Using Paulownia as an substitue for W.R Cedar

[TLW]

I have spent a lot of time searching for an answer to this question. Can any body shed some light on this. I would like to use the Paulownia strip plank but am unsure if the fiberglass sheeting will have to be upgraded to cope.
Help

[Greg H]

Hi
I assume you mean Paulownia tomentosa or bignonioides, Empress tree, Princess tree, purple flowers,big loeaves, fast growing...... you never know with strine ;) . It has natualized over here in the south.
I've never worked with it, but this is what I know about it. When it's cut and left in the weather, it rots away quickly, might not be the best thing for boat work. It is used by the japanese for carved boxes, rice bowls, furniture etc. and is often stolen from wood lots around here. I have heard about people growing it as a cash crop for carving and export.
The growth rate is listed at 60' in 20 years in a moist warm climate, @ 3 growth rings per inch.

Keep it dry, soak it in CPES and see what happens, or sell it and try one of the other Gondwanaland woods.
:D
Hope this helps
Greg

[DavidF]

I use Paulownia extensively in my wood carving. Some of these carvings I leave out untreated in all Vermont weather. This is the most stable wood I have ever worked with. I milled a 24-inch log into two inch slabs and have stored these outside. Some scraps that I pulled out of a muddy barn floor were still sound. There has not been more than a millimeter of movement in the wood and the checks in a freshly felled tree don't go more than an inch. Some of the boxes this wood is used for includes coffins for Chinese royalty (in the olden days). It takes stains very well and hardens nicely with exposure to air. The only drawback I have discovered is that it smells like pickle juice when you cut into it. But cutting it with a sharp knife is such a pleasure that the smell is easy to put up with. Some of these carvings can be seen at

http://users.adelphia.net/~ferch/art.htm

That said, although I use pieces for attachments to my boat, I have never used it in a structural and submerged way. If you find Paulownia, take it.

[Aramas]

Paulownia is a bit iffy if you just buy or cut it as it comes. Depending on age, variety and growing conditions it can be very brittle. There's a company in WA marketing plantation Paulownia as 'Kiri', and they've developed it specifically for boatbuilding. The most recent details I have are:
Highpoint Timbers, 12 Hurrell Way, Rockingham, 6186 WA. freecall (in AU) 1800 669663

[Tomcat]

One of the advantages they mention for the Kiri, is that it isn't as poisonous as WRC. Just about anything that keeps the bugs at bay is going to be bad to work with. I would be curious to know how well it sands, though the reports mention no problems. Ocume has proven more prone to rot in the scraps I have left around, than many other woods with low tolerance. It is widely used. I'd love to get some of the Aussi strips, but I'm cobling together local woods.

[Banjo]

Originally posted by Aramas:
Paulownia is a bit iffy if you just buy or cut it as it comes. Depending on age, variety and growing conditions it can be very brittle.

* Have you done any industry standard tests to substantiate that statement?

There's a company in WA marketing plantation Paulownia as 'Kiri', and they've developed it specifically for boatbuilding. The most recent details I have are:
Highpoint Timbers, 12 Hurrell Way, Rockingham, 6186 WA. freecall (in AU) 1800 669663G'day all, the company you listed are very helpfull with enquiries. I contacted them some time ago and they sent me a large info pack containing specs, prices, and a couple of samples.
I tripped over the dog on the back porch in my haste to get outside to the garage and do a bit of jigery pokery with the samples. I tried sanding, epoxy, also tried staining a section.
It has a real nice warm honey colour if just covered with epoxy and varnish.

The wood has almost no silica content so it sands very well with no build up in the paper, it also mills well with tools staying sharper longer.

I was also contacted by a fella who built a large proa using it for strip planking and he was very impressed with its strength, comparable to cedar by nearly 50% lighter.

If I were building a strip planked vessel I would definately use it for the weight advantage it has over cedar, another benefit is the cost, much cheaper than cedar.

The arguments here on will it rot any quicker than other timbers seems to me a little pointless. If you built a boat with cedar planking you wouldn't leave the hull raw would you? So why would it be any different with other species of timbers?

Well that's my 20 cents worth + GST of course! :)

[Wild Dingo]

mmmm Funny Ive had a few yarns with the fella in Freo who built the proa actually by cutting down his larger proa to make a smaller one... will gather up his name shortly... anyway he recommended the mob in Rockingham {20 minutes up the road from me!} but Im yet to get there to have a gander... but he only had glowing words to say about the stuff easy to work clean doesnt break easily but is flexible etc etc... now having said that I emailed old Mac McCarthy he of the Wee Lassie canoes legend and his view was that he wouldnt touch it with a barge pole simply because he thought it bland in color unlike WRC...

But... Im thinking of using it to add color to the canoes so... if theyre gonna be covered with epoxy and fibreglass what difference? its cheeper option than WRC at least here in WA thats for sure...

Final word from moi?... Go for it!

mmmm I seem to be having trouble accessing the old duckworks mag site... or was it that site? damned if I remember... had a bunch of builds down one side and a bunch of helpful hints on the other... flamin eck! will keep hunting must find it sooner or later and the fellas name will jump out and whack me! :rolleyes:

Anyway story was that the fella got hold of a large proa that had been sailed around the top of Aus and down to Perth this fella bought it and decided to build another out of it so as to be able to be trailed... cant stand this!!! be back when I find it!!! :mad:

[Nicholas Carey]

Originally posted by Aramas:
Paulownia is a bit iffy if you just buy or cut it as it comes. Depending on age, variety and growing conditions it can be very brittle.That makes is pretty much like western red cedar, then. :D

[Dean Preston]

I have used this stuff for tansu cabinets. The stuff with tighter growth rings is highly prized in Japan. Interestingly, it is also flame resistant. Supposedly the family valuables kept in chests made of this have survived after the house burned down. I just thought it was too weak for my taste, similar to balsa. I am considering strongly myself using it as a deck core and things like interior doors, cabinets and drawers, etc.

[Nicholas Carey]

Originally posted by Dean Preston:
I have used this stuff for tansu cabinets. The stuff with tighter growth rings is highly prized in Japan. Interestingly, it is also flame resistant.From what I found, the listed ignition temperature is 425°C/797°F. Whew...that's almost hot enough to melt lead. I just thought it was too weak for my taste, similar to balsa.18 lbs per cubic foot. That is light.

Here's a link on the properties/uses of Paulownia spp.:</font> Wood Properties and Utilization of Paulownia (http://www.idrc.ca/library/document/071235/071235k.htm).</font>It looks like it has some useful properties, but it's not terribly strong (although it seems to say that old, slow-grown wood with a high rings/inch count is stronger than fast-grown wood.
Paulownia spp. looks to be very stable. The article notes that it's used for roofbeams and aqueducts in China.
Paulownia spp. is also classed as an exotic, invasive pest in the US.

Hope this helps.

[ 07-03-2003, 07:41 PM: Message edited by: Nicholas Carey ]

[Aramas]

* Have you done any industry standard tests to substantiate that statement?
Umm....no? smile.gif
That was based on stuff in 'Australian Amateur Boatbuilder' #39 where there was a dialogue of sorts between Bruce McConkey of Boatcraft Pacific (the AU distributor for Quickstrip wrc) and Nigel Fleet of Highpoint Timbers.
McConkey related his experience testing immature paulownia strips, and Fleet replied that specifically 'selected mature Royal Paulownia Tomentosa' was actually more flexible than wrc, more consistent in it's density and similar to wrc in fracture mode.
Another issue had details of a particularly un-photogenic proa built of kiri in ACT (from memory) but I can't find it atm.

[Banjo]

G'day Aramas,

I can't quote any personal specs myself, I only wanted to stir the pot a little! :D

Originally posted by Aramas:
</font><blockquote>quote:</font><hr /> * Have you done any industry standard tests to substantiate that statement?
Umm....no? smile.gif
That was based on stuff in 'Australian Amateur Boatbuilder' #39 where there was a dialogue of sorts between Bruce McConkey of Boatcraft Pacific (the AU distributor for Quickstrip wrc) and Nigel Fleet of Highpoint Timbers.

Another issue had details of a particularly un-photogenic proa built of kiri in ACT (from memory) but I can't find it atm.</font>[/QUOTE]I read the stories as well, that mag seems to be run and edited by two maybe three boatbuilding companies that charge like wounded bulls for their services and materials. Nothing against them making a living but.......

In my opinion the stuff is pretty good, it seems to be fairly stable although large width boards tend to cup a little if exposed to moisture but so do other species of timber, WRC seems the winner there for stability in large board widths, but it's nearly double the price too!
If you sealed the timber well and used it for internal framing, cabinets, strip planks and such it would be ideal as it's very light compaired to Fir, Cedar, Oregon, Spruce etc..

Having said all that, I spoke to one of the directors at Highpoint Timber and he told me that their main target for the timber is the domestic house construction industry, they want to mill the stuff for internal house trimming, ie; door jambs, skirts, arcs etc. For me that's GREAT! any company that can offer a better alternative for that horriblle crap called MDF is a winner in my books! I have given up carpentry in the house sector mainly because of MDF, it has caused dermatitis on my hands, chest and lower neck where the dust has settled over the years on countless jobs........ HORRIBLE STUFF! anyway that's off my chest [pun intended], now I feel better and thanks for listening. er.. reading.

[Aramas]

My personal take is that, on density alone, paulownia crosses over the boundary between a wooden boat with epoxy/glass sheathing into the realms of wood cored fibreglass. It might be worth a look for a multihull or very light displacement boat, but even wrc is a bit light for my tastes. Observations over the years of old boats built of wrc or king billy pine don't endear me to light woods. Not only do the surfaces become seriously eroded from hard use, but they tend to hold so much water that they weigh more than heavier woods anyway. Comparing them to kauri or huon pine old timers, that still have the first flush of youth after a century, can be quite enlightening. Epoxy encapsulation is of course quite different, but I still prefer the solidity of 'oregon class' woods.
My 'wood of the week' is araucaria, which is an Australian native pine that's plantation grown and has similar properties to kauri or oregon. I could happily build every component of a strip composite boat out of that, and with a clear conscience.

[Aramas]

Just thought I'd ressurrect this old chestnut smile.gif

Highpoint Timbers (http://www.highpointtimbers.com.au/marinetimbers.htm) now have a web site with lots of Paulownia information.

You know you spend too much time on the internet when your own posts turn up on the first page of a Google search tongue.gif

Looking good :cool:

[ 10-17-2005, 01:51 AM: Message edited by: Aramas ]

[Jay Greer]

Among its other properties, Paulownia has a very low acid content and is hygroscopic. I have used it as drawer liners for storage of steel tools for many years.
It is great for keeping tools rust free.

[Billy Bones]

Interesting.

I grew up with a wonderful big paulonia in the yard. Its leaves would fall a few weeks after the walnuts started in autumn. All its leaves would go whump in a morning. Pretty cool.

I loved that tree. It grew incredibly quickly. If I broke a branch playing in it, there'd be another one in a few weeks.

As for boatbuilding, I dunno. It seemed to rot fairly fast, only it grew faster so you might not notice.

[Aramas]

The website has this to say about the rot resistance of Paulownia.

KIRI timber is highly rot-resistant and that any rot appearing on the timber is only superficial. Clean, white wood appears when the surface is planed. In tropical areas where wood rots easily, KIRI boards have been soaked in water for ten years then used to make a coffin which has lasted for 30 years without decay. Coffins made of KIRI timber extracted after more than 200 years have been found in good condition. KIRI logs left in forests 20 years after felling, have been recorded as only having surface decay to around 1cm. This was compared with other timbers that were completely rotten. Experience in Australia from KIRI poles left in the forest for five years tends to confirm the rot-resistance characteristic.

What bothers me is the price. 12mm tongue and groove boards work out to around $40AUD per square metre, which is about the same price as good quality marine ply, even before adding in the cost of epoxy, glass and delivery over several thousand kilometres. That's just silly.

[ 10-18-2005, 01:19 AM: Message edited by: Aramas ]

[WX]

I visited a Paulownia plantation near Taylors Arm some years back, the trees were 8 years old and I couldn't get my arms around them. I brought some scraps home to play with and I ran a power planer over one piece but couldn't get a smooth finish..it just stayed furry.
I had heard that you need mature wood and that takes about 25 years.