Stop the decay

[Brandon Sloan]

I searched around for a way to prevent further spalting. Awhile back I came across some information but I can’t seem to find it. Does anyone have any experience with stopping the spalting from ruining a blank?

I remember reading about a turner that soaked his blanks in a water and bleach mixture to kill any fungus. Will this work? I processed some logs yesterday and found some nicely spalted pieces. I know their is a fine line between nicely spalted and ruined.

 

[john lucas]

Dry it. once it gets beyond a certain percentage (and I have forgotten what) it's dry and the fungus can't live.

 

[Brandon Sloan]

Dry it. once it gets beyond a certain percentage (and I have forgotten what) it's dry and the fungus can't live.

I’ve read that, but I’m worried that it will continue to degrade as it dries. I don’t have any first hand experience with spalted wood, just what I’ve read. Until it hits that point is it possible for the piece to spalt beyond usefulness?

Is it one of those “just wait and see” situations? I have three more blanks from the spalted log and I’d hate to lose them.

 

[Jason Van Duyn]

Looks like you are in the sweet spot as far as spalting goes. It would have to degrade quite a bit further from the looks of it for it to loose significant structural integrity. Seal the ends of the blanks and dry them out, you should be fine. All of the wood that I have that has degraded too far has gotten that way as I left it outside. If it turns well right now I wouldn't anticipate any further issues other than cracks forming during the drying process. Just keep it out of direct sunlight and rain.

Here is an article I wrote on spalting, there might be some other information useful to you.
https://vanduynwoodwork.com/2018/11/14/what-is-spalted-wood-and-how-to-turn-it/

Good Luck

JVD
www.vanduynwoodwork.com

 

[Brandon Sloan]

Looks like you are in the sweet spot as far as spalting goes. It would have to degrade quite a bit further from the looks of it for it to loose significant structural integrity. Seal the ends of the blanks and dry them out, you should be fine. All of the wood that I have that has degraded too far has gotten that way as I left it outside. If it turns well right now I wouldn't anticipate any further issues other than cracks forming during the drying process. Just keep it out of direct sunlight and rain.

Here is an article I wrote on spalting, there might be some other information useful to you.
https://vanduynwoodwork.com/2018/11/14/what-is-spalted-wood-and-how-to-turn-it/

Good Luck

JVD
www.vanduynwoodwork.com

I read that article, it popped up when I was searching on google. Thanks for writing it. I think my mind is at ease. I’m going to rough turn the other three blanks and let them dry in paper bags.
Should be the ticket.

 

[robo hippy]

If the wood is still pretty wet, then a few short bursts in the micro wave would probably do it. I wouldn't use bleach unless you wanted to change the colors. Are you going to return it when dry or leave as is? A coat of penetrating oil might help. Direct sun light might be too much heat for it. If you turn to 1/4 inch thick and sit it on a shelf, it will be dry in a week.

robo hippy

 

[Joe Kaufman]

If the wood is Liquidamber / Sweetgum, the end grain in the second photo may be a problem. The radial lines may be cracks and difficult to turn and finish when dry. You might consider soaking that area in thin CA before final turning. Be careful when choosing the finish as any oil based finish as the first coat will mute the white color. Again, this is based on my experience with Liquidamber / Sweetgum.

 

[Richard Hodsdon]

Here is the web address for the Guru of Spalting . Prof Seri Robinson. https://www.northernspalting.com/spalting-info/faqs/
Spalting is best around 30% moisture and stops once the wood dries out. Seri Robinson
will be able to give you definitive answers

 

[Emiliano Achaval]

Not part of your question, but your tenon doesn't look right. Could be the picture, but the most important part is for the jaws to be sitting square with the bowl. I make mine so is half of the width of the jaws. It appears that you have a wide gap where there should be touching the bowl evenly.

 

[hockenbery]

think my mind is at ease. I’m going to rough turn the other three blanks and let them dry in paper bags.

That has always worked for me.
With spalted wood I find a higher incidence of mold.
So I rinse the bowls in the sink and towel dry before going into the paper bag.
I also move the bowl to a dry bag each day alternating bag so the damp bag has a day to dry.
If I see any mold I wipe the surface of the bowl with Clorox - does not effect any color change- and discard the bag it was in.
When the bags are dry (5-7 days) I leave the bowl in the bag for 4-6 months.

Mold will make ugly blotch stains on your bowl. These will no bleach out.

 

[William Rogers]

Not part of your question, but your tenon doesn't look right. Could be the picture, but the most important part is for the jaws to be sitting square with the bowl. I make mine so is half of the width of the jaws. It appears that you have a wide gap where there should be touching the bowl evenly.

I saw this also and not sure if I should point it out. You had a wide gap on the other hollow form also, but the jaw face were flush to the wood on that one. For a twice turned bowl the tenon should be a bit larger so it can be trued up for final turning, but yours looks excessive.

 

[Brandon Sloan]

Not part of your question, but your tenon doesn't look right. Could be the picture, but the most important part is for the jaws to be sitting square with the bowl. I make mine so is half of the width of the jaws. It appears that you have a wide gap where there should be touching the bowl evenly.

Thank you for pointing this out. I have had trouble getting my tenons seated correctly.

Should the area where I want my jaws to be touching the bowl be a little flatter?

I was actually going to ask a question about tenons, I have been tightening them as tight as I can and I’ve broken two recently. Am I over doing it or was the wood weak to begin with?

 

[Brandon Sloan]

I saw this also and not sure if I should point it out. You had a wide gap on the other hollow form also, but the jaw face were flush to the wood on that one. For a twice turned bowl the tenon should be a bit larger so it can be trued up for final turning, but yours looks excessive.

Please feel free to point out anything you see that needs correcting in one of my posts. It will help me become better and that’s why I’m here. I appreciate the constructive feedback.

 

[Dave Landers]

To get the proper grip, the tenon needs to be sized and shaped to match the chuck jaws. Straight jaws need a straight tenon, angled (dovetailed) jaws need a dovetailed tenon.

The best hold happens where the jaws of the tenon make a circle, so they contact the tenon all the way round. Jaws are machined to a circle as one piece, then cut apart. Matching that circle (usually with something like 1/8" kerf/gap between the jaws) gives you the best grip.

But the thing that really gives you a good hold is the flats on the end of the tenon. When matched with a flat ring on the workpiece, it keeps the workpiece seated and centered, but more importantly it provides a surface to keep workpiece from levering off the chuck (IDK if levering is a word, but: lever as in with a crowbar).

The other important feature of a tenon is the corner between the tenon and the flat - if it's got a fillet then that's going to push the jaws away from the flat as you tighten them. If it's sharp then the jaws will sit nicely.

Get this geometry right and you shouldn't need to crank down on the chuck so much.

 

[Mike Johnson]

One of the photos seems to show the tenon bottoming out in the jaws on the chuck, this makes it easier for a tool catch to push the bowl out of the chuck. It works better to make the tenon shorter so that it is not touching the bottom of the jaws this eliminates a fulcrum point at the bottom of the tenon. If your chuck jaws are only gripping the sides of the tenon and they are not butted up against a flat surface of the bottom of the bowl you run the risk of any tool catch prying the bowl out of the jaws.

 

[hockenbery]

The best hold happens where the jaws of the tenon make a circle, so they contact the tenon all the way round. Jaws are machined to a circle as one piece, then cut apart. Matching that circle (usually with something like 1/8" kerf/gap between the jaws) gives you the best grip.

Matching the circle gives the best hold. Being a 1/2” bigger than the circle gives an adequate hold.

A rough out to dry needs an oversized tenon because it will shrink to oval.

The perfect circle tenon diameter should be used to turn dried bowls and once turned bowl.

When using #2 jaws I turn a 2.5” tenon on a bowl turned for drying.
When dry I can shape a 2” tenon which is close to the perfect circle.
Shrinkage of a bowl tenon with the grain centered is mostly tangentgential(about 10% in most woods) a green 2.5” tenon will shrink to oval roughly 2.5 x 2.25 after shrinking 10%.

Perfect circle on the vicmarc standard jaws is 48mm or 1.89” So 2” works great and is easy to turn from the 2.5x2.25 tenon.

 

[Emiliano Achaval]

Thank you for pointing this out. I have had trouble getting my tenons seated correctly.

Should the area where I want my jaws to be touching the bowl be a little flatter?

I was actually going to ask a question about tenons, I have been tightening them as tight as I can and I’ve broken two recently. Am I over doing it or was the wood weak to begin with?

Glad we can help you! There was no internet when I started turning, my learning curve was rather steep, to say the least! Do not hesitate to ask anything else here on the forum. Aloha