Not a musing but a wondering

splits/cracks

Kevin, for cracks it depends on how big the crack is. If it is real big I see two choices: 1) designate it as firewood or 2) leave it cracked and call it a design feature. (Remember, if it won't hold soup, it is art!)

Now for smaller cracks you can fill them with something. Sawdust is OK. I've used coffee grounds that I crushed into a finer powder. Others us brass shavings. And there are some commercial products. I think Inlace is one of them. And of course drizzle it with CA as you suggested.

I turn mostly green wood and if I leave it over-night or longer I paint it with PVA sealer. It works for me. When you get back to it again all takes is a thin skim and you are back to where you left it. To do this it is necessry to leave it over size and then go for the finish in one session.

It also works if you are roughing the piece and putting it away to season.

Good luck.

BillR

I just turned a few green Maple bowls & they're cracking badly at the heart wood. I'm trying (not sure if it will work) to fix them by putting a wet paper towel over the crack & keeping that moist to let the rest of the bowl catch up. I have microwaved them some, but don't like to do it too much or that leads to other cracks. The bowls are decorative & the dark heart shouldn't show a small crack sealed with CA. Anyone ever had any luck doing this?

Jim

=======>You are treading on dangerous territory and stand the risk of rousing the COC's ire for trespassing on the Muse's prerogatives! However, I expect we can accept a "wondering" inquiry without too much fear of Music ire. As to the green wood problem, I am a proponent of the LDD method and, as a result, suffer greatly for my stalwart defense of it. You might want to try it if you are strong enough to withstand the slings and arrows of less progressive turners. Prophets in their lands . . . etc! As to cracks, you can claim them as artistic expressions in the piece, or your can pack them with colored material available for such a purpose, pour molten metal into them, stitch them together, rivet them, further widen them and call them handholds and ultimately, you can just pitch it into the firewood pile and try all over with a new piece of wood.

Best of Luck, Leif

If you look at how the wood shrinks as it dries, you'll find that the heart is under the most stress. Radial shrinkage pulls the sides down, tangential pulls them in, and focus for both seems to be right there. It's also about the weakest point in the wood, since it's the oldest, took a lot of abuse whipping around before it grew enough support, and so forth. Don't use it, and don't expect any puny CA glue to hold it against cracking. You might get away with it once, but the next ten times....

Now, considering that as the sides withdraw, and this area will remain above to be trimmed later to get a smooth rim, you can push things a bit, going within a half inch of the pith, looking at the piece daily during the first week of drying, and carving away any incipient cracking. Remember, it would have been above the rim anyway, and stopping the beginning stops the continuation. You're safe on hard maple for 1/4" of trim on a 10" bowl.

will getyou to a marvelous publication, with chapter 3 showing you in pictures andwords how wood warps, explaining the difference between bound and unboundwater, and why only the first affects warping. Armed with this information,you can make some informed decisions about where and how to turn and storeyour green wood. There are many people who believe you can dry things bysoaks, boiling, or sacrificing a virgin - a method seldom used now due tothe difficulty of finding one - at midnight on the fifth Thursday of themonth. Though they may begin elsewhere, all end up the same place, tryingto control the bound moisture loss from the surface of the piece to a pacewhich will allow steady replacement from the interior. This is done bycontrolling relative humidity. I have a basement, so I just set them nearthe floor, tossing a newsprint tent over them in the dead of dry winter.Drier climates demand more stringent control.Then there's the truth that brownheart in maple has so many cracks in itthat it's best trimmed away. As long as the heart is the more familiarblue-gray, you're good. When full brown and tobacco-smelling, it's a foolserrand chasing the cracks.

Kevin, I don't think that I've ever cut through a log that didn't have some radial cracking in the center. I used to try to cut exactly down the pith trying to line up the grain for centering in the bowl and the cracks. Now, on most logs I will usually cut a 1 to 4 inch section out of the center, to remove the pith and radial cracks. I lost a number of bowls to cracks that I thought I had turned out but didn't quite get them all out. The center section can still yield some nice bowls (more of the personal size kind) and the quarter sawn pattern is nice.

I am also rethinking the use of CA glue. I was visiting Mike Mahoney's web site and saw his guarentee. It is life time because all of his bowls are free of defects. I have always wondered how long the CA glue will hold. Sometimes, the time spent repairing a cracked bowl isn't worth it. For the art pieces I think it would be safer, but for the use and abuse pieces, which are 75% of my sales, I am refraining form using the glue a lot more.

robo hippy

Thanks, George, but darn. Full brown heart it is. I'm not really sure where the stresses in this piece are. The end of log picture in the FPL's book is a good one, but this piece is the base of a branch coming out of a big, old trunk. The grain is going all over. Several different grain patterns in the bowl. I probably should have cut the piece smaller.

Jim

Crotch figure. Remember, all warp is local, just like politics. Visualize the branch as it intersects the trunk, consider how it will warp, and figure it's going to distort the underlying accordingly.

The stress is actually compression under the branch, tension above. This is unpredictable to a degree, as you might guess from the curl. I leave it a bit fat, and dry slow. Worst part is that it tends to, for lack of a better description, flake up on either side of the branch insertion.

Bring 'er down slow after you've cleared as much brown as possible. Worst case is you wasted some floor space on a piece of firewood. That's the way it is with crotch figure. Do everything right, and a bark pocket runs wrong, making a split platter. Do everything wrong, and you blunder onto the one that shows full feathers.

Main thing is to do.

Well, it looks like I got everything balanced pretty well with the way the grain ran around, but I have that knot right in the bottom. I filled it with clear epoxy, which didn't come out as clear as I would have liked, but looks OK. The knot had a pretty even split in it with

3 legs. I ground them out a bit with a roto tool bit, so they still look pretty natural but a bit neater. Anyway, I'm trying to clean it up now & that didn't go well this morning. Kept tearing the bottom grain. I hadn't planned on rechucking it, so it's tough to get a good grip on. (I typically like to turn them green & then dry them letting any warping stay.) Anyway, it hasn't been a waste of time. I've learned a lot. Never had a piece of Maple cut like this or this wet before. Live & learn & turn, turn, turn.... As you say, George. Just do.

Unfortunately, I had to take a break to put up a fence for the horses who are trying to play with a pony on the other side & keep hurting themselves. (Half ton animals that make chickens look smart. )

Do you ever dye a filler? Ever put a dye in epoxy? I thought about it, but didn't have any on hand. Never done it anyway. Do they make special dyes for epoxy?

Jim

=============== Jim, There are several wAys you can color epoxy. Brass filings work well, as does crushed stone like turquoise. I've used artist's acrylic paints (a couple of drops in a spoonful of epoxy) and got good results. Too much of the paint will weaken the epoxy. I have heard of others using aniline dyes, but I have no experience myself. Other fillings include coffe, charcoal, sawdust, etc., anything that will give you the color you want. YMMY

Ken Moon Webberville, TX

I haven't been working much outside, as it's been snowing off and on up here, so I turned some waterlogged yellow birch pieces yesterday. They were down at least a half dozen years, so there were a lot of cracks revealed in the process. With the extent of spalt, most should remain as is rather than open as the pieces finally dry.

I take chunks of bark, run through a burr mill and bottle 'em. Runs from cherry which is almost black to birch underbark, which is yellow, down to aspen which is near white. Coffee is a bit oily, so it's not my first choice, and with sawdust you get that dead fish eye look, so I pack with grindings and glue to close to my final surface, scattering the last on top where it adheres without absorbing much. That allows a wider latitude in finishes.

Check the plumbing part of your home center for colored epoxy. I like the copper-colored stuff with cherry and birch, but they have black as well.

Thank you, Ken.

Thanks, George. Spring has sprung here, so I really should be doing more outside - fresh asparagus last night from our bed.

I have a clear epoxy that I buy in gallon jugs & mix up a bit at a time, since it comes with 1oz pumps. It's made for clear table tops & I've used it on bowls with good success. It's excellent for filling in voids in a Maple burl & making a usable bowl out of it or holding it together if there is a big chunk of bark in it. I may try some of the dyes or paint that Ken mentioned. Typically, I prefer the natural look, but that cracked knot might have looked good with something more striking in it. I'll look for the plumbing epoxy too. That might have been better in this application anyway. The clear stuff can be kind of finicky.

That bowl never did turn out. I think it was doomed from the get go. I'd touch it with a chisel, go along fine & suddenly get a catch. Get that 99% of the way out & get another. Did that until the bottom was too thin. Oh well, there's more wood where that came from.

Jim

Some are, but I know I still try to sneak around some known fault for the sake of some particularly nice figure. It's the one in ten that makes it - spectacularly - that keeps us trying.

28 April 2005 03:14 pm:

What about those issues such as:

I have two bowls at present that were deliberately turned this way. They came from logs with about an 8" dia so they aren't especially big bowls, but they do have some nice figure due to crotches (ash / emerald borer ... I hope the city isn't too disappointed that I grabbed that log they left waying by the road).

Rather than risk letting natural forces dry them, I turned them now even though I can't find the tool bit I need for hollowing them. (I'll get them from Woodcraft tomorrow on the way home from work.) Since it will be many hours before I can finish this off, I hit on the idea of dunking them in a pail full of water to keep them wet until I am good and ready to dry them (after more roughing out)

What say you? Inspired madness or did I just machine gun myself in the foot?

Bill C.

Years of logging practice has sprayed uncut timber to keep it from checking. Little disinfectant in the water wouldn't hurt, especially if you forget them until Sunday. Things can work up to fermenting in a few days.

You could also close bag them with good success.