Thread: Milling and using Turpentine

Turpentine is often loaded with silica which is why it has a blade dulling effect. BUT the amount of silica will vary according to soil type. So it can range from silica free which has no dulling effect and will cut like butter all day through to that heavy with the stuff that you can't keep a blade up to it to saw it. Much of the Turp here grows on sandy type soils which is why it has such a bad rep. I've cut stands of it with no silica though and when you get into that its beautiful sawing.

The main thing to be aware of with drying is that it does have a high shrinkage rate and a tendancy to collapse. All you can really do is to oversaw enough to allow for the shrinkage and slow the drying rate down as much as possible to reduce collapse.

It's favored here for use in the round: the pole home guys love it and it is regarded as one of the best timbers in the world for wharf piles due to the resistance to marine borers it gets from the oleoresins present that give it that distinctive odour.

I guess your talking about Colophospermum mopane...mopane tree.
Its in the leguminosae family...where as Australian version Syncarpia glomulifera is in myrtaceae family
Very hard wearing timber that has an oily texture...even used for production of woodwind instruments
No doubt would be an excellent timber for flooring and other indoor/outdoor applications
As you mentioned,the termites hate it
Doesn't split or misbehave too much apparently...MM

A question

has it been established why Termites hate turpentine?
Is it something in the tree's oils?
or is it the high silica content? If the latter, then trees from low silica soils will not have the same termite resistance as those from sandy soils.

The silica level doesnt seem to make any difference to the termite dislike for the timber. In our area the soil is volcanic on clay and the timber has a low silica level and easy cutting. White ants dont touch it.
Horizontal log construction can be a problem with our high shrinkage hardwoods. The Scandinavian Notch method leaves much to be desired with these timbers, as shrinkage is transfered down through the entire wall height. This will cause a problem at window and door heads if sufficient gap is not available. Internal stud framed walls also have a similar problem.
The Butt and Pass method with the use of reo through pins reduces this overall shrinkage to a minimum as each log shrinks but retains position on the pins. Highly flexible chinking is important with this method as the logs do not settle down onto each other. Well seasoned logs helps reduce the shrinkage to a minimum. A slow build can be the answer here with chinking being left until as late as possible.

My understanding is that the silica content in wood is not only related to how much Si is in soil but how much heat/water stress they have undergone.
To compound the effect sandy soils drain quicker than other soil types so trees growing in sandy environments suffer a double whammy.

Silica uptake by plants is normal as it helps them survive during times when less water is available. The less water there is the more they take up.
Si is even added to some fertilisers used on plants in lower rainfall areas.

I've milled quite a few yard and verge trees around Perth including Qld box trees which are notorious for taking up Si. Given that sand is the basic soil type all around Perth if it was just sand I would expect to see them all with lots of Si but it varies quite dramatically even though the soil type is the same. The Arborist who brings me the trees reckons it depends on how much water the residents have used on gardens and verges.

The CSIRO book on forest trees of Australia mentions high termite resistance and very high resistance to attack by marine organisms so its got to be the tree oils resins.

I know with marine borers the oleoresins are the major deterrent to attack and the silica content of the wood is considered to be also a deterrent but not as much so. Thats why we get such a premium for bark on wharf piles... the greatest concentration of the oils is in the sapwood and having the bark intact helps keep it there longer and also serves to protect the sapwood layer from every idiot trawler skipper who rams the wharf. Good money in bark on piles though as with most things its not as easy as it sounds to achieve.

Not real sure on the termites but I'd say Ken is right and its not silica related because we're in a no silica stand ATM and as usual theres no white ant damage in them. Though I did see a few pipes (probably from fire damage to black hearted trees) and one of the pipes had ant bed up it. Was quite unusual to see it there and of interest was that the ant nest was in the pipe but not in the surrounding wood - they'd moved inside to get out of the rain but had made no attempt to eat the log itself.

I like Turp. It's a PITA to dry and because of the high shrinkage not really suited to green framing but it cuts a nice board for KD or flooring and I've done okay out of sawing it over the last few years.

Importantly.we need to know what Genera and Species Dudeguy is referring to when he says 'turpentine'.
As far as I know,there is only one Species in the Genera 'Colophospermum'
Common names are so misleading at times...MM

Originally Posted by MAPLEMAN

Importantly.we need to know what Genera and Species Dudeguy is referring to when he says 'turpentine'.
As far as I know,there is only one Species in the Genera 'Colophospermum'
Common names are so misleading at times...MM

The CSIRO Forest Trees of Australia has numerous entries for Turpentine, but the main millable tree is listed as Red Turpentine and is named Genus Syncarpia, Species Glomulifera.
Swamp Box or Swamp Mahogany is also listed as Swamp Turpentine.
There are 3 species of Syncarpia native to Australia with Glomulifera found from Southern coastal NSW through to northern QLD.
Glomulifera is the tree prized for its termite and marine borer resistance.

Colophospermum Mopane is also know as Turpentine but is a native of Southern Africa. It's also a legume!

Originally Posted by BobL

The CSIRO Forest Trees of Australia has numerous entries for Turpentine, but the main millable tree is listed as Red Turpentine and is named Genus Syncarpia, Species Glomulifera.
Swamp Box or Swamp Mahogany is also listed as Swamp Turpentine.
There are 3 species of Syncarpia native to Australia with Glomulifera found from Southern coastal NSW through to northern QLD.
Glomulifera is the tree prized for its termite and marine borer resistance.

Colophospermum Mopane is also know as Turpentine but is a native of Southern Africa. It's also a legume!

Bob given the fact Dudeguy is from South Africa,then I assumed he would in fact be referring to Mopane as opposed to the other examples that you have cited..MM

Originally Posted by MAPLEMAN

Bob given the fact Dudeguy is from South Africa,then I assumed he would in fact be referring to Mopane as opposed to the other examples that you have cited..MM

Good point!.

Fair bit of Turpentine (Syncarpia glomulifera) was planted in South Africa as a plantation species. Its made itself right at home there... but not to the degree of the likes of Grey ironbark (E. paniculata) which is now a category 2 declared weed in South Africa.

last time I checked Australia was by volume the 6th largest eucalypt processing nation in the world, and I think South Africa was in either 5th or 7th place.... ie they mill more australian hardwood species there then we do. Brazil, India, China, Spain, South Africa, Australia, Portugal France was the order from memory, and its a loooong way back to 6th place. Just sayin...

Originally Posted by MAPLEMAN

Bob given the fact Dudeguy is from South Africa,then I assumed he would in fact be referring to Mopane as opposed to the other examples that you have cited..MM

Originally Posted by BobL

Good point!.

but given that Dudeguy did say

Originally Posted by Dudeguy

turpentine trees [are] classified as a weed here

I think John G might have the right if it