Eucalyptus: Crack or Warp - Place your bets

[Brian Kent]

The bowl on the left is an hour old. The one on the right is a week old. The cracked one in the trash is also a week old.

This is Red Gum Eucalyptus, fresh cut a week ago. The bowl on the left will either crack or warp in the next couple of days. This is the brand of eucalyptus that was brought to San Diego to make railroad ties. They twisted so much they could not be used for railroad ties.

It's free, pretty, fun, and practice. I hope it just warps ;).

[Roger Chandler]

good practice........at least it looks good for now!

[Dan Hintz]

The one on the right looks a lot closer to the pith... so I would expect the one on the left to warp a bit less, and I vote for some small splits showing up.

[Fred Belknap]

+ on what Dan said

[Faust M. Ruggiero]

Brian,
At some point you should think about beginning to make a stock of rough turned bowls. I know you like instant gratification but once turned bowls need to be kind of thin and will almost warp. Now, there is nothing wrong with that but sooner or later you will want to finish some dry bowls. Besides, turning rough outs is a hoot. You can do several in a night and stand knee deep in the curls.
If you prefer once turned bowls, you should buy some foam backed sand paper and wet sand to 320 as soon as you finish turn. That gives you the opportunity to sand on the lathe before the bowl goes out of round. Then bag the bowl for a couple weeks and that will help minimize the cracking. Obviously, you still need to avoid turning the pith to have any chance of drying crack free.
faust

[Greg Just]

It very nice looking wood. I'm guessing it will warp. Have you tried rough turning it, letting it dry and then finishing it?

[Chip Sutherland]

If this is just practice, I hope you have a lot of this wood. It's very pretty and worthy of being finished bowls without cracking and warping...unless warping is part of your finished design.

[Prashun Patel]

I would put the bowl in doubled paper grocery bags. Close it up and leave it for a couple weeks. Open the bag every few days just to make sure there's no mold forming. If yes, leave it out for a day and change the bag. The 'microclimate' of the bag will minimize cracking and or warping.

Alternatively, if like me you have bags full of shavings, stick the bowl in there for a couple weeks. Just don't throw the baby out with the bath water.

If you see tiny cracks develop thru the week, drip some CA glue in the crack; that can stymie them A LITTLE!!!

[Bernie Weishapl]

I agree with Dan. Good looking bowls and wood.

[Steve Friedman]

Brian,

Have you tried to turn one with the bark side up? Just wondering what would happen if the movement went in the other direction. I am not a turner, but do make hand hewn bowls and agree with the suggestion of doing it in stages and trying to control the rate of water evaporation if you want to keep any of these. I am not familiar with that wood, but if the one-week old bowl looked like the fresh one, that's an amazing amount of movement and shrinkage in 7 days. Did you get drenched turning it?

Steve

[Rodney Walker]

Both bowls look nice to me. I hope they only warp and don't crack.
I've heard of boiling wood to help stabilize it. Would that help on these?
Rodney

[Brian Kent]

Steve,
Yes - drenched like riding a bicycle in the rain.
Yes, I did one with the bark side out. It was so wet and stringy that the bark tended to shred instead of cut. It wasn't actually the part right under the bark because eucalyptus bark is about an inch thick that just lifts off like a loose-fitting hat.

Lots of people,
Yes, it is time to try the rough cut, 1/10 of diameter thickness, placed in a bag, placed in a cool spot, and/or placed in the shavings. My confidence in this particular wood is low, so I was waiting to try this with green wood of a more stable variety.

[charlie knighton]

Brain, nice bowls

you might get a 55 gal cardboard drum, make some blanks up from freshly cut woods, leave about 4 months then turn, this works for oak, it may still warp with bowls but if blank did not crack the bowl will not crack, works well with hf as the form inhibits warpage....just something to look for or you can buy a cardboard drum over internet

[Dennis Ford]

I think it will just warp but would be more confident if it was wrapped in brown paper for a couple of weeks.

[Brian Kent]

One of the most important steps for me - long term - is that this is the first time I have gone to a tree service and asked for free wood.

I am hoping to get into a relationship with a couple of local tree services to get green wood (mostly not eucalyptus!). I am not jumping into this too fast because it would be helpful to get a chainsaw before I get too much wood. Also, the space in our Honda CRV is pretty small. The next vehicle will probably be a small truck.

So I am taking small steps from "experimenting" to actually "doin' it".

[Harry Robinette]

Brain
I like the one on the left. I'm with Dan too, closer the pith more the crack.

[robert baccus]

This is like jumping out of an airplane---lots of maybe-probably solutions but the slow but sure way is to wax the whole thing. And then there's instant gratification.

[Kathy Marshall]

My bet is a fair amount of warping although a few small cracks wouldn't surprise me. Some of the first green woods I started turning with were Eucs. There are several different varieties here and some will warp and crack alot more than others. I find that Euc turns really nice when it's green, not so much when it's dry. It get's pretty hard, dusty and chippy.
I would embrace the warpage, turn green and thin and just let it go wild.
Here's a link to a "football bowl" I turned early on http://www.sawmillcreek.org/showthread.php?152113-Eucalyptus-and-Soap-Test&highlight=football+bowl which shows just how much movement you can get in a short amount of time.

[Brian Kent]

Thank you for that link, Kathy. Is the bowl still in one oblong piece?

[Kathy Marshall]

As far as I know it is. One of my sisters latched onto it when they saw it, so I haven't seen it in awhile. I filled the large cracks with gold metallic flakes and I think she liked the glitter factor.

[Brian Kent]

The glitter is a great idea Kathy.

Here is a piece I just worked on, live edge, sanded to 320, light coat of oil, and bagged in 2 layers of paper bag. Had to try something since you folks have given me about a half dozen suggestions.

Again, eucalyptus.

[Steve Friedman]

Brian,

I love that last one you did. Worth trying to make it a keeper. I was taught to seal in a plastic garbage bag and open the bag for a couple of hours every day, but I am sure you turners have more sophisticated ways of controlling the rate of evaporation.

Steve

[John Beaver]

Per the original question. If its thin enough and consistent wall thickness I say warp. If its thicker through the curve the I guess crack. I've played with a fair amount of euc. and the red gum can hold pretty well if turned properly.

[Reed Gray]

I am a fan of the 'one and done' bowl turning, and the more it warps, the more I like it. I turn to 1/4 to 1/2 inch max, make sure to round over the rims, wrap the rims in stretch plastic film (about 1 inch on the inside, and the rest on the outside. Go around a couple of times and make sure to stretch it out putting some compression on the rim. Down on the garage floor, which is cooler and higher humidity, for a day or three, then up on a wire rack. Dry in 10 to 14 days. I prefer to let them dry before sanding. I do power sand, on the lathe. I have a 3 phase Robust, and got it reprogrammed so it will go down to the 10 to 15 rpm without turning off. Any faster than that, and you can't keep any abrasive on the wood. You would want at least 2 spindle locking positions on your headstock spindle, and 4 is better. You can force dry them, boil, microwave, or wet sand them, but to me that is extra work, and I would rather turn than spend that extra time and effort doing some thing that the wood will do all by itself with no effort from me.

robo hippy