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Yanki
21st August 2006, 07:58 AM
Hi
I have a piece of old kauri from a post from an old railway station. It looks great but is so dry and brittle it flakes and chips when turning. Is there anything I could soak the wood in before turning to plump up the cells so it doens't chip off?
Thanks, this is my first post but I enjoy browsing.

hughie
21st August 2006, 10:55 AM
I

have a piece of old kauri from a post from an old railway station. It looks great but is so dry and brittle it flakes and chips when turning. Is there anything I could soak the wood in before turning to plump up the cells so it doesn't chip off?
Thanks, this is my first post but I enjoy browsing.


Yanki,
Hmmm, well you could try linseed oil soak in a bucket for a couple of days or longer. Then let it dry out....saves wearing a rain coat when turn it :D
Or better if you've got plenty, Orange oil, bit pricey tho :o You could thin out the linseed with turps say 60/40 linseed/turps this will help the penetration.

Also razor sharp tools, I mean real sharp and take it gently. If your a bit like me and fly in boots and all.... :D yahoo! ride 'em cowboy stuff :D

I had a piece of dry old pine crotch fly into pieces around 2500rpm. I found the whole experience quite emotional at the time....:D:mad: :D

But at the end of the day if its really old, then its gone brittle with age rather than drying out may have only a piece of firewood.:( But give it a go.

Jeff
21st August 2006, 12:44 PM
I turn a lot of brittle wood. Stuff I've pulled up off the beach after it's been in the ole briny. It kills the spalting funguses, but it also dries out the cell structure. Skip forward a few months til the wood has dried and it's going onto the lathe. The stuff I turn is often so britle the biggest trick is keeping the spur from driving through or the chuck breaking it. But those are items for another day! After the piece is roughed out, I get my scrapers razor sharp, and always leave the burr for this part, it makes all the difference in the world. I paint the piece with mineral oil, wait just a few minutes if any needs to be absorbed, then turn on the lathe at the highest speed. Make the shallowest most gentle cuts you can, just one pass through. Then shut off the lathe and paint the wood up again, and repeat. You'll be able to see by the color as you make the cut how it's going. Just don't cut into wood that is dry or you'll likely have to go back to step one. As you make your cuts you'll find that you get smoother and smoother results. You won't be able to sand brittle wood evenly, so you'll have to make very smooth cuts, and finish them up with as wide a scraper as you can fit in. I've tried a lot of different fluids for this, and mineral oil is still the best I've found. Also, it's compatible with the finishes I use. After you've turned the piece, it will still have a little oil left in it, so set it somewhere safe to dry.

Yanki
21st August 2006, 01:07 PM
Thanks for the suggestions on treating brittle wood. It might just end up as
firewood but it is worth a try to get a bowl out of it.

Hickory
21st August 2006, 01:35 PM
I turn a lot of dry re-cycled wood. I have a truck load of Black Walnut (Faded to mellow brown with age) that had been in the ceiling of a church for over 40 years, and have not had much difficulty nor need to soak in anything. Sharp tools is the trick.

If you are used to turning green wood you will find any dried wood brittle. I, of course don't have a clue as to the properties of the wood you mentioned so I may be howling at the moon. But keep the tools sharpand if you need to stablize the wood (Timber) try soaking in a sanding sealer and allow to dry or even vacuum soak as I often do to Spalted wood. I take a Pickle jar near filled with an inexpensive sealer or even thinned Poly (If I can gather some on sale) I use a hand pump and extract the air from the jar (small hole in top) watch the bubbles come out of the wood. release the vacuum and allow atmosphere to force the sealer into the open pores. Repeat a couple of time or until the bubbles stop extruding from the wood. Then set ion a rack to dry. It will be stable and easy to turn w/o splintering or chipping or flying apart.

Salty
21st August 2006, 05:53 PM
Hi Yanki,
as an expat K1W1 I just love kauri and love working with it too but I have never struck your problem. It is usually like butter to turn or work with no matter how old. Could it be totara??? which is harder and may be more prone to split?? but has a similar look to it. Maybe carving it could be better than turning - let ya hair down!! but don't burn :eek:it if possible.
Welcome to the forum - you will find answers to any and all the questions you can think of to ask. Might catch up next time we are in ChCh - all our family are still there.
Cheers
Bruce

Skew ChiDAMN!!
21st August 2006, 08:31 PM
I use a method similar to Hickory's. It's particularly effective for spalted timber with wet/dry rot areas. Too pretty to toss, too crappy to do much of anything else with. ;)

I use a vac-pump to suck it down and leave it overnight. When the wood sinks to the bottom of the PolyU, you know it's ready. Not as quick as Hickory's method but a lot less labour and I'm inherently lazy. :p

soundman
21st August 2006, 11:11 PM
What about the detergent treatment.
The on line article refered to in a recent post recomends soaking in detergent for very dry wood too.
cheers

Hickory
22nd August 2006, 05:02 AM
What about the detergent treatment.
The on line article refered to in a recent post recomends soaking in detergent for very dry wood too.
cheers

I always thought of the Detergant as a way of dealing with green wood, Although I find it rather messy method.

Jeff
22nd August 2006, 05:54 AM
I find that using sanding sealers, CA glue, ad infinitum will of course work to turn brittle wood. But it leaves a finish that IMHO is not desirable, and this is reinforced by what my customers buy. The whole idea of turning figured or otherwise interesting (spalted, etc) wood is to show off the inherent uniqueness and texture of the wood. By essentually coating the wood with plastic it takes away the natural aspect of the finished piece. Further, although infusing the wood with a hardening agent will alllow turning and sanding to a fine high polish, I would still suggest that new turners get familiar with the skills required to turn various types of wood prior to using that technique. Then, one will be able to appreciate the difference, and be better able to make an informed decision in future projects. Also, the mineral oil method is quicker, and if a polished finish is desired, it can still be applied, whilst starting with plastics eliminates any option of a natural looking finish.

Rough Country B
23rd August 2006, 05:45 PM
Gidday
Hey Salty I too doubt it is Kauri but also doubt very much that it is totara as totara cuts like butter and bever dries out because of it's natural oils.
I would think it was more likely Kahikatea which is the same colour but more brittle.