So I take out my Sweetheart Pro to have a couple tunes and there are four splits from the bell up one reaches past the last tone hole. 
It was residing in the pocket of my jacket, it is a mystery how it cracked as I am either wearing my jacket or it is hung up. Of course I have emailed Ralph, but am posting this as a sort of warning. Dymondwood can break, if you plan on geting something in Dymondwood and caring it around with you, make sure you get a hard case.
Make that five cracks there is one that runs from the 6th to 5th hole.
Iâve mentioned this before, but Iâll say it again, Dymondwood is actually more susceptible to breakage, in some cases, than many natural woods. Iâm not suggesting that itâs an inapropriate or poor material for instruments, however itâs not as strong as some tend to believe - it certainly wonât survive the same sort of abuse polymer instruments can take, nor can it even withstand some of the maximum stresses that many of the tougher natural woods can handle.
If you have a dymond wood instrument and you want it to last, treat it like youâd treat any ânormalâ fine wooden instrument, and you shouldnât have any problems. This includes the suggestion not to carry them in your pocket without the instrument being in a hard case 
Loren
When mine was new, the headpiece cracked in the first week. Ralph was very good about it, and replaced it without question. He stated at the time that heâd had a bad batch of Dymondwood that was more prone to cracking. Itâs been fine since, but Iâm pretty gentle with it.
Unfortunately this has been an issue with this type of laminate wood for over 20 years. Back when I managed a musical instrument store in the mid to late 80âs, we carried Dymond wood drum sticks, which were far more prone to breakage than your standard hickory or oak drumsticks. I also played drumset at the time, so I found this out through my own experience, in addition to that of my customers, who all agreed that while the stuff looked cool (dymondwood, or whatever they were calling it at the time), it didnât hold up so well to the pounding of the given application.
We got the company excuse about âbad batchesâ on more than one occasion, and eventually, we stopped carrying the sticks, because it seemed like they either had lots of production issues resulting in too many âbad batchesâ, or they simply werenât being honest with us. I have no way of knowing which was the case. Honestly, after 20 years, Iâd have expected them to have perfected the processâŚ
Loren
Dude, you must be near as old as me.. 
Philo
Got an email from Ralph who tells me they have not been getting good Dymondwood lately. He said they will be changing their building process. He is also sending me a new foot joint. 
I was pretty worried, this was my favorite session whistle.
Iâd better be more careful. Mine goes with me just about everywhere. (In a soft case)
Agreed. Dymondwoodâs advantage is in itâs being resistant to moisture, not any additional strength. Then, thereâs the wild and crazy color advantage, if you are interested in thatâŚ
Yeah, man, Iâm verging on Geezerhood 
Loren
Agreed, the stuff should be impervious to changes in humidity, short of dropping it in the ocean for an extended period.
I do wonder what, if any, effect rapid or extreme changes in temperature have on this material though - like the cold/heat cycles experienced by an instrument during winter time going from a below freezing cold car or backpack, to being played in a very warm room in short span of time, or vice versa? One imagines that the adhesive material chosen would be able to deal with these changes, however, this Dymondwood stuff wasnât designed specifically for this application.
Paul, has the company provided you with any specs with regards to temperature ranges etc., for the material? I read somewhere that Dymondwood is likely to suffer breakage if drilled below 40 degrees F, which leads me to believe that the resins used may become significantly brittle at cold temps.
Loren
Hmmm, that brings the question of what application was Dymondwood originally made for?
Oh poo. I really wanted on of those. Maybe heâll start making them out of mopane. I have a mopane flute that has really stood up well to less than perfect care.
I suspect it wasnât designed for a specific application, but rather it was designed to be more âMarketableâ product than the components would be until combined, if you see what I meanâŚ
Itâs used a lot for pen turning blanks, knife handles, small turned objects, and so on - applications where stresses to the wood are very low, in general.
Loren
I donât think anyone is suggesting that whistles made from Dymondwood arenât worth buying, just treat them with reasonable care. Paul and the Sweets are all stand-up folks, as theyâve proven many times over, and in the unlikely event youâd have a problem, theyâd no doubt take care you.
Loren
Thank you Loren.
Boy, that is terribleâŚI think a lot of people expect it to hold up better than wood.
Loren, what Ralph told me is that the Dymondwood they have been getting is not as impervious to moisture as it should be. Now as you and the rest of us Northeasterners have noticed, the temp and humidity have gone done significantly since last Friday. The whistle being transported in and outside because it was in my jacket could have âshockedâ the material and thus formed cracking. Plus, last Friday I was in MA and I am now back in NJ. Yes, Paul and the Sweets are still worth buying instruments from as both will go to the ends of the Earth so to speak to fix a customers problem and will usually do it for free. That makes me wonder how Sweetheart stays in business as I have met another person with Dymondwood that had this happen and Crookedtune has had the same thing happen. Both had the parts replaced at no charge and now me.
Jessie, that is kind of my reason for posting this, a warning. As much as one may respect Loren and Paul, there is more to be said when one has first hand experience.
Well, there you go, it should be stronger than it is as well, so I guess we shouldnât be surprised.
Now as you and the rest of us Northeasterners have noticed, the temp and humidity have gone done significantly since last Friday. The whistle being transported in and outside because it was in my jacket could have âshockedâ the material and thus formed cracking. Plus, last Friday I was in MA and I am now back in NJ.
Iâd highly suspect temperature to be the culprit, as humidity changes normally take days, weeks, or even months to cause damage. OTH, nearly instant cracking due to temperature changes is not uncommon at all - my flute instructorâs Olwell cracked in the unlined left hand section one night after leaving a gig and walking out into the cold with it (in a flute roll.) Itâs a shame you didnât have that whistle in a case, that way damage due to impact and/or pressure could reasonably be ruled out.
Yes, Paul and the Sweets are still worth buying instruments from as both will go to the ends of the Earth so to speak to fix a customers problem and will usually do it for free. That makes me wonder how Sweetheart stays in business as I have met another person with Dymondwood that had this happen and Crookedtune has had the same thing happen. Both had the parts replaced at no charge and now me.
Well, thatâs the chance a maker takes when using a material not yet proven reliable for a given applicationâŚ
Jessie, that is kind of my reason for posting this, a warning. As much as one may respect Loren and Paul, there is more to be said when one has first hand experience.
Well, as I said, I do have first hand experience with the stuff, and Iâd personally never use it for instrument making - did I come across as sounding like Iâm a fan of Dymondwood? I didnât mean to. OTH, Iâm not ready to condemn those who choose to use it for their whistles, as long as they stand behind the product.
I do think itâs important for end users like yourself to share experiences both good and not so positive, with regards to instruments and materials, and I have no doubt this thread has served the purpose you intended. I do hope that folks see both sides of the issue however and realize that without more facts, itâs not possible to know exactly what the cause of the damage to your whistle, or others, is. Iâm not a fan of Dymondwood, but Iâm also not a fan of wooden instruments carried around without hard cases, nor am I a fan of wooden instruments being taken rapidly through temperature and humidity extremes - as all have been known to cause cracking or other types of damage. In the case of the whistles in question, perhaps the materials are to blame, perhaps the owners are to blame, or more likely, perhaps both share some responsibility, along with the makers even, who might need to be more clear about the care needed for whistles made from this material. No offense to anyone.
Loren
Hi folks! I was going to leave this to Walt and others on the makerâs side, but wanted to get my two cents in.
The Dymondwood has been a bit of a headache recently. I have an early one that has been through some pretty rough treatment and withstood it through a few years. I have a âretreadâ that like Averyâs instrument came up suddenly with multiple cracks, and since being repaired it has held itself together happily.
But there have been too many failures, and the upshot is Sweetheart Flute Co went with a new vendor for the laminate material. This laminate is made under much more rigorous conditions, and happily we had no failures during the turning and boring of the most recent whistle batch.
Of course any problems will be resolved! Lorenâs skepticism about the Dymondwood material is not unwarranted. But the new material is used in some pretty harsh situations and Iâm putting my faith in it.
Amy (Tyg)