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And just to further screw up Bob's post---Have you ever noticed the bright green roof on the Canadian parliament buildings in Ottawa, in Ontario? Those bright green roofs were copper sheet. The Royal Canadian Mounted Police were told to save all the urine from their horses, and it was carried up to the top of the parliament buildings and poured on the copper roof, to react with the copper and turn it that spectacular green colour.
 
During WWII - POW's (like in "The Great Escape") made case hardened wire and bolt cutters from the mild steel corner brackets off their huts by heating and dunking in sugar then allowing it to "soak" in the fire to absorb the carbon.
A "sugar tax" was levied on all rations by the escape committee.
 
And just to further screw up Bob's post---Have you ever noticed the bright green roof on the Canadian parliament buildings in Ottawa, in Ontario? Those bright green roofs were copper sheet. The Royal Canadian Mounted Police were told to save all the urine from their horses, and it was carried up to the top of the parliament buildings and poured on the copper roof, to react with the copper and turn it that spectacular green colour.
That's a lot cheaper than pouring Budweiser over it! ;)
 
They could have allowed the roofers to drink the Budweiser and used their pee.... but probably too watery and very little nitrogenous compound compared to the RCMP horses' pee....
Nitrogenous fertiliser is cheap for nitriding steel... but Bud tastes better!
K2
 
During WWII - POW's (like in "The Great Escape") made case hardened wire and bolt cutters from the mild steel corner brackets off their huts by heating and dunking in sugar then allowing it to "soak" in the fire to absorb the carbon.
A "sugar tax" was levied on all rations by the escape committee.
So that's how you escaped!
K2
 
And just to further screw up Bob's post---Have you ever noticed the bright green roof on the Canadian parliament buildings in Ottawa, in Ontario? Those bright green roofs were copper sheet. The Royal Canadian Mounted Police were told to save all the urine from their horses, and it was carried up to the top of the parliament buildings and poured on the copper roof, to react with the copper and turn it that spectacular green colour.
They carried the horses up to the roof?!!!
 
And just to further screw up Bob's post---Have you ever noticed the bright green roof on the Canadian parliament buildings in Ottawa, in Ontario? Those bright green roofs were copper sheet. The Royal Canadian Mounted Police were told to save all the urine from their horses, and it was carried up to the top of the parliament buildings and poured on the copper roof, to react with the copper and turn it that spectacular green colour.

Hmmmmmmmmmm - - - - grin - - - I do believe that your preposition in the third sentence is incorrect.
You use 'were' - - - - I think that 'are' is much more likely.
One of the benefits of a 'copper' sheet roof is its great longevity.
I think it may be one of the longest lived of roofing products with only slate and clay or concrete tiles lasting longer.
 
I doubt that modern concrete tiles are so long-lived, unless of "roman" manufacture using the volcanic ash recipe as seen in their long-lived buildings in Rome. The use of aluminium accelerating agents to manufacture modern pre-cast concrete items also accelerates the chemical degradation therein. E.G. Concrete used in tower block building during the 1960s with "fast cure" concrete was destroyed 30 years later because that was the designed life of the concrete. Residents also complained that they could push a finger into the concrete as if it were plasterboard!
On teracotta ceramics, Roman tiles in the Mediterranean countries are still good up to 2000 years... Victorian tiles in the UK are mostly replaced now as only lasting 100~150 years, my house (Edwardian tiles) only lasted 110 years, Welsh slates have lasted 500 years, Yorkshire sandstone roofing slabs have lasted 1000 years (the weight on roof timbers causes the wood to fail first!).
Cheers!
K2
 
I doubt that modern concrete tiles are so long-lived, unless of "roman" manufacture using the volcanic ash recipe as seen in their long-lived buildings in Rome. The use of aluminium accelerating agents to manufacture modern pre-cast concrete items also accelerates the chemical degradation therein. E.G. Concrete used in tower block building during the 1960s with "fast cure" concrete was destroyed 30 years later because that was the designed life of the concrete. Residents also complained that they could push a finger into the concrete as if it were plasterboard!
On teracotta ceramics, Roman tiles in the Mediterranean countries are still good up to 2000 years... Victorian tiles in the UK are mostly replaced now as only lasting 100~150 years, my house (Edwardian tiles) only lasted 110 years, Welsh slates have lasted 500 years, Yorkshire sandstone roofing slabs have lasted 1000 years (the weight on roof timbers causes the wood to fail first!).
Cheers!
K2
(tongue firmly in cheek - - - - grin!)
AIUI the nails holding the slates in place are the predominant point of failure for such - - yes?

Wonder what the longevity of terracota ceramics would be in my area (can get quite cold and snow is a 'normal' thing for at least 4 months and more likely 5 months of the year?

Guessing that a pretty good balance between longevity and cost for me might be the standing seam metal roofing.
That should get me to a life in the 75 to 100 years (assuming that there is galvanizing AND a good quality paint!) and the cost is not out of this world (like slate).
Slate listed in the US at $4 to 6 per ft2. Found an engineered product out of Ontario that purports to be similar but no costs given.
 
Slate listed in the US at $4 to 6 per ft2. Found an engineered product out of Ontario that purports to be similar but no costs given.
There is a company in Ontario that produces slate tiles as well, and product from the company that produces engineered tile is a "Proprietary formulation of polymers reinforced by natural fibres and elastomers" so I doubt they'd last as long, probably something like the "25 year" asphalt tiles that last 15 years. Of course it depends on how long you expect your house to last, we installed the standing seam steel roofing, it will last longer than either my wife or me and the house too, so that's all I expect out of it. And it wasn't much more than the asphalt shingles.
Getting a bit off topic so that's it for me.
 
Sounds interesting...
being late 60s, I only expect to live around another 30 years at most. (Mother is 99 and going on...). So I figured concrete tiles OK for UK use when I re-roofed a couple of years ago. it suits what everyone else is doing round here. But at twice the roof loading, I wonder if the 110 year old roof timbers will hold that long?
My industrial experience of galvanising: on steel work adjacent to railways (Railway spec.!) and radar installations on top of mountains, plus sea-side marinas, and buildings:
Galvanising generally has deteriorated in corrosive environs in 25 years, so needs over-painting before that. The company I worked for used a thixotropic paint coat, good for 10 years per paint layer. The railways had 1 coat every 10 years (Their accountant decided that!).
The marina started with 4 layers on top of galvanising, when they built the marina in 1980-ish, and it still looked OK last time I visited?
The mountain-top radar installation had 4 coats on to of galvanising for "40 years without maintenance", which would have meant stopping flights from Heathrow airport while re-painting! 40 years was the perceived lifetime of that radar antenna (in 1978). Technology moves faster though, and despite technical electronic upgrades, I am sure that 40ft geodesic dome has gone by now.
1633182757289.png

1633182859524.png

Anyway, galvanising is good, painted galvanising is hugely better and longer lasting. Just pick the best paint, and apply properly. It keeps the moisture and oxygen off the metals - thus minimising the electropotential that actively corrodes the sacrificial zinc in place of the steel. Thus the whole system lasts at least the "sum of the lifetimes" of the coatings. - As used by people who want steelwork to last in the worst conditions.
K2
 
I doubt that modern concrete tiles are so long-lived, unless of "roman" manufacture using the volcanic ash recipe as seen in their long-lived buildings in Rome. The use of aluminium accelerating agents to manufacture modern pre-cast concrete items also accelerates the chemical degradation therein. E.G. Concrete used in tower block building during the 1960s with "fast cure" concrete was destroyed 30 years later because that was the designed life of the concrete. Residents also complained that they could push a finger into the concrete as if it were plasterboard!
On teracotta ceramics, Roman tiles in the Mediterranean countries are still good up to 2000 years... Victorian tiles in the UK are mostly replaced now as only lasting 100~150 years, my house (Edwardian tiles) only lasted 110 years, Welsh slates have lasted 500 years, Yorkshire sandstone roofing slabs have lasted 1000 years (the weight on roof timbers causes the wood to fail first!).
Cheers!
K2
There was a good article on Roman concrete on a science press website back in '17
https://www.sciencealert.com/why-2-...-is-so-much-better-than-what-we-produce-today
Micrographs and explanations of why Roman concrete actually gets stronger for some years, where as modern concrete pretty much gets weaker after it has fully cured (which can take some time).
 
Time for an update on the real meat of this thread, although both concrete and using horse urine to color copper roofs were both interesting sidelines

I had the stitches taken out Friday (October 1) and have been working toward setting up to resume work on the crankshaft since last weekend. The finger is really ugly but mostly functional. I'm very likely to have full use of it.

Back in post 39, I mentioned that I was going to round up the parts to make the cutter @Eccentric showed in his post and called it the Terry Thomas cutter. I ordered a couple of 1/4" shaft brazed carbide cutters from MEC, planning to cut the notch. Out of nowhere, I received an email from a friend of a friend recommending a video by YouTube machinist Joe Pieczynski. It's a 18 minute video, but he makes a cutting bit like what I was considering except with a wider gap in the middle. Not a slot but a rounded area. That video led to this cutting tool.

RelievedCutter.jpg


It's a little raggedy looking, but not much more ragged looking than Joe P.'s cutter. The relieved area was made using a Foredom Flex Shaft grinder with a diamond dentist's bit. The background in this image, by the way, is the gray cast iron bar that's going to become my cylinder. It's a 2" square bar (almost 2-1/16 on a side) that needs to cut down to 1.750" on a side.

After this, I positioned the cutter in a tool holder so that it was touching the metal at the same machine zero as the other tools I was going to use. Because it's a 1/4" shank and the cutter is almost exactly 0.250, I relieved the shank on both left and right sides, so that the shank of the cutter absolutely won't touch the side of the bar before the cutter does. I did that on a benchtop belt sander. Since it's a 1/4" tall shank in a tool holder set for a 3/8" tool, I put a small piece of 1/8" thick aluminum under it, visible at the very bottom of the picture along the left side of the tool.

RelievedBit_in_place.jpg


I used Joe P's method, using my 3/32 wide parting tool to take deeper cuts in the stock, which makes it look like our typical cylinder heat sinking fins, and then used the cutter I modified to sweep back and forth reducing those fins to the desired constant diameter. After that it just needed some final size tweaking of both the length and diameter of that round section.

After a two week interruption, this step is just about finished. The width is right (0.438) but the diameter is about .0015 over. @Eccentric showed some grinding stones that he uses, which I don't have as a ready option. I have sand paper (AlOx paper) in grits that will work and I have needle files. I've just come in from testing a couple of those and while they're small, they don't get my hands too close to that rotating bar that started the whole delay. I need to do a look at some of my wife's nail abrasives. She has some nail buffers with four grades of abrasives and they do produce a very smooth finish on metals. The ones I can think of are too wide to put in that 7/16" wide slot. If I need to use sandpaper, I'd prefer a tool to hold strips with than using my fingers. Maybe I can find something to print on the 3D printer.
 
Stick the various grades of abrasive paper onto some hardwood sticks, maybe 1/4" wide. Or, I use mole grips, self locking grips, that have flat jaws, and use the self-Locking feature to set the grip at a suitable pressure on the emery tape. This simulates a tool used to hone real car and truck crankshafts when I was in a workshop in the 1960s.
K2
 
Your crank is looking good Bob, I am glad your finger will (eventually) be bad to normal, at least functionally.

I do hold strips of the wet/dry sand paper in strips about the width of the slot to do final polishing. I use the standard 9" sand paper in increasingly fine grits folded over the journal. I like to run the lathe in reverse using a spot of oil on the paper. If you are .0015" out I would use a fine file to take off the first thou, then finish with the paper. I understand if you are leery getting to close to the spinning work piece, a healthy weariness. When bring the journal down to final dimension use the micrometer across the full width to make sure you are not getting localized low spots.

It is nice to see you back in the workshop. :)
 
For wider crank webs I like to get paint stir sticks from the hardware store and make em as wide as the journal.

I stick the wet dry strips on with superglue and then cut the resulting abrasive stick to width.

John
 
Hi Bob, yes, "Vice-grips" is a name I have heard. The key is that the over-centre lock gives a fixed and fairly repeatable position for the jaws. If you use simple pliers, the rubbing pressure depends on strength and consistency of your grip. Vice grips simulated the tool I had used where the jaw dimension is controlled by the screw that sets the locked dimension. Do not use a lot of pressure, as the carborundum should do the work with "just enough" pressure. And use oil. You could even use some "journal oversized" jaws made from aluminium, and grinding paste for lapping. Take care to hold the tool perpendicular to the shaft axis, and keep it moving left and right (axially) along the journal to retain parallelism. I'm sure you'll work out what to do.
Just an odd comment that I was taught. The machining is as perfect as it can be, but may not be able to give the required finish. Hand processes of lapping, etc., are to reduce the size of cut-marks (tool marks) and "level" the surface, to give a finer surface finish, not reduce an over-sized journal to size. The whole principle of machining is repeatability. So machining to size becomes a simple and repeatable operation. And "yes", it is faster and easier than hand-work. Which does not decry the accuracy that can be achieved by hand-work, by a skilled operator (not I!).
Hope this is some help? If any expert knows better, I am willing to learn, and improve my processes and knowledge.
Cheers,
K2
 
They carried the horses up to the roof?!!!

Certainly NOT! That's TOTALLY ludicrous! And completely insane!!

My understanding is the bought them jet-packs, and taught them to fly, and then told them where to go to deposit their urine. They got an apple as a reward for every successful flight.
 

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