drying green wood turned bowls in Silica Desiccant beads?

Have any of you turners every tried this. I just heard about it and wanted to get some more info on this method. Pro's and cons

 

I have a box of the stuff, haven't tried it though.

If I can find the box I'll post a link to the seller. There may be instructions in the box.

 

I think it would dry the blank too quickly and cause cracking.

 

according to Ernie Conover and Dave Hout, drying is very fast and cracking is reduced.

View: https://www.youtube.com/watch?v=DaaTbDTUsg0&t=32s

 

I have used it on hollow forms about 1/2" thickness. No cracks dried within 1 week. Put form in a bucket with a lid and filled the form and bucket with beads. checked every other day by emptying form and bucket, mixing beads to combine/mix wet and dry beads then refilled bucket/form bucket. The stuff I used is food safe. Here is a link to it: https://www.amazon.com/dp/B07N98ZR69?psc=1&ref=ppx_pop_dt_b_asin_title. A 5 gallon bucket took 24 lbs of this to fill with the hollow form inside. Must have a lid to keep excess moisture out. I have reactivated this several times and it works as advertised

 

Too bad it doesn't work for an unturned blank.

 

You can use DRY wood shavings as well. I think the idea is that it does pull water out, but at least some of the water stays in the desiccant near the bowl so the drying change is slow, or maybe not so rapid as to cause big differences like you would get if you put the bowl in an oven.

Another solution, one used by Christian Burshard, is how he dries his Madrone pieces. Bowl inside a paper bag, and the paper bag inside a plastic bag. Change the bag daily. Madrone is difficult to dry without cracking, and this does the trick. I have tried it with just the paper bags, and that didn't work too well for me. I think the drying was too fast with just the paper bag, and inside the plastic bags, it slows things down.

robo hippy

 

Not the same thing but I did try a similar process with absorbent cat litter. Didn't work for me and the dust, mess and digging it out of the litter on a regular basis was too much. I guess the beads wouldn't be as messy as cat litter.

 

Not to mention what the cat added to the mix.

 

There has been a lot of interest in this lately in our local club (Wine Country Woodturners). We have a resident enthusiast who is really bright and methodical, and has been taking the scientific approach to exploring this, and some others have been following suit. The basic thrust is - the crystal cat litter is the sweet spot for effectiveness and cost. Don't be surprised if this becomes standard practice.

 

Is the crystal cat litter able to be dried in an oven and reused?

 

The fellow in Wine Country Woodturners who did the experimenting with the cat crystals, made some screens and put it out in the sun to dry.
Basically would rough out a bowl and dry it to about 10% in about 45 days. Some movement, but no cracks and the movement was not too bad.

 

It may depend on each individual block of wood, and species. Some species tend to warp and crack more than others, and some individual examples may differ, as well. On top of that, some shapes, and wall thicknesses can contribute to the likelihood of an unsuccessful seasoning process.

I'm interested in hearing more about the desiccant and cat litter processes, so those of you who are experimenting with this, please do remember to come back to this thread and give us your findings.

The one returning theme in all the different seasoning techniques, is they all have only one purpose in mind......reducing the time element to stabilize a roughed bowl. As long as the process brings the roughed bowl to stabilization with a minimum of warpage and cracks, the goal is achieved.

I'm still using the old anchorseal, and checking weights monthly method. When there is at least 3 months of unchanged weight, I consider the roughed bowl ready for final turning. (On some roughed bowls, it depends on what time of year it is, species, etc., and I may increase the time of stabilization to 4 or 5 months of unchanged weight for determining stabilization.) On top of that, I've changed the 10% of diameter wall thickness formula, to about 15% wall thickness. This, of course, means added time to stabilization, but if you have enough quantity of roughed bowls in the seasoning process, it makes little difference if the total time is 6 months, or 9 months to stabilization.

-----odie-----

 

I echo Odie's interest and look forward to future reports.

 

odie has a good idea. I thought of rice as many people use it to "dry" cell phones and other electronics that get wet. Anyone used rice?

 

Attended a Zoom meeting of Lighthouse Woodturners today. One of their members has been using crystals and gets dry bowl in 4-5 days. Said bowl mist be covered in crystals and that the crystals are only good for one bowl and then need recharge.

 

Hi Gerald.....

Amazing!

How did he determine it was dry?

-----odie-----

 

Our fellow's results suggest that drying is both rapid and even (i.e. unlikely to result in cracking). He is using crystals that can be dried and reused - certain brands/types allow for this. He is very methodical/scientific - uses both weights and (accurate) moisture content meter readings. I forget if he had multiple species, but knowing this guy, he likely did. We all know nothing is perfect, but this was remarkable for both the speed and the quality of the drying. He's got my attention, that's for sure.

 

I think he said by weight

The crystals come in color and when they change it is time to recharge. Think he said 180 in oven but do not recall the time.

 

If it was by weight, then what was the reference point? If the drying period was 4-5 days, then how does he know the weight wouldn't have changed over another week.....a month.....etc.?

-----odie-----

 

The driest bowl blank I've ever seen was about 6% MC. It was kiln dried. Most all of my seasoned roughed bowls stabilize at around 10-12% MC. If the bowl has a MC of less than the surrounding atmosphere will allow, then the finished bowl will, by necessity, increase in MC until it's stabilized....to MY atmosphere. This has come up in private communications recently with another experienced turner. My bowls are distributed over many of the 50 states, and to my knowledge, none has had problems with warping and cracking, but I guess that's not any guarantee that they haven't. All you can do is stabilize a roughed bowl to your own climatic conditions, and once that changes, there is no guarantee that changes in climate will not adversely effect any particular bowl. Species, grain patterns, etc., will all have varied effects on a bowl that has changed climate conditions.

For sure, it's not an exact science!

-----odie-----

 

My understanding is the he is doing experimentation which would involve different time frames. If I were doing it I would weigh daily and record. When the curve (Bell Curve used here) of change flattens then we are done. Isn't that what you would do. I looked up the price on Amazon But I think you can get it in bulk . The indicating (color change) is Probably best at 8# $35 . But there are many types and research would be required.

 

Can someone PLEASE gives more information on the brand names that these "crystals" are sold by? There are more kinds of cat litter than there are cats. And wading thru the marketing language and claims of superiority written on each bag is beginning to....smell.

 

Tim.......I don't think the brand name makes much difference. A quick search came up with these on Amazon. Sold by the gallon, or 7.5 lbs. Rechargeable

https://www.amazon.com/Gallon-Premi...ica+gel+desiccant+beads&qid=1607344512&sr=8-3

 

Thanks Odie... - my confusion comes from the crystals in kitty litter. I have used the silica gel dessicant beads for other purposes....but the cost of use + the hassle of regeneration has me hopeful for the far less expensive kaolin clay kitty litter with ease magical crystals in it that turn cold to indicate adsorption of moisture and thus - exhaustion.I have 4 Ash bought urns in my freezer right now that are 18". So, I am interested in setting up a vat ( large plastic storage container) that will accommodate large rough turned bowls. The cost and regeneration hassle of the silica beads would be my second choice.

So - I hope that someone can enlighten me as to what brand of kitty litter they have been successful with. Figure I will try that first, then if need be, cry a little....and order a 55 gal. drum of the silica gel dessicant beads....

 

It has gotten a little confusing as to whether we're talking about silica gel crystals or cat litter crystals, or whether it matters?

 

Hockenberry: I don't know if there has been systematic exploration re: size. I do know some of the bowls were on the order of 16 inches. No issues reported with returning - same as if they had been dried longer with anchorseal/air.

 

I know this isn’t a systematic response, but rather a buckshot response, but here are some tidbits culled from various club emails over the last several months, to give you some flavor for what we’ve found:

First of all, the product we are considering is “crystal kitty litter,” which is silica crystals.

“I just used it on a fresh 15" Liquid Ambar natural edge bowl with great success, as compared to its Anchor Sealed, air dried twin; which developed hairline stress cracks.“

“So far none of the 12 bowls I have dried have cracked, Walnut, Sycamore, Lombardy Poplar, Silver maple and Monterey Cyprus.”

“Now that I have moved the crystals in and out of the containers that the bowls sit in and dried the same crystals several times, the fragrance is slowly going away. The So-Phresh crystals have less fragrance.”

“I have found that covered or not covered the drying time remains about the same. I also think that a thicker or thinner layer of crystals around the bowl has some effect, I arbitrarily picked a minimum of 2”, you can try more or less. And see what happens.”

So-Phresh and Fresh Step were cited as prime examples, widely available, not expensive, and much less than formally named desiccant.

“Scoop Away will likely work...once. It is clay, so it will clump. The type of litter we have been discussing is a silica crystal that absorbs moisture without clumping and is reusable perhaps indefinitely.”

“(Traditional) cat litter is typically bentonite clay. This is an extremely widely used natural material. One of its most amazing qualities is that it expands about six fold from dry to saturation. Silica crystals absorb moisture without appreciably expanding in volume. When we dry rough turnings with kitty litter, they need to be covered outside and inside to dry equally, thus reducing the risk of warpage and cracks.”


In going back through our emails, there are more and longer reports. Rather than trying to digest it all here, I’m considering trying to write something more systematic for the journal. But all reports have been positive so far.

 

THIS>>>>
So-Phresh and Fresh Step were cited as prime examples, widely available, not expensive, and much less than formally named desiccant.

Thanks Steven! That was exactly what I was hoping for. At least by trying the same products(s) as others have found success with - it will save time and frustration.
T

 

That would be greatly appreciated.

 

Here are some unscented cat litter crystals from Pet Safe ($17 for 4.5lbs):

https://www.amazon.com/PetSafe-Scoo...ords=crystal+cat+litter&qid=1606665983&sr=8-5

 

Hey Gerald.....

Yes, I weigh.....monthly. For sure, I'm a bit skeptical about how accurate you can be for determining stabilization by weight, over a period of only 4-5 days. I'm open to more input on how this is done, though. If the silica desiccant beads are the magic solution they are touted, then this method is going to be very popular.

-----odie-----

 

I am presuming he kept weighing and found that after a period longer than 4-5 days he got a stable rough bowl at that point, but I have no idea what size he was doing either which would also affect the results.

 

Well gents, I bit the bullet and bought 65lbs of silica beads. I have been experimenting with them for a couple weeks now. Old science teacher you know. I bought an airtight container with a lid that can be secured easily. I had some spalted sweetgum rounds that had been under my spalting tree for a while. Partially dried but still somewhat wet. I turned five, 12" to 13" bowls varying in depth from 4" to 3" one of magnolia that was completely wet. Each bowl was a learning experience. The spalted sweetgum bowls were all a complete success. Average drying time varies depending on the freshness of your silica beads. None more than a day and a half. And the bowl that took a day and a half was in beads that had previously dried 4 bowls already, quite a few were somewhat pink instead of deep blue. I am a firm believer that with experience this method can be a great blessing to those of us who move a great deal of bowls or inventory. Or to those of us who need a specific piece in a limited amount of time. There are so many variables that only with experience will someone get this down to a science for their geographical area. One conclusion I came to quickly is if you have a deep enough layer of beads to completely cover a bowl top and bottom with say at least 1 inch of beads. Time to dry some bowls is in hours not necessarily days. The more bowls you have dried in your beads without recharging them will cause the drying time for the next one to be much longer than say in the beginning. The only bowl that I let dry too much was the last one the wet magnolia bowl. I let it dry a full 24 hours in the beads that were weaker then I recharged the beads and put it in some fresh deep blue beads and forgot about it for a half a day it was too dry when I checked it. Warning fresh beads work much faster than partially charged beads. I spent a whole day recharging 30 Lbs. of beads In my oven at 220 degrees. I don't know if there are different type silica beads probably are, but these should never be recharged (or dried) at 250 degrees because these will burst and become useless. Deep blue good, pink need recharging. I also now know how to dry these beads in 1/4 of the time. The wife was a champ because she wasn't using the oven all day.
I intend to keep experimenting until I can get this down pat to where I feel secure drying a money bowl in the beads. It may take a year or less who knows every type wood probably dries differently.

 

@Breck Whitworth , thanks for sharing your experience. That's valuable information.

What happened to the magnolia bowl? Was it harmed by excessive drying?

 

Yes a few capillary wood cracks but no fatal ones. I had to turn it thinner than I usually do in order to save it, It had a small punky area also. I didn't want to turn real good fresh wood that will make money bowls until I learned more about the process. One thing I failed to mention was each bowl was turned about one inch or a little less in thickness; Say 11/16th. I am a member of the lighthouse turning club here in MS and a few other are trying these beads also. My advice to one was to be sure the thickness of your bowls are uniform throughout just like we always should to prevent too much stress between the end grain water loss vs. the face grain. One turner told me he was trying his beads on red oak and the first one had fatal cracks. Too long in the fresh beads no doubt. He said he turned another one very thin and it dried good enough to finish turn. (I am sure he checked it quite often to make sure it wasn't too dry but I don't know. I personally haven't tried straight grain wood yet but I am sure it will be more challenging. One other thing that helped on my second wet magnolia bowl was to take it out of the beads after a period of time and let it rest or stabilize for a few hours. I then put it back in the beads and it dried very well. I don't use a moisture meter because I've turned so many bowls over the years I can tell like most of us when it is dry enough to finish turn by weight contrast to wet feel. Still experimenting but I am encouraged enough to try drying some money bowls soon.

 

How do you think a big un-turned square blank, say 8x8x4, would fare? Have any fof your club members tried it?

 

Based only on what I've heard is it would not work very well. Turning wall thickness 1 inch or less seems to be optimum. There may be a way by waxing the end grain and allowing the moisture to come mainly from the face grain. But that is something I want to experiment with but have never had the chance. I did hope that green anchor sealed bowls could be dried using these beads but I tried that repeatedly at first and there was absolutely no water loss from any of my bowls that had been sealed completely with anchor seal (the original formula). None of our club members have communicated with me about drying un-turned blanks.