Stopping spalting

[Don Armour]

Have spalted maple log that have cut into two blanks. Have turned outside of one and appears fungus still active. Other has some work to do to stabilize some over spalted areas. This is a gift that I need to get to friend soon so cannot let rough bowl or blank sit for year plus.

Am internally debating the following on the partially turned blank

A. Bring into house and place in coolest part of house...... which happens to be pantry. Let it sit till the spalting stops. Not sure how long this will take

B. Take to local kiln as is. If I do this would likely take second blank at same time.

C. Rough turn inside then take to kiln

D. Finish turn inside then take to kiln.

I do expect to get distortion as drying occurs. Depending on amt. might leave in or try to turn out later.

Any and all thoughts appreciated. Pict of partially turned bowl below

Don

 

[robo hippy]

Well, spalting will go on as long as moisture content remains above a certain point. Once it goes below that, spalting stops. I would not wrap them in plastic. I would rough turn them, or in my case, I would finish turn to about 1/4 inch thick, make sure to round over bowl rims, and let it sit. Takes about a week to be totally dry. I would be hesitant to take it to a kiln. Any wood that dries too fast will crack, and that is highly variable between different species.

robo hippy

 

[Kevin Jenness]

If you don't object to distortion, completely turn the piece thin. It will dry out pretty quickly. I would suggest putting it in a paper bag or cardboard box initially. If you want to speed up drying of a roughed out blank, boil or steam it or immerse it in denatured alcohol before air drying. Putting it in a commercial kiln is risky as there is so much end grain compared to lumber. If you do that, sealer on end grain areas inside and out might help prevent problems.

That looks like oak to me.

 

[Don Armour]

Thanks to both of u.

Will finish turn then bring in house.

I certainly am not a very good wood identifier so it may very well be oak. Live in N FL so do see lots of live oak. Was able to see leaves when tree was taken down and they looked more like a maple leaf...... but I defer to those who are more experienced.

Either way think it will turn out very nice with combo of spalted and non spalted.

Thanks again.

 

[Don Armour]

Kevin - please accept my humble apologies. As I began turning the inside I see indeed you were correct. It is definitely oak. Smell did the trick for me.

Thank you for setting me straight.

Don

 

[Gary Beasley]

Thanks to both of u.

Will finish turn then bring in house.

I certainly am not a very good wood identifier so it may very well be oak. Live in N FL so do see lots of live oak. Was able to see leaves when tree was taken down and they looked more like a maple leaf...... but I defer to those who are more experienced.

Either way think it will turn out very nice with combo of spalted and non spalted.

Thanks again.

Looking online I saw an image of a shumard oak with vaguely maple like leaves. May have been the culprit. Oaks have an amazing variety of leaf shapes.

16 Common Types of Oak Trees in Florida (Including Native)

treevitalize.com

 

[Dean Center]

"Cool" may not be the best place. Seems like gardening instruction said most soil fungus like a temp of 65 F +/-10. In your JAX environment, 'dry' will be different than for the rest of us, and I would guess that typical strategies to slow drying, like wax and paper/cardboard, may not be necessary. How to get it dry as fast as possible without cracking is an interesting dilemma. Maybe this is a situation for an alcohol soak, microwave, or silica beads.

 

[Kevin Jenness]

Kevin - please accept my humble apologies. As I began turning the inside I see indeed you were correct. It is definitely oak. Smell did the trick for me.

Thank you for setting me straight.

Don

No worries. I am no great expert, especially for woods outside of my area, but the large rays and ring-porous structure in your photo are not characteristic of the maples we have up here.

 

[Marc Banka]

With my once turned bowls, including very wet wood, I turn to completion, sand right away and finish with something that penetrates- walnut oil or even a Danish oil. Let it dry on the shelf. So far, no cracks, including with Oak.

Against common wisdom, I know.

 

[Don Armour]

Thanks all.

Dean - OK. Hear ya. Certainly not 65 in the house. My shop has AC but no insulation so get to low humidity (under 50%) but certainly not to 65 deg. Outside it is 100% humidity in AM and maybe gets to 50% if gets hot enough. Even in Winter almost never see outdoor humidity below 40%.

Gary - now that the smell... and wood color have confirmed Oak ( at least in my mind) I cannot say with any certainty what the leaves looked like. Thanks for the site though I will use it in future before I pick up a log beside the road. ...... which I tend to do

I have turned the bowl as Robo suggested. Right now it's in the house in the pantry. However I have ordered some crystal cat litter and will be here tomorrow. I will take moisture reading of spalted and non spalted wood tomorrow then daily and update all when done. I thought about putting it in shavings in my shop shavings can but was concerned the wet shavings would enhance continued spalting.

Marc - interesting. Don't have either. Do have tung oil and Waterlox universal but not sure I want the slight color change imparted. I have not used walnut or danish oil but assume they do the same?


Thanks so much to all - have learned a bunch.

 

[Marc Banka]

Yes, they’ll darken the Oak, or as I look at it, give the Oak its full richness and increase the contrast, which is what I want to see. Plus, that’s best for highlighting the medullary rays that Oak is famous for.

Punky spots or anything not well sanded will get muddy with any oil based finish. If that’s a concern, fully dry the piece and use a surface finish, like lacquer.

 

[Gary Beasley]

One thing Ive noticed about spalted wood is the spalting tends to relieve stresses in the wood. As it dries there seems to be somewhat less movement and way less cracks. However red oak is bad about both movement and cracking as it dries so best of luck getting it dry!

 

[Norm Marentette]

With my once turned bowls, including very wet wood, I turn to completion, sand right away and finish with something that penetrates- walnut oil or even a Danish oil. Let it dry on the shelf. So far, no cracks, including with Oak.

Against common wisdom, I know.

How thin do you turn your finished bowls. I am turning some red oak and turned 2 large bowls around 15 inch diameter. and finished with a coat of tried and true danish oil. They look great so far.

 

[Norm Marentette]

Sorry I was asking Marc, regarding once turned bowls.

 

[Charles Cadenhead]

Thanks to both of u.

Will finish turn then bring in house.

I certainly am not a very good wood identifier so it may very well be oak. Live in N FL so do see lots of live oak. Was able to see leaves when tree was taken down and they looked more like a maple leaf...... but I defer to those who are more experienced.

Either way think it will turn out very nice with combo of spalted and non spalted.

Thanks again.

Hi Don, I'm in Tally so I'm not far from you. I suspect your wood is sweet gum or maple. Sweet gum grows like weeds so we have tons of it here, as well as oaks, and it spalts as soon as it hits the ground. Maples, including sweet gums, have a high sugar content so it makes sense they spalt quickly.
I would rough turn the wood, watch out for punky spots, and leave it fairly thick and then I would let it dry. You could put it in a paper bag or cardboard box but I would not pack it with shavings and I wouldn't finish it until it's dry. You could try drying it silica desiccant beads (there's threads here on the forums about it). I've had good luck using it to dry blanks but I haven't tried it with rough turned pieces. You can pick up silica beads pretty easily, there's brands of kitty litter than contain them or you could order it from Amazon.
Unfortunately with our high humidity it may take a while to dry so may need to wait a while or pick another piece of wood.

 

[Marc Banka]

How thin do you turn your finished bowls. I am turning some red oak and turned 2 large bowls around 15 inch diameter. and finished with a coat of tried and true danish oil. They look great so far.

I aim for wall thickness of 1/4-1/2“ depending on the species and size of bowl.
15 inches is big for a once turned bowl.
I thin the tried and true with turpentine, but I’m using the varnish oil which is thick, like honey. Especially for once turned, I want as much finish to penetrate as possible.
The oak is still going to move, no stopping that. Try to have a plan for the movement. Maybe a taller foot that allows you to remount the bowl to true up the foot. Some just use a belt sander, or similar.
The trick with Oak is that slow is better to avoid cracks.

 

[Norm Marentette]

Thanks for the info Marc. Do you let the bowl dry for a period of time before applying any finish for once turned bowls, put in paper bag or anything of that nature? I don't mind the movement and look of the warped shapes. I am still learning what works best for out climate in Kingsville Ontario. Would you use the varnish oil mix of Tried and True for a safe food finish? Thanks again for the info Marc! Appreciate it.

 

[Marc Banka]

I used to do the bag thing for drying a once turned bowl. Didn’t always like the outcome, seem to get some cracking, especially around the figured sections.
Found that simply finishing right away worked better.
I finish cut, let the surface dry a bit, usually 20 minutes is enough for sanding to work. Finish sand, sign it, and put the finish on immediately. Oils, or blends (Danish oil, tung oil) thinned enough to penetrate well. Flood it till it’ll take no more. Let it soak, but not dry. Wipe it down. Repeat the next day.

For the best outcome the bowl/blank should never be in the open air from the time you begin the piece, until the finish is applied. Except for when you are working on it, of course. Bag it when leave the lathe!

 

[robo hippy]

For once turned bowls, most of the time, I will wrap the rim in stretch film. I don't do that with maple because of all the sugar which mold just loves. I like to let them dry all the way, which takes at most a week, even in the Pacific North Wet. Mostly, the sanding is easier when the wood is dry compared to wet or even 'damp'. I do power sand, and that requires a lathe that will go down to 10 to 15 rpm. Any faster and you can't keep the drill on the wood. I had, with Brent's help, my Robust AB reprogrammed to go that slow. My old PM 3520A also went that slow. My Vicmark 240 goes that slow. Many of the newer lathes turn off at 50 rpm. Their reasoning is that with the slower speeds, the 'motor will overheat and you will fry your electronics'! After getting my AB reprogrammed, Brent told me to keep checking the motor to see if it was overheating. It actually ran cooler when sanding than it did when turning. I do make my lathes work when I turn. I would guess that if you were trying to hog off material with the lathe running at 15 rpm, that could cause heat issues.

robo hippy

 

[Don Armour]

Just took bowl out of silica cat litter after one week.

Moisture on 8/17. Non spalted area avg 24.5, spalted 33.5

Moisture on 8/24 non spalted 15, spalted 20

Know I said was going to test daily but decided that was too anal - even for me.

No cracking, no obvious distortion but will see when put on lathe to turn base, sand and finish.

Will send pict when done.