Hand Tools Archive
I have a test piece of khaya (it'll be a guitar body at some point). blanks like this aren't always on ebay, but when they are and appropriate density, I get them (more often two piece flatsawn or one piece flatsawn - the ribboned blanks make a nicer looking guitar).
I think most people wouldn't be able to plane this without using a very steep plane - one ribbon goes one direction, the next goes another. I had trouble with this kind of stuff when I was a beginner, and working with a 60 degree angle or something on much of this from rough would be miserable. It can be done, but it's miserable.
A 55 degree flat edge will tear this out some in a heavy cut but clean it up in a fine cut. It's not quite as bad as the cocobolo blank that I showed, but the problem is different - the ribbons facing away will be fuzzy if you just choose to scrape or plane them with a really steep angle.
I came up with a freehand (but with an angle reference) hone of the iron with a diamond hone totaling about 50 degrees, and then a brisk buff on the yellowcake. I think this equates to about 50 degrees. The beauty of using the buffer for this instead of going to a guide is that it's a lot faster. My angle guides are just a triangular gap that I used to use to stuff an iron under while it resided on an eclipse guide. I don't use them (obviously), but you can stick an iron under one freehand and then lift a little and have a pretty reliable angle (but it can also be done well enough by eye). The importance is that the sharpening cycle time is cut and with a bevel up plane ,you'll be sharpening at least twice as often.
So, just as with 55 degrees, this yielded some fuzziness in the ribbons in a heavy cut, but a lighter pass (standard procedure) resulted in a really nice surface.
The last guitar I made of khaya had more interlocking and it took a little bit more in terms of smoothing passes to get all signs of tearout out. I started to think I might keep this plane and use it as a smoother on guitars.
What I learned is this - these planes do have a feel that make them not stay in the cut very well compared to a stanley - the urge is to get behind them and push them, but a better idea is to use the off hand and give more assistance on the front knob - they start the cut much better that way and the cut accuracy is far better than getting behind them. That is, it's more of a two handed affair and then you can take even shavings.
Just for comparison, I'd sharpened the trusty late stanley 4 with washita and linde A and then set the cap iron about twice as close as I would normally set it ( this is probably a setting of about 6 thousandths).
The stanley is much sweeter to use. The cut is more regulated and far more even feeling. BU planes have sort of this on and off again feel in a cut as long as the shaving has any strength (in figured wood - it reminds me of a push version of what it feels like to go fishing and pull a line in while fish are nibbling at the lure - you get a pattern of little tugs that make reeling in the line not feel totally smooth). Something about the cap iron makes the stanley plane cut far more evenly in the alternating ribbons, but you still have good feel (with the bronze LN 4, i can't feel much of what's going on even though it will produce the same result - it's arguably better with all of that weight in super hard woods that we don't use often).
I don't have the camber honed into the LN yet, but I don't believe it left any significant tracks.
With the stanley, I'm more accustomed to honing the iron to finish smoothing camber, and the blank is completely mark free on the surface.
This could be finished as-is, even the opposing ribbons are smooth.
The pictures show the surface much closer than you can actually see it in person, so if they show no defects, then you will see none in person. How cleanly this is planed shouldn't bely how it can turn on you. I planed the board through and through, but with this plane setting, even something as simple as skewing the plane induces tearout (both planes) in the ribbons oriented facing toward you. Since the ribbons alternate one after the other and are close to each other, you can't just plane downhill everywhere and avoid controlling the tearout.
The conclusion - freehanding the irons is what I would do if I used this type of plane to avoid faffing with a guide and to have the hand control to apply camber more freely and quickly. It's doable. If an edge isn't steep enough, you can freehand it steeper next time or just buff the edge a little bit steeper. In an earlier trial, the edge honed at 45 degrees total bed+ bevel and then buffed heavily didn't match a 55 degree flat bevel on the block plane. It was remedied quickly by buffing a little bit more and a little bit steeper.
In a world where an LN 4 was considered ready to go and this is considered ready to go and a deep pocketed beginner asked which to get, I'd never recommend a BU plane, though. A beginner taught the cap iron right away (and the cap on LN planes modified with a front edge curve and then blued so that the set is easier to see) would master it faster and it just works better in the cut and has far wider range.
All that said, there is a quality to buffing the front edge with yellowcake that's a lot like chisels - with chisels, if you still get edge damage, buff a little more. With a BU plane, if you're not getting a clear surface, buff a little more and you can just hone a little steeper next time.