Thread: Chip breakers ... not cap irons .. and what they really do!

Originally Posted by pmcgee

Yes 100%.

I've read that the cap needs to be closed up to the edge ...
I'm sure I have even read "as close as possible" ...
but I would never have imagined putting the cap-iron closer than about 1/16" ... have never planed anything that would need it.

So regardless of anything else, I've learnt something.

And a good dig into old books is always fun.

Cheers,
Paul.

'close as possible' isnt such a bad description really, just keep moving it up till you get the best result, pull it back when it gets worse

J. A. Walton's book is still a good read, used in Aust schools for decades (edit; still the book used in Tassie high schools, i was informed today), i am sure you would enjoy it, its quite a comprehensive intro to carpentry...it says to set cap iron about 1/16th for jack plane, 1/32 to 1/64 for Try plane or Jointer plane and about 1/64 for smoother (i havnt got the metric version of the book)..then it gives you a pop quiz at the end of the chapter...name three planes that use a cap iron? what is the purpose of the cap iron? and quite a lot of other questions, fun

Some notes I made and re-found ... on chipbreaker setting ...

1934. "Plane Craft - Hand Planing by Modern Methods". See pictures.

1950. "The Australian Carpenter - C Llyod". See picture.

1970. "Woodwork in Theory and Practice - John Walton". 1/32" or 1/16" (as Chippy wrote).

1975. "Australian Carpenter & Joiner". No figure given.

1979. "Basic Cabinetmaking - Peter Jones". All machinery

1980. "14-1 Carpentry + Joinery. Basic Hand Tools". 1mm.

1983. "Woodwork and Carpentry for Australians - Haines & Smith". No figure mentioned.

1985. "Woodworkers Handbook - Roger Cliffe". 1/32"

1989. "Woodwork Basics - Spence & Griffiths". 1/16" - 1/32". (But Spence book original was 1925)

1997. "Hamlyn Book of Woodwork". No figure mentioned.

Ah - it's coming back.

2nd picture from the Record book - says to not make a back bevel on the iron because it will cause shavings to clog between iron and cap.

So ... Derek? ... does a back bevel limit how close the cap can be put to the front of the edge in a practical way? or is it too small to make a difference?

Thanks,
Paul

And Chris Scwartz has also written on the topic of late.

It seems from reading some of his blog post's comments the woodwork fraternity in the US of A is as equally divided about the topic as earlier in this thread.

Nick

Thanks for the link Nick.

Why stop at two?

KELLETT'S 1884 PATENT TRIPLE PLANE IRON PATENTED CUTTER TOOL COMPLETE | eBay

Originally Posted by nick_b00

And Chris Scwartz has also written on the topic of late.


Nick

so in that blog he says he is teaching woodwork (and no doubt getting paid for it) but basically up until now he didnt understand the chipbreaker at all, good greif ..perhaps some of his students should be getting a refund...

Originally Posted by ch!ppy

so in that blog he says he is teaching woodwork (and no doubt getting paid for it) but basically up until now he didnt understand the chipbreaker at all, good greif ..perhaps some of his students should be getting a refund...

He's also very interested in how the shavings look! I'm sure that's incredibly important to the aesthetic woodworker.
Cheers,
Jim

Originally Posted by ch!ppy

so in that blog he says he is teaching woodwork (and no doubt getting paid for it) but basically up until now he didnt understand the chipbreaker at all, good greif ..perhaps some of his students should be getting a refund...

Indeed, if I'd written a book called Handplane Essentials, I'd be somewhat embarrassed...

"Replace the back iron, adjusting it in accordance with the work the plane has to do. Its purpose is to break the shaving as it is raised and so minimise any tendency of the grain to tear out. The closer to the edge it is set the more effective it becomes, but the greater the resistance it offers. It is, therefore, a matter of compromise. For the jack plane it can be set about 1/16 in. from the edge; the trying plane (when set fine) about 1/32 in., the smoothing plane 1/32 in., or less." Charles H Hayward, Cabinet Making for Beginners - 1947

Garrett Hack also sums this up (without the measurements) on p41 of his work, The Handplane Book.

Of course, although Mr Hayward refers to it as back iron, he knew what it was for. It is when the term chip breaker went out of vogue that the real problems started

cheers,
B-D.

Originally Posted by Blue-deviled

Indeed, if I'd written a book called Handplane Essentials, I'd be somewhat embarrassed...

"Replace the back iron, adjusting it in accordance with the work the plane has to do. Its purpose is to break the shaving as it is raised and so minimise any tendency of the grain to tear out. The closer to the edge it is set the more effective it becomes, but the greater the resistance it offers. It is, therefore, a matter of compromise. For the jack plane it can be set about 1/16 in. from the edge; the trying plane (when set fine) about 1/32 in., the smoothing plane 1/32 in., or less." Charles H Hayward, Cabinet Making for Beginners - 1947

Of course, although Mr Hayward refers to it as back iron, he knew what it was for. It is when the term chip breaker went out of vogue that the real problems started

cheers,
B-D.

Charles Hayward suffered from one great disadvantage. Before he started to teach and write he actually worked as a cabinet maker for a living.
Cheers,
Jim

Originally Posted by Blue-deviled

Indeed, if I'd written a book called Handplane Essentials, I'd be somewhat embarrassed...

"Replace the back iron, adjusting it in accordance with the work the plane has to do. Its purpose is to break the shaving as it is raised and so minimise any tendency of the grain to tear out. The closer to the edge it is set the more effective it becomes, but the greater the resistance it offers. It is, therefore, a matter of compromise. For the jack plane it can be set about 1/16 in. from the edge; the trying plane (when set fine) about 1/32 in., the smoothing plane 1/32 in., or less." Charles H Hayward, Cabinet Making for Beginners - 1947

Garrett Hack also sums this up (without the measurements) on p41 of his work, The Handplane Book.

Of course, although Mr Hayward refers to it as back iron, he knew what it was for. It is when the term chip breaker went out of vogue that the real problems started

cheers,
B-D.

Oh well kudos to him, for despite having a vested interest as a 'plane expert', he's accepted the 'new' position on cap irons.

I think it takes a decent set of bouncing "round spherical objects" for a successful author and well-known expert to get up and admit a gap in their own knowledge and be able to admit that they can learn something from our predecessors.

Compare it to the behaviour of people online who bicker over the smallest of points and refuse to concede any possibility of any viewpoint but their own being right, and often continue to do so after being confronted with facts, just to save face. Mr Schwarz has put a lot more on the line by making such an admission than many internet pundits.

To me, it seems like a minor point he's conceded. However, I bet that since conceding that point, there are people itching to slag his books in Amazon reviews using that info.

I guess it won't cost me anywhere near as much to take a closer look at my chip breakers

Craig

It shouldn't do him any harm as he seems to revel in his role as an pricker of vanities. I must admit I find his blogs amusing and he's just as willing to poke fun at himself.
Cheers,
Jim

Originally Posted by Blue-deviled

Indeed, if I'd written a book called Handplane Essentials, I'd be somewhat embarrassed...

"Replace the back iron, adjusting it in accordance with the work the plane has to do. Its purpose is to break the shaving as it is raised and so minimise any tendency of the grain to tear out. The closer to the edge it is set the more effective it becomes, but the greater the resistance it offers. It is, therefore, a matter of compromise. For the jack plane it can be set about 1/16 in. from the edge; the trying plane (when set fine) about 1/32 in., the smoothing plane 1/32 in., or less." Charles H Hayward, Cabinet Making for Beginners - 1947

Garrett Hack also sums this up (without the measurements) on p41 of his work, The Handplane Book.

Of course, although Mr Hayward refers to it as back iron, he knew what it was for. It is when the term chip breaker went out of vogue that the real problems started

cheers,
B-D.

Hi B-D

Charles Haywood seems to be one of the more reliable writers in this regard (and in all areas, so it is not surprising).

I did comment on the writings of David Charlesworth and Garret Hack at the beginning of the thread. Here it is again, so you do not need to move a finger

In the same light, I looked up plane tuning with a couple of well known woodworking experts. David Charlesworth is known for his books and videos. I have chatted with him via email, and more often he is available on the UK forum. He has been involved with these discussions (there), and posted his experiences of late. It turns out that he has also never considered that the chip breaker could increase the performance of a smoother. He only saw the dangers it presented in degrading performance. In one of his books (I pulled out yesterday) he described filing the leading edge at a low angle, basically getting the chip breaker out of the way.

Another I looked up was Garrett Hack. In the USA he is a god. Garrett has a couple of classic books to his name, perhaps the best being The Handplane Book. This details a vaste range of handplanes, along with their use and heritage. I was interested what he would recommend to tune a Stanley #4. Garrett does not describe any tuning with the chip breaker proximity. Instead it is the mouth size that he describes as the vital ingredient, along with a fine shaving.

David has continued to discuss his recent experiences with chip breakers and is now a convert to their use for tuning. I'm not surprised that Chris Schwarz wrote it up in his blog - he could not ignore the discussions on Wood Central and Saw Mill Creek forums, especially the former.

It now seems relevant to revisit a number of "laws". One in particular is mouth size. It has long been accepted that one closes up the mouth of a plane to reduce tearout.

This has been recommended by many (such as Garrett, above), but now I suspect it had more to do with setting the chip breaker at 1/16" with a common angle plane. At 1/32" it may actually be counter productive (the plane may struggle to cut). David Charlesworth is unconvinced, and I think that there may be a trade off. We do know that the mouth is unimportant with cutting angles of 55 degrees and above.

Just wait until someone brings out a cap iron with a micrometer adjuster for depth and angle at the leading edge!

There will be versions for Stanley/Record (that goes without saying), and LN, and retrofitting Spier and Norris infills!

Regards from Perth

Derek

Originally Posted by derekcohen

........ We do know that the mouth is unimportant with cutting angles of 55 degrees and above.

Well, not exactly unimportant, Derek. My experience so far with the high-angle planes I've made over the last few years is that the mouth MUST be generous, or it will jam with the finest shavings. The crinkly shavings that come off a high angle blade (with & without cap-irons -I am using both), are wont to choke in the lovely narrow mouths I sweated so hard to attain! It varies with wood types, but can be a real nuisance in some cases.

Incidentally, while I'm happy to recant a little on its functions, I don't see why we can't go on calling it a cap-iron. Having spent my working life keeping abreast with name changes for bacteria and plants every time a PhD student gets hold of a gene kit, I'm not keen on name without a very convincing argument. "Cap-iron" is a good non-committal name (& shorter), with a long pedigree. With everyone having their Damascan moment concerning its other duties, lets not lose sight of the fact that it still serves the vital role of pre-tensioning the cutting end, as well as deflecting shavings. Anyone who needs convincing of that, try using a standard Stanley thin blade on some knotty pine, with the cap-iron set back as far as you can set it. If you want to be pedantic, 'shavings deflector' would seem to me a more appropriate term, anyway, since there are no chips (well, not with decent woods, though maybe with that stuff you are forced to work with over there.. )

Cheers,