from recommendations given to me over the years: To avoid wasting steel and belts, you can practice many of the grinding motions on wooden blanks. Inexpensive wooden yardsticks (that used to be given away for free) are great stock for this. You still need to start with a new sharp belt, but the grit lasts a lot longer. Get as much light as you can on your grinder area, particularly at the point where the edge is. Filing jigs with carbide faces are great tools for getting your plunge and tang shoulders really well defined. Order of operations for grinding a typical blade as I see it: profile, flat ricasso, tapered tang, distal taper for blade, bevels, swage, edge Change grinding angles slightly if possible for different grits to be able to see when you clear scratches Can use Dykem or permanent marker and machinist's layout tools to layout bevels and find edge centerline. This can really help with symmetry. Each to their own, but I prefer the look of saber grinds with the primary bevel is parallel with the blade edge rather than the spine. When beveling, once a flat is established "find" that flat each time by lightly touching the platten before pressing hard to begin grinding. Trizac belts are awesome... So are ceramic belts, but they are optimized for high pressure grinding. If your grinder motor can't take it they are less effective and long lasting. Flat plattens wear over time. Check yours with a steel square.

If I were forging my own, I might be tempted to forge it like a tennon with a larger diameter top that protruded above the socket. That way you could slide a purpose made claw tool under it to lift the pin if it ever got jammed. Kind of hard to describe, but easy to sketch if you need.

As I'm not an acoustic or jet engine expert (though my father once designed turbine blades for Pratt & Whitney), I don't completely follow this article. However it does have something interesting to relate regarding combustion generated noise: https://www.sciencedirect.com/science/article/pii/S1540748914004003 .

My pin appears to be mild steel, but I haven't spark tested it. I can certainly see the logic for making out of at least 4140 or the like, but I don't know that I would harden it. Some day you might have to drill it out... If nothing else it is good to have the pin project up out of the locator slot at least an inch or so. This will allow use of a vice grip to help pull it out. Actually my pin is cylindrical, rather than "D" shaped, so it can be rotated to help free it if jammed.

As far as I am aware, while stainless steel is often used for health care tools and surfaces, it is NOT inherently anti-bacterial, before or after forging. It's surface is relatively inert due to the chromium oxide coatings that develop, limiting rusting, but while that surface can be easily cleaned it does not prevent organic growth like silver and copper are reported to do. What you may be referring to is the problem that some stainless steels exhibit once forged; where they lose their chromium oxide layer due to the excessive heat. If I were making surgical instruments I would bring the surface to a high polish with successively fine abrasives, then investigate "passivation" (an acid based electropolishing operation).

Even in poor condition a A&O power hammer can be repaired to something fairly desirable. In good, working condition it would likely fetch in excess of $6,000 around here (location does matter). You shouldn't have trouble getting better than scrap prices from a smith. I would look for a local association for assistance.

Frosty, Yes originally I thought it was a 20 x 20 space (like mine), then I reread the OP and saw 200 SF rather than 400 SF... Mia Culpa