Tear out - are cap-iron, high EP equivalent?

[D_W]

Makes the original invention all that more amazing really.

The 1700s cap iron plane? If that's what you're referring to, definitely. Did someone have the thought or examine how wood fibers lift and literally think they could create something that would hold them down until the cutter arrives? It's genius. Trivial once it's understood - like lots of things, but genius to come up with the original thought.

 

[DoctorWibble]

Makes the original invention all that more amazing really.

Just as ideas fail for unexpected reasons so too sometimes ideas work out but not for the reasons the inventor imagined they would.

 

[D_W]

Makes the original invention all that more amazing really.

Just as ideas fail for unexpected reasons so too sometimes ideas work out but not for the reasons the inventor imagined they would.

In this case, it would've almost certainly been for reducing tearout, because the increase in the amount of work done in the 1700s would've been substantial to slot an iron, make a cap iron, thread it and make a cap iron screw. I could be wrong, though, the first planes (I've never studied the issue) may have had two irons almost the same where both were loose. I know we've seen some old french planes recently where they were made that way with a back iron almost as long as the cutting iron.

 

[woodbrains]

Hello,

Someone here has just said what I've been saying for ages, a close set cap iron makes the plane harder to push..YAY. close cap irons have been given some sort of miracle status, but there is a trade off, you have to put more effort in. Justaiable, of course, when needed. However, I have always thought the common descriptions of high pitched planes acting more like scrapers, is wrong. Scrapers, as in card scrapers with proper burred and ticketed edges, make type 2 shavings. High pitched planes don't. In fact if you look at a proper scraper and a close set cap iron, the cutting edges are the same. It is not too much of a speculation that the inventor of the cap iron in 1700 simply made a logical assumption that he could make a plane iron act like a scraper by making a double iron. The condition of the shavings were not necessarily the starting point for the design.

Mike.

 

[Trafalgar]

Truth.

 

[D_W]

Hello,

Someone here has just said what I've been saying for ages, a close set cap iron makes the plane harder to push..YAY. close cap irons have been given some sort of miracle status, but there is a trade off, you have to put more effort in. Justaiable, of course, when needed. However, I have always thought the common descriptions of high pitched planes acting more like scrapers, is wrong. Scrapers, as in card scrapers with proper burred and ticketed edges, make type 2 shavings. High pitched planes don't. In fact if you look at a proper scraper and a close set cap iron, the cutting edges are the same. It is not too much of a speculation that the inventor of the cap iron in 1700 simply made a logical assumption that he could make a plane iron act like a scraper by making a double iron. The condition of the shavings were not necessarily the starting point for the design.

Mike.

The cap iron doesn't have to be that close to work on anything you'd make furniture out of. If it's close enough to be that difficult, and if it leaves hair on moderately soft woods like a heavy scraper cut does, it's too closely set. Of course that hair on a scraper cut suggests too large of a cut for the size of the burr, too.

The only reason the cap gets so much attention right now is that nearly no one mentioned it for a long time, and it's generally free to do with common planes. There was a notion on a lot of forums that you had to buy specialty stuff that turns out to not be that nice to use day to day, like 60 degree bedded planes, etc.

Even this forum has extremely scarce mention of it before 2012. Iirc, a couple of Scandinavians. The reference to it in old texts is prevalent now, but is rare more than a couple of years ago.

 

[Derek Cohen (Perth Oz)]

I do not find that a closed up chipbreaker makes the plane harder to push. However, I find that a closed up chipbreaker that is closed up too much makes a plane harder to push. You can tell this visually as the shaving becomes wrinkles like a concertina.

Regards from Perth

Derek

 

[swagman]

I much prefer Peter Seftons approach to controlling tear-out.

You may find to can get a good finish from your standard bench planes again sharp tools, close set cap iron and a fine mouth and small shavings. Getting the cap iron or chip breaker as close as possible to the blades cutting edge is the best remedy for your standard plane, but with a back bevel or high angle effective pitch this is the cutting edge and will get a cleaner finish in my opinion.

I demonstrated all three in the DVD, so use which ever plane you have and if you don't get on with it then try another method or plane.

Cheers Peter


_________________
Peter Sefton

 

[D_W]

Yes, we know. Because Derek has developed a preference for the cap iron.

 

[David C]

Personally, I do not think the ultra close set cap iron is the same as high EP.

I have no suitable explanation just a feeling!

What I am certain about is that a very fine mouth will not prevent tearout on nasty timbers.
My Stanley 5 1/2 has a 4 thou, 0.004" mouth and this does not prevent tearout on cranky timbers, or Yew come to that.

I feel that the fine mouth argument has been over stated by Hoadley and many others, including myself, over the last 50 years..

Best wishes,
David Charlesworth

 

[D_W]

I have also built a plane with a 4 thousandth mouth AND 55 degree pitch (single iron), and it is not quite as capable as a stanley with a cap iron. It's good, but not quite as good. The tearout is smaller, but it is still there if you finish the surface and look across it.

I believe that the plane of mine has crept a little bit and the mouth may be slightly less than 4 thousandths now.

a mouth of 1 hundredth will do nothing in terms of making a finish-ready surface. I made another plane for coarser work (a panel plane) with a 1 hundredth mouth and it was unrewarding to use until filing the mouth's top side to allow the cap iron close enough to work.

When I made those two planes in 2010, the general consensus was that they were the best option available, and I was looking for risk free so that I could move toward fewer power tools.

 

[essexalan]

OK so if a close set CB is the business why did Bailey bother to design his planes with an adjustable frog? I mean he had planes for every purpose and the frog is in my planes at least the worst example of machining imaginable, I don't doubt his original creations were superior. His CB design was just about spot on. Why did Norris produce a superior smoother with a very tight mouth if all they had to do was provide a CB ground at the correct angle? Why do all the Bailey clone manufacturers still persist with the adjustable frog and provide CBs ground at the wrong angle? You can include all the blade manufacturers there as well. Does somebody like Holtey go for the tight mouth route? Why has my LN #5 gone concave in it's length which makes it impossible for an old git like me to plane a piece of wood flat? Just got in from the garage hot 'n sweaty after prepping a pile of cherry for something as mundane as chopping boards but my family and friends will love them.

 

[D_W]

I don't have a holtey plane (I would take an A13 donation from Karl, though!), but I can't imagine his planes have anything like a large mouth in them.

I would imagine that the adjustable frog for stanley planes exists mostly because the frog had to be manufactured separately so that it could be properly machined on the face. Just a guess. If it's going to be made separately, it needs to be adjustable just to make sure it can be installed so that the plane works properly. I didn't read the patent, Bailey may have intended it to allow users to set the mouths on their planes, too, just because some people like to do that. The older double iron wooden planes had quite tight mouths when they were made, as did a late-make marples that I had. It was so tight that the cap iron couldn't be used, the wear had to be adjusted.

Current bailey clone manufacturers, couldn't tell you. I don't think they use the cap iron. LN is aware of it now and they call it "too fiddly" and recommend high angle frogs. It may be if most customers are complete beginners, but it would seem a good trick even then. A large # of their planes made before 2013 or so had the cap iron made so that the plane would run out of adjustment if the cap iron was set close - nobody was using the cap on those, and nobody ever said anything about it until after 2012.

By the way, if you have a concave plane, I would think they'd do something about that if it's out of spec (more than 1 1/2 thousandth). Personally, I'd just lap the toe and the heel off unless you think you may sell the plane some day. It's the worst condition for a plane sole on any plane that does other than rough work.

re: the norris planes, some of them have ultra tight mouths and some are tight but not that tight. I have a #2 (pre-war) that has a tight mouth, but it's not tight enough to control small tearout. It does, however, have a wonderful cap iron - I guess made by ward - that works fabulously when it's set, and the tight mouth has been filed to a shape so that you can use the cap without interference. It is maybe the most lovely smoothing plane I've ever used when the cap is set right. The later A5s that I had didn't have such tight mouths, but they had the same wonderful cap iron design and worked a treat when set right. I have 7 or 8 (maybe more) other infills, and none of them have a mouth tight enough to do anything other than prevent the most disastrous of tearout. Curiously enough, though, none of the cap irons look like they were ever cleaned up except for one plane that was in current use when I bought it - they were just used at factory setting.

 

[essexalan]

Thanks for the response DW. LN is definitely out more than that and will be taken to the lapping glass when I can be bothered, it's probably over 20 years old and was bought as a present along with a bronze #4, not the silver bullet. Perhaps I should have kept it on display in a glass case! My Norris #1 makes an excellent smoothing plane except it tends to suck on to pieces of timber being planed, modified Ibbotson cap iron and an O1 iron, nothing in it to go wrong. I am sure I read somewhere about a Norris super smoother with an ultra tight mouth, may have been different bed angle, do not remember the number but they bring big bucks if you have one.

Point taken on the Bailey planes and they work well enough for all the hard work which is cleaning up and sizing sawn timber with the bliss of no tear out.

Holteys? Don't like the colour!

 

[D_W]

When I made what I thought would be the holy grail (workmanship isn't the holy grail, but the design being the 55 degree with tiny mouth and an iron 1/4" thick), I made it 5 1/2 pounds for a 2" wide smoother. It was more or less a copy of the basic shape of what Ron Brese was making at the time, so the sole and sides are thick and heavy.

Now that I've gotten a bunch of infills, no smoother is anywhere close to its weight. I don't think I have any smoother over 4 1/2 pounds, and the group are mostly 3 1/2 pounds to 4. I hate to say it, but I notice that extra weight when using the plane (this is getting toward the holtey thing).

I'd love to have a holtey plane, but if it's as heavy or heavier than mine, I ultimately wouldn't use it much, anyway. The norris 2 that weighs somewhere around 4 pounds with a 2 1/4" iron is just about as close to perfect as anything I've ever used. More weight would only be enjoyable if planing something harder than Beech, and I don't do much of that because soft maple, walnut, cherry and poplar are the easiest things for me to find here (I live in the middle of the area that produces scads of Cherry in the US).

I did just pick up a bronze LN smoother, though - a 4. At 4 1/2 pounds, it's a good comparison for what an infill should feel like. It feels like a stanley that has rubber engine mounts and an extra pound. My goal when I built my first ones was to build a plane that felt better than LN, which I managed to do at the time, but I think the difference is only due to the extra weight. Now my goal is just to build one that feels as good without being heavier. Shame yours isn't straight - they are lovely planes, though I still prefer stanley's proportions better in terms of weight.

 

[essexalan]

The LN #4 bronze is straight and feels nice to use compared with a Record equivalent wish I had got the #4 1/2 I like a bit of heft in a plane, the #5 will be straight I am just a bit hacked off with it might get a Viking burial. Intention was to run the various steels on the same timber and come up with some sort of subjective result, perhaps another time.

My Norris #1 weighs 7lb 6oz so is a bit of a lump but then smoothing timber is the easy part, wish I had bought a lot more when I had the chance the shop was stuffed with them including a beautiful ebony stuffed version. Guy told me not to buy the ones with adjusters but then you already know that. So I ended up with a #1 and a Mathieson coffin smoother. I think the LN planes are far better engineered and feel it but they only do the same job as a Bailey.
Not sure if your cherry is the same but this stuff I have is highly figured and as hard as you like long time seasoning, wasted on chopping boards but I don't need any furniture and I have no pretensions of being a cabinet maker. I did pick up some US black walnut the other day purely for stone boxes and it looks good.

Best of luck with your infill builds, mines a 20 incher if you have time, dovetails are compulsory, like the idea of the wedges and I hope you have some good double irons sitting around, I do have a few but none that fit my planes.

 

[Cheshirechappie]

Both a close-enough cap-iron and the high enough effective pitch
will reduced tearout. Are the mechanisms (in fact) the same,
or do they work in different ways to achieve the same result?

On the face of things, it seems "quite reasonable" that adding a cap iron with a 20 degree
bevel to a plane iron at 45 might behave very similarly to a single iron bedded at 65 degree.

I am aware that most of the "cap iron conversation" took place on US and AUS
forums, so the answer to this might be well known, so any links
to previous discussions would be just as good as laboriously typed out answers,

BugBear

It's a fair question, but the evidence from this thread (at least, so far) suggests the answer is that the mechanisms are not fully or completely understood.

That would explain why the subject gives rise to so much comment. There is accumulated experience, there are some who have done a lot of planing, there are some who have tried a great variety of planes (those two are not necessarily the same group of people), there are some with insights to offer, and some with strong opinions (in some cases bordering on repeated messianic tub-thumping), and there is some interesting, but not wholly conclusive video evidence. However, nobody (so far) has pointed to a comprehensive study along scientific lines that illuminates the mechanisms at work.

That probably explains WHY there's so much debate. Nobody really KNOWS. A few people THINK they know, but nobody can provide a full and conclusive answer backed by research and evidence. Thus, debate continues - and that's a perfectly human consequence, of course!

 

[Derek Cohen (Perth Oz)]

Nobody really KNOWS. A few people THINK they know,

I don't think I know. I think therefore I know. I do know ... I think ... :?

Regards from Perth

Derek

 

[D_W]

Both a close-enough cap-iron and the high enough effective pitch
will reduced tearout. Are the mechanisms (in fact) the same,
or do they work in different ways to achieve the same result?

On the face of things, it seems "quite reasonable" that adding a cap iron with a 20 degree
bevel to a plane iron at 45 might behave very similarly to a single iron bedded at 65 degree.

I am aware that most of the "cap iron conversation" took place on US and AUS
forums, so the answer to this might be well known, so any links
to previous discussions would be just as good as laboriously typed out answers,

BugBear

It's a fair question, but the evidence from this thread (at least, so far) suggests the answer is that the mechanisms are not fully or completely understood.

That would explain why the subject gives rise to so much comment. There is accumulated experience, there are some who have done a lot of planing, there are some who have tried a great variety of planes (those two are not necessarily the same group of people), there are some with insights to offer, and some with strong opinions (in some cases bordering on repeated messianic tub-thumping), and there is some interesting, but not wholly conclusive video evidence. However, nobody (so far) has pointed to a comprehensive study along scientific lines that illuminates the mechanisms at work.

That probably explains WHY there's so much debate. Nobody really KNOWS. A few people THINK they know, but nobody can provide a full and conclusive answer backed by research and evidence. Thus, debate continues - and that's a perfectly human consequence, of course!

All knowledge still has uncertainty in it. I am the cap iron tub thumper. Sometimes it's more like pro wrestling promotion, and I play the heel.

In terms of proof in use, if time counts, the cap iron wins. It won that on an economic basis 200 years ago. The reason other things have gathered steam since large scale hand woodworking died out is because the demands of planing are a lot less these days unless you are still going from rough to finish by hand. If you do that and count time, the cap iron's superiority is easily seen except by the most dense.

 

[Cheshirechappie]

I am the cap iron tub thumper.

We know.

You've been banging on about it for damn near two years on this forum.

We get the message. Actually, we got the message some considerable time ago.

Maybe time to drop it and move on to other matters?