Howdy Martyn,
Sometimes I get so long winded I don't want to read my own message <g>.
If I suggested "soaked in oil" then I misspoke. I concur as to the
possible damping effect on the wood.
Interesting that good old Strad would be highlighting the grain, so
many think of him as pure music. I think I'd have done it too, nothing
wrong with making the instrument beautiful to the eye as well as the
ear.
Wood is a relatively unique beastie, it is plant life so has cells that
need to absorb moisture but it is also solid and hard. Grasses and
other forms of plant life will shrivel and die when cut but wood lives
on. Wood is "green", in a sense, forever - unless it rots away or
petrifies. If it is kiln dried the moisture is taken out of it and the
cells contract, the wood becomes stable. Wood that isn't kiln dried
dries out and stabilizes gradually, but never completely. In fact I've
been turning a bowl from mahogany that was kiln dried for the past few
days. I've been busy so it has been sitting on the lathe unfinished. It
has warped, and I've had to "re-round" it even though it was supposed
to be dry.
There are two basic grain structures in the wood (actually three, but I
can never remember the third). The longitudinal (up the trunk, or along
the brand, and parallel to the pith) is the most open. If I cut a log
and strip the bark I have to coat the ends with a "breathing" sealant,
else it will split at the ends as the moisture goes out. That may seem
logical, and it is, but the point is breathable. If I coat the ends
with a solid sealant then the moisture will leak out in the radial
direction and I'll get a different form of cracks.
Oil treatments are not meant to substitute entirely for the water, but
are meant to inhibit the fast transfer of liquid so as to give the wood
time to adjust to the new climate. I remember a guitar I bought in
Spain when I was in the Navy, a locally made guitar from a moist region
that was untreated. I brought it home to NJ and in one of our dry
spells (yes, NJ isn't always wet) the thing split apart. Wood becomes
brittle when dried out, unless it is done with a careful process. I
doubt that Stradivari used kiln drying, he probably used his skills to
ensure the wood neither dried out quickly nor soaked up moisture
quickly. If the change isn't rapid the wood adjusts.
There is an argument in the harp community, my main instrument these
days, about laminated versus "solid" sound boards. It is a false
argument as the "solid" soundboards aren't solid. Unlike the lute and
the violin the soundboard of the harp must resist the direct pull of
the strings, and it adds up to about 800 to 1200 lbs. on mid sized
harps. The only way to do this is to have the long grain cross the
harp, and for a 4 foot long soundboard that would require a 4 foot wide
log, not very practical. So the solid soundboards are actually sections
with back braces to hold them together. The fine laminates are actually
better (not plywood, 7 to 9 level laminates with no voids).
I digressed, the object of a finish on lute, guitar, violin, etc. is to
preserve the characteristics of the the wood at the time the instrument
was made - be it seasoned for 1 year or 20 years. That involves a
finish that is both breathing and sealing - in balance. Which are the
best is above my pay grade, I'm only listing the criteria.
Best, Jon
On 1/24/2015 9:46 AM, Martyn Hodgson wrote:
Dear Jon,
No problem whatsoever.
The Stradivari business is that there is evidence (first researched in
the middle of the last century by Michelman 1946 and still relevant)
that Strad (and some other contemporary makers) applied linseed oil to
the bare wood - but before varnishing. From what I recall this was not
so much to preserve and protect the bare wood (the varnish did that)
but to highlight the grain and figuring. Not being a fiddle maker I
never took this line further. Linseed oil was, of course, very common
and readily avaiable in early times (widely used amongst other things
for paints).
Stand Oil, as I suggested, plays a different role to Strad's (and
others) use of the oil. Stand Oil is v viscous and forms a hard coating
itself on the surface of the wood. I wouldn't say it is brittle even
when fully oxidised and I have never seen or experienced cracking etc
of the sort you are concerned about.
I suspect being soaked in oil (linseed or any other) as you uggest is
not at all the same thing and I'd personally be reluctant to do this -
for fear of perhaps producing a damping effect in the wood.
I know nothing of working green wood.
MH
From: Jon Murphy [1]<j...@murphsays.com>
To: Martyn Hodgson [2]<hodgsonmar...@yahoo.co.uk>; Paul Daverman
[3]<daverman.p...@sbcglobal.net>; [4]"lute-builder@cs.dartmouth.edu"
[5]<lute-builder@cs.dartmouth.edu>
Sent: Saturday, 24 January 2015, 13:35
Subject: Re: [LUTE-BUILDER] Re: Lute top finish/treatment
Dear Martyn,
My comment on the Stand Oil was from your most recent email on the
topic , if I misunderstood it I apologize. I may not be able to access
your earlier posts as I'm not active on the list, and emptied my
computer about a year ago. I now save everything as I have a new
system. I am interested in the links to the Strad techniques.
I tried to confess lack of direct knowledge on the finishing of the
lute top, but being a normal pontificator (Murph Says) I tried to offer
thoughts. I look to be corrected, I like to learn. I have a good
knowledge of the use of finish on woods as I am a wood turner who makes
pieces from both seasoned and green wood, and hollow forms with walls
of about 1/16. But these skills don't carry over to the musical
instruments. the only commercial product I use is WaterLox, a
combination of tung oil, some resins, and mineral spirits. It is a
water-proofing designed in the early 20th C. for boats and piers - but
not a hard sealant. Where we might disagree is the matter of coating
versus a finish that soaks into the wood. For my work I prefer the
soaking in rather than the coating, I think of the wood as wanting to
remain in contact with the changes in moisture around it, but with a
bit of a slow barrier to change. A hard coat, in general, can be
cracked and invaded - and that can cause a differential moisture
absorption or release.
I'd like to look at the Strad links, although some current research
attributes the sound of the Strads and Amatis more to the tight grain
wood they had available in the Little Ice Age than the finishes they
applied. That is open to argument, and probably is a combination of
both.
One more point. When I turn a bowl or other piece from "green wood",
and by green wood I mean any wood not cut and kiln baked. I have turned
pieces from wood cut and dried for three years and it is still living.
Oops, broke the sentence. When, etc., the wood will warp as I turn it.
It is a pain and a joy, one has to finish the turning quickly then wait
to see what final shape it takes. No finish will stop the warping, and
the chosen finish will enhance it. Hope to hear back on your thoughts.
Best, Jon
On 1/24/2015 7:23 AM, Martyn Hodgson wrote:
Dear Jon,
This isn't really right. If you look at the earlier communications (in
the archives of this list) you'll see I specifically cautioned against
the use of modern commercial Stand Oil which, as you say, is generally
heat treated Linseed oil and doesn't seem to ever harden off after
application.
Stand oil was originally simply Linseed Oil which was partly oxidised
(thus becoming more viscous) by being allowed to stand in dishes. You
can easily do this yourself - it takes a few months to get to the
required consistency.
The point is that it doesn't sink into the wood particularly but leaves
a thin surface coating which, being already partly oxidised, soon
hardens ( a few days) into and invisible coating resistant to moisture
and the like. But plse look at previous postings on the matter and on
links to Strad's methods.
MH
__________________________________________________________________
From: Jon Murphy [6]<j...@murphsays.com>
To: Paul Daverman [7]<daverman.p...@sbcglobal.net>;
[8]lute-builder@cs.dartmouth.edu
Sent: Saturday, 24 January 2015, 11:49
Subject: [LUTE-BUILDER] Re: Lute top finish/treatment
I haven't worked with lutes for a long time, and should probably drop
off the list - but I like reminiscing <g>). I'll venture an answer, I
do
work still work with harps. Wood is never dead until it petrifies, it
always takes in or gives off moisture depending on the environment
(humidity and temperature). If you don't treat it at all it will be
more
susceptible to the changes in atmospheric conditions, but if you seal
it
then it can't "breathe". I wasn't familiar with the Stand Oil that
Martyn mentions, but just Googled it and see it is a pure linseed oil
heat treated. That fits my criteria. You mention a beeswax concoction,
I
am familiar with them from my wood turnings as I make several
"concoctions" for different purposes. The beeswax concoctions at the
simplest are a mixture of pure beeswax and generic mineral oil - but
could be mixed with a vegetable oil (like linseed or tung). The tung
adds color, the linseed doesn't.
Your purpose in treating your sound board (the lute top) is to maintain
its flexibility and sound production. The lute, like the guitar and
violin (each to a greater or lesser extent) produces its sound in
combination with the enclosed body of the instrument. The function of
the sound board is somewhat modified by the nature of the transmission
of string vibrations through a bridge over which the several strings
are
in contact with the sound board. That sounds gratuitious, but the harp
that I deal with is quite different. The sound transmission of the harp
is almost entirely from the vibrating strings in air, the function of
the sound board (top), which is under tension from each string, is to
pass the sympathetic vibrations from one string to another by direct
vibration. The bridged instruments, like the lute, separate the sounds
and produce the fullness in the body and top by combining them there.
I could put a sealing finish on a harp sound board (athough I wouldn't,
it would reduce the sound a bit), but not on a bridged instrument. The
sealant stiffens the soundboard and it is a part of the sound in a
bridged instrument.
I think you should treat the sound board (the lute top) on both sides.
I
wouldn't use a varnish, it soaks in but hardens. I certainly wouldn't
use a shellac as it is a surface coat and stops the breathing (although
I do use a home made shellac compound with mineral oil for some
pieces).
You want something that allows the "living" wood fibers to absorb or
give off the moisture, but not too fast. If you use a pure oil, like
the
Stand Oil, you would want to refresh it now and then..
Here is a pure speculation, and I leave it open to suggestions. A
gentle
sealant like one of the beeswax (or other wax/oil) concoctions for the
underside of the sound board and a pure oil for the topside. Inhibit
the
drying of the internal wood cells through the internal body, but don't
block it. Once the instrument is built you can't change the finish on
the inside. Use an oil on the topside, and reuse it.
Best, Jon
On 1/23/2015 6:59 PM, Paul Daverman wrote:
> I am wondering if some of the builders would be gracious enough to
> weigh in on their treatment of the lute top. Some say absolutely
> nothing should be put on the top. Others say varnish. I believe
> Lundberg had given a recipe for a bee's wax concoction. I'm
curious if
> there is a consensus or standard.
>
>
> Thanks,
>
>
> Paul
>
> --
>
>
> To get on or off this list see list information at
> [9]http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html
--
References
1. mailto:j...@murphsays.com
2. mailto:hodgsonmar...@yahoo.co.uk
3. mailto:daverman.p...@sbcglobal.net
4. mailto:lute-builder@cs.dartmouth.edu
5. mailto:lute-builder@cs.dartmouth.edu
6. mailto:j...@murphsays.com
7. mailto:daverman.p...@sbcglobal.net
8. mailto:lute-builder@cs.dartmouth.edu
9. http://www.cs.dartmouth.edu/%7Ewbc/lute-admin/index.html
