Instructables

Build Your Own (metalworking) Lathe - Part I

You can make an entire machine shop worth of power machine tools, using basic hardware store/home center supplies and scrap metal. Melt aluminum in a metal-pail furnace, using sand, charcoal, and a clay flowerpot! Cast sophisticated metal tool parts using supplies from a gardening shop and modified kitty litter! End up with a full machine-shop lathe ("the only tool capable of making any OTHER machine-shop tool, including itself!") for just the cost of your time, some scrap steel and aluminum, and a motor!
 
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Step 1: Overview

OK - we're (well, I'm - but we're using the imperial 'we') making a lathe. Like, for machining metal. Out of melted beer cans, in a flowerpot in a trashcan full of sand. As the great Dave Barry said: "I am not making this up."

Why?

Well, as the immortal John Belushi said: (loud belch) ... "why not!?"

Our Good Book is the Orange Book of St. Gingery - also known as "The Metal Lathe", by the late Dave Gingery. This handy pamphlet-ish book, the 2nd of a series of 7, has step-by-step instructions for folks wanting to build a lathe from scratch. Many folks around the world have built or are building "the Gingery lathe" -- there's an entire newsgroup on Yahoo dedicated to 'Gingery machines', as well as a ton of websites.

I'm putting together pictures, notes, and so on, to help others on this sacred journey -- and for a few friends who think I'm nuts (but secretly wish they could do this if only their wives would let them, and if they thought they could get away with it without burning their ... ummm ... fingers ... off).

The books are available at Lindsay Books' website, and/or at Amazon, Barnes & Noble.com, etc. Check out: http://www.lindsaybks.com/dgjp/djgbk/series/index.html for the main series.



This is how the project works: (a) You make 'patterns' of the parts, out of easy-to-work stuff like wood (pine is good), plywood, hardboard (the dark brown stuff that lots of pegboard and 1950s elementary-school fixtures are made of), etc. (b) You make molds in sand, with a few other ingredients; melt metal (easier than it seems, and DARN good fun!); and pour the molten metal into the mold cavity. And, (c) you combine the parts you make, with a few bits of steel, machine bolts, and such, from the local home center or hardware store.

Tools needed are simple: while a drill press is VERY helpful, the plans are designed around simple tools like a power hand drill, a few threading taps (not too hard to borrow, or fairly inexpensive at the local home center/hardware shop), etc.

The most important thing, imho: you'll learn a LOT about Making Things -- metal casting, machine tools, parts, tolerances, etc. -- it's a thrilling learning process! And - when you're done - you'll have the core component of a fully functional machine shop!

Step 2: Background, & Metalcasting Notes

A few thoughts, tips, pointers.

First of all, there's an excellent Yahoo! group devoted just to the Gingery books, machines, etc. You should definitely check out the Lindsay books (see link in step #1), and the Yahoo group: http://groups.yahoo.com/group/gingery_machines/.

There's a TON of good information and suggestions on the group. Some of the more popular ones seem to be: make the ways (a slab of 1/4" x 3" cold-rolled steel, on which the carriage (the main cutting-tool holder assembly) rides) thicker and thus sturdier; secure the ways to the bed with many more fasteners; and use a modified tool-post/toolholder. There are designs, photos, corrections, bills of materials, etc. (I'll try to add much of that information here, as I'm able.)

Secondly - the Gingery method mostly assumes using scrap aluminum. A few things I've learned:

(A) "Can you use beer/soda cans?" This is often referred to as "beercanium", or some similar funny term. The concensus I've seen, and have experimentally verified, is this: you can't really use JUST beer cans -- aluminum exposed to air instantly develops a thin layer of aluminum oxide (for fun, this is also. in crystalline form, basically ruby!). Beer cans are thin, with lots of surface area, so melting beer/soda cans alone just doesn't really work well (especially since melting tends to produce MORE oxidation.

HOWEVER -- if you melt some aluminum, such as window frames, pistons, etc. -- and THEN drop in some well-crushed and dried beer/soda cans, they'll contribute to the mix just fine.

SAFETY NOTE: if there's ANY moisture left in the cans, you are probably going to witness a SPECTACULAR explosion several milliseconds before losing your vision permanently. I'm not an expert, and if you follow my instructions, you'll probably DIE, be seriously maimed, or end up on some very, very pernicious mailing lists -- do NOT take ANYthing I say as anything other than potentially *very* dangerous activities. YOU HAVE BEEN WARNED.

(B) Using Metals Other Than Aluminum -- this is my personal choice. I cast a few parts out of Aluminum, then switched to a Zinc-Aluminum alloy (called Zamak, among other things).

Why?

Several reasons. (1) Zinc melts at MUCH lower temperatures, in the 700-degree range vs. 1,400 degrees for aluminum. (The common zinc-aluminum alloys also melt in the 700 degree range -- even though aluminum needs a higher temperature to melt, it's actually DISSOLVED in the zinc -- just as common table salt, with a VERY high melting temperature, DISSOLVES in room temperature water....).

This means you can melt zinc alloy over a propane flame -- like a barbecue or gas stove. Note: I would NOT recommend doing it on your kitchen stove. I've done this, but then you have to carry a 700+ degree pot of molten metal through your house and outside to where you have the mold. (If you try to pour molten zinc inside your house, you're insane -- just *melting* it inside is crazy enough.)

(2) Zinc alloys don't shrink nearly as much as aluminum -- so you can basically make a part prototype the size you want it to be, without calculating in shrinkage; and (3) Zinc alloys are nearly as strong as steel, in many respects.

WARNING -- the BIG drawback to zinc is this: THE FUMES ARE TOXIC. If you breathe a lot around melting zinc, and inhale a lot of the fumes, you're going to be very, very sick, and possibly die.

Now -- with lots of ventilation, and doing things outside, I understand it CAN be pretty safe. After all, gasoline fumes are toxic; so are toluene, turpentine, etc. -- and we're not utterly terrified of them. Just use some caution, mmmm'kay? And - read up on it a little.

One last note -- it's not the most economical source of zinc, but it's kind of fun, especially for small parts: you can simply use pennies. Since 1982, pennies are mostly just zinc. Look at http://www.gizmology.net/stovetop.htm for more information. Seems to me it's about 2x as expensive as what I can buy scrap Zamak for, around here, but sometimes for small parts it's just easier.

That's all for now -- on to making the lathe!

Step 3: Make the Bases & Bed

Here's the first part(s) -- the bases. These hold the bed of the lathe. On the left is the wood pattern; to the right are the two bases, now nicely (well, sort of nicely) painted.

I'm casting the parts with a zinc-aluminum alloy, instead of the aluminum called for in The Orange Book. Several reasons: (a) it melts at roughly 740 degrees F, which you can hit on a gas range; (b) it doesn't shrink much at all, and (c) it's fairly close to as strong as mild steel. Cost me about US$1 a pound (.454 kilos) at a nearby foundry company. (For curious folks - it's ZA-12.)

Legal warnings & such: Zinc fumes are reasonably toxic, I hear. Do NOT melt zinc without serious ventilation and several college degrees in chemistry. I'm an idiot, and if you try to do this stuff following my descriptions, which are NOT good directions, you'll probably die. I'm not kidding. You're responsible for your own life and safety -- I'm not.

Step 4: The Bed

Here's a shot of the bed pattern and resulting bed. This is actually the most recent casting I've done -- I was terrified and put it off until after most of the other castings. Why? Well, it's two feet (~61cm) long, probably 8 lbs. (3.6 kg) of molten, 750-degree (400C) metal to pour, and the dang mold is about 70 lbs (32 kg) of sand that needs to be VERY carefully carried without disturbing the mold cavity.

I almost succeeded. ;-)

The casting has a yucky spot in the middle (that's technical jargon, for you non-metalheads) - but that's not a problem -- it's easily filled with this miracle stuff called FastSteel I get at the Big Orange Home Store. I also like JB Weld, which'll fix anything duct-tape won't. Nay, the problem is that, somehow, the mold flexed slightly as I was carrying it, and the *&#%@! bed is just slightly curved up at both ends - about a millimeter or two. Sigh. Much filing/grinding to do.

Here are shots of the pattern for the bed, above the bed casting; and then the bases and bed together.

Step 5: The Carriage

Here's the pattern and casting of The Carriage - it rides back and forth on The Bed (actually, on the "ways" bolted to the bed; more on that later), holding a fairly adjustable mechanism, which ultimately holds the cutting tool that cuts the workpiece.

The top part blew out a bit - I patched it up with that miracle FastSteel epoxy-stuff again. (Note: you can drill and tap FastSteel -- the package says so, and my experience agrees. BUT - you cannot centerpunch it. Well, you CAN - but it'll break all over the place. Finally, there's a good chunk of solid metal under the epoxy to really hold the threads. ;-) Also, I gotta fix that green paint - yuck. (Turns out you really ought to use a metal primer before paint, even though I'm using engine enamel.)


Here's a picture of the bottom side, with the clamps attached. The shims (under the clamps) need some fixing - they're snipped from a beer can, and I finally found some good brass shim stock in various thicknesses.

Note the screw-eyes in the wood pattern. They serve 2 purposes: they give you something to grab onto to pull the pattern out of the sand/mold, and they're handy to rap on to loosen the pattern so it can be pulled out.

Step 6: Gib and Set-Screws

Here's the gib and gib screws for the cross-slide (the green thing, above).

It fits under one of the two clamps (the steel pieces on the bottom that hold the carriage to the ways) -- the one on the 'far' side where the thumbscrew is.

The gib is for adjusting the tightness of the cross-slide, as well as the angle. By tweaking the two outer gib-screws, you can true-up the cross-slide to a 90-degree fit on the cross-slide. The thumbscrew lets you loosen or tighten the overall fit, including locking the cross-slide to the ways. (In practice, all 3 need to be sort of balanced for the right fit and tightness - you want it loose enough for the cross-slide to slide smoothly on the ways without sticking, but tight enough that there's no 'play' - that is, wiggle-room.)

You need the gib adjustment screws pointed, to fit into dimples on the gib -- otherwise it'll slip right out when you move the carriage. It's not quite clear in the book, but it's simplest to get a couple of cap-bolts for the gib screws, and make 'em pointy yourself (I used my 4" x 36" belt/disc sander, holding the bolts in a vise-grip, trying to keep the points around 80-ish degrees -- took about 15-20 seconds each.)

You need to dimple the gib with a drill-bit (hence the 80-ish degrees), and the dimples need to be lined up with the gib-screw holes in the cross-slide. (This part is not quite clear in the book, by the way.) Probably the most logical way is to put the cross-slide, with the gib, on the ways, and drill through the cross-slide into the gib slightly. (You'll want to do this before you tap the holes in the cross-slide, or the drill will mess the threads up.) What I did, which worked great, was to drill the cross-slide first (all 3 holes), tap all 3 holes, put the cross-slide on the ways and clamp the gib with the thumbscrew, then screw the gib screws in until they mark the gib a bit. Then I removed the gib, center-punched the gib-screw holes, and dimpled them on the drill press. (Why? It's easier to see and control the depth of the dimples, I guess. Worked very nicely for me, anyway.)

Step 7: The Cross-Slide

Things are getting seriously neat, now. This thing rides forward and back on the carriage (well, on a piece of steel bolted to the carriage). So - the carriage goes left and right; the cross-slide goes forward and back.... the only thing left is to set an angle...hmmm...is THAT why there's a circular pattern on top of this thingy...?!?!

I'm pretty pleased with how well this casting turned out. The wood pattern is coated with spray shellac, which works pretty well, and is grayish because I'm using powdered graphite as a parting dust and mold release (in English: "to slick it up so the two mold halves come apart at the right place, and so the pattern comes outa the sand"). I'm not sure graphite's the best choice, but it seems to be working. The hole in the pattern was made with a 1/2" steel rod core, which you then whack (carefully) out with a punch. The whole thing is driven forward and back by a threaded rod through the "handle" at the left; the rod goes into the "tunnel" in the carriage casting.

Here's a picture of the bottom -- as with the carriage, there are 'pads' that ride along the steel 'ways'. My next step is to drill and tap the side for 3 screws just like the carriage -- these will adjust and hold it to the ways with a gib (again, more on that later).

Step 8: The Cross-Slide: Polishing the Swivel Pad

The cross-slide has two jobs: the bottom part rides forward and backward on the carriage; the top provides a rotational surface for the "compound swivel base" (the thingy that rotates so you can get different angles). To review -- the carriage goes lefty-righty; the cross-slide goes fronty-backy; and the compound swivel base (coming soon to a theater near you!) goes clockwise-y/coun....well, you get the idea.

SO. I thought I'd polish up the round "pad" that the CSB goes on. I had a wood disc from making the pattern, with a conveniently located center hole, so I just stuck on a sandpaper disc, put an arbor from gawd-knows-what through it, and started polishing. You can see it's about half done, mostly on the right side away from the 'handle". Looks nice! Might even be worth some of the effort.

Step 9: (Intermission) Toolzyottahave

One of the big premises of the Gingery books is that you can build your own entire machine shop out of old shoelaces, that one thing in that drawer in the kitchen that has kind of a threaded part and probably belongs to something so don't throw it out, and that old tractor part the previous tenant left in the basement, so it's all free.

Well, to echo what a few people have pointed out, I coulda just gone to Harbor ("'cause the Chinese work for free!") Freight, bought a lathe for under four hundred bucks, and have been done with it. Based on what I'd be earning per hour filling out TPS reports (extra credit if you get that), I'm probably about $50k into this project by now. ;-) BUT -- it's fun, and interesting, and fulfilling. (I figure people who build flyable R/C planes probably could've gotten a pilot's license and half a Piper Tomahawk for what they spend, timewise, on a nice model. So there.)

That said - here's the first of a few shots of the tools I've used on the project. The Orange Book (thanks be to Dave) emphasizes that you mostly just need a drill and a hacksaw -- well, ummm, hah. There are a few things you MUST have, and there are MANY more things that are, let's just say, VERY NICE to have.

The hammer handle on the left is for ramming up the sand molds. (I ended up buying some "Petrobond"-type sand from a local supplier - at $30 or so for 70 lbs, it's just too tempting vs. water-based casting sand mix.) At the top is a circle-cutter from Sears for my drill-press -- handy for the compound-slide pattern and a few other things. Continuing clockwise: a metal scribe for marking the (multiple) steel ways. You can get great results with a masonry nail (because it's high-quality steel) ground to a point -- don't get it hotter than hand-comfortable, or re-harden and re-temper it if you do. Next is a fat dowel you'll need for a sprue plug -- I'd also suggest a short length of thin-walled metal tubing of some kind for cutting sprues and risers.

On the right is a skimmer I found at the local Ace hardware for skimming dross (= 'crud') from the molten metal, followed by a standard tap. You'll need a few sizes of taps, and possibly an exterior threading die -- easy to find, but not super-cheap. A tap-and-die set at The Big Orange Store runs in the $20s. You'll need some tapping fluid or a tap-lubricant "crayon" - cheap. And - you will most probably break at least one tap. Then, you'll swear like a sailor -- taps are made out of VERY hard metal. It's a fine and delicate art to actually REMOVE a broken tap -- it's usually easier to junk the part and start over -- new part, new tap.

My advice? Never, ever, drink-and-thread. ;-) Seriously: take it VERY slowly. Do NOT use lots of muscle power when tapping/threading -- if you're applying lots of torque, you're about to break a tap. Back off a full quarter-to-half-turn EVERY quarter-turn -- it's a pain, but it's MUCH less of a pain than a broken tap.

Finally, in the center, is a cheap crappy "wrench" (I hate to call it that -- it's just stamped metal) that came with some dang thing we bought. But it seems to be ideal for rapping a pattern out of a mold. (Put wood mold in casting sand. "Ram up" (compact) sand with hammer handle etc. Screw screws or screw-eyes into (previously drilled) holes in wood pattern. Using cheap crappy "wrench", rattle the screws about so as to loosen wood mold from sand and slightly compact sand about said mold. Gripping screws/screw-eyes, gently remove wooden pattern.)

Step 10: Intermission(2): Stuffyottahave

More tools, supplies you may or will need:

Layout fluid - fast-drying blue stuff to spray on metal you want to mark for cutting, drilling, etc.

Prussian-blue oil paint - $3 or so at the local hardware/art-supply store. For coating a metal surface you want to make Very Flat.

Eye protection - every time a chip of very hot, sharp metal hits my cheek at high speed, I say a little prayer of thanks that I'm wearing these. And I'm not religious.

My rule is this: when my hand touches a power switch, I am wearing eye protection. It is SO easy to think "this quick little cut won't be a big deal" -- and have a tiny piece of wood or metal shoot straight at your eye. They do NOT yet have artificial eyeballs on the market, as far as I'm aware.

If you touch a power switch -- you're wearing eye protection. End of story.
Learn it. Live it. Enjoy stereoscopic vision for the rest of your life. It's easy - and it's free.

Other tools -- an automatic center-punch - quite handy.

A 0.001"-accuracy calipers - almost necessary.

A "Dremel"-style tool - if you do everything perfectly, you won't need this. (And, if you do, please contact me. I have some walking-on-water jobs for you. ;-)

Finally, the FastSteel I've been mentioning. (See above comment on Doing Everything Perfectly.) It's an epoxy/steel-powder mix that comes in a stick. You cut off what you need, knead it until the color is uniform, and press it into place. It's certainly not as strong/tough as steel, but it's come in handy when I need to patch an area that just didn't cast well. It will take a thread, can be drilled, etc. I wouldn't trust it to hold me over an alligator pit in the place of real steel, but it's not bad when you need something more cosmetic and/or somewhat strong.

Step 11: Starting the Assembly

Now we're starting to see the whole thing come together.

The blue parts are the bases and the bed, supporting the "ways". The ways are (is) a strip of 3"-wide, 1/4" thick cold-rolled steel (CRS). It's pretty solid and heavy, but actually can flex a bit -- which is why it's important for the bed to be very, very precisely flat, as the ways will be bolted quite tightly to the bed and thus follow its flatness (or lack thereof). The bed I cast, as you may recall, has a nearly 2mm dip in the center. That may sound like very little, but in fact would result in unacceptable imprecision -- most machine-tool work is specified in terms of thousandths of an inch. 2mm is about 1/12th of an inch -- a HUGE error in machining-land.

In any event, the "ways" are/is resting on the bed. The green piece is the carriage. On top of the carriage yet another "ways" (a piece of 1/4" thick, 2" wide CRS) for the cross-slide, and the cross-slide itself (the unpainted chunk of metal with the circular pattern on top).

So - briefly -- the bed ways will be bolted down to the bed/base; the bed/base will be bolted to the two base castings; and a long threaded rod along the front will let me crank a handle to move the carriage left-and-right.

Then, the cross-slide ways (the 7" long x 2" wide piece of steel) will be bolted to the carriage, and a screw with a crank-handle will be installed in the cross-slide (so, when I turn the handle, the cross-slide will go back and forth). Then, the compound swivel base (coming soon) will be installed on top of THAT, so I can turn the cutting tool clockwise or counterclockwise.

Step 12: The Compound Swivel

Here's the compound swivel base. A 5" piece of steel goes on top of IT, for the final thingy to ride on.

That 'final thingy' is the Compound Slide -- and it holds the actual 'tool' -- a sharp bit of very hard steel -- which ultimately cuts the workpiece.

Where are we, now? Well, let's pretend we want to make a chess piece -- a pawn, say -- about an inch across at the base.

We'd need to put a piece of inch-diameter metal in the lathe. We'd need to move the cutting tool left-and-right to cut from the top of the pawn to the bottom (using the carriage, controlled by a 2' long threaded rod we'll discuss later). We'll need to cut more deeply and more shallowly to shape the various contours -- that's the cross-slide. And, finally, we'll need to alter the angle of the cutting tool to shape, say, the round head of the pawn -- the compound.

All of this is in place. Mostly what's left is the stuff to actually hold the workpiece (a headstock and tailstock -- like the two jaws of a vise, except in this case they allow the piece to spin); and the motor to turn it.
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animedude075 months ago

We're actually using a different cover sheet now. We're putting them on all the TPS reports. Did you get that memo? Because we're putting the cover sheet on all outgoing TPS reports now...

Do I get the extra credit?

Morgan_Demers8 months ago
I'm just about finished with my own Gingery Style Lathe, which turned out quite nice. Mine is a bit oversized, and I designed a digital controller / driver which powers a 2hp treadmill motor on my machine ( a bit overkill, but why not ). Anyways, I've documented the project quite a bit, so if anyone is interested in seeing some videos, photos, etc.. of my machine checkout my Lathe Project here: http://morgandemers.com/?cat=6
skaar1 year ago
lindsay still carries the books.
Lindsay Publications is "Out Of Business"!! But you can still buy a few of their books at:
http://www.youroldtimebookstore.com/
http://gingerybookstore.com/index.html
http://nbbooks.com/
http://homebuiltedm.tripod.com/
and
http://www.hpfriedrichs.com/
or if lucky in ebay!
mrlunna132 years ago
Does everybody knows you can get all of the books from "Dave Gingerly" from Google Books for free? I thought I'll pass it along just in case. As I just found out about it.
Mr.Lunna13
Searched for 10 minutes then tried Gingery NOT Gingerly, with success.
Lol! You are absolutely right, his name is (for inmortality) "David J. Gingery", not David J. Gingerly, which was his evil twin!!


Came across your tip at this later date. How do you access Mr. Gingery's books on Google? I tried and failed. Are they still there? Thanks.

Hello,
Sorry for replying so late. Yes, you can still have them for free. Just "Log In" in your G mail Account, Go to Books, Type: Gingery, and all of "David J. Gingery" books will be shown on links to Google Books. You can Print them, Or Save them to your Library on Google Books.
I hope you enjoy them like I am.
Cheers,
Mr. Lunna XIII

Everything on there says no eBook available. How did you get them?
Hello, Mr. Lunna.
I am just geting around to trying access to the books and find that if I Go to Books after signing in, yes, there is a listing of Mr. Gingery's books. If I click on one there are opportunities to buy via links or search for a library copy but all said "no ebook available." If I click on "Get One in Print," I am directed to book sellers. "Saving to Library" appears to simply be a way of conveying one's interest in the book, not actually getting it or a link to it.
If you see the fault in how I am going about it, great...please help. Thanks.
would your name happen to be lionel?
corradini (author)  Metalcaster145 years ago
Nope. I know who you're talking about (backyardmetalcasting.com, as I recall) -- nope, that's not me.
lies
corradini (author)  mattgr5195 years ago
Ummm...what? What the heck do you mean by "lies"? Could you be more vague?
I dunno about him, but I definately could, example:
Get the thingey with the color and move it nearby the thingey thats the other color from the other thingey until the thingey has the other thingy in the right place.
nope he ain't lionel , lionel finished his lathe and he did not paint it
cchamlin4 years ago
What's being discussed here is not actually poisoning, but an illness known as Metal Fume Fever [wiki] 

long story short, it won't kill you, but save yourself a few days in bed and go buy a proper respirator.  (not a dusk mask. there's a difference) 
corradini (author)  cchamlin2 years ago
I'ma hafta disagree, slightly -- although it's just terminology, and the result is the same. (I.e.: you feel like crap.)

"Illness" *can* be defined broadly enough to encompass just feeling bad physically, but generally if you say "Dave was in the hospital with an illness", most people will assume he had a disease. (An infectious agent (bacterial or viral); cancer; some manifestation of a disorder (like, say, MS, or sickle-cell anemia), etc.) One would NOT, given the word "illness", assume that he had ingested Drano, or breathed a lot of H2S, or overdosed on valproic acid.

If you get a free exciting ride in a boxy trucklike vehicle with flashy lights and a siren, because you accidentally poured insecticide on your Wheaties, that's poisoning, not illness. Ditto if you're a plumber and melt (and breathe) way too much lead. And...ditto if you melt a bunch of zinc and breathe it. You've ingested a substance that's bad for you and causes negative symptoms -- that's poisoning.

Again - that's nitpicking over terms. But the *crucial* thing is: that I'm right and you're wrong. >;-)

Movin' on: you make a decent point that it (probably) won't kill you, but from what I've heard, you might *want* to die -- it apparently feels like a serious case of flu: fever, chills, nausea, headache, fatigue, muscle aches, and joint pain. (Check out "Metal Fume Fever" on Wikipedia.)

You're totally right that a respirator is a way different thing than a 'dusk' mask (sorry, I *do* know it was just a typo - just couldn't resist ;-), and far more appropriate in this situation. However, I'd recommend not relying on that either - ventilation is in turn far more effective than a respirator. (Note that chemists generally don't wear respirators; they use laminar-flow fume hoods -- as I do. ;-) And when you're melting a few lbs of metal at 700C, as a hobbyist -- frankly, I can't see doing it indoors anyway (even if you *don't* have a wife to help you understand all the ways in which you've screwed up) -- you wouldn't build a campfire in your basement or garage, right? You do it outdoors -- AND YOU STAND UPWIND. If there's yellowish-green smoke coming off it -- pretty likely -- be on the other side. If you can smell it (and it's not horrible, but it's distinctive, like smoking a roll of pennies), you're breathing it.

Don't. (Just trust me on this one.)
SirDave6 years ago
I have seen reports that if you start to feel like you have the flu, you have been poisoned. Drink a lot of milk as soon as possible, it will reduce your recovery time and can help prevent more serious problems.
drolfs SirDave2 years ago
http://www.anvilfire.com/iForge/tutor.php?lesson=safety3/demo

Milk won't help.
corradini (author)  drolfs2 years ago
drolfs - appreciate the comment! I'm NOT sure you're correct, though. A few thoughts:

a) It wasn't my suggestion (that came from "SirDave"), but I thought I'd look into it and respond.

b) I read the link you mentioned. Lots of reasons to not breathe lots of zinc fumes, but nothing about milk. (And there was a lot of MIXED info there; e.g. ZnCl poisoning mixed with ZnO, + lead, cadmium, etc.)

c) OT1H, breathing loads of concentrated Zn fumes is Real Bad and will kill you, no matter what you drink. OTOH, as with lots of folk wisdom, there's often some truth to it.

And here's why I immediately thought this one might be "true": I work with chemicals, including glass labware, which means I'm familiar with HF - hydrofluoric acid -- one of the scariest damn things you can find in a chem lab. It's like the inorganic equivalent of anthrax, plus ebola, imho.

Funny thing is - it's technically not even a 'strong' acid, like hydrochloric or nitric or sulfuric - it just happens to do 2 things: (1) unlike those acids, it WILL eat glass (Breaking Bad had a plot point based on this!); and (2) fluorine, being the most electronegative element, wants to replace all other anions - including calcium. Which your bones are kind of made out of. SO: when you spill HF on your skin, nothing much happens. It doesn't hurt, your skin doesn't burn or smoke, you may not even notice. Until it sinks down to the bone and starts dissolving it, by which time it's usually too late -- and the pain is apparently rather spectacular.

Here's the deal, though: people who work with HF keep a supply of CALCIUM GLUCONATE cream around, to rub on the skin at the site of any spill (just before calling 911 and taking an ambulance to the ER, which is mandatory at many/most university chem labs). The calcium provides a sort of 'decoy' for the HF to bond with - it's highly electropositive, and thus forms calcium fluoride, or "fluorspar" - a common mineral that's so insoluble as to be essentially harmless. (Unless it's formed from HF + your bones.)
---------------------------------------------------------
Somewhat similarly, calcium interferes with zinc absorption in the body - this is pretty well documented (see, e.g. www.ajcn.org/content/65/6/1803.short).

Personally, I'd go with a massive calcium supplement from the pharma counter (like crushed oyster shells) rather than milk -- but this here pseudo- episode of Mythbusters ends with the conclusion: Milk WILL in fact help. (How much is an issue, but it WILL at least help somewhat.)
_soapy_ SirDave5 years ago
This is pretty much right, except you will also have a blinding headache. Melting zinc-based stuff will give you the worst headache you have ever had, and then some, and it will last for a few days if you've overdone it. I wasn't smelting aluminium alloys, I was doing brass (a mix of copper and zinc, much like Zamac is zinc/aluminium) Despite doing it outdoors and upwind, I still breathed enough zinc in to cripple me for three or four days. And yes, I drank lots of milk (might just be me, but I tend to down a few glasses every time I work with lead or zinc alloys, just to displace it with calcium) As for other stuff, yes, take care that people and pets are excluded properly, and plan for what you are going to pour before you start the heat! You want a mould that is stable and dry, and I'd suggest having a couple of ingot trays ready for anything left over. Make sure you are wearing an apron and have your trousers outside your boots. Think about where the water would get in if you threw a bucket of water at your chest - anywhere water could pool would be a possibly fatal burn when switched to molten metals - so you want the least chance of that. Make it so everything will run off you and hit the floor. And read the guy below's comment (he's the author) too, as it is very wise.
As a welding student & amateur metalworker, I've had "zinc flu" myself before I knew what it was. At the time, I wasn't doing anything more than heating galvanized nails in a studio apt. I did get a vile headache and a tender stomach, but (considering my lifestyle) at the time I just chalked it up to a bad hangover.

HOWEVER...

Don't mess with zinc poisoning. Remember the rule of 1* - because that's exactly what you have. (translations will be left to the reader.)
corradini (author)  SirDave6 years ago
That sounds quite reasonable -- thanks for the tip!

I'm still really heavily slanted towards PREVENTION as a strategy. If you start to feel like you have the flu, from melting zinc (etc.) -- YOU'VE PROBABLY DONE SOMETHING WRONG (and something which was easily preventable).

This is simple - but requires the difficult step of THOUGHT (and planning):
1) Ventilation is your very best friend. (Ummm...after safety glasses. And your brain.)
2) Breathing fumes from molten metal is probably going to shorten your life -- so don't do it.
3) ALWAYS ask yourself: "what's the WORST that could happen?" Then plan to avoid that. And what you're going to do if it happens anyway.

Have an "escape plan":

What if you trip? What if your crucible breaks? What if your tongs break? (mine did, once!) What if you get stung by a bee -- and drop a crucible full of molten metal near your feet? What if the phone rings? What if your kid runs out the door and tries to hug you? (Kids do that.) What if your grip on the crucible starts to slip -- do you have an "emergency-dump sand-bed" nearby? (Hint: do NOT dump molten aluminum on concrete!)

What if you DO get a severe burn -- do you have ANY plan for that? Do you have a "buddy" nearby, who can at least call 911 and/or pile you into the car and head for a burn center? Do you KNOW where the nearest burn center, or even just hospital, is?

Yep - that's overkill. Until you need it. >;-)

"Luck is the residue of careful planning." -- paraphrase from some important dead white guy
dbear corradini4 years ago
Corrandini has it absolutely correct - Prevention is the key.

Read up on Zinc poisoning people - Any heavy metal poisoning is bad news.
It can affect your health years after it occurs.
sharlston4 years ago
hey you know when your tapping the best method is to go 2 turns forward and 1 turn back and keep repeating that will get rid of any rubbish in the tap
corradini (author)  sharlston4 years ago
TOTALLY depends on what you're tapping, what kind of tap you're using, lubricant -- and a lot of just experience and "feel".

It's easy to break a small (cheap) tap in 316 Stainless in a LOT less than 2 turns. (Trust me - I know.) And just backing to break chips isn't enough - using a sulfur-based oil (like Re-li-on) will change your life.

Conversely, you can tap a big fat hole in 6061 aluminum without ever backing to break chips.
i use a lube in a blue can with a red triangle i cant remember what its called but ill take a look
corradini speaks the truth. I've broken taps in less than a quarter turn in stainless. The worst is like when you should've drilled 7.80mm but only had a poorly ground 7.50mm bit and figured it would precess enough to over drill, then never bothered to measure before you started tapping.
No amount of lube will get a cheap tap through stainless if the holes too small.

Other problems happen when you let the drill overheat in the hole and end up accidentally semi tempering the metal to be tapped.

I've given up on those cheap tapered, all in one type taps. Better with a good set of first, seconds and plug taps (each one cuts a little deeper for the same thread).

I totally agree alu, nylon, delron etc. I usually just tap the first turn or two then set the lathe on a slow speed and release the tail stock so it can feed itself. No backing off, no problems. Keep it lubed though.
corradini (author)  lasersage4 years ago
Good point about overheating -- very similar (but not identical) issue w/ work-hardening). Great points about cheap taps (see below) and all-in-one's. They're fine for mild steel, non-ferrous stuff, esp. for sizes you don't use often -- but I'm now evangelical about high-quality (= expensive, and for a reason) tooling for S/S. Especially after having to deal with 316L. :-(

My Story of Learning: After losing a couple of taps in 304 :-( (and worse, scrapping the parts), I went down to the nearby machine supply shop that's been around for 40-50 years for a new tap and some advice.

The owner asked how I was doing it and with what. I was using a tap from the standard Home Depot set (I think Irwin brand), with Tap-Ease stick, doing the turn-a-little, back-it-off to break the chips method. He gave me The Look over the top of his glasses, and said "they actually still teach that?".

He put the part on his Bridgeport, chucked up a Swiss-made tap, put a couple of drops of Re-Li-On on it -- and, to my horror, fired up the mill at about 150rpm and plunged the tap into the part....

It went through the s/s like it was Brie.

I bought the tap on the spot - I think it cost about as much as the whole Irwin tap-and-die set, something like $25 - and a pint of the fluid. Went home and hand-tapped the remaining holes -- it was easier 'n screwing a cup hook into an eggplant. (DAMHIKT. >;-)

(I also swore off using 304 - not worth the savings over 303, unless you MUST weld it.)
Here is an easy fix for broken taps, drill bits and bolts even if they are in an engine block. Weld a nut or bolt to the broken piece and put a wrench to it, the heat will loosen the rusted seized bolts and soften any temper making them easier to get out. A TIG welding unite works best but I have had success with a stick welder or even an acetylene torch. This would work great on your stainless projects.
corradini (author)  Papa_20142 years ago
So - first off: I believe you, and that that's a good method -- for certain situations -- and thanks for the input!

BUT: (a) you're throwing rather a lot of different veggies in the same stewpot, and (b) this would decidedly not work for a number of situations (including all of the ones I've had - but to be fair, that's not your fault, and your tip is a good one, for some situations.

A 10-24 tap broken off flush (or below) in s/s, 45 seconds (of cursing like a sailor) ago, in a precision part -- has very little in common with a "rusted (!) seized bolt " (say a UNC 1/4-20) "in an engine block".

I'm trying to imagine the skill involved in welding a bolt to a hardened, fluted tap about 2 mm across, without welding the bolt to the workpiece as well, never mind other types of damage due to the heat -- I know I don't have that kind of steady hands, especially after 12 or 13 margaritas for breakfast. Even jober as a sudge, I think you'd need a robotic welder for that kind of precision. In which case EDM is probably at least as convenient, and far more assured. Oh - and that's assuming the tap is made of a type of steel that's weldable -- some steels (e.g. the most common s/s: 303) are NOT.

Sure, if you've got a big rusted seized bolt broken off above the surface, and have some threads available, welding a nut on makes perfect sense, and is easy to do, and will loosen the threads. (Of course, if you're not much of a welder, or don't own one -- you could try heating the end with a propane torch to expand/contract it and detemper it, then apply some PB blaster spray, then drill a pilot hole (it's now drillable, but I'd use a cobalt bit or even a dremel diamond-coated grinding pin - any hardware store - anyway) and use an extractor bit to try to back it out....)
an impressive demo to see I bet.

great to get sound advice from a proper machinist

We do have specific tapping fluid but I'm going to investigate this re-li-on after hearing you rate it so highly.

We gave up on re-li-on and moved to Rocol RTD - even better results in exotics.
Wow this is an awesome project .Im not gonna try and do it myself though cos im not so brave (or is it insane) to attempt playing around with large amounts of poisonous 400 degC molten metal in my back garden.I may try somthing a bit smaller and simpler with one of those flower pot smelters though.Ive had limited casting experience with toy model kits in lead and plaster and once had a mishap when the mold was not completely dry when i cast hot metal into it. luckily i was not hurt but that sure was one scary and very violent reaction.Makes you think a lot more clearly about what you are doing.
Non the less very interesting and im sure gonna google your links and research more on these ginger machines and flower pot smelters.
thank you very much for a great tutorial.
the lubricant is break free
-A-N-D-Y-2 years ago
have enjoyed reading your instructable :) as much so for the sense of humour as the project itself ;)

I have a similar thought when a chip of very hot, sharp metal hits my cheek at high speed... "$#!+, that was close.. I should put the glasses on!". (I am learning! experience (or close calls) is not the best teacher in this case) That's good advice re the power switch.
digus3 years ago
And I said, I don't care if they lay me off either, because I told, I told Bill that if they move my desk one more time, then, then I'm, I'm quitting, I'm going to quit. And, and I told Don too, because they've moved my desk four times already this year, and I used to be over by the window, and I could see the squirrels, and they were married, but then, they switched from the Swingline to the Boston stapler, but I kept my Swingline stapler because it didn't bind up as much, and I kept the staples for the Swingline stapler and it's not okay because if they take my stapler then I'll set the building on fire...
corradini (author)  digus3 years ago
Ummm, I'm gonna need you to go ahead come in tomorrow. So if you could be here around 9 that would be great, mmmk... oh oh! and I almost forgot ahh, I'm also gonna need you to go ahead and come in on Sunday too, kay. We ahh lost some people this week and ah, we sorta need to play catch up.
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