Thread: Drying green blanks

Hello Bruce
There are heaps of methods to slow dry or fast dry wood, it depends on what types of timbers, where you live, what you are prepared to do.
1. I sometimes turn them green (add 10% extra wood for truing up later), then coat the rim and end grain with end grain sealer, or molten wax. Oh, and write the date or weight on the wood before sealing
2. Wet sheoak can be turned to the final dimension, then apply metho (a small amount) to the whole surface, ensure the area is clear of flammable materials, ensure you have the phone handy for the fire brigade and ambos. Then set the bowl alight and slowly spin by hand (NOT under power). Do this at least 5 times. The metho draws out the water and the heat helps. Do this until the wood is dry then sand and finish as usual. I like this method as it is quick and easy. (Also, I like to invite the kids out to the 'studio' and watch Dad set fire to his creations)
3. Place in a microwave for a minute or two, ensure the wood doesn't burn. Also get permission from SWMBO. Weigh the wood and let it cool. Do this until the weight stays the same.
4. I know of a guy who immerses the whole item in a vat of water for a few months (??)
5. Some people used to use PEG, but it costs money etc and may be an expensive proposition.
6. Turn the bowl, then place it in a paper bag with a heap of the shavings you just created, or simply bury it under the shavings in your garage to prevent massive water loss.

No doubt other forum members will contribute as there are endless ways of drying wood
Hope this helps
Regards
Willy

Hi Willy,
Thanks for the tips!
I like the idea of the paper bag and shavings - I can do that, the others sound pretty adventurous!! How do you turn a flaming bowl by hand - asbestos gloves??
Bruce.

HI BRUCE,
One method I have found pretty successful is to rough turn the green wood, then I soak it in a sealed tub of Metho overnight. I then wrap it in paper to dry but allowing some air to get into the middle of the bowl. The theory is that it will dry slightly faster on the inside surface and contract, therefore reducing any splitting.
I know a bloke who has great success by turning his bowls green, quite thin, then freezing them for a few days and then putting them in the fridge to dry out. My fridge is fan-forced and tends to dry them too quickly and they split.
To coat the bowl blanks, I bought some beeswax on ebay which I use for dipping green bowl blanks. I bought 2 kgs which I heat up in an old electric Frypan. It will do a lot of blanks!
Candle making shops will sell paraffin wax which is what most people use.
Here is one online candle making supplier:
http://candlemaking.com.au/index.php...d=28&Itemid=26
ANd this one is cheaper:
http://www.stacksofwax.com.au/materials.htm


From my experience, if you put the green wood in a plastic tub you can get some nasty mould occuring. I ruined some light coloured timbers getting blue stain mould this way.

I have found that paint is okay only as a short term method for protecting timber.
Good Luck!

Originally Posted by bellyup

1. When I rough turn green bowls and put them aside to dry, they seem to dry out too fast as the wood distorts or starts to show feather cracks with in the first 24 hrs or so.
Broken Hill is hot and dry at this time of year - do you think if I put them in a plastic storage box with the lid on they might age better or, would I be better off keeping the uncut billets/blanks and leaving it for a suitable period of time coated with wax/paint.

One method is to pack the rough-turned bowl into a plastic-lined cardboard box (a gar-bag does nicely) surrounded by it's own shavings. I used to do this, with some success, although sometimes it also started unwanted spalting. Then I realised I may as well just slather it all over with end-grain sealer, which is way more effective.

(I don't mean NC sealer as used for finishing, I mean wax, paint, mobilcer or whatever you use to minimise checking on the ends of blanks. )

After all, it's only rough turned and is going to be remounted for further turning later on down the line... so why not treat it the same as sealing any other blank? 'Cept all over?

2. What exactly is "mineral oil"?

Paraffin oil.

3. Where might I buy the wax stuff that is used on blanks?

Good ol' ordinary, everyday beeswax is fine and should be easily obtainable. Paraffin wax (for candles) is a bit more expensive but not really any more effective and carnauba wax is, IMHO, better used elsewhere.

Personally I prefer to use Mobilcer-C, a commercial sealer, but that's pretty expensive so I go shares with a few mates in a 20L drum. At a stretch you can even dissolve polystyrene in turps and use the resultant goop as a sealer, although I've found that it does tend to discolour the first mm or so of the timber surface.

Wow,
Thanks guys, great ideas - I'll give them all a go and see what works best out here.

P.S. saw a good bumper sticker on an old cocky's truck today - " Honk now if you have never seen an Uzi fired from a moving vehicle"

Hey Skew/ guys,
On reflection - I thought Parrafin oil was Kerosene? No?
I have just bought some bees wax on ebay - should it be applied all over the timber or only on certain faces??
Thanks.

Hi again Bruce.
I cut my turning blank round on a bandsaw and then dip each side and the edge into the melted beeswax.
If you don't have a bandsaw you can just wax every side of the piece of wood.

Originally Posted by bellyup

On reflection - I thought Parrafin oil was Kerosene? No?

It's a by-product of making kero. Wikipedia has the low-down.

I have just bought some bees wax on ebay - should it be applied all over the timber or only on certain faces??

Only the end-grain needs to be sealed, but a roughed bowl is almost all end-grain...

I have used some very cheap acrylic paint from Bunnies ie $14 per 4litres and mixed about 250ml of cheap PVA glue also from Bunnies.

This is working quite well on some Silky Oak logs, only one split open as it copped a fair bit of sun one day But it did split right down the middle for me

Styrene foam and turps used to use it allot until Bunnies started playing with the formula. Last lot would not melt the polystyrene But in the past it has worked well on several Mulberry logs, no splits and even with some small burls as well around the logs.

The majority of sealing I do is using an old electric frypan and wax. I do not buy it, but plenty of people keep their old candles for me (stubs, ends or unwanted candles). Now, I must admit, that the smell of all these aromatherapy candles being rendered down makes my workshop smell nice and keeps me calm
Regards
Willy

Read recently about a turner that uses isopropyl alcohol. Pours several liters in a plastic tub, immerses the turned piece in for a day or two. The alcohol combines chemically with the water and displaces the moisture. If the alcohol tub remains covered you can use the alcohol for awhile. It will get funky, still works. As soon as I get my lathe uncovered, I gotta try this way....if anyone else gives it a shot???post results??

Hi There,

It may be mission impossible to use green turning techniques in Broken Hill except in mid winter. The key is to limit air movement past your green turned stock and to keep humidity up. Try storing your bowls in containers in the green turning shavings that you have just produced and leave them alone for 6 or 7 weeks.

Unequal distortion during drying is normal because radial shrinkage is characteristically half that of tangential shrinkage. Its just a matter of leaving enough wall thickness to recover the bowl when its dry. Here in Tassie with our species a green 25mm wall thickness is usually plenty.

The material you see coating bowl blanks in the shops is simple paraffin wax. You can buy it by the bag lot of about 20 kg by ordering from your petroleum agent. That quantity costs about A$75 and that amount will do you for many years. Don't do any coating indoors as it could be a little hazardous. Use an old electric fry pan from the tip shop to heat the wax to a suitable temperature usually well below smoke point.

Old Pete Tasmania

Again, thank-you guys for your valuable advice.
Thanks Skew - Wikopedia tells me mineral oil is essentially baby oil ???, where would I buy plain mineral oil or would baby oil be ok to use on timber?
Bruce.

Hello Bruce,

Lots of good advice. I have used a few methods. I paint the roughs with a mobilseal type product. On some timbers I use two coats. I leave the roughs out for 3-5 days for the sealer to dry.

I have started putting some in the freezer for 2-3 days to speed up drying (also kills any borers). Then for a week or so in the fridge. I only do this for pieces I wish to speed up the drying.

I then put the painted blanks in paper bags. I have found that during winter when the humidity drops, or on some hot days in summer cracking can/will still occur. The roughs are left for at least 3-6 months - depending on size. I'm lucky as I have an old 10,000 gallon tank I've converted into my wood storage "container", it's connected to my workshop with a door for easy access. It has a "whirly-bird" in the roof to stop any mold from forming, a problem I used to have. It's cool and dry so any cool dry place will do.

I used to use plastic bags but the problem with that was mold would form, also drying was inhibited because moisture was trapped. It can give some nice spaulting on some timbers (Mango, small leafed Fig, Black Wattle sap wood, Jacaranda) on some others it was a pretty awful grayish colour. You'll need to experiment and keep an eye on it.

Some Timbers microwave really well - Gmelina, Mango, Bunya Pine, Red Cedar. I paint these with sealer too. I use an old superseeded Microwave - luckily a large one. Again you need to keep an eye on each piece. I weigh them to keep track of weight loss. A medium sized bowl will get about 1 to 1.5 minutes on full - your microwave will determine this depending on the output. The rough should be "hottish" but be carefull as you can burn the piece - from the inside. The sealer will almost be absorbed by the wood (not too deep though and in easily removed when returning later). You know it's "done" when fine cracks start to appear. It's better to err on cautious side re the heat and time. You should wait untill the wood has cooled before re- microwaving.

I have heard that boiling is good, if you do a google on this there is a bit of info on this on the web, also soaking in detergent. I tried the soap but it still get quite a lot of cracking so don't use it too much.

I actully had shellac sanding sealer induce cracking , particularly on Bunya and Hoop Pine, anyone else had this happen to them??


Bruce, I hope this is of some use, just a few things that have worked for me - Peter.