Some accurate documented cap iron history

Regarding the 0.004”

Wiley Horne

The first reference I ever saw to 0.004” was a graphic on Steve Elliott’s website. Steve had an early interest in chipbreaker mechanics, and he had found a graphic with some data from the Zeiss company in Germany, which indicated that 4 thousandths was the right setback. I never knew the context, but Zeiss of course would only have had an interest in machine planing.

This was before the Kato/Kawai info; it was the only reference that existed that was specific to setback.

Wondering if that Zeiss reference was the source of the 4 thousandths belief...

Wiley

Re: Somebody wake me

Eric Rathhaus

I have no dog in this fight as I'm new to this forum. I took my one and only hand tool class back in 2001-2002 taught by Steve Wynn. I just reread his material, and he made the same statements that Warren makes about the utility of double iron planes. He didn't present it as new or ground breaking information but just as part of what the different hand tools are, their parts, and uses. (I hadn't remember any of this as I didn't attempt to use hand tools until recently.) I know at that time Steve did bespoke hand-built work for clients in the SF Bay Area.

I don't know but speculate that the history of teaching and use of double iron planes for the hobbyist world lagged because the learning curve for these tools is nearly flat without access to a good deal of hands on instruction and access to experienced users. Diagnosing much less correcting problems for double iron planes can be so hard, at least for me! Enter the internet and the rapid expansion of discussion fora like this one. Suddenly hobbyists have virtual access the knowledge needed to allow adoption of this technology. In short it seems that there's a parallel anthropology for the use of double iron planes between the professional and hobbyist worlds.

Re: Regarding the 0.004”

Warren in Lancaster, PA

Wiley, I mentioned Chris Schwarz and Larry Williams referencing the .004 setback.

On 12/5/2007 you posted a link to the Kato information on Elliott's site. There ensued a 52 post discussion of this information.

On 12/31/2007 Chris Schwarz posted a blog about "chipbreakers". He referenced the Elliott site and said:

The chipbreaker actually did its job when it was located .004” from the cutting edge.

The next day, 1/1/2008 there was a thread about the Schwarz blog post on Woodnet. In it Larry Williams wrote:

I suppose one could attempt to set the cap iron .004" from the cutting edge as the link Chris provided suggests but I don't think that's practical or worth the effort.

There were probably other occurrences that I can't remember so well. It appears that your reference to the Elliott site was the source.

My training in the 1970s

Steve Elliott

I went through a vocational course in cabinetmaking in the 1970s where we were taught that the chipbreaker (is the instructor called it) should be set back about 1/32" from the edge. I did that for about thirty tears and assumed it had some effect.

In 2005 I read a summary of a video that had pictures showing the actual cutting action of a cap iron set much closer to the edge. I tested the .004" setting on a piece of Bolivian rosewood and found it gave a much better surface than a setting of a little less than 1/32. I didn't do any comprehensive testing of cap iron settings.

Most of the hand tool instructors I was aware of at that time (as well as my fellow employees in cabinet shops) used settings that put the cap iron too far back to be effective. For me it was the Kato article and later the video it came from that gave me the information I needed.

Re: Regarding the 0.004”

Wiley Horne

Warren,

Ok! That settles that. Schwarz was referring to the early Kato reporting by Elliott. (Even though Steve’s text indicates 4 thou is too close.)

Different subject: I am curious about cap iron practice in Continental Europe. I had a conversation years ago with a German fellow—great guy by the way, Christof. In the conversation, I was speaking about tight mouth being more effective than close cap iron. He immediately replied, ‘I’m not so sure of that’, which was his nice way of telling me I was wrong. I’ve wondered recently whether double-iron practice was continuous in Europe, despite the two world wars. They certainly had the practice early-on because Josef Greber in his ‘History of the Woodworking Plane’ tells that a 1798 inventory of the Roentgen workshop in Neuwied had planes marked as German or English in origin, and that the English planes (only) were marked ‘with double iron’. Greber elsewhere says that uptake of the double-iron was

immediate upon its discovery, and that it was the only real change in plane technology since the Greeks and Romans.

Wiley

Where the 0.004" came from

Bill Tindall, E.Tn.

The least cap iron set back in the Kato video, or at Steve's early encounter with the still shots from it, shows the set back variable at 0.1 mm or 0.004". In the video this set back with the other variables produced little torn grain. So did other conditions. This setting may have been assumed by some to be optimum.

Those unaware of the origins of the Kato video often misinterpret it as a tutorial. In fact it was a demonstration video for the planing machine. It was made for a conference Kato presented at in the States (NC State), 1989. Abstract for the conference had the still shots and by some means they got to Steve Elliot. It in no way was intended to demonstrate optimum set up of this or any other planing machine to minimize torn grain. Some of the variables shown in the video never were used in any of the work published, for example.

The above information was revealed to me by Professor Kato in correspondence 2012

Re: Regarding the 0.004”

Warren in Lancaster, PA

I had a nice talk with a German cabinetmaker years ago. At that time I thought everyone used the double iron the way I did.

As to whether there is a stronger double iron tradition in Europe, I don't know. Some seemed to have known it had an effect, but maybe not its full potential. Some have seemed wholly ignorant of the process. I must say I was tempted to keep quiet about it, and probably would have if I had not been towards the end of my career.

Cap Iron in Japan

Bill Tindall, E.Tn.

At first Kato was puzzled by our interest in the video. It was clear from correspondence with Kawai(who was currently teaching) that use of the cap iron was taught in the trade classes in 2012. They sent me the tutorial they prepared for teaching setting it up. They were surprised that use of this plane feature, beyond holding the blade on, was not commonly known in the US.

I wonder: Did use of the cap iron in the US and maybe Europe wane as sanded surfaces became the norm, while Japan still valued the planed surface? Did the ROS and belt sander provide a "better" way to prepare a surface that was tear-out free in most shops leaving use of the plane to achieve this end uneconomical? In Japan where the planed surface was still valued they solved the problem of economically preparing a surface with the planing machine.

from my travels into guitar making...

David Weaver

...where things like fine thicknessing without tearout and surface preparation quickly without scraping softwoods would be useful...

....the industrial belt and drum sanders replaced planing and scraping long ago.

It's gotten to the point that makers consider any hand tooled area to be unfinished, even bracing. There's a video in japan at alvarez-yiari where someone is planing beautiful clear facets onto guitar tops (at a high rate of speed - it's in a factory in japan - guy is using very sharp japanese chisels that any of us would consider to be very sharp. An unusual thing to see in what is really a large factory and not just a boutique shop). The attendant leading the tour says at the end "when he is finished with the bracing, they will move to another department to be sanded so that they have an improved finished look.

I relayed to warren and others here before that my grandfather was friends with a clock and cabinet maker. That fellow did nice crisp work, much in the 40s through 70s - if he ever used hand tools, he removed all evidence of it. I suspect he had duplication setups for the curved parts and sanded them, and the flat parts looked like they went through a drum sander. Something like a beach oscillating drum sander would make short work of anything that would normally be planed. They can take a tiny amount off a surface or remove 1/8th of an inch at a time if you'd like them to and leave a 100 grit surface behind to be finish sanded.

If cabinetmakers stop using planes and scrapers, instrument makers use drum sanders to thickness guitar parts and sand to remove evidence of any hand tool use and the largest museums in the US determine they're from an era prior to cap iron use, what's left?

In japan, some high end interior woodwork is still left unfinished and while a lot of the shops show a guy doing the initial work with a portable planer or a super-surfacer, someone still needs to know how to plane the surfaces to finish. If they were sanded and left unfinished, they'd get dirty.

Sgian returns us to earth

Bill Tindall, E.Tn.

These conversations can get so esoteric it becomes easy to loose track that woodworking was invented to make stuff, and its not that hard to do.

Re: My training in the 1970s

David Weaver

Thanks for the account of this, Steve. It's much like what I encountered on the UK forums, but with less accurate recollection than yours.

Which was "I already learned this when I was an apprentice, but we don't do it much because it's not that effective. We were taught to set the blade close in difficult wood, but I have a stanley 80 that works better".

That was a typical comment, that it was learned, but something else was more effective.

Re: My training in the 1970s

Eric Rathhaus

Thanks for providing this context, Steve.