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flatsawn stuff is going to crack more readily thatn QS stuff.....

Finally...are we really saying that well seasoned wood moves significantly less with RH changes?

Hello, i am really sorry for you, it is always bad to see wood cracking, having problems with already finished work and so on, BUT, i would like to leave a few comments, opinions:

1. Mun Ebony is pretty new to the tone-wood market, isn´t it? I would say it is sold now for 3 or4 years, not much longer, via Allied or LMI or others. This means to me, you bought a set not so long ago, and built with it. This is nothing i would do or recommend. A flatsawn set like this, if i would buy it, I would at least have it stored and "aged" for not less then 10 years, to see how it behaves, moves, cracks. In the mean time i would use other, OLD wood. But buying from a tonewoodseller, even if he swears by god that it is old, and use it more or less immediatelly is nothing I would even think about.

2. Of course I explain my customers how to store and treat a guitar I built. But my goal is that my guitars don´t crack, never. So I use old wood and built in the range of 35-40 %, not higher. Here in Europe winters are strong long and cold, so we often have central heated rooms. Humihity often drops belwo 30%, and then the wood shrinks, arches drop in a bit, but the backs don´t crack.

3. "Making the guitar wet" again and then hoping that the crack closes and then glue it, is in my opinion a mistake. Because what will happen if the guitar comes into a dry environment agin? Just the same game starts again. The wood shrinks and it wil crack, just on a differnet place of the back. It is just the fact that the guitar-back has lots of tension still inside, and this will let its stress off somewhere, it has to.

4. I would go just the other way around. Put the guitar in a really dry environment, for a few weeks, and then close all the cracks, re-laquer the back, and then call her done. For closing the cracks i would perhaps use a really hard drying epoxy, like UHU endfest 300, mixed with sanding dust. Of course you will see these cracks, but they won´t open up again.

5. I know it is not..?...nice...?..... to buy a nice piece of wood, and then you have to say to yourself: Ok, in 10 years i will use it, but I think this is just a big and important part of guitar building. Patience.

6. I dont think ziricote or Mun ebony or other wood deserve to be called "Crackwood". I just think it went the other way round: Ziricote appeard on the market and everybody used it immediatelly without having it really well seasoned. Just to measure to moisture content, and then say: "Ok it is down to 8 %, lets built" just doesn´t work. It has to be:"ok, it has been down to 8% and went through 10 winters and summers, now we can start having a closer look at it."
So lots of people didnt wait long enough, so lots of problems occured, and then these woods got a bad reputation. But if you season the wood long enough, I think it will be as stable as any other high-density-dark-wood.

Wishing you the best, Alex

One other thing: gradual, and yet sustained, decreases in RH cause less damage than sharp drops.

A second point: seasoning is the process of drying wood - it ends once the timber is at usable MC; aging is something else entirely. We should not confuse these terms.

Just to be a little clearer, I see no evidence that wood movement due to change in RH decreases significantly over time in any given piece of timber . What is apparent is that vendors and folks that process their own wood end up tossing a certain percentage of loss due to warpage, splits, and other defects which become apparent over time, therefore suggesting that holding the wood for a time is of interest. I believe there are benefits from that practice (fewer returned sets; etc.), but they are related to 'culling the herd' versus some sort of reduction in wood movement.

A second point: seasoning is the process of drying wood - it ends once the timber is at usable MC; aging is something else entirely. We should not confuse these terms.

Todd I have cut and dried a lot of ebonies. One in particular comes to mind. It was some gorgeous Black and White ebony that was curly to boot. During the drying process the sets shrank close to a 1/4" in width. Are you saying that over time and changes in RH this wood would expand that 1/4" . I see no evidence of that. The sets that survived were just fine with no cracking.

I have bought wood from Bob at RC Tonewoods on a number of occasions and I will keep going back simply because Bob knows his stuff and delivers great wood. It still goes in a press with the rest to season out though

I am not saying that this 'must' be done, or that one should never build with wood straight from the vendor. Rather it is what 'I' do as a matter of course. To my mind wood is a natural product which has countless variations from one board to the next, even within the very same species. It is only fair to say that regardless of how good a tonewood vendor is, some responsibility must lay with the instrument builder to account for those variations.

I feel that storing wood as I do reduces the margins of variability..Think about good cheese and good red wine. Quality examples of each will improve with time....but you rarely buy them from a vendor at their best, you must cellar them correctly yourself to reap the rewards of time. I see 'good' tonewood in the same light, it 'must', be good to start with to be worthy of the time, but it will improve if it is stored correctly.

P.S. It has some relevance that I live in Western Australia.......I have never seen snow on the ground here. I have never seen anyone in WA wearing ear muffs to keep warm. When I was a kid, on hot summer days I would sometimes dig molten tar from the road side to use as mastic for sealing the ends of my galvanized iron canoe. On my way to the lake on my push bike with my canoe in tow, I would see flat crispy frogs laying on the road. These were the road kill from the previous night now dry enough to be used as gross frizzbies to throw at your mates....and its only 10am.....it gets quite warm in WA.

Cheers

Kim

During the drying process the wood shrinks the most through it's life. After that the shrinkage is minimal compared to it. But wood becomes more stable from the ageing process which can take quite a long time depending on the type of wood. Some woods age faster than others. Exotic woods such as ebony and ziricote take a long time compared to domestic lumber and reacts differently with the speed at which it is dried and can crack if dried to fast by cutting thin when green.

Look up "Sorption Hysteresis", it shows what Kim is talking about
Wood which has been cycled up and down in moisture content or just dried down to a low moisture content, returns to a lower EMC for a particular RH than wood which has just been dried down to that EMC from green
And that had implications for movement in service.