Kozzy

Maybe I'm not understanding which style you are speaking of but every image for "japanese box bellows" is hand operated and therefore you would control the airflow by the speed you "pump" Here is a dimensional drawing of one--a couple of others come up with dimensions also in a google image search.

Yes, I know that refractory questions have been about beaten to death but this one is a hair different and I need a little guidance. I need to re-cast the hard cement portion of an older johnson type forge--the stuff under the surface fire bricks that forms the "trough" that the tuyeres blow into. I've cross referenced a couple of products that appear to be close but the rated temperatures seem to be a little lower than I would think is appropriate. Because the blown tuyere shoots across approximately a 5" gap and directly into the refractory on the other side, I don't see something rated to 2200-2300 degrees F (that's about 1250 c) taking the constant flame all that well. Maybe I'm wrong. This is the heavy cement type--as dense as mortar (roughly) and not the lightweight stuff. It also has to be castable to about 4" thick by 6" wide, something that many castables say they cannot do. Is anybody able to point me to a proper product for this use? (preferably available mail order in the USA) Thanks For those who are not familiar with Johnson type forges (gas hogs to be sure but that's for a different days debate), here is a photo of the same model (but not my unit)

Regarding what you see as being treated a little gruffly-- My business is heavily telephone related and in my youth, I always felt that people's tone implied they were annoyed and frustrated. It took me a while to learn NOT to read tone into phone calls. Sometimes it's just the way people communicate. Now that the world has moved on, the same thing applies to posts. Don't read an implied tone into them. If someone is annoyed, they'll say so. Usually very clearly. Even if you get bit, let it roll off except for the lesson they are trying to get across--it's just the internet and that means you deal with all kinds. Nothing worth getting wound up about.

Bright pocket flashlight along with the tools. Possibly something like a dental mirror too. The parts that will bite you are broken gear teeth or impeller blades. The rest is pretty bullet-proof as long as things aren't so badly rusted that you will damage it when disassembling. At $ 20 bucks I'd buy several because you can make good money refurbishing and reselling--just choose the best for you and put the others on the back burner until you have spare time. Since time is money you might also consider if the savings is actually worth the difference in cost between a working unit and an unknown unit. Doesn't take many hours of fiddling to chew up that $ difference based on what you think you can get a "fixer" for.

Be aware that T304 stainless should not soak in the roughly 600 to 1200 degree F range because the material can degrade by a process known as "green rot" "Green Rot A form of high-temperature attack on stainless steels,nickel-chromium alloys and nickel-chromium iron alloys subjected to simultaneois oxidation and carburization. Basically, attack occurs by first precipitating chromium as chromium carbide, then oxidizing the carbide particles." The material can actually become brittle and flake away/crack. Whether this will happen in your case, I can't say--it's sort of a hit and miss things. Often even if it does happen the results are often still better than lesser materials. Just an FYI

You'll need to ask him again what he actually wants the numbers on. He said "strength" implying tensile strength--something which really doesn't tell you much in a knife but might be used as a selling point with people who don't really understand what it is. Hardness testing probably won't give any usable information either--a good knife is a different hardness on the edge vs the spine vs the tang. There are pocket penetrators for hardness that aren't that expensive if you need to give a rockwell hardness number but again, it's mostly meaningless in a knife. Rather than go crazy trying to figure out what he wants, pin him down. You can then target your production to meet what he is seeking. And as others have said, you really do need to use certified materials rather than unknown scrap. By doing that you can make the tensile claim in a form that's useful as a sales pitch. "We make our knives from material that has a 70K PIS tensile strength" Remember and learn this lesson: In selling, PERCEPTION TRUMPS REALITY. You can give the buyer perceptions of strength and hardness (implied quality) with numerical values even though those don't really mean much in the grand scheme of a knife. The customers PERCEPTION of the knife will be better with numbers they don't really understand anyway.

Back in the dark ages, I worked at the Space Needle. One of my spine crushing jobs was to help empty all those pay telescopes. We'd come out with several 5 gallon buckets so full of quarters you could barely carry them. Dang, what a racket. I can't remember the numbers but it sure made my paycheck look like cracked corn. Nothing really to do with forging...just a memory flashback that had to puke itself when 50 lbs of nickels was mentioned.

Maybe I'm confused but I don't see a comparison. Current US nickels are 75% copper and 25% nickel which doesn't equate to the 15n20 you mentioned in any way. FYI there is a mild congressional push to change the metal in all US coins to have a high steel content due to costs and the fact that the NI and CU tend to be imported rather than domestic. Count my vote in--there are MUCH better alloys available these days than the old standards. I'd love to see those giant sized Eisenhower dollars come back too but that just make me an old geezer.

Here's what looks like a good write up on welding AR to dissimilar metals http://www.thefabricator.com/article/consumables/cracking-the-case Pre-heat, slow cool, low hydrogen. The write up lists some specific mig wires to use.

You are correct. I read a couple of history pages on hammers too quickly and got it wrong. In any case, I also mistook the weight of the hammer in question..much heavier and larger than I thought. Zero for 2. Guess I need to up the coffee intake.

This conversation shook loose a rusty memory of something I read in the long ago times (so don't take it as fact). Someone mentioned that an old timer had chided him about not sharpening his hammer. The guy, of course, thought he was being punked so wouldn't play along until the oldster boss grumpily insisted. The old guy had the whippersnapper rough up the surface of the hammer just a little with coarse sandpaper: not smooth but a little "grippy" and it actually worked better when driving nails. It's sort of a smooth hammer version of a waffle-head where you get less slip from the slight misdirect of the blow. It does help....some...in some cases. Nice polished face looks good but a little rough IS good. Of course my hammer work is impeccable and I NEVER have a misdirected hit so it's hard for me to do a proper test

Hard to say the age. I'd guess early 1800s or so. The claw end didn't come about until later and the general hammer end shape is correct. That hammer looks a bit like a pin maul which had the pointy end to help drive wooden pins (no, I don't know how it a pointy end helped except maybe to drive pins below the surface)--however those were generally straight instead of curved. The photos I can bring up in a search of colonial era (usa) hammers have a slightly different handle mount and tend to have a flat back rather than a point. Probably either home-made or from a very small shop: Q&D.

Speaking of folklore, there is still an old one floating around about putting butter or similar on a burn. My Grandfather's sister pulled a boiling wash-kettle off the stand back in the "good 'ol days" and burned herself pretty badly over a large part of her body. They slathered her in lard and kept it up. She basically suffocated [as in died] not from the burns but because your skin has to breathe (skin is not just the largest organ but the largest excretory organ). Grandma's recipe for first aid is NOT always a good idea. Mine insisted I put raw bacon on the spot I stepped on a nail to "draw out the poison". I must come from some pretty hillbilly stock--thinking about the story above reminded me that my other grandfather accidentally chopped off some of HIS sister's fingers with an axe. So in addition to not larding a burn, I suggest you never hold wood for your brother to chop either.

Moglice has been used to re-cast worn out nuts and screw boxes on precision equipment. I haven't done it so don't know the details but their site says the info is in their applications manual. Appears that you cast it over the existing screw and remaining nut threads, heat slightly after a day, and end up with a perfect thread to match. Supposed to be about as strong as the original material. Moglice.com your mileage may vary.

This youtube video about maintaining an efficient coal forge fire is pretty good and addresses some of your questions. He sees benefit in fines as well as ash in terms of keeping the fire efficient. https://www.youtube.com/watch?v=yeC9bNxQ2Zs

"Smithy" is an adjective as in when your wife tells you "You're starting to smell a bit smithy" :)

Bearings probably have an ABEC number stamped on the side so should be easy to chase down. If not, take excellent measurements and work backwards--bearings have been pretty standard for a long time. Sometimes an orphan bearing shows up but not that often. But...whether it's worth the work might be questionable. Some of those old grinders were not really all that good in the first place. Even though large, they were often underpowered. Do a comparison to the newer/used quality grinders available before you dig in too deeply to see if it's better to head that way vs fixing the old one. Some of those hobart welder-generators are nearly bulletproof and people still like them. Depends on the model. The generators that are dead not so much. Some are worth fiddling with but many were never really built for more than the occasional use so wear out or burn out) quickly. Pics of what you are speaking of with specific questions would help...The better the info you give, the better the responses will be.

If your casting volumes are pretty small (a pound or two at a shot) there are now some fairly inexpensive electric smelters available from places like Amazon. The units are generally chinese made (what isn't these days?) but do give reasonable service without the fuss. You would simply buy spare crucibles which fit the specific machine for each metal you want to melt. The lead you mentioned is generally considered to be a bad idea these days for obvious health reasons. Think twice on that one. No use reinventing the wheel with a "home brew" set-up if you really don't need to. Counting your labor it will cost you more to roll your own and will take much longer to be pouring liquid. If your shots are larger, there are commercial crucibles available. Again, no benefit to reinventing the wheel so it's better to save your cigarette money until you can buy something standard. For some real fun, look up "fixturing metal". Those are the specialty metals which melt at very low temperatures..often hot water is enough...which can be cast and re-cast. Fun to play with when you are just experimenting. Your molds can even be plastic (the right plastic, of course) because the temps are so low. Vacuum formed candy molds often work for example.

Bore size has to do with several factors when designing a machine. The two main factors are torque to be transmitted and load/bearings that will be used to support the shaft. High loads require stronger bearings which generally leads to needing a larger shaft. Lots of torque can twist a shaft (especially a long one) and can strip out a small keyway so again tends to lead to needing a larger shaft. In reality, there is not that much load or torque on something like a belt grinder in the 2 x 72" range. Even a small-ish shaft is likely adequate in terms of torque and loading. The decision then tends to lean toward mechanical issues like space, available pulley bores, motor shaft size, and the in's and outs of machine bits. Personally, I lean toward 1" dia shafting on my builds but that's because it's common in stuff I already do. It's overkill but I'd rather be over than under.

Just pondering here...if you started with a cap nut/acorn nut instead, you're already halfway there and just have to round and close the seam on the rod end. Thoughts on this based on your experience with a plain nut? They're not as common in uncoated steel but I see that black oxide is available which would be gone in the first firing.

I got to wondering if anyone had spoken to very old school smiths and seen which body part(s) went south on them. Carpet layers lose their knees...electricians often do too but usually more of a ladder-climbing way. So does a lifelong smith lose shoulders? Elbows? Lower back from haunching over? What prompted me to ask is watching the attached old-school video of iron chain making. In one scene a smith is using a foot-powered hammer to do the weld. I would guess that a year of doing that a hundred times daily with his right leg and this guy would be walking with a permanent lean....and have a hip joint that made a rustier grinding sound than the chain he is making. Video is quite interesting in it's own right. https://www.youtube.com/watch?v=nLIbObCltfQ

Thanks for the info. That hatchet was one of those gimmick items for splitting kindling wood--was supposed to give a side thrust to peel off only one direction. Got it as a christmas gift and soon "re-gifted" it to someone who was going to use it for something like chicken killing. Awful to use which is why I asked about the single bevel on this one. Yours looks interesting and highly useful--especially on water sprouts on my orchard trees as Charlotte mentioned. My goats would appreciate me making a tool that prompts me to cut them snacks more often :)

Is the bevel on both sides or just one? I have seen both done. Opinion on balance when whacking when it has only a single bevel? I was given a hatchet once that was single bevel with the mass out of balance (a commercial product) and every time you whacked it tried to twist out of your hand.

In the real world rather than the blacksmithing world, we do parts that are used in large food processing plants, generally from T304 stainless. I had a weird one come up where the customer needs to be able to spot a specific tiny link on a long fast-moving chain so that the machine can be stopped at a proper location. What they want is to color this specialized part on the chain blue (or some other easy to spot color except red or white variants). Item has to be appropriately food grade for incidental contact. Anyone have suggestions? I am not even sure of a path to start digging. What I see on the internet so far is not really conducive to do on a very small scale of onsies and twosies. Ideally, I'd love to come out like a dyed aluminum anodized part, but even something with lesser coloring is better than nothing. Magic marker (colored sharpies) won't stand up to the constant cleaning chemicals (tried that "KISS" suggestion already...gotta start with the easiest). The problem with standard bluing, graying or blackening is that the USDA inspectors will tend to have a little tantrum. They see that range as "dirty" rather than coated. Explaining doesn't cut it because inspectors change and well...are sometimes tyrants regardless of fact. Any wild XXXXXXX suggestions on where to start a search? Some way to do the old fashioned "gold wash" easily that won't peel? I'm open to ideas. First suggestion is to watch your language