Thread: Purpleheart tear(ing my hair) out ??

Sounds to me like you have a very recalcitrant bit of wood there, Ross. The couple of pieces of Purpleheart I've used were nowhere near as uncooperative as the piece you describe - I would've classed them as relatively easy to work. I'd do pretty much what you've tried already i.e., start with a jack plane to get close to dimension, then switch to smoothers & lighter cuts to finish off.

If a piece is tearing-out even with a close-set cap-iron or with a high-angle, & light cuts, I pull out my scraping plane, which is slower, but very few woods can defeat it. However, there are some bits of wood I've met that simply will not be tamed, no matter what I throw at them. Purpleheart is rather precious stuff, so I'd try very hard to get it into shape, but I reckon I would've hurled that particular piece in the kindling box by now if it's as bad as it seems!

Heresy, I know, but don't you know anyone with a decent drum sander?....

Cheers,

I have used a drum sander with very good results.

Purple heart was being sold in Townsville as floor joists in the early 2000's, so I purchased a couple of 4 m lengths. I now wish I had purchased more at the time. I've had similar experiences to both IanW & RossM using it in woodturnings.

One length is very compliant and turns nicely. Another is as Ross describes, tears out and when it does its usually a quite deep "pothole" typically getting towards 1 mm deep. I tried all angles of attack with the skew, spindle gouge and even tried scraping on spindle turnings. All approaches appeared to have promise then a buggar moment, and very frustrating to overcome. Most of the PH I have left comes from that one recalcitrant length. There does not appear to be any real difference in grain properties between the two lengths but I'm not confident they came from the same tree so I'm wondering if it is a drying issue, like case hardening, or perhaps there are several of the 23 known species of Peltogyne sold under the trade name "purple heart".

Originally Posted by Mobyturns

... There does not appear to be any real difference in grain properties between the two lengths but I'm not confident they came from the same tree so I'm wondering if it is a drying issue, like case hardening, or perhaps there are several of the 23 known species of Peltogyne sold under the trade name "purple heart"... .

Could be any of the above, MT, but the "Wood Database" does mention that some Purpleheart can be particularly tear-out prone. Variation within a single species is typical, and for a few the variability can be extreme. We used to cut fence-posts from a particular type of Stringybark up on the Tableland. Most of them were fairly straight-grained and easy splitters, but you could hit some in the middle of a patch of lovely splitters that just would not cooperate. They would either spit the wedge back at you before you got it in 2 inches, or if you did manage to drive it in, there would be a split about an inch each side of the wedge. The old bloke was very frugal, and very stubborn, he hated to waste the wood & the effort to get them felled, barked & docked, but we walked away from a few that defeated us!

So in my view, there is no shame in giving up when all reasonable approaches fail. I probably would have changed my mind about using the piece the OP is struggling with by now, but if I was really determined to use it, I would seriously think of using a thickness sander, if one was available. Much as I hate abrasives, they are occasionally a more practical solution...
Cheers,

Did you close the mouth of the plane right up?

I've found this terribly important.

Originally Posted by Mobyturns

... a quite deep "pothole" typically getting towards 1 mm deep. ... then a buggar moment, and very frustrating to overcome...

Exactly this!! Even being careful with very light shavings there is that deep tear-out "buggar" moment! The wood seems extremely brittle.

I don't have a drum sander or thickness sander, so can't use that.

As I mentioned, the scraper works, so maybe I'll just have to persevere. I don't have a lot of it to do, just playing around making a small box with some off-cuts I scored a while ago.

Originally Posted by woodPixel

Did you close the mouth of the plane right up?

I've found this terribly important.

Thanks WP.

My HNT Gordon smoother has a mouth tighter than a fishes ar5e !!

Hey...i'm in the house...you know what's coming next....I've got my cap iron tights and wrestling boots on.

This is an opportunity to learn to use the cap iron - it's not going to make the dimensioning nice - purpleheart isn't a nice wood. It sucks to dimension to say the least, cuts nice with a saw and then ruins plane blades planing across the end grain.

Cocobolo can be much the same, though the reason is slightly different.

you want to be using a common pitch plane when you're going to do any significant work on it and you want the shaving of purpleheart to straighten a little when you plane it. If it's getting under the cap iron, then it's too close (some of these terribly stringy woods get under a cap, too - but they will not tolerate a high pitch single iron plane. YOu will be stopped like you're pushing against a bulldozer, and they will destroy the edge.

have a look at these shavings - this is what you want to see:
https://i.imgur.com/jr9O8ZI.jpg
https://i.imgur.com/ybiuuLT.jpg (notice that this shaving isn't straight, but the cap iron has manipulated it enough holding it into the wood to cause it to not roll up into a toilet paper roll shaped thing).

This is cherry, and these are about 12 thousandths thick. You're going to be shooting for about a third of that. Ridiculous as it may sound, the forces involved will probably be similar.

There are woods so bad they won't finish plane with anything, but the cap iron will always help you get to the point of dimensioning them within shooting range of scraping and sanding whereas a single iron plane or a scraper for this is going to torture you.

This is a heavy cocobolo smoother that I made years ago. The iron is a bit soft and it doesn't do thin shavings well, but it turns out to be a great plane for removing fairly stiff amounts from sticking or wiping out planer chatter marks in one pass (including the crushing that they leave below the surface).

https://i.imgur.com/FDWoPOG.jpg

this is the surface after those smoother shavings:
https://i.imgur.com/WzVgbaI.jpg (those were about 6 thousandths - your 2 or 3 in purpleheart will be the same amount of work - the objective isn't to be absolutely finished, but to have a surface that's very close to it and will become "fine" once the surface is finish planed and profiled).

strangely enough, i made the cocobolo plane by sizing the blank and planing the surfaces with a common stanley plane. I sharpened only once in the whole process. You're potentially chancing into something big here if you like to work by hand.

at this point, you're thinking that this has nothing to do with purpleheart. This plane is purpleheart - every bit of it cut and planed,e tc, by hand - it's a skew infill, and I have no power tools that would work on something like that. I planed the endgrain on it, too. With a common stanley 4. this is the hardest purpleheart I've ever seen and when I was done with the plane, I took the wedge offcut and tried to plane it with an LV shooter as well as this one. It destroyed the edges on both.

Purpleheart comes with some specs hardness-wise on some sites that make it seem like it's a little bit harder than maple. There is definitely a wide range of density and hardness as I've not planed anything harder than this piece of wood.

quite often, i am also accused of not being familiar with other methods and just touting what I like to be a blowhard. (i prefer to think of the latter as gimmicking - I'm trying to make the cap iron application memorable because it will halve your physical labor if you do more than smoothing and scraping).

Here's where I started - my second infill plane (look away, ian - let's just say, it's not aesthetically wonderful).

https://i.imgur.com/ZBtX1Et.jpg

This plane has a 3 to 4 thousandth mouth (it varies seasonally). That's what you need to be assured of no tearout with 2 thousandths shavings.

I know you probably don't believe that it has a mouth that fine.

wait for it...


....

..

https://i.imgur.com/NK7Ank4.jpg

if you take 1 to 2 thousandth shavings, it is almost as good at preventing tearout as a properly set stanley 4 - but you have to sharpen it more often, it cannot go thicker (or the shaving going through the mouth creates huge resistance) and it took me enough time to make that I could've made an entire piece of furniture.

I made another plane with a mouth of a hundredth when I made this one - another infill. A hundredth isn't fine enough to prevent tearout. It's enough to prevent severe tearout, but it won't yield a surface that can be finished.

Thanks DW -

I will see how a Stanley goes - but I'm not holding out high hopes. My experience in the past has been that on very hard & figured timbers the Stanley planes chatter WAY too much, no matter what is done with the cap iron & frog settings.

Originally Posted by D.W.

..... (look away, ian - let's just say, it's not aesthetically wonderful)......

Looks fine to me, D.W., but why did you have to launder it??


I think a mouth that fine would drive you nuts in a very short time down here. Many of our woods are gummy and 2 thou shavings will clog a mouth that is comfortably wider than the thickness of the shavings. And when I say clog, I mean clogged! This 60* (single iron) has a real penchant for clogging, and the mouth isn't all that fine, about 0.75 mm (0.030", or more than seven times wider than yours). I can usually clear it with a sharpened stick, but more than once I've had to pull the blade out to clear it when planing gummy eucalypts. On 'decent' woods it will roll out shavings quite happily: b.jpg

But even fine shavings like this can clog it with some woods: c.jpg

I think that plane is my 4th effort but I didn't get the D/Ts as perfect as yours, you can see a couple of very faint lines on mine if you blow it up enough (I can't see any on yours)..

I've made a couple of low-angle BU planes with fine mouths (something more like 0.5mm, certainly not as fine as your example!) and they are useful in some woods, but a pita in others. In my experience, cap-irons & high cutting angles do more for me than fine mouths when it comes to controlling tear-out in many of our woods. And I will be the first to agree that it probably has as much to do with the particular planes I own/use as anything. There are so many variables!

Cheers,

those look fine to me, ian!

depending on wood orientation, I can get telegraphing details on a perfectly made plane (well, close to it). Shootenstein, I made in the middle of winter here with purpleheart - in the summer, it expanded enough for the tails to start to telegraph. It would be lovely to have 20 year old wood to make every infill so that you can make them thousandth tight and not have the wood expand, I get "guess the age" wood when I get it.

Not long after, my spouse was cleaning my workspace (this is a banned action that occurs sometimes, anyway, because she doesn't like a mess at all and that's all I make) and it took a nosedive off of one of those rolling tool chests onto a concrete floor. That made the dovetails telegraph more in some spots!!

for me, to make a plane and have nothing telegraphing ever is hard. On that brese-ish style plane (ron actually sold lever caps and irons back then, which is where those came from), there's ugliness on the bottom - a couple of deep peins and my billet of wood was ever so wide when I put it in, showing some telegraphing down there. Chasing perfection is a pain!! especially on plane number 2.

We're blessed with lots of pitchy pine, but luckily, our medium hardwoods here are very "dry" working and don't leave much behind. I was just getting into mostly working by hand at that time (2010) as I didn't like working by machine, and I was pleased to have a plane that really didn't create tearout. But after a while, pushing a 5 1/2 pound smoother back and forth on panels that weren't as well done in the prior step (I couldn't figure out the double iron and had an old 50 degree single iron jointer - quite a nice plane, I still have it). learning the double iron solved that but then kind of obsoleted this plane (it's still one trick, it feels nice to use when waxed, but it takes longer to finish actual work with it).

Yes on the mouth vs. the cap iron. In order of usefulness, I'd say cap iron is miles ahead of anything (I can cease tearout on a 38 degree japanese plane without any issue), then angle (even if you prefer the cap like me, still needs to be understood for profiling planes and grooving planes), then mouth last. I think a tight mouth on most older planes is a matter of displaying quality (but the insides of those mouths were always filed away to let the cap set get to the edge without clogging -I learned that the hard way on infill #3, but eventually fixed it. Not that a mouth can't get too big - they can get so big that you can catch the opening on the beginnings and ends of cuts.

I see the use of the common stanley (getting good at it) as kind of like training with a skew on a lathe. It seems like a tool that's destined to create disasters (skews), but if you come up with a few turning projects and you absolutely don't allow yourself to use anything else, then all of the sudden, you prefer it for a lot of things to specialty turning tools. But you can't ever get there if you don't force yourself to put those specialty tools aside (this isn't a "you, ian", but I'm thinking of another thread where a stanley is suggested as being unable to plane purpleheart without chatter - it can chatter if you allow yourself to not solve it and fall back to something else, but once the plane is set right, it'll just plane thicker and more per sharpening with less tearout than anything else. I learned the stanley after being convinced that it must work and then forced myself to put all of the planes like above. It took less than a week (sans literature or videos, this was before any of that stuff came out) to suddenly realize that not only did it work, but it was better. At the end of the week, I put the laundry plane up against my new found gimmick on the stanley and was somewhat deflated to see the stanley was better at controlling tearout....what about the plane I just spent 80 hours making almost entirely by hand? It's good at sitting on a shelf!!

I'd still like to make another 10 infills, but they'll be a lot more like vintage norris patterns than new patterns. in setup, as well as weight.

Originally Posted by RossM

Thanks DW -

I will see how a Stanley goes - but I'm not holding out high hopes. My experience in the past has been that on very hard & figured timbers the Stanley planes chatter WAY too much, no matter what is done with the cap iron & frog settings.

I literally burned my last purpleheart offcut last week. I have a chattered bubinga guitar neck blank, and a long board of macassar ebony or something similar (heavier than water). Neither will be a challenge for the stanley and when the kids wake up, I'll show you what I mean (without resharpening, etc, I'll use the planes as they are).

If you are getting chatter on a shaving less than a hundredth, there is a setup issue. I don't want to overcomplicate the issue of using the double iron (sometimes you use less of it for ease once you've mastered it and tolerate a little bit of tearout, but not disastrous amounts - to allow a heavier cut), but anything 5 thousandths or below in a wide fat shaving will not chatter - the plane will stand you still. Stock thickness iron and chipbreaker and all.

Trust me, this is something you want to master. no record stayset or any of those gimmicks, just a plain late model stanley smoother and a record jointer (the stanley cap iron is actually better than the record cap, even though the record is thicker). The point in learning this isn't just so you can see that I'm right (I don't care about that), it's so that every time you have a situation like you have now, you know you can pull an inexpensive plane out, and literally plane to any mark in any wood with no damage. The stanley plane with the mouth opened up a little is absolute genius, and they work perfectly, all the way up to at least the undesirable type 19 (I don't have anything newer) with the belt sanded frog. The idea that the surface of the frog contacts much of an iron is an old wives tale in the first place - the iron is flexed by the cap and touches at the top and bottom - it is a bias of genius.

From this point on, you will be able to plane without tearout and without chatter, and if you accidentally set a cut too deep, instead of inducing tearout, you'll just stop yourself in your tracks.

Imgur: The magic of the Internet

OK - record 8 and stanley 4 - I made a little error in the gallery and neglected to show the tearout around the grain swirl. It was only as much as would be easily removed in normal smoothing, though, you have to back off of shaving thickness on wood like this to eliminate the tearout.

The cap iron set that you see is the entire story here - like that for the jointer, slightly closer for the smoother.

This plane was originally sharpened on a washita, but it did a lot of work before these boards (both planes did, that is), and I didn't resharpen them to prove a point. relying on sharpness to reduce tearout is bad policy until the very last shaving (in wood that is as nasty as ribboned bubinga, you will need to go to thin shavings, but you will absolutely punish yourself constantly sharpening if you try to get all of the work done like that, and you will at some point accidentally set the plane too deep and create tearout, starting the whole process over. It won't be minor tearout like seen here, either.

The first step in all of this since you're restricted to a fairly thin shaving is finding the high spot and working the plane through it. If the continuous shavings have holes in them, you have tearout and you'll find it on the board sooner or later if it's not immediately apparent.

This is a two step process - joint (limiting the tearout) and then progressive smoothing, first with thicker shavings and then backing off until the tearout doesn't occur. At the final smoothing point, you may wish to resharpen. I did not, again, to prove a point. When your plane doesn't pick up a thin shaving (these were struggling to due to dullness), wax the sole. if it still doesn't, then sharpen for final smoothing.

If you set your cap like this and set the shaving too deep, there will be no disaster - you just won't be able to push the plane. There is no chatter in any of this. no heavy replacements and no trick sharpening stuff. This is exactly how these planes were designed to be used.

friendlier wood with a jointer allows double or more of the shaving thickness without issue. You can get a lot done without risk. With a freshly sharpened pair of planes, I could flatten 6 or 10 of these before resharpening. Somewhat fewer if an iron is soft (like a round top stanley iron). I made these irons - they're XHP (V11 type steel), so they will plane about double in clean wood that good O1 will. However, they will not plane double in an interrupted cut like the sawmill marks in this board - only in clean wood with no silica will they achieve that. decent O1 would do the same thing as shown here - the irons aren't the secret, the cap iron is.