habu68

For someone with a knee mill this would be a fairly simple milling job, a couple of end mills to hog out the majority of the hole and a smaller one to fine cut the radius for the corners. It is done all the time for tool and die work to make pockets for inserts. Check with your local high school tech school you might find they could do it as a project. It is basic milling.

Somono Bala of the Upper Niger ... - Google Book Search

When my brother was an apprentice in a machine shop he flung a key across the shop that he left in a drill chuck. The shop foreman, an old time German tool maker, riveted the key to a short piece of chain around my brothers neck so he had to put his nose against the drill press to use the key. Paul said, that after wearing the key like that for a week he never left a key in the chuck again.

what you need is a Harry Watt square drill bit. It is a special drill for drilling square holes.
Reuleaux Triangle -- from Wolfram MathWorld

another method would be to use a small drill in each of the four corners to define the radius for the corners, (square inside corners are never good, they are a point for cracks to start). Then with a larger drill remove the majority of the material from along the edges of the square, this will leave a series of wave like cuts when you have the center drop out. The next step would be to use the pre-industrial milling machine (an apprentice with a file) to remove the excess metal to the line of the square hole.

Our City municipal building is in a cul-de-sac , it contains both the city tax offices and the police department. For years the sign read "Dead End" until someone posted a sign that said "Where you taxes go to die" and it was published in the paper. Now the sign reads "No Exit", still fitting for the police department.

Funny you mentioned this. I was having a similar discussion with someone(MRobb) this past weekend. It's a method that I've used for the past few years, and it does help. Stumbled on the method while forging some other elements(besides scrolls).
bill

Andy Morris, my mentor studied for a year with Francis Whitaker who apprenticed, in turn, atSamuel Yellin's shop, I just kind of figg'ed that he had it on good authority:rolleyes:.

My smithing mentor ( you don't mind if i return to smithing :-) pointed out that when making scrolls if you look only at the negative space as you are hammering, your scroll will turn out much more even. It improved my scrolls in minutes.

Philip do you live in the house with the red roof?
31

Heck,My son-in-law built a Gingery Lathe out of car pistons, a 6' ladder and auto running boards.
His first threading setup used All Thread with a 10 tpi. He did use a bigger lathe to build the head, then used the head to build the tail. It was quite the project, and I would have spent the money to buy one, but by the time he had it built it he had a good idea how to use it.

Home-built Gingery Lathe

These may be some type of adjustable spanner for wagon wheel nuts or heavy equipment with the pivot jaw acting as a ratchet and may fit into a hole in the nut. There is also a similar tool for attaching fellows to a wooden wagon spoke.

not an answer just a guess.

Ice Czar

I seem to remember a mapp torch years ago that used a tablet in a tube that was burned to produce oxygen. Chem-ox is what sticks in my mind. I could not find it on a goggle. Is this what you are calling a oxygen candle?

I found it, called Solidox and was available at kmart. I guess it is no longer available Homeland security and all of that....

My mind is not what it ever was......

If you are looking to build a forge to be left behind after a demo you might want to look at some pictures of American forges from 1860 to 1920s. Many forges were tables framed with rough cut lumber and filled with clay or sand and the fire pot was nothing more than hollowed out clay with a pipe to the blower or bellows forming a side blast forge. The whole setup could be built in less than an hour depending on the air source, with little or no cost.

http://dsf.chesco.org/ccparks/lib/ccparks/heritage/forge.gif

Encyclop

I followed a few safety procedures when I tried (my leather apron, gloves), and I put the piece in question in the yard.

I might be 18, but I generally think things out (or over think them).

Leather apron, gloves. safety glasses, full hood face mask, welders jacket, steel boot covers will all melt or vaporize with thermite. The only effective protection from thermite is distance. Also remember that once started thermite cannot be put out until the reaction is over.

"When I was a boy of 14, my father was so ignorant I could hardly stand to have the old man around. But when I got to be 21, I was astonished at how much the old man had learned in seven years." Mark Twain

Standard blacksmith's answer: get it hot and hit it! Can't realy hurt to try I guess, supposing you observe suitable safety precautions for working an unknown material (full face mask, good ventilation, bucket of sand etc.).

That was the first plan when I picked up the sprues two years ago....dang I hate having to work for a living....

looks like a piece of bog iron, at one time bog iron was the primary source of iron ore for wrought iron.

Another string on thermite:
http://www.iforgeiron.com/forum/f7/thermite-welding-4245/

pellet stove pellets work fairly well in the forge and Master Hofi has used sheep and i believe camel dung with good results. (it just shows that when you know what you are doing you can forge with @#$%^)

Also check with local law enforcement, possession of a pyrotechnic device may be frowned upon.

Another thought, what is the chemical structure of spent thermite? At the reaction temps it would seem that all of the carbon would burn out leaving pure iron. I ask because I have access to the sprues left over from the welding of rail road track they are about 1 1/2 " thick and 10" long. and covered with the sand from the casting pot. I just wonder how they would forge.

I seem to remember reading in an old blacksmith text of an "uneducated" smith who was snookered into to buying Hydrated Sodium Chloride from the local pharmacist to use as a quench. It was $.10 a gallon. The man swore by it as the best ever. Seems cheap enough now.

Posted earlier but it still might catch a new-bee

"Ring on a post in a smithy
I read this years ago in A blacksmithing primer by randy mcdaniel.

A Ring was attached, 6' above the ground, to a post in the door way of a smithy. Below the ring was written the words:


toti
emul
esto

what was the purpose for the ring "


the answer is on another sting on Iforgeiron. Use the search at the top of the page and enter "toti"

$.50 cut one link and slip the other 4 pieces of chain into it and weld. short chain but it should keep the old skinflint happy;)

I have a 1 lb jar of pure lanolin that i've had for 10 years. You just have to stay out of the local saloons "'cause this is cow country and y'all don't want to smell like a sheep man"...

700 years of engineering have designed an elegant, powerful machine with one moving part that takes 20 to 30 ft/lbs of human effort and produces many tons of momentary effort and returns the unused portion of that effort to the return stroke. The two, three. or four start screws and nuts are machinable in most automotive machine shops. The frame must be massive to take the strain, The trick is the knowledge to turn the screw and calculate the strength of the frame that you are able to fabricate. Get any edition of Machinery's Handbook for about 10-20$ us on ebay to work out the math. What we are trying to do here is re-invent the wheel(fly) and the inclined plane(screw), most of that engineering was done by Galileo some time ago.

Habu now dismounts his high horse.:rolleyes:

so the equipment included co2 converters as well as the blasting equipment. I thought you could buy the pellets in bagged form and shoot from regular equipment.