Milling some ironbark

[BobL]

Today I got back to the milling yard and decided to tackle this 12 ft long 24" diameter Ironbark. This is the first time I have milled an Iron Bark - I knew they were hard, even harder than almost anything else I have milled. I have milled something harder called Wandoo so I thought I was OK.

Green Iron Bark has a Janka hardness of 2650 lbs so about twice that of most dry oaks. Dry Iron Bark is over 3000 lbs force Janka hardness and it has a density of 72 lb cuft.

The log has been down for a few months so was partially dry but the sheer hardness is the easy bit. This thing has bark on it like a bullet proof vest.

On the outside it looks almost pine like.

milling through the
The bark is about 2" thick and impregnated with hard red resin blobs which knock the edge off the cutters within about 2 ft of milling/cutting.

The bark is also heavily ridged so it renders standard 2" wheels on the mill almost useless.

But the resinous component of the bark is just the start, it has an underlayer of very tough fibers about half an inch thick that smothers the cutters and rakers and stop them cutting.

At the end of the cut I was using a wire brish to brush the fibres off the chain.

Combined with the sheer hardness of the timber the result is huge amounts of dust.

 

[BobL]

Like Mtngun first day back, the first thing that happened was my Tacho died. This thing is 15 months old, no display, sealed unit, I'm somewhat pissed.

Then the bark protruded up 1/4" higher between the log rails and I didn't notice it.

This pushed the mill out of alignment and because this wood is so hard I thought it was the wood and not the protruding bark that was causing the resistance and before I knew it I had a bowed bar diving into the log. Once this starts in hardwood it is very hard to correct and it stays bowed and keeps diving.

Look closely at this pic and you will see the diving cut.

I raised the bar to cut above the bow and eventually got a flat cut but the slab below it was butchered.

Was it worth it, I guess so.

I was touching up after every cut (24 sq ft) so I took some time out to debark the sucker which was not that easy but it definitely speed up the cutting - I even started to make chips again!.

I cut 5 slabs and called it a day - I'll guess I'll chalk it up to getting experience with these super hard timbers.

 

[1harlowr]

Very nice color in the wood!

 

[houtworm]

mean stuff:chainsawguy:

 

[smokinj]

Wow the squeeze is worth the juice!

 

[mtngun]

Like Mtngun first day back, the first thing that happened was my Tacho died. This thing is 15 months old, no display, sealed unit, I'm somewhat pissed.

Is that the Sendec or the Fast Tach ?

After you get used to having a tach, you feel deprived milling without one, don't you ? I guess we are spoiled.

I'll guess I'll chalk it up to getting experience with these super hard timbers.

You have more experience CSMing super hard timbers than anyone I know.

What sort of thing is iron bark used for ?

Thanks for the pics. It was a great story, probably more fun for us to read than for you to experience.

 

[Beefie]

There sure is some nice color in that wood. Would make for a nice project.

Beefie

 

[huskyhank]

Tough going!

And I'm about tired of milling the last white oak logs I finished today.
I wonder if I'd try to cut something as hard as that ironbark.

 

[BobL]

Cheers guys.

Is that the Sendec or the Fast Tach ?

It was the Sendec.

After you get used to having a tach, you feel deprived milling without one, don't you ? I guess we are spoiled.

Sure do.

You have more experience CSMing super hard timbers than anyone I know.

Maybe of the people posting on AS, but I consider myself a newbie compared to some of the old timers around here that milled hard stuff for years. Just imagine cutting this stuff by hand.

What sort of thing is iron bark used for ?

It's most common use is for flooring. Being so hard it makes great floors that resist dents. Even though it is very hard on machines, a few (crazy?) people make feature furniture with it I certainly won't be going out of my way to mill more of it in a hurry.

There's a link to a description of the species and uses etc here: http://new.dpi.vic.gov.au/notes/foestry/farm-forestry/ag0901-private-native-forestry2

Thanks for the pics. It was a great story, probably more fun for us to read than for you to experience.

Yeah there sure was a lot of frustration and cussing involved.

 

[discounthunter]

beautiful wood.that would make a nice bar top,probably only need some BLO and call it done.

after seeing some of the stuff you mill over there, i wont grip(out loud,lol) about pecan again.

 

[twoclones]

Very cool looking wood!

 

[PineFever]

Dang Bob, Great looking stuff! Thanks for posting your milling experiences both good and bad. The up and downs are what make for the most informative reading. I'm sure learning a lot.

 

[discounthunter]

is this species considered an ever green. with the bark and the sap it has the characteristics of one ,but not with its hardness .

 

[BobL]

Cheers fellas.

is this species considered an ever green. with the bark and the sap it has the characteristics of one ,but not with its hardness .

Yep - its a eucalyptus. The bark can be up to 4" thick and is extremely abrasive in itself but also traps very large amounts of grit and so just murders the cutters.

 

[splitpost]

yep thats hard stuff forsure ,if u can ,mill it green cuts real good that way and not as dusty heres a log i did awhile ago<cut and barked 2 weeks>

 

[BlueRider]

We have some iron bark growing in California. A friend of mine mills it with a woodmizer. not sure if it is the same with the iron bark down under but the stuff I have seen moves and warps more than just about anything, particularly if you try and cut it 1" thick. the color and grain make it tempting to gamble on a 50% yeild of usable boards.

What is your expeiriance with 1" boards and with thicker slabs.

 

[BobL]

We have some iron bark growing in California. A friend of mine mills it with a woodmizer. not sure if it is the same with the iron bark down under but the stuff I have seen moves and warps more than just about anything, particularly if you try and cut it 1" thick. the color and grain make it tempting to gamble on a 50% yeild of usable boards.

What is your expeiriance with 1" boards and with thicker slabs.

This is the first one I have milled so I have no direct experience but what you say is what I have heard as well. Perhaps Splitpost can tell us what his experience is?

 

[splitpost]

like any wood ,it will twist and warp to a degree depending on how its cut,when its cut, and where its stored if being seasoned,generally i have found that cutting green is better of course , removing bark as soon as possible,usually within hours if its a hot day ,this is where it gets tricky, if there's been dry spell your gonna work hard to remove the bark , but if u drop a tree, usually a week or so after rain it is nearly effortless when removing bark, once barked i then leave the complete log sit off the ground and under a tarp if its hot for about 2 weeks this way most of the shrinkage has occurred and moisture level is down then i mill, as for the inch boards i always predrill no matter what thickness ironbark is prone to splitting when in thin boards and when you find a piece that dont split you more than likely bend nails and twist off screw heads , it is a very universal timber here in AU hope i didn't ramble on too much