I think painted tamas can take longer to egg out, since the paint will effectively seal the moisture into the tama, so it releases slower. When wood is alive, the moisture content is higher, once it is cut and milled, it will slowly dry to about 6-12% depending on species and local climate. It can take years for wood to fully dry, it depends on the species and the thickness of the lumber. For example, some of the ebony I have was dried for 8+ years before I bought it, to ensure it's very stable. If wood isn't properly 'seasoned' (dried), then it will warp and change shape over time. Generally, 2 years per inch of board is the basic timeframe, so I could see a freshly cut and painted tama slowly egging out over the course of a year or two. The honous falls on the factory/producerto ensure the starting material is quality. Cheaper wood is often cheaper because the drying process was sped up or skipped, so if you check out the really low quality toy damas carefully, you'll see a lot of eggy tamas (and cups). At a certain point you can't make the process much faster / cheaper, so if you want to cut costs you can produce damas out of cheaper cuts of wood. Beyond drying, wood can still change shape over time just based on local climate. The moisture content of the wood will change with the local humidity. Different wood species will expand different amounts, and in some applications this is very important (think: furniture. You don't want to use two different species to make a big desk, and then have one species expand a lot more than the other and warp your desk out!). Maple and walnut have very similar expansion coefficients, which is part of the reason you will often see the two paired together, in kendamas and other wood products.
Lucky that your enjyu is solid, the one I have is mega egged! Ha. While some species are more stable than others, any species is susceptible, it's just a matter of how well the wood was dried ahead of time.
Slightly eggy KUSA Kaizen 2.0 in the middle. Think this might be the first off tama I've ever got from them. Still slays, and has the good silk paint, as I've found the silk to be inconsistent between wood types and different damas.
I have a couple eggy tamas and I really don't mind them. For me, if I just play the kendamas and they start to kind of "adapt" to my style and I end up not noticing them being eggy. It feels like it the kendama changes shape as I play more, shifting to my style. I personally like when a kendama has some imperfections. It gives it character.
What exactly causes a tama to become eggy? Is it improper storage, too much moisture, a bad cut of wood? Anyone got any good answers to this one? And is there anything you can do to reverse or correct an egged out tama?
I've had my fair share of eggy tamas before and they all happen to be from damas that are mass manufactured overseas, which makes sense cause technically there's less quality control compared to like in-house CNC work that RWB/GT/Sweets (HG line) does. I wish there was a solution to make an eggy tama perfectly spherical, few of the ones I have I really like aesthetically lol
2 of my eggy-est tamas were also from mass manufactured brands, both were maple stripes too. One was a maple walnut stripe from Lion Head and the other was this beautiful maple ebony stripe from Ali Express. Ended up gifting them away after they became shelf pieces. Another one currently in my collection is my homegrown tama actually. Another maple stripe (larch wood stripe with cushion clear). Still slays, just not very happy with the wobbly lighthouses and lunars. I believe @htimSxelA stated in another post about how climate changes and other environmental factors can affect a tama making it eggy, whether it’s being stored somewhere or just sitting on your shelf or rack.
There are two main reasons: 1) Local climate. Wood changes shape as it absorbs/releases water from the air, and a little bit with temperature as well. A tama that was round somewhere humid might be a little bit off if it is shipped to a very dry place. Even summer/winter variations can be noticeable if you get really intense. 2) Using wood that isn't fully dry. When a tree is alive, it'll have a very high moisture content. Once felled, the wood should be milled down to size, and then dried until it reaches equilibrium with its environment (~6-12% moisture by volume iirc). There are a number of ways to dry wood, but the most widely used technique is just sealing the endgrain, and then leaving it somewhere that has a relatively stable environment for a few years (I think ~2 years per inch of wood is the benchmark used for a lot of species). If you turn the wood into a sphere before it has reached equilibrium ("is dry"), then it will keep losing moisture after being turned, and will likely not end up very round. Good, stable wood is more expensive that freshly felled lumber, which may help explain why some tamas egg out (production looking to save money). So if you have something a little bit off, that may just be due to local environment, nothing you can really do about it. But if something is waay off, the starting material used was probably not legit. Related: I've had people message me with links to big chunks of ebony being sold online for great prices. "If I buy this big chunk of ebony for $20, can you turn it into a ken for me?!" What they don't know, is that piece of ebony was probably fresh cut within the year, and ebony takes a LONG time to dry. So yea, you can save some money buying this cheap piece online, but your kendama is gonna be eggy and full of tiny stress cracks, which is not good at all. My source for ebony buys the wood, and then lets it dry for 8+ years before selling it. Thats one factor that contributes to the price of the wood!
I think it kind of depends on if the wood has a lot of areas where air can get in and out like ash or hickory. Not sure if it affects the drying time or not, but my guess is that the rough, open grain allows ash and hickory to dry a bit quicker than other woods. Not that I've tried it or anything.
Possibly, like I posted above most of my egged tamas are mostly made of maple wood. The only other one that is (slightly) egged is my Mugen Musou Glacier Turquoise tama (cherry wood). Saw on the KUSA site reviews on it that at least one other person had the same happen to them so it most likely happened to it somewhere between going into storage and it getting shipped out (to KUSA and/or to customers). Haven't had this issue at all (as far as I could tell from just playing) with ash wood or the one hickory tama I have.
@lategreat808 Merged similar topics so everyone could see the previous replies. Also moving to The Lumber Yard since it's kind of wood techy.
Hmm yea I think @James Hoang has got it correct: tightgrained & non porous woods will probably take the longest. You also want the wood to dry evenly, which is why you sometimes seal the wood in wax, even though that slows the drying rate down. If unsealed, the wood close to the exterior of the board dries more quickly than the interior, and shrinks as it dries. This will cause cracks and fissures to form, since it is restricted from shrinking evenly by the still wet interior. Sometimes you only wax the endgrain, sometimes all of it. Depends on the wood species and cut of lumber I guess
Many, many years ago I went to a Weyerhaeuser processing plant and they had giant oven-like devices that dried/cured plywood. I wonder if there's something like that for regular wood too.