Thread: Back Bevel vs Steeper Frog

what planes do you have?

have you followed the discussions on tuning and setting cap irons?

If you get the cap iron tuning and setting right you may not need a back bevel

Originally Posted by ian

what planes do you have?

have you followed the discussions on tuning and setting cap irons?

If you get the cap iron tuning and setting right you may not need a back bevel

Cap iron or chip breaker? I didn't realize the cap iron positioning could affect the shaving.

No, I haven't followed that discussion. Haven't seen it. Does it have a funny name? Would you mind posting a link?

I have a Veritas #4 and BU Jack, a Stanley #3 and #7, and a Lie Nielsen #8. All bevel down planes are at 45deg. I have a blade with a ~50deg effective angle available for the Jack.

Cheers!

Luke

I am no expert on any of this but I do not think that putting a back bevel on the blade will do much about the tear out. The frog angle sets the angle the blade attacks the timber on a bevel down plane. The idea of a back bevel was more about ease of sharpening. And the actual amount of back bevel was always very small. It seems to me that you would have to create a very severe back bevel to make much difference.

It is true that raising the angle does limit tear out. I use a Veritas bevel up smoother and I grind the blade at 40 degrees. The bed is 12 degrees so that gives an effective angle of 52 degrees. At this angle, provided the blade is very sharp and I take thin shavings, I do not get any significant tear out. (Thanks to Derek Cohen for this configuration)

I have been playing around with a Veritas scraping plane recently. That seems to eliminate tear out completely but there is a bit of learning curve to using the thing.

Originally Posted by chook

..... The frog angle sets the angle the blade attacks the timber on a bevel down plane. The idea of a back bevel was more about ease of sharpening. And the actual amount of back bevel was always very small. It seems to me that you would have to create a very severe back bevel to make much difference......

Chook, the frog angle = the cutting angle only when the blade remains parallel. Putting a back bevel on the blade of a BD plane will increase the cutting angle, or angle of attack. Perhaps it was used initially by lazy sharpeners, but it's been long touted as another way of decreasing tearout. How big a bevel you need for useful effect I don't know as I've never tried it myself, I have a couple of high angle planes to reach for when things go ugly with my standard-pitch planes.

There has been much written about super-close cap-iron setting, Luke. This thread starts out talking about stones but morphs into some serious diatribes on cap-iron setting. It's worth a try, some devotees seem to be deriving great benefits, but be careful if you muck about re-shaping the cap-iron on some modern planes, as you'll note from the woes of one poster, who ended up with a cap-iron too short to allow useable blade extension. I will say up front, I cannot make super-close cap irons work for me. I still use the 'fat 32nd' rule I was taught at school on most of my Bailey style bench planes. Closer than that and the shavings crinkle up & will not exit smoothly. I've attended to every aspect you are supposed to attend to, but obviously, something essential is eluding me. I don't shy away from highly-figured woods, and my Stanley #4, with cap iron set at about .8mm and a sharp blade, cuts chatter-free & produces wispy clean shavings on most wild-grained woods I've fed it to. When it does throw in the towel, a switch to one of the high-angle planes may do the trick, though interestingly, on softer 'mongrel woods' like Camphor (which can be a really difficult customer at times!) the standard pitch plane does the better job if the blade is kept super sharp & I keep shaving thickness on the fine side. Sometimes, neither high nor standard pitch prevails & I have to move on to the scraping plane. The harder the wood, the better it scrapes, is a good rule of thumb.

I like to take the easiest path to the destination. Some years ago, I flirted with the idea of a thickness sander, but my aversion to noise & wood-dust won out in the end.....

Cheers,

Originally Posted by Luke Maddux

Cap iron or chip breaker?

Cap-iron = chipbreaker = back-iron. They're all the same beastie. Not to be confused with the lever-cap.

Cheers, Vann.

Originally Posted by IanW

Chook, the frog angle = the cutting angle only when the blade remains parallel. Putting a back bevel on the blade of a BD plane will increase the cutting angle, or angle of attack. Perhaps it was used initially by lazy sharpeners, but it's been long touted as another way of decreasing tearout. How big a bevel you need for useful effect I don't know as I've never tried it myself, I have a couple of high angle planes to reach for when things go ugly with my standard-pitch planes.

There has been much written about super-close cap-iron setting, Luke. This thread starts out talking about stones but morphs into some serious diatribes on cap-iron setting. It's worth a try, some devotees seem to be deriving great benefits, but be careful if you muck about re-shaping the cap-iron on some modern planes, as you'll note from the woes of one poster, who ended up with a cap-iron too short to allow useable blade extension. I will say up front, I cannot make super-close cap irons work for me. I still use the 'fat 32nd' rule I was taught at school on most of my Bailey style bench planes. Closer than that and the shavings crinkle up & will not exit smoothly. I've attended to every aspect you are supposed to attend to, but obviously, something essential is eluding me. I don't shy away from highly-figured woods, and my Stanley #4, with cap iron set at about .8mm and a sharp blade, cuts chatter-free & produces wispy clean shavings on most wild-grained woods I've fed it to. When it does throw in the towel, a switch to one of the high-angle planes may do the trick, though interestingly, on softer 'mongrel woods' like Camphor (which can be a really difficult customer at times!) the standard pitch plane does the better job if the blade is kept super sharp & I keep shaving thickness on the fine side. Sometimes, neither high nor standard pitch prevails & I have to move on to the scraping plane. The harder the wood, the better it scrapes, is a good rule of thumb.

I like to take the easiest path to the destination. Some years ago, I flirted with the idea of a thickness sander, but my aversion to noise & wood-dust won out in the end.....

Cheers,

When you say parallel-do you mean parallel to the sole of the plane? I have never heard of it before, which should not surprise me very much.
As for camphor, I have heaps of it and it and did have some issues with tear out. But the BU smoother set as I describes seems to have largely fixed it. The scraper plane may totally deal with it once I work out how to set it up properly.

Originally Posted by Luke Maddux

...
I am about to embark on a big furniture project with some moderately to highly figured timber and I would like to avoid a tearout nightmare.

So can I achieve the same tearout reduction by using a back bevel which can later be ground off as I can with a "York" pitched or otherwise higher angled frog? I've had some good results with grinding steeper angles on my bevel up jack plane, but that's only one plane, and I will definitely need to use the jointer and the smoother a lot on this project.

Thanks a lot in advance,
Luke

Hi Luke

There are many ways to control tearout, some more successful than others, and some you choose to use simply because they are expedient.

It all comes down to two methods: high cutting angles vs low cutting angle-supplemented-by-a-chipbreaker.

High cutting angles leave a slightly matt/fuzzy surface compared with a low cutting angle. Hard woods tend to show this less than soft woods, and a lot gets obliterated by the type of finish one uses, so sometimes this whole issue is a moot one.

One measures cutting angle differently with BD and BU planes. BD typically involves taking the cutting angle from the bed angle, while BU typically involves taking the cutting angle from a combination of the bed plus bevel angle (as the blade bevel faces up).

High cutting angles may either be created by a plane with a high angle bed, a back bevel on a bevel down plane blade, a high secondary bevel on a bevel up plane, or a scraper. Use as a rule-of-thumb a Stanley #4. This has a "Common Pitch" bed of 45 degrees. "High angle" typically refers to 55-60 degree beds. The bevel down HNT Gordon smoother (non mechanical adjuster type) has a bed/cutting angle of 60 degrees. A bevel up plane, such as a LV BU Smoother, has a 12 degree bed to which is added a blade with a 50 degree bevel, creating a 62 degree cutting angle.

All the above reduce tearout by changing the angle at which the shaving (or chip) breaks away from the wood. Low cutting angles allow the wood to break away further from the blade, which cause tearing of the wood fibres. A high angle causes the wood to bend up at the bevel and not split away.

The chipbreaker can be used in a similar way. Moving it close to the edge of the blade (about 0.4 - 0.5mm) causes the shaving to bend, and preventing tearing in a similar manner to the high cutting angle. If the chipbreaker is set further back, it does not affect the chip formation.

Use of the chipbreaker goes back centuries, but became the forgotten art for the last few decades, possibly as much as the last 50 or 60 years. Emphasis was instead given to high cutting angles. The chipbreaker has been "revived" in the last 3 years, and is starting to make a come back. It does have a steeper learning curve to other methods.

Lots of choices. Depends on what you have and what you have time to learn.

Regards from Perth

Derek

Originally Posted by chook

When you say parallel-do you mean parallel to the sole of the plane? ...

I mean a parallel blade as opposed to a tapered blade (as on old woodies). For parallel blades, cutting angle = frog angle. For tapered blades, cutting angle = bed angle - blade taper angle. Just simple geometry....

Originally Posted by chook

.....As for camphor, I have heaps of it and it and did have some issues with tear out. But the BU smoother set as I describes seems to have largely fixed it. The scraper plane may totally deal with it once I work out how to set it up properly.

Camphor has to be the most variable wood I've ever worked with. Some boards are straight-grained and plane easily with any plane you pick up. Others are rowed and irregular as heck, and will pick out no matter which way you come at them. You can try scraping, but scraping doesn't work nearly as well on softish wood like Camphor. It's do-able, but your scraper needs to be very well set up to get consistent results. If the bade dulls, you can end up with a shredded surface. As I said, I often get the best results by taking it very slowly with a regular plane, fine shavings and a very sharp blade are the go...

Cheers,

Ok... so THAT's the chipbreaker thread. I saw that floating around for weeks and never read it because I thought it was about waterstones...

There is a lot of information there with a lot of strongly supported opinions from respectable names. It also seems like there is a very very small margin for error in the whole process. I'm kind of at a point where I need to chill out on the spending of money and I worry about needing to replace plane parts.

I'm going to have a more close, educated look at the chipbreaker/blade interface on my planes. If there is a way for me to get shavings like Derek's on figured timber without too much effort then I want to pursue that. Kind of like how if there is a way for me to dunk like Michael Jordan without growing 6" then I want to pursue that...

So here's the one question that I can't seem to get past...

If the companies want to sell more planes than the other guy, then why the hell are they ALL setting up their chipbreakers in a way which is fundamentally flawed?

Originally Posted by Luke Maddux

If there is a way for me to get shavings like Derek's on figured timber without too much effort then I want to pursue that.

I think a lot of effortless endeavour is preceded by many long hours of effort spent developing the skill and technique needed to give the appearance of effortlessness.

Originally Posted by Colin62

I think a lot of effortless endeavour is preceded by many long hours of effort spent developing the skill and technique needed to give the appearance of effortlessness.

Amen!

Originally Posted by Colin62

I think a lot of effortless endeavour is preceded by many long hours of effort spent developing the skill and technique needed to give the appearance of effortlessness.

So true. There is little in life where this doesn't apply.
I seem to be constantly referring this to my kids, who seem to want to give up in the lack of first time perfection.

Well I had a major breakthrough with my planing which kind of voids the topic of this thread. For anyone interested, see my post in the Waterstones/chipbreaker thread referenced a few posts back by Ian.

Cheers,
Luke

I use Chinese and Japanese finishing planes as I find them to cope better with tear outs than Stanley's. Althought I like my no 7 for flattening boards. Interesting to serious hand tool users. I know very little about them other than trial and error...