Issues with apple wood, part II

[Fred Oliver]

I have a dozen or so apple wood bowls roughed out. They range in size from 6-10" diameter and 3-5" deep. I left the wall thickness about 10-15% of the diameter.

Several developed cracks during turning, so I filled them with sawdust and CA glue.

I've had so much apple wood lost from cracking and checking, I thought I'd try something different; has anyone tried this?

After roughing them out, I completely wrapped the bowls in plastic shrink-wrap and then cut a large hole in the top to let the inside of the bowl dry.

Should I do anything to slow the moisture loss, or just let it leave as it will from the inside of the bowl? I figure I'll need to check them every couple of days for signs of mold. If I start to see mold, do I just remove the plastic wrap and hope for the best?

Your thoughts are appreciated.

Fred

[Scott Conners]

Fruitwoods like apple are notorious for cracking and splitting. The trick is a very controlled, even drying process where moisture can be lost evenly from all sides - drying only the inside with allow the inner wood to shrink faster than the outer wood and increase stresses in the wood, so probably is not a good idea. I've heard success stories using both DNA and microwave drying techniques.

If they are cracking while you are roughing them from green wood during a single session, I'd suggest seasoning the logs a bit more to hopefully allow some of the stress in the wood to dissipate.

Some woods just can't be turned without cracks, because of the stress that has built in the wood during the growth process, especially where the grain is the most flambouyant. As the supporting wood is removed, the tension in the fibers is released and the wood splits.

[Bernie Weishapl]

Fred I am no expert by a long stretch but I have had fairly decent luck with soaking apply wood in DNA for about 3 days to a week. I figured if they were going to crack it wouldn't make any difference how long I left them in. I then took them and wrapped them in a brown grocery sack held good with masking tape. I cut a hole in the bowl part. I put them upside down or hole down on a cooling rack my wife gave me and I got 3 more at Wally World for a couple of bucks each. I put them in a controlled room with not much air movement and fairly cool about 68 degrees. I leave them for about 3 to 4 weeks. I really don't weigh or check them. Some will still have small cracks and some don't crack at all. If they are small cracks or hairline cracks I mix 5 minute epoxy well and then mix in DNA to make it kinda like milk. I paint it on the cracks, let dry for 24 hrs and then finish turning. If the cracks are bigger I save some sanding dust from another bowl that didn't crack and mix it with epoxy to fill the crack. Works fairly well for me and haven't lost a apple wood bowl so far.

[Frank Drew]

Fred,

This also addresses your question in another post regarding freshly felled applewood.

I've had very good results using green wood sealer (Anchorseal is one brand), but the key is early application, early like as soon as you can once the end grain is exposed. I bring a gallon of the stuff and a cheap paint brush out to wherever I'll be cutting the logs and slather it on as soon as I can. Also, I'll rip the log sections in half down the middle to further lessen the stresses that cause end-checking, maybe not that day, but not too long afterwards.

When I rough turn a bowl I found that the best conditioning is to coat the entire thing with the sealer, and I've had very few crack on me except for some minor checking right at the pith, if it was included in the form (usually at the rim rather than at the base.)

Good luck; apple is pretty nice once turned, and not that easily come by.

[Fred Oliver]

Thank you, all, for your advice.

The dozen or so roughed out apple bowls that I wrapped in shrink wrap, and then cut an opening in the top, are still drying. I've been checking them every couple of days.

A couple have developed some mold under the plastic, and I guess I'll take them out of the plastic and put them in paper sacks for a couple of weeks.

Several have water condensation under the plastic at the base/foot. Probably not good.

Four or five have developed surface checking on the inside of the bowl. Mostly it looks fairly shallow, so maybe it will be removed at final turning. OTOH, I probably should put a little CA in the cracks in the hopes of preventing/retarding their progression.

The first couple of days I had them stacked up, so the open top wasn't so open. The ones on top, which were open, developed the cracks. The bowls underneath were very moist inside but had no cracks.

Maybe I should have put them in paper bags, even with the shrink wrap, just to slow the moisture loss from the inside.

Scott, I get what you're saying about the even drying, but I left the inside open based on what some people are doing with the DNA drying. It seems they think the inside should dry a little faster than the outside. It sorta makes sense to me... or at least it did until I saw all the checking on the inside of these bowls.

In the future I think I'll rough out the bowls and then completely cover them with end-grain sealer.

[Leo Van Der Loo]

Hi Fred et all.

Of course this keeps coming up, but I have had very good results with Applewood and other woods be they fruitwood or not.
Now mind you I don't live in the desert, but we do get some hot and cold, dry and humid weather here in southern Ontario.
So why don't I have the splitting problems ??, I do believe there are a couple of reasons for this, first I make sure the rough block doesn't have splits hiding to play havoc later with me, so a thin slice off the ends will show if there's any or not.
I do turn them in one session, period.
They do get a close once-over look and any spot that tells me there is a possible weakness that could lead to a split gets some CA glue applied to it.
And as soon as I'm done with one he goes into a brown paper bag and close it, then they go either down into my basement or my drying shed, (hot summer weather into the basement), they get placed so there will be no heat or draft to the bags.
I will check the bags for the next couple of weeks a couple of times, if there's some mildew showing it gets rubbed off with a dry cloth and the bowl goes back into the old or into a new dry brown paper bag, just depends how I feel about it.
There's one other thing, I try to turn Applewood from trees that grow wild or from old orchards that have not been as severely pruned as the newer low stem trees, as they are more likely to split for the stresses that have grown into those tree with very heavy loads of apples and the way the trees are pruned (wide open).
Lots of hot air here, ?? :) , well I made these two pictures of applewood bowls that are dry and for a trial there are 5 bowls in there that are sealed with Anchor seal, the only difference there was, it took quite a bit longer to get those dry than with my usual brown bag drying.
O yes I do take my bags off the bowls when they feel much lighter to me, nothing scientific, I just pick them up and feel the weight :).

[Reed Gray]

Fred,
I love apple wood, and just finished turning a bunch of it. As far as the DNA, or LDD (liquid dishwashing detergent) soaks go, the only measureble difference I have noticed is that the DNA soaked ones are harder to sand out, and the LDD ones are easier to sand out when compared to air dried without soaking. This is on thin turned bowls in the 1/4 to 1/2 inch thick range. I haven't tried the thick turned/dry/return method. I have always thought that the success of the DNA method might have more to do with the wrapping with paper than the actual soaking. I have been experimenting with Madrone which is the most difficult wood to dry that I have run across. I left a number of them about 1/2 inch thick, which is considered suicide if you don't boil them, and then wrapped the outside with 2 layers of newspaper, and the plastic film around the rim (the stuff that you wrap around boxes on a pallet to keep them from spilling). I also don't leave any square edges on the rim. I did some with just the plastic wrap on the rim, and some with the plastic wrap over the whole outside (no condensation on the inside of the plastic on these). In all cases, the inside of the bowl was left open. I also included several bowls with knots in them which again will always cause more cracks. My success rate was almost 100%. I also included apple which had some big knots and the knots did crack, but not the rest of the bowl, and some big leaf maple which is fairy easy to dry. The total count was about 100 bowls. I need to do a lot more experimenting, but the result are promicing. I do stack the bowls like they are in a dish rack for drying. Definatly, wrapping the rim is important, and rounding the edges of the bowl is important. Wrapping the whole outside of the bowl isn't as important, depending on your local weather. I have never wanted to mess (pun intended) with sealing the bowls in anchor seal. This works for me, and I like warped bowls. They are a pain to sand unless your lathe speed can go down to about 10 rpm. Most of the variable speed lathes, like my Robust, can be set to go that slow, but come from the factory set to turn off at 50 rpm which is too fast for sanding a 14 inch bowl that has warped 4 inches out of round.
robo hippy