Thread: Aussie Iron Bark Kicking my A$$ Help Appreciated

A belt sander can only get you so far otherwise thicknessing with a BS is going to take a LOOOOOOOOOOOONG time.

As an aside here are some of Iron Bark milling experiences.

In 2010 I tackled chainsaw milling my first Iron Bark log.
By then I'd chainsaw milled close to 100 logs including sugar gum, spotted gum, and Tuart which is nearly as hard as Iron Bark.
What I was not prepared for was the Iron Bark bark - it was about 1.5" thick and full of gum into which all manner of sand grit and abrasive dust had embedded itself becoming a fine grade abrasive.
It did not help that I started out with a less than freshly sharpened chain
The bark knocked the remaining edge off the chain in the first 30s of cut, then cutting slowed drastically and the chain started producing a lot of fine dust. The mill shook and rattled and then it got harder and harder to cut. What had happened was one of the bar locking bolts had come loose and the RHS of the bar had dived further and further into the log (see red dotted line). Eventually the bar got jammed and I could not back it out and I had to take the saw apart from the mill to remove the bar.

If this had been my very first cut experience with a chainsaw mill I would have given up and gone home.

Bironbark_bark2.jpg

At this point I went into the treeloppers big shed and looked for implements to remove the bark
Got myself an axe, shovel and a HD crow bar with an axe head welded onto the end and methodically peeled the bark off.
Sharpened the chain and went for it - huge difference and the result was worth it.
grain1.jpg

12 years later we put a large Iron Bark onto the bandsaw mill with the Bimetal blade.
That had no problems, even with the bark on, but to protect the blade we still took as much of the bark off as we could..

ironbar3.jpg

Hi Peter,

How wide are your bench tops going to be? are you going to glue 3 or 4 pieces together? will your sledge be able to router the full width of your bench tops?

If your sledge can router the full width of your bench tops then concentrate on the edges that you are going to glue together if you don't have a track saw (or circler saw) then you can use your router with say a 50mm ball bearing guide bit (ball bearing at the top of the bit) then place a rip of say 18mm ply (this will be your straight edge reference for your ball bearing router bit and will need to be at least 190mm wide, but no more than the width of your planks) on top of your piece using shims and clamps to allow you to level out any undulations in your planks.

Once you have all your edges routed put the planks (pieces) together in a way that gives you the flattest bench top when taking into account twist/cupping/bowing etc. then glue them together, when glue as cured put the bench on a flat surface and shim any rocking (hot melt glue the shims) the use your sledge to router the top flat, then flip it over and router the other side.

Originally Posted by GraemeCook

....Peter, could you post some photos showing how you operate the sled. I presume the router slides along the bottom of those rails, not sure how the ends of the rails are supported, how they slide and how they are stabilised. {Reason I ask is to look at your technique.]
....

I can Graeme, here's a video to assist in understanding my setup.

Originally Posted by GraemeCook

If wood is going to move, then it will do so irrespective of whether you or a joinery does the dressing.

True, that is why I am keen to invest in my own gear if possible. I had planned on taking the boards down within 1-2mm of the final thickness I am seeking and then re-level / replane that last 1-2mm once the wood has had a chance to aclimatise and settle down after being machined. Do you reckon that is a good idea? or am I making unneccesary work for myself?

Originally Posted by GraemeCook

I use a lot of salvaged timber, and know first hand how hard it is on machinery. Besides nails and bolts (magnetic), I have found many embedded nasties including rocks and gravel, shells, concrete, and dirt & sand.

I really think the wood should not have a lot of foreign bodies as these boards have been sawn (in thirds) from thicker rail way sleepers, and then put through a '4-square' machine set at a speciffic dimension already.
I am hoping this will be in my favour if I end up having to pay someone to flatten these boards.

Thanks for your reply mate.

Hey mate,

Thanks for posting the video.

I'd be scouring the second hand market for a jointer thicknesser combo with a spiral head. Look on the bright side - if you can mill these boards you will be able to mill almost anything.

Good luck,
Zac.

Originally Posted by Treecycle

You say the 2" bit is skipping over the surface and creating a dome. Could it be that because you have used the bit at the higher RPM you have already dulled the cutting tips and therefore it won't cut easily anymore.

Thanks for the reference info Dallas, have saved that one in my wood working bookmarks. I tried out the recommeneded speed settings from your article which lined up with previous recommendations, and the bit had a fresh edge on it (I sharpen it with a card shaped diamond hone) Check out the video from my previous post, it might help to illistrate whats going on with my setup.

Originally Posted by rustynail

A thicknesser will give you a smooth surface but it will follow the line of the timber which may be bowed, warped or out of wind. If you can find someone local with a Lucasmill with a planer attachment you will be able to clean them up in no time and make them flat.

Interesting option thanks Rusty, what sort of finish do you get from a Lucasmill? and how consistent are they in getting a repeated thickness. This is deffinately viable to me especially if I cant find any local shops willing to do the work,

Originally Posted by banana

i have zero expertise so listen to others before me, but i wonder if you'd have more luck if you treated this a bit like a metal rather than a timber

i see (on youtube) metal machinists using a tool called a "face mill" in their milling machine for this sort of operation in metal. face mills look vaguely similar to surfacing bits --

I can assure you I have less expertise than you mate, but I have wonderred the same thing?! surely if we can machine metal with relative ease iron bark would be easy. I think my router will struggle with the inertia of a metal working face mill bit, but I do have some chinese end mill bits I use in my drill press. I'll give these a go in the router and report back.

Cheers guys, keep them good suggestions coming!

I am still chasing a recommendation on a planer that will stand up to the work at hand.

Originally Posted by woodPixel

100% I would use a FAT belt sander with 40 or 60 grit. Get good belts.

These are amazing tools. One of my great sorrows was selling a Festool 75mm belt sander in box with its cage.

The Festool BS75 could easily handle this job. The cage keeps everything nice and flat.

That is a nice looking piece of kit, but how does a hand belt sander get a piece of wood flat? (forgive my stupidity) especially in my inexperienced hands!

Originally Posted by Camelot

Hi Peter,

How wide are your bench tops going to be? are you going to glue 3 or 4 pieces together? will your sledge be able to router the full width of your bench tops?

If your sledge can router the full width of your bench tops then concentrate on the edges that you are going to glue together if you don't have a track saw (or circler saw) then you can use your router with say a 50mm ball bearing guide bit (ball bearing at the top of the bit) then place a rip of say 18mm ply (this will be your straight edge reference for your ball bearing router bit and will need to be at least 190mm wide, but no more than the width of your planks) on top of your piece using shims and clamps to allow you to level out any undulations in your planks.

Once you have all your edges routed put the planks (pieces) together in a way that gives you the flattest bench top when taking into account twist/cupping/bowing etc. then glue them together, when glue as cured put the bench on a flat surface and shim any rocking (hot melt glue the shims) the use your sledge to router the top flat, then flip it over and router the other side.

Mate, thats actually bloody genious. You are essentially getting a 4 square glue up with just a router sled from your description above. If this was softer wood, I would be all for it. In my case, my bench top is 7m long so the sled setup I have will not accomodate its length. I also have the issue that I am stuggling to take material off this hardwood with my current sled setup and I need to take off around 8mm of material to get the thickness I need for the benchtop, hence my first thought is to find a planner capable of doing the bulk of the thicnkessing.

Interstingly I have a 1400w hitachi circular saw with one of them diablo ultrafine blades and find I need 2 passes to cross cut these boards.

I am going to keep this idea in mind for future projects though as it is genius in my opinion.

Originally Posted by Petoriss

That is a nice looking piece of kit, but how does a hand belt sander get a piece of wood flat? (forgive my stupidity) especially in my inexperienced hands!.

I mentioned it for three reasons.

First, I saw a video from Steinway pianos and that was EXACTLY how they did those massive tips.

Second, if you've a frame for your router, you are half way there. Do the same to mount your belt sander. There was mention of high spots... This will rip those down super fast. Use 40 grit, it's unreal!

Third, I've done it myself on three table top restorations. Went splendid. They were not ironbark, but it was easy.

I'm not talking about some Bunnings elcheapo POC beltie and just freehanding it... Use the process outlined in this discussion: Flattening table top with belt sander - FineWoodworking

I’ve only ever dealt with ironbark wth a chainsaw for firewood and that was with a carbide blade. I know how quick it makes tools loose their edge so I’m sceptical whether a belt sander will get you far. Especially with how much you’re doing. Make sure you have the best belts and a heavy duty machine (hire). Maybe glue up your tops and hire a floor sander. Don’t laugh , they all over a belt sander. Come to think of it if I was doing your job that’d be the first way I’d try. It won’t get em even but it’ll get em smooth.
Once you get a floor sander moving do not even think about stopping - you’ll make a groove. Hire from Bunnings.
id also be sending your router bits in to get pro sharpened. And slow the bits to the appropriate speed.

A SEVEN METRE benchtop in ironbark??

Im glad I’m not installing that, or warranting it.

A Lucasmill planer attachment gives a good, even finish but leaves marks across the timber as it is a rotary cutter. This can be rectified by following up with their sanding attachment. Grits start at 25 and go up to 120. A final sand by hand, with the grain, removes any cross scratches and you have a mint finish ready to polish. You can play snooker on a fresh finished slab with no ball diversion so its pretty bloody flat.

Originally Posted by Petoriss

I can Graeme, here's a video to assist in understanding my setup. ...

Thanks, Peter; that looks like a pretty good set up. The big enemy of router sleds is flex - yours looks pretty rigid, but the cross bars may be a little light. You can test this by putting the router in the middle of the slide and pressing down firmly =- if you can see movement then you have flex - it ain't rigid enough.

With regards to technique, that squealing noise when using the router sounds like it is overloading. This could be any, or a combination of:

• You are cutting too deeply for such hard timber,
• The router is underpowered,
• The bit is too big or too blunt.

Any of the above could account for the crowning.

... and then re-level / replane that last 1-2mm once the wood has had a chance to aclimatise and settle down after being machined. Do you reckon that is a good idea? or am I making unneccesary work for myself? ...

I try to do that, but I am usually too impatient. Occasionally I regret my impatience.

... I really think the wood should not have a lot of foreign bodies as these boards have been sawn (in thirds) from thicker rail way sleepers, and then put through a '4-square' machine set at a speciffic dimension already.
I am hoping this will be in my favour if I end up having to pay someone to flatten these boards.

Thanks for your reply mate.

We are on the same wavelength. With the "4-square machining" all burried nasties should be visible - solely the aim with my belt sanding technique.

You will probably need to get the joiner to look at your timber, before he routinely says "no".

I hope you timber is as spectacular as Bob's photos!

Originally Posted by BobL

A belt sander can only get you so far otherwise thicknessing with a BS is going to take a LOOOOOOOOOOOONG time. ...

Whoa, there, Bob. I was definitely not advocating thicknessing with a belt sander.

What I do is to use the belt sander with very heavy grit to remove the "dirty" surface layer as quickly and painlessly as possible to then expose clean wood. This will remove surface nasties and make virtually all embedded nasties visible. These I gouge out.

Then, once I have "visibly clean" timber, I use conventional jointing and thicknessing techniques.

On reflection, how the hell would one actually thickness accurately using a belt sander?

Originally Posted by GraemeCook

On reflection, how the hell would one actually thickness accurately using a belt sander?

Big surface plate and a dial indicator

Originally Posted by elanjacobs

Big surface plate and a dial indicator

But my 30 year old Makita doesn't have a surface plate or a dial....