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barryr
6th October 2005, 02:58 PM
Anyone use something other than cyano for stabilizing burl pens or other turnings to stop the cracking .
I turned a pencil of Griffith Grey gum burl recently . The wood had previously been dipped in Spescoat deeptreat . After turning and sanding I finished with Shellawax cream but as I found out it's got way too little shellac to stop the cracking which happened a few days later . Super glue is fine for pens but not so great for my pool cue butts . Hard shellac is ok for the pool cue butts but takes heaps of coats to be enough to stop the checking (and then
you may still get a little) .
Any other decent and easily available stabilizing products about locally in Oz ?
or is just a matter of sticking to super glue ?

Bazz

rsser
7th October 2005, 07:07 AM
Good question Barry. FWIW I've found that burls vary in their propensity to crack in pen turning; I've had some that were fine and others cr*p. Part of this may be the amount of heat generated in turning/sanding - I'd guess the less the better - and part the soundness of the blank to begin with.

You might experiment with a thin coat of epoxy; just a thought. Or Adease floor sealer: http://www.woodworkforums.ubeaut.com.au/showthread.php?t=19100

barryr
7th October 2005, 08:41 PM
cheers rsser , I was thinking with some of it that the burls haven't settled long enough before use (they're dry when I get em but I wonder for how long), most of my other timber is kiln dried and no probs with that , just burls !

Skew ChiDAMN!!
7th October 2005, 11:01 PM
It seems to be a problem with some types of burls in general, not just with smaller pieces. A fellow turner I know recently scored a couple of 20" redgum burls; he's turning one for the owner and taking the other as payment. [mutter, mutter, rhubarb.]

These burls have been sitting in a shed for over 20 years, so dryness isn't an issue. Yet when he rounded one down before roughing it out, the surface started cracking overnight. He's not happy about it... trying to turn and finish such a beast in one sitting is not my idea of fun either.

barryr
8th October 2005, 12:09 PM
Then it sounds like stabilization/sealing is almost a must . It's not the pens I'm so worried about , however , as I sell the pool cues I make I need as stable a product as possible !

interesting info about the old burls Skew , that's something to commit to the memory banks , cheers !

rsser
9th October 2005, 08:30 AM
Not surprising that some Burls are going to crack; the grain runs every which way and at some points on a bowl say you must be turning poorly packed end grain. It all depends on the piece. The ony redgum burl I turned was fine (and was semi-green). Jarrah on the other hand usually has voids and sap inclusions if not outright cracks; NSW red mallee burl I've found to be usually sounder.

Skew ChiDAMN!!
10th October 2005, 12:30 AM
Yep. Further, because the grain runs in every direction I imagine the stresses incurred during drying would also be every which way, so when a piece is sliced off altering the balance of stresses... "CRACK"

In the case of the burls I mentioned, I suspect their age and long drying time may actually have been detrimental. Wish I had access to enough to do some empirical testing... not so much 'cos I want to do the testing as simply to have access to that many big burls. :D

gatiep
10th October 2005, 12:55 AM
Just a thought on these burly things. How about using 2 part epoxy resin thinned quite a lot with the appropriate thinner ( acetone will work for most epoxies ) and then brushed onto the burl getting it really wet. From my limited experience with burls, they soak up thin liquids like blotting paper, so I imagine that the resin will soak in really deep, a bit like stabilizing pen blanks with poly U in a vacuum. ( You can find some posts on this on penturners.org ) To my way of thinking the resin should bind the fibres, displace most of the moisture ( by the acetone ) and the resin/burl can be turned. If a casting epoxy resin is used, it is clear and won't discolour the timber.

Please bear in mind that I have not done this but I think that it is worth a try, the resin will go off relatively quickly and is a lot cheaper than CA. I think that thinning it down a fair lot with the solvent will get it to penetrate really deep, but one will only have one chance to soak it in, so make sure that you apply enough so that it saturates the wood. Should one turn deeper than the penetration, it can be coated again. I know that it will work if the burl or roughed out project is immersed in the resin in a vacuum. Most compressors from old fridges can be used as a vacuum pump. Go slow with the hardner and test the time it takes to go off. Remove the burl from the vacuum and resin before the resin goes off, otherwise you'll end up with a resin encapsulated burl.

Hope this helps.

Cliff Rogers
10th October 2005, 10:30 AM
As Ern says, read this post....

http://www.woodworkforums.ubeaut.co...ead.php?t=19100

Adease floor sealer is cheaper that CA & less dicking around then trying to thin a 2 pack.... give it a go, you might be surprised by the results. ;)

barryr
10th October 2005, 12:12 PM
Thanks , Ern , Joe , Cliff ... all interesting stuff - the vacuum idea sounds good , never even thought of thinning down epoxy (I have some clear casting resin) and didn't even know you could .... but I will definitely first look in to the Adease floorseal and see whats in it , as mentioned before I have used Spescoat Deeptreat before but with a limited positive effect - it's really more for slowing/stopping moisture movement in/out of the wood .:)

barryr
11th October 2005, 01:46 AM
Cliff do you know where I can Adease Floorseal , a quickle Google only found Erns' post !:rolleyes:

Cliff Rogers
11th October 2005, 10:08 AM
I found it at Bunnies.

You should be able to find it in the paints/finishes section of big hardware shops or even in the specialty paint places.

barryr
11th October 2005, 12:20 PM
ok thanks , there's a bunnies fairly close to me .

Bazza

barryr
11th October 2005, 02:23 PM
darn , tried Mitre 10 , Home and Bunnies , no go at any of them .