Thread: What machine causes this texture ?

Possibly "sand-blasting" with crushed walnut shell abrasive.

Originally Posted by apricotripper

Wondering how they do it.

http://www.greenable.net/Products/15...tml&hierarchy=

Anybody seen it done ?

I haven't. I'm guessing, maybe, they wet the timber to soften it and have a large diameter roller with irregular like shapes in to push that look into it… ?

hi Jake

It looks very much like a Jin di sugi finish which originated in Japan.

Fine Woodworking has a little bit about it here http://www.finewoodworking.com/how-t...the-grain.aspx (unfortunately it's behind the pay wall)
while the maker in the FWW article uses a wire wheel in an angle grinder, it can also be done by grit blasting with a suitably soft grit -- nut shells is one option


for the technique to work you need a timber where the early wood is distinctly softer than the late wood -- I think that's normal for trees with distinct growth rings
the effect is achieved by abrading the softer wood to leave the harder wood as ripples

I'll also guess that the wood is a conifer. Typically, conifers have an abrupt finish to each growth ring. Useful examples from up here would be the pines and Douglas-fir (Pseudotsuga menziesii.) Spruce, true Firs (Abies sp.) and Hemlock would be second choices.

Crushed walnut shell has all but replaced sand in sand-blasting. Engine cleaning with sand has been too brittle with iron silicates, not to mention the health hazards.

I am required to have real winter tires. On my 454cid GMC 4X4 Suburban, I run Cooper Discovery winter tires with crushed walnut shell in the rubber as a traction compound
as opposed to the old-fashioned tungsten carbide studs.

thanks for your responses.

I know what you mean on removing the earlywood, which leaves the latewood. I thought too that maybe that was how it was done. I quite like wire brushing oregon where its quite distinct. Know too of just wetting the timber and scraping it, which pulls the earlywood out.

But, I thought something is going on differently here, because when I looked closely at the picture, the high points aren't all the darker yellow late wood I'm used to… ??? I see some dark yellow lines in the valleys. So thought it was the result of some kind of press.

I don't know. maybe that can happen with a conifer. ???? I've never used it before.

Looks like it has been textured with a wire wheel to me.

+ 1 for a wire wheel, by my faulty logic any other method would leave sharply defined profiles in the texture.

Having done some paint stripping with a wire wheel, this is the effect that you get.

I'd be more likely to bet that it's done on something like this:
http://www.youtube.com/watch?v=ydUOXr-cd4s

Being recycled attic flooring & with the knot patterns it appears to be plain sawn - hence the absence of growth rings & early / late wood.

My bet is, the finish is achieved with abrasive nylon brush wheels with the nylon bristles radially orientated. Perhaps blasted with walnut shell but I will go with the radial nylon wheels..

Perhaps a powered wire brush of some sort or being flailed then sand blasted. Not a look I would be after however as the look of the wood gets lost.
Regards.
John

Originally Posted by Master Splinter

I'd be more likely to bet that it's done on something like this:
http://www.youtube.com/watch?v=ydUOXr-cd4s

Thats exactly what I was picturing. If there was more of the texture to see I'd guess it be provable by seeing a repeating pattern (every revolution of the wheel pressing thingy)

Just feel the texture has that gradual pressed look. wire brush I think wouldn't be as smooth. Don't know about blasting it with walnut shells, but feel its not something aggressive at least.

Having cleaned a wooden launching ramp or two, I'm guessing that you could achieve a very similar effect with the use of a high pressure water hose like a Gerni.
It leaves a much smoother finish than media blasting on wood.
The finish can be adjusted with choice of nozzle, angle and distance from the wood.

Any wire brush treatment would do no more or less than any sand-blasting treatment with crushed nut shell. Crude, but wire brushing would work. The surface should appear quite ugly with the shredded wood fiber. Try that, do the experiment.

The entire lack of the abrupt coloring of the late wood suggests that they have some other trick for the texture.

Originally Posted by Robson Valley

The entire lack of the abrupt coloring of the late wood suggests that they have some other trick for the texture.

I agree.

thats why I'm thinking its a pressing action. eg. softening the wood (heat and/or moisture) and then pressing an irregular pattern on it slowly.

I relate with that, from my steam bending experience… especially when I don't pad a clamp properly with softwood… When the clamp comes off there's a big ding in the timber.

also, uno how they pressed patterns on chair crests in de old days.

Also, I'd guess, someone in charge of organising a factory process that lead to this result, would prefer a clean machine that involved simply putting the timber on a conveyer belt of sorts, and out the other side is the completed result…..rather than something involving some messy process involving blasting substance everywhere……big enough pressing machine that any repeat of pattern isn't noticed so it keeps in form with that natural look.

thats just a guess though.

but I would like to see walnut blasting in action, and the finish it leaves on wood.

Try a wire wheel & see.

I have used it on several pieces of my work.

Take care, you can burn the edges.

I have made carved fruit bowls out of slices of gum burl & wire wheeled it to make it look like leather.

I found that I get a better result by sanding the surface after turning or carving it & BEFORE wire wheeling it.