An experiment with soap

[Kathy Marshall]

Lately I've been using the soap and water mixture, either just sprayed on while turning or soaked for a day before finish turning, followed by my usual routine for turning green to finish.

Several months ago I got some elm, enough to do another salad bowl set. The set should work out to a big salad bowl and 6 serving bowls. Knowing how much green elm can move, I decided to do a little experiment with the soap and water mix. According to Ron Kents site (where I learned of this method), soaking in the mixture greatly reduces warping and cracking.

So far, I've rough turned the 1st serving bowl then let it soak for 24 hours. Today I rough turned 2 more of the serving bowls (which are now in the bucket) and I removed the 1st one. I've brought the 1st one into the house and I'm going to let it air dry for a few days and see how it holds up. Hopefully it won't crack. If all goes well, I'll finish turn it on Saturday and continue with the roughing, soaking, drying and finishing on the rest of the pieces, saving the big bowl for last.

I'll post pics as it goes along.
Theses are the first.
The 1st roughout ready to go to the house. About 5-6" diameter roughed to about 5/8" thickness.
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The next 2 roughouts in the bucket. You'll notice how dark the mixture is. This is an old batch and the color come from all the wood that's been soaked previously. Some african sumac had the bark on and that darkened it up alot, also the mesquite that's soaked seemed to release some tanins in the mix, but I haven't noticed any "staining" in the recent pieces I've soaked, so I don't think the color will be a problem. As a test, I have a dry spindle blank of hard maple and I think I'll cut off a piece and let it soak awhile and see if dries to it's natural color.

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More to come.....

[Bernie Weishapl]

Bowls are looking good. So how long do you let them dry after soaking before final turning? I will be watching your progress.

[Richard Madden]

Thanks Kathy, I'll be watching this. Your beaded cherry piece where you mentioned Ron Kent's article kind of sparked my interest. It sounds like you will wait 3-4 days before finish turning, but after that, how long will you wait before applying finish?

[Kathy Marshall]

Bernie,
I'll let it dry just 3 or 4 days. If it doesn't crack then I'll finish turn. I'm trying to see if the mixture reduces warping and cracking enough to basically green turn to finish. I do expect at least a small amount of warping, but with elm if I can cut the warping by 50% or more I'd be happy with that.

Richard,
Since these will be salad bowls (users), I'll finish with walnut oil as soon and the finish turning is done.

[Kathy Marshall]

Update - Day 2

So far so good!
The blank I started drying yesterday shows no signs of cracking and doesn't seem to be moving, so I took it out to the shop and put it in the chuck just to see if it was still true. A very little bit of movement, 1 or 2 light passes would have been enough to bring it true again. So I brought last nights rough outs into the house to start drying and roughed out 2 more to start soaking.
The blanks I'm bringing into the house for drying are not bagged or wrapped or protected in any way, they're just hanging out in the open on a table. Temps in the house run between 81-85 and the humidity is very low.

[Russell Neyman]

Practical question: What's the theory behind this? Why would it work? I heard of using soapy water as a lubricant, but not to decrease warp/cracking.

[Bernie Weishapl]

Thanks Kathy. I appreciate it.

[Kathy Marshall]

Practical question: What's the theory behind this? Why would it work? I heard of using soapy water as a lubricant, but not to decrease warp/cracking.
Russell, from what Ron Kent says on his website (just do a google search for Ron Kent), the theory is that the solid soap particles migrate into the cells of the wood, replacing the water and preventing the cells from collapsing. No scientific evidence, but it seems to work for him and for me so far.

[Fred Belknap]

Kathy thanks for posting this as I have been curious how it works. I normally use DNA but if soap would work it could be a lot cheaper. Is there any particular brand or type like dry or liquid. Laundry or dish washing soap. Curious minds would like to know.

[Kathy Marshall]

Kathy thanks for posting this as I have been curious how it works. I normally use DNA but if soap would work it could be a lot cheaper. Is there any particular brand or type like dry or liquid. Laundry or dish washing soap. Curious minds would like to know.
Fred, I use the Kirkland brand concentrated dishwashing soap from Costco. I get it from the Costco Business Center (geared more to businesses than retail) in a 5 qt jug for about $8, but I don't see why other brands wouldn't work just as well. I dilute it about 50/50 with water, but I don't measure I just guesstimate.

[Steve Schlumpf]

It will be interesting to follow your results. I hope it works for you!

[Kathy Marshall]

Update - Day 3

No signs of cracking on any of the drying pieces, but the 1st piece now shows a bit of movement, a little out of round but nothing that won't be fixed with final turning.
Tonight I roughed out the last small bowl then roughed and cored that large bowl. I'll rough out the core tomorrow. Since the big bowl is the most important one and I wanted to leave plenty of wood for finish turning, I made sure not to go too deep on the core so it's a fairly shallow core and not worth trying to get a 3rd bowl from it.

I also started weighing the bowls last night (wish I would have thought to weigh the 1st one on the 1st night), and here are the results so far:
in lbs (I know, I got a little carried away with the frequency, but it's interesting how quickly they lose weight)


date/time

bowl 1

bowl 2

bowl 3

bowl 4

bowl 5

bowl 6

big 1

core



6/27 6pm

1.13










6/27 11pm

1.0

1.15

1.19








6/28 6am

.97

1.04

1.09








6/28 5pm

.90

.96

1.01








6/28 10pm

.83

.93

.97

1.09

1.32






6/29 6am

.80

.90

.93

.97

1.20






6/29 7pm

.78

.87

.90

.90

1.13

1.15





6/30 10am

.76

.85

.87

.83

1.04

1.06





6/30 7pm

.38

.83

.85

.80

.98

.99

5.83




7/1 9am

.38

.82

.84

.78

.91

.93

5.45




7/1 6pm

.37

.44

.51

.42

.88

.90

5.23

1.80



7/2 7am

.37

.43

.50

.41

.83

.85

4.91

1.62



7/2 7pm

.37

.43

.50

.41

.46

.83

4.75

1.51



7/3 6am

.38

.43

.50

.41

.45

.81

4.49

1.43



7/3 8pm

.37

.43

.49

.41

.44

.44

4.28

1.37



7/4 10am

.37

.43

.49

.41

.44

.44

4.12

1.34



7/4 8pm

.37

.43

.49

.41

.44

.44

4.03

1.32



7/5 7am

.37

.43

.49

.41

.44

.44

3.94

1.31



7/5 8pm

.37

.43

.49

.41

.44

.44

3.84

.69



7/6 6am
.37
.43
.49
.41
.44
.44
3.78
.69


7/6 9pm
.37
.43
.49
.41
.44
.44
3.69
.67

[Richard Madden]

Thanks for the update. I appreciate the chart and the effort to put it together. Those babies are dropping quick!

[Roger Chandler]

I did a little research a couple of years ago on the soap method..........read Ron's article myself. He does recommend Kirkland's liquid detergent [I thought it was laundry detergent - concentrated - I may be wrong!!!] as his mixture is 50/50 with water. He also states that the soap can change the finish color of some woods, if I remember correctly............

I have not tried his method as of yet myself.........so far I am getting decent results with the DNA process........so I am going to continue with that as far as I know now.

[Jim Howe]

Just curious, what finish are you planning on, and do you think it will seal in the soap so that it won’t impart any soap into the salad?

[Baxter Smith]

Interesting topic Kathy. I have often thought about trying the soap if just for the ease of sanding later(suppposedly) on once turned bowls. Still on my to do list!

[Kathy Marshall]

Update - Day 4

Still no signs of cracking. The 1st bowl is slowing down on the weight loss, so I'll probably finish turn it tomorrow. I roughed out the core from the big bowl and it's soaking now. I left the big bowl in the mix to soak for 1 more day (bigger, thicker bowl, so I want to be sure it gets saturated through). I've updated the weight chart.

Just curious, what finish are you planning on, and do you think it will seal in the soap so that it won’t impart any soap into the salad?
Jim, I'll be finishing them with walnut oil. I'm hoping once the water evaporates the soap will be trapped in the cells of the wood, but I guess we'll find out!

Interesting topic Kathy. I have often thought about trying the soap if just for the ease of sanding later(suppposedly) on once turned bowls. Still on my to do list!
If I can start twice turning green wood with only a 4 or 5 day drying period instead of waiting 6 months, I would definitely do it more often. I'm anxious to see how the final turning, sanding and finishing go, and if I'll notice any difference.

[Kathy Marshall]

Update - Day 5

I finished turned bowl 1 today. I took a pic after I trued up the outside and still had plenty of thickness left to finish up the inside. After sanding, I gave it a heavy coat of walnut oil (no suds while I was rubbing it in), then weighed it again and it was down by exactly 1/2.
I removed the large bowl from the soap mix and let it drip dry while I was finishing #1. When I brought it in the house it weighed in at a wopping 5.83 lbs.
After truing up the outside.
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Group shot of the small bowl roughouts, l to r and top to bottom 6,5,4,3,2,1.
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I'll post pics of the finished pieces after a few more are done.

[Kathy Marshall]

Update - Day 6

Today I finish turned #2, #3 and #4. I had only planned on doing 2 and 3, but when i went to finish the bottom on #3 I saw that it was actually #4. Pulled the core roughout out of the mixture and updated the weight chart.
I was surprised at just how much weight the big bowl lost in just under 24 hours, over 1/2 lb.

[Kathy Marshall]

Update - Day 7

Finished up bowl #5 today. Just 1 more small one left to do, then it's on to the core and the big bowl, they may need a few extra days of drying due to the size and thickness. I'm really looking forward to getting this set finished.

[Dave Mueller]

Kathy,
Congrats on adding "Moderator" to your long list of accomplishments. Also, thanks for all the work you have done on the soap drying process. There is a lot of work in that table and I'm sure everyone really appreciates it.

Two questions. First, did you have any further info on the dried maple blank you did to see if the color changed? Second, I believe you are using walnut oil to finish the bowls. Do you have any idea if an oil finish like WTF that cures hard would work with all that soap present. I will try that if you haven't, but can't until after the holidays.

Happy 4th to you and all the Creekers.

[Kathy Marshall]

Kathy,
Congrats on adding "Moderator" to your long list of accomplishments. Also, thanks for all the work you have done on the soap drying process. There is a lot of work in that table and I'm sure everyone really appreciates it.

Two questions. First, did you have any further info on the dried maple blank you did to see if the color changed? Second, I believe you are using walnut oil to finish the bowls. Do you have any idea if an oil finish like WTF that cures hard would work with all that soap present. I will try that if you haven't, but can't until after the holidays.

Happy 4th to you and all the Creekers.
Thanks Dave!
I didn't notice any color change on the hard maple piece, as you can see in the pic. Just played around with the piece, fresh from the gouge, no sanding. The dark spot on the top bead is a smudge of BLO.

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As far as finishes, I don't think they would be affected by the soap (haven't tried it yet). Except for a very slight aroma, once the roughouts were dry you'd never know they'd been soaked in soap. The liquid from the soap evaporates along with the moisture in the wood.

[Kathy Marshall]

Update - Day 8

I finished up the last of the small bowls tonight. I was hoping to finish the cored bowl tomorrow, but it's still losing a fair bit of weight each day, so I'll probably give it another couple of days.
Taking tomorrow off from work, weather forecast is calling for some rain with temps in the mid 90's :D (almost unheard of this time of year), so I guess I'll be turning something other than a bowl tomorrow!

[Reed Gray]

I have been using this method for years. The only thing I have been able to determine, for sure, that the soap does is that it makes dried pieces way easier to sand out. I do turn my bowls to finish thickness, around 1/4 to 1/2 inch, soak them (50/50 mix), rinse, drip dry, stretch plastic film around the rim (rim edges always rounded over), and let them dry. Final drying time, 10 to 14 days. I do not return them. I did a daily weight test once with 3 sets of bowls. One air dried, one DNA soaked, and the other LDD soaked. Absolutely no difference in drying time, or warping. I did use Madrone which warps insanely anyway. I soaked maybe 500 plus bowls in the DNA, and have done thousands with the soap. The soap will pull color out of what ever wood you are soaking (madrone leaves a beautiful purple color in the soap), and that color will penetrate what ever wood goes in next. Black walnut being the worst offender. I save a separate vat for it. When dry, there is no soap smell or taste. I haven't noticed any problems with finishes. Most of the time I use walnut oil, and have used penetrating oil finishes, and some sprayed lacquers. The scented soaps do leave a little smell to the wood, but that soon goes away. I have heard that blue or green soaps can color the wood as well.

I believe that Ron developed the soaking for dealing with the Norfolk Island Pine. I have noticed that when sanding soaked pieces, the dust comes off more like big wet snow flakes rather than powder. The discs tend to clog up less. With the DNA soaks, the sanding is more difficult than air dried pieces. I would think that if you twice turned your bowls, most of the soaked wood would be turned away, except for the end grain.

The soap may make it easier for water to escape from inside the wood, but that is a science level beyond me. I do take the old soap and pour it on ant hills. Don't know if it kills them, but it does at least irritate them.

I haven't turned much elm, but know that Windsor chair makers preferred it for seats as it has an interlocking grain and resists cracking more than many other woods.

robo hippy

[Kathy Marshall]

Update - Day 10

Finished up the core from the big bowl. Just have the big one left to do. After tonights weigh-in the big bowl is down 2 lbs! That's a 34% reduction in just 5 days. Should be ready to finish in a couple more days.
I'm holding out on pics until the whole set is complete.