turning green cherry

Clark O'Neill

Member
Messages
177
Location
Decatur, Illinois
this is the second time i've had a problem with wet cherry cracking. the first time i had rough turned a hollow form and soaked in alcohol then left it dry on a rack, and forgot it overnight. i attributed the cracking to leaving it exposed too long after the alcohol flashed off. some replies to that incident on this forum said maybe the rough turning was too thick (10% of the diameter)...and i remember bill grumbine saying that he turns wet wood all the way to the final thickness in one session and doesn't have much problem with cracking.

so today i turned the outside of another green piece into a H.F. shape and started hollowing out the interior. when i'm about to the midpoint i stopped to change tools or something and noticed several cracks starting on the outside!! the upper half was turned to about 1/4" so i was going for the final thickness and intending to bypass the alcohol soak and paper bag routine. in other words i can't turn this piece fast enough to keep it from cracking???i do admit to being a novice in woodturning and not hogging out the inside as quickly as i could as i've had some pretty fantastic catches trying that. but this all happend in one session of maybe 90 minutes.

i haven't had this problem with any other woods. i bought both of these pieces online from the same seller but it's not clear to me what that would have to do with anything.

i'm thinking i may have to seal the outside while i hollow out the inside so the entire piece can dry as one.

does anyone else have any experience like this? is it peculiar to cherry??
DSC01286.JPG
you can't see the crack in this pic but it is top dead center and in the part of the H.F. that is still solid.
 
Clark, I turned a lot of cherry, and most of this wood cracked.
For sure it crack when you turn it wet. Fruit wood is always tricky wood.
The best is to seal both ends, and put it in your woodstore for a long long time.
 
Clark,

I'm very new at turning, but the few times I've turned cherry I've had it crack. I also experienced the "on the lathe" cracking that you did. When mine did it, I was part way thru' a bowl, stopped the lathe to change speeds and during the minute that I was changing belt sheaves I heard a sound like cracking from the bowl. I spun it by hand to check and sure enough it had cracked just sitting there - very frustrating!!

cheers - better luck to you

(and to me also - I have a spalted cherry crotch waiting for me right now)
 
well, i've thought a bit more as i continued working on this piece today. btw, i coated the outside with shellac sealer before i continued on the inside.

i know from dvd's that you're supposed to control the drying process on a bowl or H.F. from the inside out. in other words, seal the outside with something after you rough turn it and leave the mouth open so the inside can dry first. this is supposed to induce compressive stresses in the piece as the inside dries..and prevent cracking. these two cherry pieces dried so quickly with the inside still solid but the outside exposed from fresh turning that the recommended process was reversed and, indeed, the outside started cracking. i guess that makes sense but it's not clear to me how to avoid it. i've never seen anyone hollow out the inside first on any training dvd's or pdf's.

i guess just be quicker and seal the outside immediately before starting the hollowing?
 
Fruit woods are especially difficult to turn wet or green. But an alcohol soak will more than likely solve the checking problem. I don't like wet turning but have done it and have used Alcohol to cure the problem. Fruit woods don't seem to follow the norm, but Alcohol seems to calm them down, (not unlike the way it calms me down). Try turning to within 10% of size, soak overnight in Alcohol and wrap in brown paper bags for a couple of weeks till it stabilizes and then finish turning. Problem solved. The practice of turning and storing in wet chips does not seem to work with Fruit woods.
 
Clark when I turn a HF I turn it to finial size green or not. If I do get a crack I put some thin CA in the crack from end to end going past each end a ways. I then will sand enough to fill the crack and reapply thin CA. This will control the crack that has started. If it is a little on the wide side I will mix some 5 minute epoxy, get me some sanding dust from the piece or instant coffee and mix it in then fill the crack. This works rather well. HF's I don't soak in DNA as I said I take them from start to finish to about 3/8" and no more than 1/4" thick walls. As soon as it is done I soak it immediately in Minwax Antique Oil. I really slop the finish on to soak till it won't soak any more then let it stand for 10 minutes or so making sure you have no dry spots. I wipe off the excess after 10 minutes or so. If you make sure both surfaces are soaked and the finish is standing on the outside I haven't had a problem with cracking at all if it hasn't cracked on the lathe. I guess you could use Danish oil and do the same thing but this has been what has worked for me with fruit woods of cherry, walnut and apple.
 
My experience with fruitwoods including cherry has not been pleasant. That stuff cracks while I putting it between centers to rough it. But it's the prettiest wood!
 
Clark - I have had the same problem with cherry multiple times and it is frustrating! I read on a forum somewhere that the fix is to keep the outside wet/damp while you are turning so it doesn't have a chance to crack. Whoever it was suggested using water in a spray bottle and just misting the HF every so often until you have finished hollowing it. You plan on soaking it in DNA afterward so the little bit of water that didn't evaporate while hollowing will be taken care of then. Hope that helps.
 
Cherry is well known for cracking and warping. I have just been given some which I will cut into goblet length logs, do as Ad suggests, seal both ends and store for a long time with fingers crossed.

Pete
 
So far I've only turned one cherry hollow form. It was green wood, but it didn't crack on me. (I did the usual DNA soak and dry method.) The one cherry bowl I've turned was done with kiln dried wood. It reinforced my dislike for turning dried wood. ;)
 
well i've somehow missed the story on cherry in the past and thank all those who answered. that's one of the best things about this forum..sharing information. the verdict seems pretty clear...cracking in green cherry is diffiicult to control.

i have several more pieces i bought online to work on in the future. i was trying the bill grumbine approach on that last piece which is to turn it to the final wall thickness while wet. if i try that again i will either follow the advice to spray with water while turning the outside, or immediately seal it before starting on the inside.

one of the conclusions i've reached about turning wood is to not waste time on pieces of wood that don't have any beauty (in my eyes). that's sometimes hard to determine before turning but i've started hand planing the four sides of pieces to get a good look at the wood. that also helps in determining top from bottom as the character of the wood is exposed. for what that's worth...
 
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