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Ernest Martel

Ernest Martel's Bench

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The method I use for measuring speed of sound was first discussed in this thread. Thanks for the offer to send wood to test, but I think you can do this yourself if interested.

As for why some wood has strong late growth, I can only guess that the winter conditions might be good for growth... not too cold that growth shuts down, and maybe good sun and rain as well.  But I don't know.

I don't think that the hard growth is a structural problem, but perhaps (but not necessarily) an acoustic difference.  Although I have encountered it enough times to become convinced that wide winter growth tends to have lower speed of sound, the one set that I have with the highest speed of sound (6500 m/s) has very strong winter growth lines.  I would expect high density and low speed of sound to primarily hurt the high frequencies.  But again, I don't have enough real experience to say for sure, just a few examples.

Torrefying tends to darken wood, so the denser winter growth (which is dark because of the high percentage of wood vs. air) tends to get very dark, or visually "harder".  Wood that starts out with a relatively low speed of sound generally tends to improve more, percentage-wise, than wood that starts out with a higher speed of sound, but it still doesn't "catch up" to the good stuff.

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9 hours ago, Don Noon said:

As for why some wood has strong late growth, I can only guess that the winter conditions might be good for growth... not too cold that growth shuts down, and maybe good sun and rain as well.  But I don't know.

The dark wood is not winter growth but late summer/autumn and the light is spring/early summer fast rate growth.

Too wide late growth can be sign of reaction wood. (compression on conifers)

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On 1/19/2020 at 9:06 PM, Ernest Martel said:

To be honest Don, I don't know the method of how to check for sos.  So, at least you are familiar with this type of wood. It is noticeably different from anything I've come across so far. I can send you a billet if you would like to investigate the properties. What is the reason for such hard late grain?  Is there any weather or growing properties that would contribute to very hard winter grain?

I don't know how old the wood is or how long it was sitting in Merrill's shop. I bought it after his death and his relatives didn't know anything about it, only that they called it German spruce. I'm guessing that the hard grain would increase the density but do you think this would contribute any negative effects structurally?

Do you find the winter grain lines harder after torrefication compared to non torrefied wood?

 

For inter-annual variation of late growth density, higher temperatures with lower precipitation at the beginning (August/September for Picea?) of the late growth period are positively correlated in the literature.  However, if all your late growth is unusually dense you would have to speculate if specific growing conditions (micro-climate) and genetics favored dense late growth.

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2 hours ago, Jim Bress said:

For inter-annual variation of late growth density, higher temperatures with lower precipitation at the beginning (August/September for Picea?) of the late growth period are positively correlated in the literature.  However, if all your late growth is unusually dense you would have to speculate if specific growing conditions (micro-climate) and genetics favored dense late growth.

Interesting...one section of the wedge was noticeably harder and could be felt when gouging across grain and cutting the f-holes.

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On 1/22/2020 at 1:51 AM, HoGo said:

The dark wood is not winter growth but late summer/autumn and the light is spring/early summer fast rate growth.

Too wide late growth can be sign of reaction wood. (compression on conifers)

Thanks HoGo. The late grain isn't abnormally wide but is definitely harder than normal, mostly in an outer section of the wedge. 

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Well, I'll use a few different things to seal the sycamore. I did a sample today and I think it will be the method I'll use.

First thing applied to the raw wood is an aloe ferox tincture in alcohol. Since this is the sap from the Cape Aloe plant, besides coloring it lightly sizes the wood. I brush the first coat on and let it dry.  It will dry lighter just like aniline dye. Then brush a generous second coat on and let that dry completely. Then I apply a 1:1 oil varnish, let it sit on a few minutes and then wipe off with cheesecloth dampened with turpentine. This will seal in the color but not completely seal the wood. This is much the same as Joe Robson's (wipe on, wipe off) ground application method. After this is dry you can brush on a very thin coat of something refractive, like dewaxed shellac, spirit or copal varnish, all the time trying not to seal the wood all in one shot. This allows you to continue to build in more color until the wood is completely sealed and ready for stronger colored varnish.

When applying the aloe to the spruce I will apply first a very light sizing of gelatine (maybe 1-2%) just enough to ensure an even appearance.

Here is the sample I did today. It has two coats of aloe and one coat of varnish, rubbed in and off. The wood is not sealed yet so I can continue to build color into the wood if I want. I like how the aloe turns the sycamore from pink to yellow.

863598016_aloesample.jpg.7033577a8a11834e3f3ac86455ccea00.jpg

 

 

 

 

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Great thanks! That is beautiful color. I have a couple sets for cello that I want to try my hand at. Unfortunately mine is two toned. 
 

Jesse

BC7F6DEF-EC70-4C13-BF38-85AAF1006596.jpeg

Edited by JPherson
Added pic

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Cool! You should be able to darken the lighter side to match with some aniline dye and/or sodium nitrite. Sycamore is definitely a nice wood to work with. Bending cello ribs should be a breeze. The violin ribs bent like buttah on the iron...;)

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19 hours ago, JPherson said:

How would you advise or recommend using sodium nitrite? I have never used it before. 
thanks!

I like to use 3% SN mixed with water, warmed in a water bath, then sponged on. Place in the sun or UV chamber 6-8 hours.

Old Wood Varnish have some good video's on how to apply a protein size and then their A part of their ground system. I 've used this product and it behaves very much like nitrite so follow the application technique shown on the video. 

You can use a protein sealer (gelatine) before applying the SN or skip it. I've done it both ways it really depends on the wood. Test samples of course are the best way to tell. One added note worth mentioning that I ran across. When using on Englemann spruce you should suntan the fresh wood for a few days before applying the SN. It has a tendency to give the wood a pinkish hue. 

https://www.youtube.com/watch?v=mEU_9_s-R6s&list=PL9FDAD2ABA98E53E9&index=1

https://www.youtube.com/watch?v=rA3lCUldgDI&list=PL9FDAD2ABA98E53E9&index=2

Another great product I use when necessary is Color FX aniline dyes. I think you could match your sycamore really well with the the wood tone kit. The small kit will last a long time and you only need a few drops in water or alcohol.

http://www.woodessence.com/ColorFX-Dye-Wood-Tone-Kits-P48C12.aspx

A great video showing how to apply the Color FX amber dye.

https://www.youtube.com/watch?v=q1n_g6PA_c0

 

 

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Sweet! Thanks again. Looks like a lot of studying and testing in my future lol

camt wait to try to either bleach it or darken it. Or both 

 

Jesse

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