Stringman, I recently made a couple of crepemyrtle bows - one hollow-limbed shorty and one typical ALB. I'd been curious about the wood for some time, and could only find a few examples of crepemyrtle bows online (until a month or so ago, when a lovely example of one showed up here in the message boards). As luck would have it, the tree in front of my house had a trunk splitting and trying to die, so I felled it and got a cpl of useable staves. I will say to begin with, that there are two different crepemyrtle species out there and I can only speak for the one I used, which is the pure bone-white wood –NOT that wood that has the cross-grained figuring like tiger maple. Best I can tell, from observing every single crepemyrtle tree in my neighborhood here in S.E. Texas, the white-blooming trees all show a dark brick-red inner bark, when their skin-like outer bark sheds each year, and I believe they are the ones with tiger-striped grain. The trees with ALL the other color blossoms (pastel pink, pink, magenta, lavender, hot pink, hot red) appear to reveal more skin-tone-like colored inner bark, from pale beige, to tan and even olive green; and that is the type I got my wood from. And that wood is bone white, with hard to distinguish anular rings that are full of paper thin "lunar rings". When you sand through them, they look like the thin sap rings on the back of a yew bow.
This wood is extremely elastic in tension, but a bit weak in compression, which means it benefits immensely from a heavy heat-treating of the belly. I don't mean a light temper, I mean a heavy toasting, from long, slow, repeated heatgun work. In fact, this wood seems to just laugh-off any attempts to heat-correct or temper; dry or steam. So don't bet on straightening out a severe twist, or dogleg lateral bends, or drastic kinks of deflex or reflex. Make sure that regardless of wonkiness, your string tracks pretty close to center. The amount of dry heatgun work I did on those 2 bows would have completely destroyed an Osage stave! I cooked them with the heatgun repeatedly and got areas that needed correction 3 times as hot, for 3 times as long, just to get minimal results. That wood just does not move when heated, like other woods do. I finally had to narrow the handle width, down to barely an inch wide, and steamed it for an hour, then forced it to bend, clamped it down and then continued to heat it with the heatgun several times, to barely get the string alignment right. And even after all that dry heat, it never once checked or cracked or burned.
As far as designs go, the ALB pattern works well, keeping the inner limb width parallel to at least midlimb, to prevent any set in the inner/mid limbs, and keep the limbs fairly wide - I think mine were 1 5/8" wide out to midlimb, then a long taper to the tips. The hollow-limbed shorty I made from the more highly-crowned stave seemed a bit sluggish–I suspect because this wood is so elastic that it doesn't fight the bend and store much energy, but still a fun little bow. Whatever design you try, I'd trap the back edges pretty well, unless it's already a highly crowned back, and keep the belly flat & square to avoid set. I personally want to try an ELB from this wood some day. It is lighter and less dense than Osage, but similar in that it's tough yet elastic. It dents way easier than most bow woods, especially before it's really dry, cured & tempered. Knots & pins (on Crepemyrtle the pins are lenticels, and there are many) don't seem to cause any problems on the backs, but when I tried to make a stickbow from one of the 1" thick canopy shoots of the tree, those same lenticels–running sideways from heart to edge–were exposed on the belly during tillering and compression failed instantly. A clean break across the belly –and STILL the highly elastic back did not fail with it.
This wood needs to be dry! It will seem dry and even reach equilibrium indoors in the AC, but still ooze a watery sap, when heat treated. Strip the soft bark and cambium off within a day of felling, while it peels easily and seal the cut end grain multiple times with glue. The only drying issue I saw was on a piece of drop that didn't get sealed ends, where it checked immediately and those end checks quickly ran into longitudinal cracks, and that piece basically split itself apart. But after that initial drying of the juicy green wood has passed, it's a non-issue. You can tell if there's even a hint of moisture left in a stave when filing or rasping, it gets real furry and fibrous looking. On the other side of the coin, I don't recommend leaving an un-peeled, unworked stave lying around for years to dry, because it gets unworkably hard. Wood that is left dead-standing, on the stump, will get dry & hard and crack open. The wood does contain some tannins, and responded well to "Ebonizing" with the vinegar & steel wool solution. The white wood, that when dry looks like sun bleached bone or antler, turned a faded charcoal gray with the treatment. I gently buffed off the high spots to give an aged, well-worn look. Looks like I made bow from some old gray barn wood.
All that said, I think it makes a good bow, with a good design & tempered belly. Perfectly good, hard-hitting, hunting weight bow, but does not seem to have the snappy cast of Osage. You can rough it in to the same basic dim's as an Osage bow, but leave the belly a hint thicker. The wood is less dense and the limbs will finish a bit thicker, for any given draw weight. Get the roughed-in, mostly-dry bow bending evenly (it will show some set), then go ahead and heat the belly some, with it clamped-down how you want it. Get each limb good and warm, then go back & forth, repeating a few times, slowly warming & drying. You'll prolly see some juice exude from end grain, where rings on the belly taper down. It will turn brown in the heat. Let it cool and then keep it dry till you next work on it. Plan to do that a few times.
I know that was long-winded, but when I made mine, I couldn't find ANY good info on the wood–especially the white wood species; on this site or anywhere else, so I figured I'd go ahead and share everything I learned building my two Crepemyrtle bows. BTW, this white Crepemyrtle makes lovely, strong, tough tools, batons for chiseling & tool handles. I made a primitive arrow shaft straightener and also a beautiful handle for my new farrier's rasp, from a length of 1" dia. canopy shoot, that looks just like it's made from bone or antler. I also made a few primitive arrows from the thinner canopy shoots (don't try and cold-bend any kinks out of those shoots though, cause they will get little cracks through any of those lenticels).
Hope this answers some Q's.
–John
