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Colin ,what wood was used on the back and sides ? I know this is off the point,but it`s so darned pretty.
James

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James W Bolan
Nashville Tennessee

James that is Madagascan Rosewood. I bought a lot from Madinter some years ago (just got another load from them) that was less than $100 a set.

Colin

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I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

That fast drying oil formula starts looking kind of like what Waterlox is...a long oil varnish with alkyd and phenolic resins with tung oil and driers. Note also the references to how moisture resistant tung oil is. That's a constant theme on the Waterlox site. How about egg white, shellac, varnish, and then a light topping of FP? That should be one of the ultimate small shop finishes for those without a spray booth.

Wow! All this talk about egg whites used to prep the top for finishing got my attention.... It seems like a wonderfully organic approach, but I just have to ask. Is there no possibility of bacteria growth and thus an objectionable odor arising over time? I am sure that I am speaking from ignorance and inexperience, but I am sure there must be some kitchen science that applies to what happens to the wood once these proteins bond with it.... also, has anybody used something like "egg beaters" commercially available egg whites in a carton for this procedure?

Thanks!

Don

Have you ever tried to remove dried egg white from a car? First of all, it does not smell, once dried. Second, it is really, really hard to get off. Third of all, it will etch the finish of the car. It is powerful stuff. It has been used as the only finish on many early instruments.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

No Waddy, I've not tried to remove egg from a car.

But it sounds like you have some stories to tell in the OT threads.

Which side of the experience ladder are you speaking from... The victim or the perpetrator cleaning up his prank?



(sorry, couldn't resist)

Welcome to the OLF Don!

I think most here would favor the genuine article in terms of eggs, real eggs, from a steroid encrusted, antibiotic fed cloned chicken.......

One way to use egg whites is as 'glair'. You beat the whites up, let them set for a while, and drain off the liquid from the bottom. That's the glair. I guess it's the lower molecular weight protiens.

As long as egg products can dry quickly they will cure up on exposure to air into a tough film that is surprisingly non-reactive. Traditional tempra painting relies on egg yolks as the binder, and the old books tell you to get the eggs from town chickens, as there will be less color to them. Even then there's probably too much for use on light woods.

Lots of protiens have been used as binders over the ages: iirc, some of the 14,000 year old cave paintings used urine. I'll wager you haven't seen any guitars that old, so there's no question about durability. In this case, though, I'd bet the smell would be an issue.

I was told about one fellow who wanted to make his own varnish by cooking resin and oil together. He figured that olive oil would be something they'd have used in Italy, so he tried it. The varnish never dried; it just turned rancid, and it proved impossible to get the smell out of the wood. He should have used egg whites.

Thanks! I figured that real eggs would be the preferred, but laziness and lack of kitchen expertise prompted me to ask the question. I am still a ways out from puting the finish on my first guitar, but is the one aspect above all others which feels the most intimidating, though perhaps I will feel otherwise when I tackle the seting of the neck angle. At any rate, this is the forum which seems to have the greatest breadth of experience combined with the willingness to share, so I truly appreciate the resource and hope that I can enventually contribute something worthy of the tradition embraced herein.

This is hilarious! "...14,000 year old cave paintings used urine. I'll wager you haven't seen any guitars that old, so there's no question about durability. In this case, though, I'd bet the smell would be an issue."

Urine will extend the open time for hot hide glue (no, I haven't and won't try it), and urine and sunlight were the combination used by Southern Italian ladies of leisure to bleach their hair way back in the day... They must have also had a lot of perfume...

Maybe they kept themselves well hydrated, and didn't drink a lot of beer.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Except for the egg white, I heard about this same finish being used by Lynn Dudenbostel from the DIY network series that featured him.

http://www.diynetwork.com/diy/hb_musica ... 62,00.html

However, I think he sprays the shellac for the sealer coat. He does not go into the details of the varnish though. The implication by him from the series is that this is how Martin used to do their guitars, but I'm not sure. Anybody know what type of varnish he uses for that?

Thanks Colin for posting the picture of your oil finished guitar - it looks great!.

I haven't seen this program, but I'm pretty sure he didn't say that. I bet he said that is how Gibson finished their Loar period instruments, including the F5 mandolin. Lynn Dudenbostel is a great mandolin maker (yes, I know he also makes guitars...), and the FP over varnish finish is favored by many of the best arch top mandolin makers today.

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Rian Gitar og Mandolin

[quote="Arnt
I haven't seen this program, but I'm pretty sure he didn't say that.


No he didn't actually say it. However, the premise behind the show was how he is trying to make his guitars just like the pre-war martins. When referring to his procedures (not finishing specifically) he says he is very traditionally based and does things the way they used to because he thinks those methods work best.

So I'm not sure if his finishing is like the old martins and that's why I used the word "implied". I am sure someone out there knows for sure.

[quote="Alan Carruth"] Frankly, I find that to be a bit too much. Oil varnish has the added bonus of having a refractive index that is much closer to that of wood, so it looks 'deeper' than most other finishes. quote]

Wood has a refractive index??

This is a very intersting conversation. Thanks!!!

Mike

All mater other than a black hole has both reflective and refractive properties if you can see it, it reflects and refracts light at some ratio above zero.

Can some one explain this "French Polish over varnish" thing? Doesn't this violate the "fat over lean" rule, i.e. the shellac is less flexible than the varnish underneath and will crack, etc.

Thanks!

/Rob

I believe you have that backward but neither will crack unless exposed to harsh environmental abuse. French polished Shellac is near if not the least dampening finish you apply. I am not sure where you got the Idea that shellac is prone to cracking but I can assure it is not under proper and normal environmental conditions.

Wood??? Yes it has a reflective property, but the refractive value is nil (it does not transmit).

Thus, one cannot not match refractive properties of wood and finish. Sorry, but it does not make sense to me.

Mike (who believes in being educated and corrected)

Refraction has nothing to do with transmitting light. Refraction the alteration of light as it passes from one media to another, i..e. from air to water, from a finish media to wood, from wood to air. Granted the wood must be thin enough for the light at a given power to pass through it, but tops we work with are thin enough to allow pretty light at a fairly low candel power through it.

I know picky picky

Cellulose has a refractive index, and is transparent in bulk. Wood only looks opaque because it's porous (just like a snow bank, which is made out of transparent ice) and many kinds of wood have pigments that add color. If your finish matches the refractive index of cellulose then the light will not be reflected from the first finish/wood interface, but will penetrate the structure of the wood for a little way, and then reflect from the next wood/air boundary. Even a 'pretty good' match helps; that's why wetting wood makes it look 'deeper'.

A bit of trivia: the refactive index of a material depends on the dielectric constant.

Shellac is harder than many oil/resin varnishes (and softer than many others), but putting shellac over varnish does not usually cause problems. This is because shellac is much tougher and more flexible than most resins. You can get into trouble putting nitro over shellac, though.

This IS interesting. Can this be used to prevent rosewood from leeching into the middle piece on a back? Here, I am referring to the sanding stage.

What about cornstarch in water? Guessing the water part would be the issue...

Mike

Weeeelll. Still having trouble with the thought. Woods refractive index would have to be very high (if it makes any sense at all). I still think there is something else at play with the surface interaction of water on the wood. But, if you have a source on the Inet to point to, I would appreciate it!

I don't recall referring to water on wood (I still want a scratching head emoticon) but none the less; Refraction is the bending or alteration of light as it passes from one medium to another. Dictionary, encyclopedia and like Al said wood is not a pure solid the cells do refract light. It is also a diffuser so at a given density it will defuse enough to stop a given amount of light from being visible on the other side. The amount refraction and diffusion being subject to both density of the wood and intensity of light.

Look at it this way you can put a lamp inside a guitar and view the braces. If it did not refract light, If it was purely opaque, this would not be possible. Now you’re going to say but you can’t see the braces on the back. Well you can, if your light source is intense enough. But with that much intensity come heat that just might create an issue.

I do agree that the wood would (???) transmit light. But in a different manner due to the porous nature of wood. Take a large bunch of flat black marbles and shine a beam at the bunch. Some of the light will leak through the other side by virtue of clear path and diffuse reflection (mostly that). But the light will not refract. Maybe its a "diffraction" effect as well!

Same with wood. I am sure I am not making this point well. I thought refraction had more to do with the crystaline properties (dielectric). Yes, fluids and gases refract as well.

Perhaps the surface effect (enhancement) when water is applied has more to do with multi-reflection paths induced by the surface water.

Google "refractive index for wood" and "refractive index for glass" and compare the hits. Perhaps its just a linguistics thing...

Mike