Re-working pry bar

On Thu, 4 Aug 2016 10:06:10 -0400, "Jim Wilkins"


I've never built a pole barn, but I undersand that they do it with the gravel-bottomed rammed-earth style, similar to the way you mention. I'm lucky, too, in that I don't even know what the term "frost heave" means, except from reading about it. <g>

Galvanized U sunk in the concrete footing, with post on top? Works well.
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On Thursday, August 4, 2016 at 7:33:46 AM UTC-4, Jim Wilkins wrote:

I remember hearing some people say that rock and mineral collecting is a big deal in Maine.
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On Thursday, August 4, 2016 at 1:56:55 PM UTC-4, snipped-for-privacy@hotmail.com wrote:

I guess not enough for anything business wise - according to pp. 11-13 (pdf) on this govt. survey website: -- http://minerals.usgs.gov/minerals/pubs/mcs/2015/mcs2015.pdf
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On Thu, 04 Aug 2016 04:50:39 -0500, "Lloyd E. Sponenburgh"

Those are very nice bars. I've worked with those and the type with the mushroom end. I prefer the San Angelo's flat cutter for tree roots, having cut through 4" roots with one when attempting post holes.
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wrote:

Cleaning fingernails, prying nails, opening boxes, opening cans, prying apart fingers from Scotsmen's wallets, splitting wood for traps/fires/lean-tos, popping off dome light covers, opening stuck windows, separating frozen food slices, opening phone cases, opening remote control cases, scraping, saving the tip of your best knife.
Is any one of those worth a buck?
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wrote:

My only mod to it was to sharpen the wedge, as I do on all prybars which I'll be using for close work. 1" belt sanders are the easiest tool for this. Then I have to be careful of the knife edge.

Jewelcome.

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Thanks for the replies, but if I still wanted to forge shape it, is there a required process?
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Well, I guess the answer is it depends. Is it a work hardened steel or a heat treated steel? Or is it just a hard enough alloy to do the job hot rolled and stamped to shape while still red?
Nail bars aren't $5 anymore, but they are still cheap enough to destroy a couple if you just want to try it.
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Rehardening and tempering it is the tricky part, and a very good reason to grind a commercially hardened tool to shape instead. You can practice on a discarded circular saw blade. I annealed one, cut it into strips and rehardened a piece as hard and brittle as glass.
The few times I've hardened a tool I tempered it around 700F on an IR meter, and if it was too soft to cut steel I rehardened it and tempered cooler. That's less work than making another if it breaks from being too brittle. http://www.westyorkssteel.com/technical-information/steel-heat-treatment/tempering-temperatures/
http://www.ctmuzzleloaders.com/ctml_experiments/tempering/tempering.html The thermocouple adapter on his DVM looks like an expensive Fluke 80TK. The inexpensive TM-902C thermocouple readout I would have suggested is out of stock at Amazon. Omega's GG-K-24 thermocouple wire is a good choice to make your own. Wood stove gasket cement will bind the cut ends of the insulation. Do you have or know someone with an acetylene torch to fuse the end? http://www.omega.com/pptst/XC_K_TC_WIRE.html
When you heat the end with a torch to reharden it part of the shank will lose its temper. Perhaps that won't matter for a prybar for molding. Good luck with it. --jsw
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No TIG required. The old hack is a 100-watt incandescent lamp in series with the TC and a carbon rod from a D-cell, across 110 Vac. The TC wires are twisted together, heated in a flame, and dipped into borax.
The arc from the lamp turn-on surge will weld the ends of the wire together. Tap the weld bead with a hammer on an anvil to crack the fused borax off the bead.
What also works is a charged photoflash capacitor discharged through the same twisted wire and carbon electrode.
Commercial TC welders are the photoflash capacitor et al, but with an argon blanket and no borax.
Joe Gwinn
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wrote:

How do you safely clamp everything into position?
--jsw
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The TC is held in a vise, and the carbon is held in an insulated holder which is held in hand. There is 110 Vac between vise and carbon, with the 100W bulb as the current limiter.
The vise should be clamped to a wooden bench, and ideally is on the cold side (white wire in the US) of the 110 v line and the 100w bulb is in series with the carbon rod, so if carbon touches the vise, the bulb lights up, but no big bang.
Joe Gwinn
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On 8/1/2016 8:54 AM, Joe Gwinn wrote:

Cool stuff!
Just to clarify: the carbon rod is touching the end of the TC?
Bob
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I used to design and build custom power equipment of that ilk, and last week found a 50VA 120/240/480 transformer for my current HV project. It was always difficult to find high voltage, high temperature insulation that could take mechanical stress.
Fiber gasketing from the auto parts stores chars and smokes above 600F. Teflon emits nasty fumes if overheated. I have some carbon fiber scraps that withstand 2000F but it conducts electricity. Fireproof ceiling tiles would be good thermal and electrical insulation if they didn't fall apart so easily, same with wood stove door gasket cord. Fiberglass cloth melts in a flame, which at least is useful to seal the cut edges.
I have some Fel-Ramic 2499 exhaust gasketing to try the next time I need high heat resistance, but it has conductive wire reinforcement in the center.
--jsw
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Yes. See other answer.
I learned this trick in the late 1960s from a Grad Student who was welding the ends of platinum tubes closed using this trick, but using 110 V DC from the University's own 1900-era power plant.
Joe Gwinn
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I learned a lot of tricks like that in the 60's, most of which I wouldn't publicly admit to today.
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On 8/1/2016 7:57 AM, Jim Wilkins wrote:

I think will play with a saw blade - easy way to get some experience.

I annealed-hardened-tempered something once, but I think that its hardness & temper had a wide acceptable range and was much easier than this is looking to be.

Cool chart.

I do have a thermocouple meter (for casting), but even with it I think that this re-forging is a bad idea. Thanks for giving me enough info to see that!
Bob
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On 01/08/16 12:57, Jim Wilkins wrote:

I think that chart only applies to plain carbon steels. I was just looking for information about tempering EN24 (4340) and the information I found gave a far higher temperature range for tempering, the chart giving the various properties curves and temperatures and ranged from 450C to 650C and needed a longish soak time compared to carbon steel. I made a few replacement pipe cutting rollers from EN24 and when hardened and tempered according to the carbon steel chart they crumbled, now I need to take the remaining one and temper according to the new information and see how it performs, fortunately I have an accurate temperature controlled furnace. Just got me thinking that if the alloy effects the tempering temperature that much then trying to temper an unknown alloy is likely to be hit and miss.
Regarding the IR temperature reading how did you assess the emissivity in order to get an accurate reading from the meter.

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My $15 commercial unit doesn't have that adjustment. However it's close enough when aimed at the corner of the wood stove where the thermocouple is. I use them if accuracy matters and to check the IR reading.
Judging heat by color was good enough for many centuries of blacksmithing. In Scouting we stuck our hand where the cooking pot would go and counted to determine the temperature.
At Mitre I used a high quality IR thermometer with an emissivity adjustment but the temperature reading didn't vary much on most electronics materials no matter where I set it.
--jsw
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