Matt Bower

Just for my future reference, can anyone out there tell me how many CFM of air it takes to run one of these presses reasonably efficiently? I don't have a compressor, but I need one and will get around to it before too long. It'd help to have a number in mind when I go shopping.

The problem with the electric igniter, like in a domestic oil furnace, is that the oil needs to be extremely finely atomized to ignite that way. It's not that easy to do with waste oil. I think it could be done, but it's not especially simple.

The Complete Modern Blacksmith is my very favorite general smithing book. I third (or whatever) that recommendation!

That's probably within the margin of error. I'd pursue that cavalry forge angle a little further, if you're really interested. Maybe the folks at Anvil Magazine can put you in touch with the guy who owns the one described in that article.

I second that.

It really isn't hard to find a piece of tree trunk. Around here, rather than paying to dispose of trees after they're cut down, people advertise them as free firewood on Craigslist.

That said, Tim Lively mounts his bladesmith's anvil just like you're suggesting. He works sitting down. I don't prefer to work that way, but I guess it works for some folks.

Not sure why you want all that loose rock in your bucket. I think it's only going to make the anvil less effective and less stable. I think it'll work much better if you fill the whole thing up with solid concrete. It's really not that expensive.

Larry,

Just a guess here, but I wonder if it's an old cavalry forge. I know they existed and some of them were very compact, but I've never seen one and I haven't been able to find many photos online. I did find one reference that indicates that some of them were made by Champion and had measurements of 23"x19"x8": http://www.anvilmag.com/smith/112f1.htm

How big's that one of yours? The proportions look about right . . .

Right. I never meant to imply that the edge would be something other than high carbon. (Or at least medium carbon. 50 points carbon is actually considered medium carbon by modern standards, though those kinds of distinctions are somewhat arbitrary.) I just meant that behind the edge there can be any number of different approaches.

Thanks for all the help. I'd like to ask one more thing what tool do you use when you Hot cut? I saw a guy doing it but it took two people to cut the metal to the shape of the knife. Is that how it is always done or is there a one man way to do this? I much rather do the hot cutting then stock removal.

I use an angle grinder with a cutoff wheel. If you're a purist, you'll probably want to make yourself some kind of hold down tool for hot cutting.

I don't hold myself out to be any expert on Japanese swords; 90% of what I know comes from just one of Dr. Hrisoulas's books (and at the moment I don't recall which one). But I'm pretty sure it's gross oversimplification to say that " The inner steel is the one you want to harden up nicely. The outside surrounding layers are the ones that you want to be softer to absorb impact and allow for flexing." To my understanding, historically, Japanese smiths used many different lamination patterns. Some put the higher carbon steel on the inside, surrounded by softer steel. Some did just the opposite.

At least that's what Col. Hrisoulas seemed to say. Hopefully one of the hardcore Japanese sword guys here can illuminate the issue a little further.

I'm looking to build a forge out of a old grill I have. I've built a forge before out of a old tire rim. I've seen a few plans to build this but the problem I have is finding firebrick can regular brick be used? Also if anyone else has any plans for a square grill I'd like to see them.

 

Next question I have is about tongs what are some good tongs to get? I was looking at some V-bit for now but I'm not sure how big I need them do I go to 1 inch just to be safe or should I start smaller and if I need bigger ones build them later. Also does anyone have plans on how to make tongs? Last I bought a section of railroad track to make an anvil out of I had two ideas on how to mount the railroad track one was to weld a bar on the bottom then mount the bar in cement. The other idea I had was to mount the track on a tree stump. I'm looking for other ideas so any thoughts would help.

 

Thanks for the help.

I wouldn't use regular brick for a forge. I did it when I was starting out, and it didn't work well at all. Red brick does not tolerate heat well; it tends to slump (start melting), but prior to slumping it can also spall and pepper you with hot, sharp brick fragments. Not very cool.

Just about any brick yard will carry fire bricks. Lots of hardware stores also have a little section devoted to fireplaces and woodburning stoves; they'll often carry boxes of light duty (2000 degree F) fire bricks, which aren't great but will probably be fine for general forging.

That said, you don't really need bricks at all. Just line your forge with a clay/sand adobe mix, per Tim Lively. http://64.176.180.203/washtubforge.htm

There are lots of instructions online for forging tongs. Here's one set: http://www.anvilfire.com/iForge/tutor/tongs/index.htm A little googling will turn up some more for you.

As far as your RR track anvil, lots of good ideas here: http://www.anvilfire.com/FAQs/RR-rail_anvils.htm You could also just set it on end in a bucket of concrete.

I don't have a proper horn, either. One approach to an improvised horn that I've used is to take a short length (maybe 3"-4") of pipe of the appropriate diameter. Insert a piece of square stock through the length of the pipe. (The square should be a couple inches longer than the piece of pipe.) Set the pipe between the jaws of the vise so that the jaws of the vise will bite the open ends of the pipe. The square stock sits on top of the vise jaws, so what when you hammer downward on the pipe the square stock takes the force of the blow. Tighten the vise down to grab the ends of the pipe and help keep it from rotating.

You have to keep the hammer blows directed straight down. This can be a bit awkward, but you'll get used to it.

This may not work so well with small diameter pipe and thin square stock. It works passably well for counterbending with 1" square and a chunk of 4" diameter pipe. It's not as good as having a real horn, but it seems to get the job done.

Eric,

AFAIK you're right about ash and organic materials that will convert to ash having been used in refractories since antiquity, and I'm sure they do add a great deal in terms of insulating value. However, I have the general impression -- I'm no expert on the archeology -- that in antiquity, enclosed furnaces where the liners were expected to get quite hot like the liners of today's gas forges (e.g., crucible steel furnaces, bloomeries, etc.) were considered more or less sacrificial. In other words I don't think they were expected to hold up to those temperatures for more than one run, at least not without major repairs. But you're probably right that the small amounts of fluxes contributed by organic "grogs" weren't the main culprits. I'd guess the natural fluxes in the clays caused most of the trouble.

It's neat that you were able to get three years out of that forge. In worrying about fluxes in clays and things like that, I sometimes have to remind myself that even clays that potters consider "low-firing" vitrify at right around forge welding temperatures. At basic forging temperatures the flux problem probably isn't that big a deal.

If you decide to homebrew the lining in your next forge, try the styrofoam bead grog. (If need be you can shread an old cooler with a rasp, though buying the beads is a lot less hassle!) I'll give good insulating properties with, as best I can tell, no fluxing action at all. Just do the burnout outside.

I like Alan's suggestions best so far. I have "rolled my own" in terms of forge refractory and insulation, and I have also used modern materials. I find modern materials vastly preferable in terms of ease of installation, effectiveness and durability. (Over time you'll probably also find that they're much more commonly available than you now realize. It's all about knowing where to look. Pottery studios and pottery supply shops are very good places. So are boiler and furnace installation and repair companies. I recently bought a 100 pound bag of insulating castable refractory from a local boiler repair place for about $40.)

The problem I see with Eric's recipe is that it contains all kinds of fluxes: ash, calcium oxide from the cement, more ash from the sawdust, and whatever impurities (e.g., iron oxide) are present in the natural clay. Fluxes lower the melting point of clay. This is no big deal in a Lively-style forge that's kept cool by exposure to outside air, but in an enclosed gas forge where the lining may get very hot, all those fluxes could cause a lot of mischief. (How long have you been using that mix, Eric, and how hot have you gotten it?) That mix will also have very poor insulating properties, so it'll be slow to heat up and terribly inefficient. Should be a real propane hog.

If I were going to roll my own (again) I'd stick with pure kaolin (EPK is one common variety -- again, ask at Cal Poly or a pottery supply shop), grogged with several times its own volume in styrofoam beads. The styrofoam won't flux the clay, and on firing it'll vaporize and leave behind insulating voids. This mix can easily be as insulating as commercial insulating firebrick. It's fairly fragile, but you can hardface it with a layer of 50/50 kaolin and sand to make it more durable. Regular play sand should work well enough, though pure silica sand from a pottery supplier would be ideal.

Of course if you're in a big hurry you can always use whatever's readily available and see how it goes. It'll probably work well enough to get you started. But again, I'd start with the pottery studio at Cal Poly and see if you can get your hands on small quantities of the good stuff.

OK, I asked a bladesmith friend of mine in Guanajuato -- a few states north of Oaxaca -- to try and translate the message on that blade. Here's what he had to say:

Hello Matt, that is a very common knife arround here... they are not very good, but very cheap they are...

 

it says "No son igual las habladas" "De lengua me como un taco"

 

it is difficult to translate because it is a form of expresion, but it refers to the kind of people who usually brag a lot about themselves but when the time to prove themselves come, they become cowards. here in México we call a man who brags a lot about things that are not true an "hablador".

 

De lengua me como un taco... well, that is even harder to explain... first you must know that here, it is common to find tacos de lengua, that means the cattle tongue, even pig tongue... in tacos hahahaha... but it is considered to be a food for the poor people.

 

the expresion would be directed to an hablador to ridiculize him, telling him that he can talk big and brag a lot, but its no more important or worthy than a taco de lengua...

 

hope this all makes sense... here in México we have a lot of expresions that for be understood, you need to know the context for it.

 

Andrés

I'm not sure he's reading the second part right, actually. (It is a little hard to make out.) But his explanation of the first part certainly makes sense. I've asked him to take another look at the second part.

UPDATE: My friend wrote back:

You are right matt, it says "me acavo un plato" which is in fact an error, cause you dont write acavo, but acabo...

hahaha, anyway, it means the same, as it is the same expresion only with other words... sorry, i didnt read it right the first time cause it is very blurry... and i automaticaly completed the phrase from the first words...

 

Andrés

There's a smith on another board I frequent who's somewhere pretty deep inside Mexico. If I can get in touch with him, I'll see if he can offer anything more definitive.

Col. Hrisoulas describes tooling for making a medial ridge in his second book. Unfortunately the description is a little difficult to follow (for me, at least), and there are no photos. But yes, essentially it boils down to a set of dies or reverse fullers.

Scott,

Make video, put it on DVD, and sell it -- along with any accompanying handouts and similar materials. (Or tell the ASM to do so.)

I don't know how it works in the heat treating industry, but in my profession that's done all the time for continuing education.

holy crap some one should show the smith a hammer handle

Yeah, Africa is full of premium hardwoods. You'd think he could find a piece. I love the interview with him, though, where he talks about selling weapons to rival tribes. Talk about playing a dangerous game.

Mike, what the hell is that thing, exactly?

Just from a strictly aesthetics point of view:

I don't really like blood grooves on tantos

The hamon looks too close to the edge, especially toward the tip.

I doubt many potential customers are going to be thrilled about a "some assembly required" blade, even with a discount. You're the maker, and you apparently don't have the tools to finish it. How likely is it that many of your potential customers will?

I second MrBaz's comments.

I guess I just don't understand how, if you're forging with hot steel, a harder face will make the work any easier.

Well, I guess in theory a harder face will undergo less deformation (inelastic or elastic) during forging, which should mean more energy transmitted to the work. I would think the effect would be pretty minor compared to mass, though, as long as you're not trying to forge on a 500 pound marshmallow.

If I had a 200 pound double horn I wouldn't even be thinking about this. Having said that, I agree with Greg: mass under the hammer is your #1 concern, and the chief problem with a soft face is that it's easily dinged up.

My current anvil is welded together out of RR switch plates. I'd guess it weighs perhaps 80 pounds, most of which is directly under the hammer (the anvil is tall, with a relatively short, narrow face). My educated guess is that the switch plates are medium carbon and would harden if quenched, but I had no way of properly heat treating something that size. Instead I resorted to a couple passes of hardfacing sticks, followed by a couple hours' work with an angle grinder. So far, so good.

Mike (Krall):

Sorry I missed your question; somehow I missed a lot of the end of this conversation. The other day I discovered that Don has Houghton on Quenching right here on his site: http://dfoggknives.com/PDF/Houghton_On_Quenching.pdf

Mike Blue,

It may well be that for the average small maker who doesn't abuse his oil, its life is effectively infinite. (I haven't used mine enough to have a personal opinion.) But even if that's true, always there's bound to be one guy out there who's edge quenching a couple dozen blades a month, flashing his oil constantly, and can't figure out why he's having trouble getting them to fully harden. That guy could benefit from knowing that burning your oil will hurt its quenchant properties. Accurate information is almost always good to know, if only so you can determine that it doesn't apply to you.

I know, I know.

 

I did find something else out though. I need to put in a CLC circuit in my etcher in order to get the smoothed out DC that you get from a computer power supply.

Normally I just use a 6V lantern battery. Last night I used my portable jump starter/DC power supply for a test run, since my lantern battery was dead.

Crude, I know. But it works surprisingly well!