Christopher Tidy on Fri, 14 Aug 2020
09:47:03 -0700 (PDT) typed in rec.crafts.metalworking the following:
Am Freitag, 14. August 2020 15:57:53 UTC+2 schrieb pyotr filipivich:
Christopher Tidy on Wed, 12 Aug 2020
16:30:09 -0700 (PDT) typed in rec.crafts.metalworking the following:
I've been thinking about this topic for a week or two, and I was curious, so I submerged a block of softwood (pine, I think, but perhaps fir) in a tank of writing ink for 8 days.

Today I split the block of wood open with a chisel to see how far the ink had penetrated into the wood. Something like 3 to 6 millimetres parallel to the grain, but only a fraction of a millimetre perpendicular to the grain. The ink also soaks much deeper into the dark rings (summer growth, perhaps - does anyone know?) where the wood is more porous.

Here are some eye-candy pictures of my experiment for the wood fans to enjoy...

http://sphinx.mythic-beasts.com/~cdt...aked_Wood1.jpg
http://sphinx.mythic-beasts.com/~cdt...aked_Wood2.jpg
http://sphinx.mythic-beasts.com/~cdt...aked_Wood3.jpg
http://sphinx.mythic-beasts.com/~cdt...aked_Wood4.jpg

Thanks for the stories!

Chris

Cool. Now, what's your conditions?

I placed the block (cube with a 60 mm side length) in a sandwich box filled with ink for 16 days. The block was held under the surface using a small chunk of foam. I turned the block over every four days, so it had four days with each end-grain surface at the bottom, and four days with each of two opposing cross-grain surfaces at the bottom.

If I remember correctly (I don't have the paper in front of me), the moisture content was 13% before the experiment. Afterwards it was off the scale, as you might expect, and the wood had absorbed about 25 grams of ink. It took about a week until the weight returned to its original value (about 85 grams) and the remaining dye didn't seem to affect this figure.

I'm planning to repeat the experiment (probably with water rather than ink), but coat some surfaces of the blocks with two-component epoxy paint, to determine the proportions of the water absorbed through the end-grain and cross-grain surfaces. I might also try the same with some blocks of okan instead of pine, but I suspect this will absorb very little water.

It looks to me that there is very little cross grain absorption.
Which is to be expected, trees move water 'vertically' with the grain.
Hence the reason for painting the end of an exposed 'stick' to prevent
checking, etc.
--
pyotr filipivich
"With Age comes Wisdom. Although far too often, Age travels alone."