laminated irons (again)

[nabs]

thanks Dave, at least it is consistent with the theory that Bailey/Stanley started off with solid steel cutters, then introduced laminated blades later on having realized/remembered that they are quite a good idea (1900s-1920s? No one seems to know for sure) only to going back to solid steel in the 1950s having concluded laminated irons were 'old-fashioned' (possibly abandoning British made cast steel at the same time?).

Here is an article about a sheffield steel maker (Jessop and son) from 1893 that mentions a US plane maker using the other non-forging approach to welding a laminated plane iron mentioned by Andy (referred to as 'roll welding' in the article).
https://babel.hathitrust.org/cgi/pt?id= ... up;seq=334

I found the article via a wkfinetools post below which also mentioned that the Jesson's brightside works eventually occupied 35 acres! This has further shaken my confidence that Record actually melted their own crucible steel since their factory is piddly in comparison. Perhaps the lab they mention in planecraft etc is just for testing/specifying cast steel made elsewhere?

toodles

http://huk1.wkfinetools.com/05-Steel/Je ... hist-1.asp

 

[AndyT]

Another thought about the demise of laminated irons by the 50s or so.

From what I have read, it's surprising how long crucible cast steel continued to be made. It must have remained the craftsman's choice for edge tools, long after 20th century metallurgy brought in scientifically controlled alloy steels of comparable properties. But the skills to make it became unavailable after WW2, when there was an attempt to modernise UK steel production.

There's a very good episode of Time Team where they go to Sheffield, excavate an old furnace, and have a go at making crucible steel again, with what could be remembered of the old techniques. It's available on YouTube and well worth a watch.

[youtube]Xu5R-xUyZXg[/youtube]

(Bonus content - towards the end - Ken Hawley shows how a saw smith's hammer worked!)

 

[D_W]

A separate and aside, I wonder how the yasuki steels are made - what the process is. I've never looked into it, but the higher grades (white 1 and 2) of carbon steel have a very low tolerance level for impurities, and as much as i like vintage steel, I have to admit that white 2 would make a better western plane iron than any vintage steel I've ever used. It is so pure and so fine, even as a commodity, that if it's brought down to about 61 hardness (which is where my iyoroi chisels are), it sharpens well on natural stones and still holds a very good edge that fails only by wear.

In terms of the iron I mentioned above, I don't know why I thought it would be laminated, but you never know. I have more natural stones than anyone else I've ever met (perhaps 100 at the moment) so finding a stone to illuminate the lamination line at the bevel is no problem. I can see the records on the grinder, but sometimes with other irons, not so easily - the right natural stone always shows a good contrast on the bevel.

But also what I've said elsewhere (and I think this gets confused) using the natural stone to show the bevel line also gives me a very good idea regarding the hardness of an iron. I would guess this older stanley to be 57-58 (intentional, I'm sure), and there is a very large difference between that and 61 when it comes to something like a washita. I'm sure some of the laminated stanley irons were closer to 60-61.

Strange, though, that in the land of cheap steel (by the time they were making laminated irons) they decided to laminate. Wonder if it was customer pressure, because it sure couldn't have been any savings by then, unless there was a savings on tooling to mill the slot in soft iron. Perhaps better behavior in heat treating, too? But the old irons that I've gotten, including this set that has no 1892 patent date, are nicely flat. This one was completely unused.

 

[MusicMan]

The way a metallurgist would see if a blade is laminated is to polish the bevel (enough so that scratches do not obscure the contrast, and a fine oilstone or emery would do) then etch it. For regular irons, dilute nitric acid is the usual choice, but many dilute acids would work, probably vinegar though I never tried it. Brief electrolysis in almost any salt solution - with the blade on the + terminal - would also work. As mentioned above, in old irons corrosion has often done this for you.

Keith

 

[Jacob]

The way a metallurgist would see if a blade is laminated is to polish the bevel (enough so that scratches do not obscure the contrast, and a fine oilstone or emery would do) .............

Keith

Exactly the opposite.
In my limited experience fine polishing the bevel obscures the join line between hard and soft, but coarse grinding reveals it. Don't ask me why. That's how a discovered I'd got some laminated blades.

 

[Phil Pascoe]

He did say polish then etch. I assume as a metallurgist he's looking at it under a microscope not just giving it a cursory glance.
i agree with you though on looking at it from the grind - to the naked eye it's more obvious then.

 

[Cheshirechappie]

Yes indeed - Musicman set out the standard METALLURGICAL preparation for examination. The clue is in what he wrote - "The way a metallurgist would...". The WORKSHOP tests wouldn't involve etching.

Good workshop tests include rubbing a file down the bevel to see if some parts are hard and some soft, or cleaning off patina and oxide skin to reveal differences in colour and texture, which is often quite easily seen. Also, of course, using the tool for it's intended duty will tell all a craftsman needs to know about the metal at the cutting edge.

 

[nabs]

a good 'etch' which may be close at hand for tool collectors/fiddlers is Sheild rust remover which discolours the two metals to different shades of grey

 

[Jacob]

a good 'etch' which may be close at hand for tool collectors/fiddlers is Sheild rust remover which discolours the two metals to different shades of grey

I wouldn't touch Shield products with a barge pole. They are extremely expensive - verging on rip off. Designed for a small but gullible market of amateur woodworkers.
Basically the same stuff available under many brand names at a fraction of the price

 

[D_W]

That's not the same stuff as "hone rite" is it?

 

[D_W]

a cheap cold blue (don't know if you guys are into that kind of stuff over there) would do the same thing as the etch, but with enough exposure, it will just make all of the metal black.

Also, any fine natural stone slurried will make a dull finish on the soft backer and bright polish on the hardened steel - almost instantly.

(i like the file idea presented above - very practical).

 

[Phil Pascoe]

Same firm. :lol:

 

[MusicMan]

Yes indeed - Musicman set out the standard METALLURGICAL preparation for examination. The clue is in what he wrote - "The way a metallurgist would...". The WORKSHOP tests wouldn't involve etching.

Good workshop tests include rubbing a file down the bevel to see if some parts are hard and some soft, or cleaning off patina and oxide skin to reveal differences in colour and texture, which is often quite easily seen. Also, of course, using the tool for it's intended duty will tell all a craftsman needs to know about the metal at the cutting edge.

Yes exactly (Phil.P too). Of course polishing on its own would show nothing. The point was that sometimes you need an etchant to reveal details of the structure. Normally done with a microscope, but the naked eye would be good enough for this job.

Keith

 

[nabs]

I wouldn't touch Shield products with a barge pole. They are extremely expensive - verging on rip off. Designed for a small but gullible market of amateur woodworkers.
Basically the same stuff available under many brand names at a fraction of the price

the rust remover is expensive, but I only use mine for my extensive collection of sharpening jigs and chisel back-flatteing equiptment so it is lasting ages!

 

[Jacob]

I wouldn't touch Shield products with a barge pole. They are extremely expensive - verging on rip off. Designed for a small but gullible market of amateur woodworkers.
Basically the same stuff available under many brand names at a fraction of the price

the rust remover is expensive, but I only use mine for my extensive collection of sharpening jigs and chisel back-flatteing equiptment so it is lasting ages!

Spend, spend! :roll:

 

[nabs]

I have completely forgotten what this thread was about - was it something to do with polishing? in other news i have completed a thrilling calculation on the costs of making a laminated iron in 1850 and will report back soon (as far as I know they could not get rust remover in those days so the calculation was much simplified!).

 

[MusicMan]

I can't find the post now, but Bugbear posted a pic of lines of corrosion on old irons and Custard asked if laminated steels were more prone to corrosion. I replied that they could be, due to a different composition. BB has kindly emailed me to point out that the ones he posted showed corrosion along the line of the cap iron. He correctly says that this would be due to moisture getting trapped by the crevice between the iron and the cap, aided by any shavings jammed in there.

Technically know as crevice corrosion, this is caused by the oxygen concentration being higher at the surface than deep in the crevice, setting up a little battery. The surface part is cathodic and the deep down part anodic so it is that which corrodes.

Laminated irons could still corrode at the junction between the steels, but that wasn't an example!

Thanks for the correction, BB!

Keith

 

[nabs]

many moons ago I said I was trying to investigate the economics of making laminated edge tools in the 19C (yes I know :roll: ). I have now reached a tentative conclusion:

with some worst-case assumptions on wages and material costs I worked out that a tool maker producing laminated (e.g) plane irons would be able to produce them at the same cost as a maker doing the same but with solid steel, so long as the extra work to weld the two bits of metal together did not slow the blacksmith down by more than 50%.

Using more favourable, but I think still plausible, assumptions then the tool maker could create tools at the same cost even if the blacksmith needed 3x as long to forge the laminated version.

I am making two other major assumptions -
1) hand forged blades were the norm up to the end of the 19th century
2) the welding process adds some time to making the tool, but does not double the amount of time needed.

Quite possibly my sums and/or assumptions are nonsense, but if if not they indicate that - regardless of utility to the end user - it would have been economic for makers to create laminated edge tools despite the extra labour involved. And the (not very revealing) reason was that they preferred to use crucible steel and this was extremely expensive.

workings out can be found here : http://www.smallworkshop.co.uk/2018/01/ ... revisited/ (note very boring!).

Corrections/comments gratefully received!

 

[D_W]

Thanks, Nabs. I'm sure that the blacksmiths enjoyed working wrought (for the remainder of the iron) a lot more than they would've enjoyed hammering a full tool steel iron, too.

Presumably, the irons were made (before 1800) in water powered shops with power hammers of the wooden beam type?

Another presumption is that before commercial heat treating processes, quenching water hardening steel attached to wrought was a lot safer than quenching water hardening steel (which would've cracked at the thickness of irons if it was quenched unlaminated in water or brine). I have quenched water hardening steel in oil when it's thin, but i have no idea if it's "great" because it's just knife blades, and they don't get the kind of wear cycle that irons do.

I can attest that hand hammering high carbon steel harder (it moves more slowly with each blow) than I expected.

 

[nabs]

I can attest that hand hammering high carbon steel harder (it moves more slowly with each blow) than I expected.

my own investigations were inspired by Stephen Shepperd's post on laminated irons (where, btw, he concluded the exact opposite to me, based on the prices he uncovered!).

http://www.fullchisel.com/blog/?p=1215

one of the comments to his post suggests it may even have been faster to laminate the blade than forge a solid steel piece. I hope this is not true else laminated blades would be cheaper for both materials and labour, meaning all my calculations will have been a waste of time

In terms of the use of machinery in the forging process, by the time my figures were taken (1880s) steam hammers were old technology and machines for stamping and drop forging existed, but it seems that Sheffield tool makers were very slow to adopt the technologies.

Even larger makers with permanent staff relied heavily on 'little mesters' for much of their production and it seems they continued with hand forging right into the 20th century.

I haven't found any detailed contemporary account of how the work was organised at large factories, but there is plenty of physical evidence that piece work done by hand was the norm (not least all the obviously hand forged tapered irons still in existence, but also the pictures and remains of factories with rows of tell-tale small rooms with their own access etc).

It is fascinating to consider the circumstances that allowed such an archaic system to persist from so long. Here is a interesting interview with Albert Craven, a Sheffield blade forger who was trained by a large firm at the turn of the 20th century and worked as a little mester.

[youtube]zpeyhC-UIFg[/youtube]