Can I check a bagged bowl?

[Donny Lawson]

Is it alright to open the bag from time to time and see how the bowl is doing or would it be better to leave it alone? Also what is the reasoning behind putting shavings in the bag with the bowl? I did not do that.Was that wrong?
Donny

[Ken Fitzgerald]

The shavings...along with the bag are to keep the relative humidity in the bag fairly constant which should slow down the drying process. Slowing down the drying process allows the wood to equalize the moisture across the wood as a whole and thus reducing cracking...end grain and side grain give up moisture at different rates....bagging and using shavings helps slow down and equalize this difference.

Most people weigh the bowl...when it's first put in a bag...write it on the bag and then weigh it again periodically and note the weight on the bag. When it quits losing weight the moisture has reduced it to its lowest level.

[Bernie Weishapl]

Ken pretty much nailed it. I bought a postal scale off the big auction site I think for $18 which weighs from 1 oz to 55 lbs. I use it to weigh mine when I bag them with the bag and shavings. I write the weight and date. I watch until it quits losing and then return to the lathe.

[Donny Lawson]

If I bagged the bowl a few weeks ago would it be too late to add shavings now.?
Donny

[Steve Schlumpf]

Donny - just my opinion but I would leave the bag alone at this point. By sealing the bag you create a micro-climate and the turning will start drying at a reduced rate. If you open it and add shavings with some additional moisture content - hard to say how that would impact your turning - but why take a chance?

[Donny Lawson]

Thanks,
I guess I will know on the next ones I turn and add shavings in with it.
Donny

[Ken Glass]

Donny,
X2 what Ken said. I also only uncover and finish turn it when it has weighed the same 3 days in a row. That way you know it is stable. Best of luck. You will learn quickly which woods take longer than others.

[Dan Forman]

The bagging routine I read about and use says to leave the bowl sealed in a paper shopping bag (no shavings needed) for about three weeks, then remove the bowl and let dry for another two months or so, before final turning. When bowls crack, it's usually early in the process, when they are losing water at a fast rate. Once that first rush is gone, the rest goes more slowly and the structural changes are more subtle, and less likely to cause cracks. I haven't had any cracks since adopting this method, your mileage may vary. Sure is less messy than the DNA method, and faster than using Anchor Seal.

This came from Ernie Conover's book on bowl turning, but Leo on this forum endorses the same routine. If you have included shavings, that might add a little time. Does the bag feel damp on the outside?

The relative humidity of your shop may be a factor. I have a basement shop, humidity varies between 35% in the winter, up to around 50% in the spring and fall.

Adding shavings to the bag is done to decrease the drying speed, is generally not necessary, and will sometimes cause mold growth and discolor the piece.

Certain woods such as fruit woods are more prone to cracking than others, and in those cases it may be desirable to go the Anchor Seal route.

Dan