Smoothing plane

[Karl]

David

Can I ask - are your students using tuned up old planes (Stanley, Record), or high quality new planes (LN, LV or Clifton)?

Cheers

Karl

 

[Paul Kierstead]

If one takes the trouble to master the various techniques for raising effective pitch, one can plane anything. Albeit with fine shavings.

The scraper plane then becomes redundant for everything except complex veneered surfaces.

This is not a rhetorical or critical question: Why do we want to make the scraper plane redundant? Not that I am against high-angle planes; I have a plane set at 52.5 degrees coming. But I do wonder why sometimes we work so hard to plane something when it could easily be scraped (or, I suppose, sanded, but that is a different kettle of fish). Is the planed surface that superior? I take it you do not subscribe to the results published a while back that found no differences in surface quality between the various methods in a finished surface.

I'd be interested in hearing your thoughts on the merits of planing, scraping and sanding.

 

[David C]

The current group all chose L-N, but the same result can be got from any serviceable bench plane with a back bevel. (I doubt 55 deg pitch would be steep enough to work on this particularly difficult timber).

Thicker blades do perform better, but I used to do this with standard Stanley & Record blades in the bad old days. i.e. 1970's They just blunted extremely fast.

I have no wish to make scraper planes redundant, but sharpening and setting a scraper plane blade takes me longer than a back bevel in a conventional plane.

I wrote about surface finish in my third book. If your chosen finish needs sanding between coats, on a table top say, I think that a little sanding will be essential to achieve flatness, regardless of which tool is chosen to prepare the surface.

One interesting technique which I plan to try soon, is to explore the use of toothed blades to do preparation of cranky timbers and then perhaps a scraper plane to finish?

best wishes,
David

 

[Paul Kierstead]

I wrote about surface finish in my third book. If your chosen finish needs sanding between coats, on a table top say, I think that a little sanding will be essential to achieve flatness, regardless of which tool is chosen to prepare the surface.

I have the third book (I have all of them, actually; excellent books) and recall the article, but don't recall it answering the question I have in mind; I recall the importance of eliminating scalloping if you sand your finish (and it was an excellent point!). I'll go back and re-read and revisit the topic. You may be hearing from me again

 

[pam niedermayer]

Big difference between sanding the wood and sanding the finish. Finishes were made to be sanded, fantastic plastic...

Pam

 

[Paul Kierstead]

Big difference between sanding the wood and sanding the finish.

The article is -- in part -- concerned with the need to sand the wood if you are going to sand the finish as any scalloping left on the wood can play havoc since the peaks will have the finish sanded through. It is worth reading.

 

[dchenard]

Big difference between sanding the wood and sanding the finish.

The article is -- in part -- concerned with the need to sand the wood if you are going to sand the finish as any scalloping left on the wood can play havoc since the peaks will have the finish sanded through. It is worth reading.

In theory it makes sense. In practice it depends on how the wood is finish planed.

Let's say you are planing at a 0.001" depth (very fine smoothing), with, let's say, a #4 smoother, with a 2" wide iron. Let's assume that the iron is cambered to that amount, i.e. flush with the sole at each end and sticking out 0.001" in the middle. Assuming full width shavings are taken next to each other with no overlap (which is more precise plane handling than most of us can achieve), the peaks would be 0.001" thick. I was just reading a finishing article by Chris Minick tonight, where he states that varnish coats are in the 0.003-0.004" thick range. In that case the finish would have no risk of being sanded through the scalloping.

There are lots of variables at play here. All other things being equal, if one chooses an oil finish, which leaves nearly no film on the surface, then sanding through could be an issue. In the same vein, if one uses a heavier camber and still takes full-width shavings, then the peaks will be higher, and more prone to sand through.

The way I was thought to finish plane at Rosewood Studio was to plane full width with a small camber, aiming for the 0.001-0.002" thick shaving range. The last step was to retract the iron to the point where it was taking only a little bit of "fuzz" from the middle of the iron, and take lots of overlapping strokes (it is faster than it sounds). My guess is that this took no more than half a thou off, possibly less, therefore lowering the peaks down to the un-measureable level (or close to it).

Another factor is that as we plane, with any kind of overlap in our strokes the plane sole burnishes the surface somewhat, reducing the height of the peaks further.

Although it would be interesting to make controlled experiments, playing with all the variables of influence, my take is that we don't need to worry much about sanding trough the finish (hasn't happened to me yet). If anyone has had such experiences I would like to hear about it.

My $0.02,

DC-C

 

[Paul Kierstead]

It is worth reading.

 

[dchenard]

It is worth reading.

Can I borrow it? :-k [-o<

DC-C

 

[Paul Kierstead]

It is worth reading.

Can I borrow it? :-k [-o<

Absolutely! Whether it is a problem in any given situation, the article is good food for thought.

 

[David C]

DC-C,

I like to use very thin wiped on shellac, a method developed from Krenov.

If any scalloping or burnishing lines are left on a plain surface like Swiss pear we seem to see streaks or unevenness in the finish film, which is very very thin.
This only shows at very low incident viewing angles using a good light source like a bright grey sky.

I deduced that the film thickness varys if the surface is not completely "without scallop" and uniform in appearance before the first coat of shellac. Hence my practice of light sanding to flatten and make the appearance uniform.

Sanding through these ultra thin films is a problem as they are nowhere near the thickness of varnish.

I don't doubt that a leg surface say, can be completely flat and perfect, if the timber is mild and cut with a straight blade, perfectly sharp plane.
Scraped surfaces of difficult timber are not as bright or perfect, and sanded surfaces are in fact a mass of uniform scratches.

Back bevel surfaces on difficult stuff also benefit from a little fine sanding, but they do exhibit zero tearout.

These are all very small differences, but really good finishing seems to be a difficult and precise art.
It would be so nice to leave wood unfinished, straight from the plane, but these surfaces can become disapointingly dirty some years later?

best wishes,
David

 

[dchenard]

DC-C,

I like to use very thin wiped on shellac, a method developed from Krenov.

If any scalloping or burnishing lines are left on a plain surface like Swiss pear we seem to see streaks or unevenness in the finish film, which is very very thin.
This only shows at very low incident viewing angles using a good light source like a bright grey sky.

I deduced that the film thickness varys if the surface is not completely "without scallop" and uniform in appearance before the first coat of shellac. Hence my practice of light sanding to flatten and make the appearance uniform.

Sanding through these ultra thin films is a problem as they are nowhere near the thickness of varnish.

I don't doubt that a leg surface say, can be completely flat and perfect, if the timber is mild and cut with a straight blade, perfectly sharp plane.
Scraped surfaces of difficult timber are not as bright or perfect, and sanded surfaces are in fact a mass of uniform scratches.

Back bevel surfaces on difficult stuff also benefit from a little fine sanding, but they do exhibit zero tearout.

These are all very small differences, but really good finishing seems to be a difficult and precise art.
It would be so nice to leave wood unfinished, straight from the plane, but these surfaces can become disapointingly dirty some years later?

best wishes,
David

Interesting...

Do you see these scallop and/or burnishing lines on the raw wood before applying the shellac?

Also, what pound cut are you using for the shellac?

I'd like to test this myself, not that I don't believe you, but I would like to see the effect myself, and you're living some distance from here... :wink: Would black cherry be a good substitute for the Swiss pear (which I don't have in my possession) for this exercise? And would the effect be more noticeable with a lighter wood like maple?

Thanks,

DC-C

 

[David C]

Yes, the minute scallops are present if one looks hard enough.

Pear is exceptionally fine grained and often very bland, cherry has more visible fibres and tubes and prominent graphic lines.

The Shellac probably has 3 or 4 times more alcohol than a conventional cut.

Ebony might be a good candidate?

David

 

[bugbear]

If one takes the trouble to master the various techniques for raising effective pitch, one can plane anything. Albeit with fine shavings.

The scraper plane then becomes redundant for everything except complex veneered surfaces.

This is not a rhetorical or critical question: Why do we want to make the scraper plane redundant? Not that I am against high-angle planes; I have a plane set at 52.5 degrees coming. But I do wonder why sometimes we work so hard to plane something when it could easily be scraped (or, I suppose, sanded, but that is a different kettle of fish). Is the planed surface that superior? I take it you do not subscribe to the results published a while back that found no differences in surface quality between the various methods in a finished surface.

I'd be interested in hearing your thoughts on the merits of planing, scraping and sanding.

Steve Knight's research indicated that planing at the lowest EP that avoids tearout (which may well be quite high by "normal" standards) does indeed give a better finish than scraping.

I would further maintain that sharpening a plane blade is easier than sharpening a scraper blade, and that edge retention is better in the plane.

Thus, while there may be reasons to sand (mainly to do with finishing technique), I am happy to try to do away with scraper planes.

BugBear

 

[Paul Kierstead]

Steve Knight's research indicated that planing at the lowest EP that avoids tearout (which may well be quite high by "normal" standards) does indeed give a better finish than scraping.

That is pretty easy to see; just about anyone who planes a reasonable amount will see the extremely lovely finish of having just enough pitch (hence the Japanese planes with their pitches all over the place). The question is, does that improvement carry forward when you put a finish on the wood, especially a film finish. You would think it would, but at least one magazine article ran the tests and claimed there was no perceptible difference between sanded, scraped and planed surfaces.

I would further maintain that sharpening a plane blade is easier than sharpening a scraper blade, and that edge retention is better in the plane.

This is very clearly true in softer hardwoods, but I am not so sure (not enough experience, both are bad) in nasty woods. Still, scrapers -- hand or plane -- can be a PITA, I'll give you. But I am not so sure that the obsession with perfect smooth planing is really about results; it is more about the challenge. There is a fair bit of smoothing ******y, where we find the toughest piece of wood we can and try to plane it. This isn't *really* about smoothing, it is about the challenge. Mind you, it can be very satisfying.

I dislike sanding with a deep and abiding hatred, so I am always keen to smooth or scrape (but sometimes still give in...)

 

[Big John]

Decided to go with the BU smoother after a play with it yesterday. The only downside is I can't use it yet
Got some nice new socks to put my growing number of essential pieces of equipment in whilst I was there !!!
Thanks to Martin Brown who managed to make my wife go pale when he told her how sensible it was to buy all four planes.
Thanks to all for your advice.

 

[Lord Nibbo]

You gotta post a pic, or it never happened... :lol: