Thread: Karri

Originally Posted by DaveVman

Did I make a bad purchase decision?
Anything I should be aware of?

Karri would be towards the end of my list of WA timbers to use for the sorts of things you intend.
I find it's a bit of a pig to work with even with sharp tools.
It's real value lays in its great strength so it's main use is in construction.
More info here Karri | Forest Products Commission

Well that's a shame to learn but I've bought it now so I guess I'm going to learn the hard way.

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Well so far it has been OK to work with. My tools are sharp which is vital I think.
Next I have to do some more fiddly bits so I might have more issues.
It certainly is heavy and dense grained.

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Well I'm still chipping away with this project in my usual glacial fashion. Mostly due to limited time in the shed. I am close to the finish line with the lamp stands now.

I made the timber for the stand far too thick. They are heavy and strong enough to hold the house up. This was deliberate because I have never used the mitre locking router bit before so I wanted to make sure the join was good. The end result is two extremely solid bits of furniture. I resisted the urge to over engineer the base so the foot-print is small. Also I found the sheer weight of them helps to keep them stable.

I am trying to find a photo. I did take some video of parts of the build but it takes time to edit video.

I'm learning that it is a hard and very dense wood. Heavy too. In some respects the density is pleasing, since up to now I've mostly only worked with pine. However one major drawback with it being so dense is that it gives no warning that it is about to break. It is extremely strong. However once it's strength is exceeded it seems to split without warning. I know this because I had to redo a piece which I "persuaded" into position with too much force. Then after redoing that I noticed another piece had cracked when I wasn't looking. That one I've just filled the crack because I've spent too much time on this project already. I imagine this is due to my lack of experience with hardwoods. I'm used to allowing for a little compression with pine. There is very little compression with Karri. Very little.
I took some video of this mistake so perhaps eventually I'll put up something on YouTube to show you what I mean.

I say that it is pleasing in some respects because it is a straight, close grained timber, with very few knots. Where there is a knot they are small and the grain is so dense that the knot is not such a problem. I find it easier to get clean joins than I have done with softwood.

I noticed that even with the rather extreme heat and humidity we get in the middle of SEQ summer, this timber didn't warp at all. Of course it had a few weeks in the shed before and after machining but I've learnt that is no guarantee with pine. With Karri, it seems unconcerned. Especially if you store it vertically.

I ended up machining all the boards I used to exact sizes. When I came to do the project I realised I need everything to be straight and square for my design to work so 'good enough' would not have been good enough. I had no problems jointing, thicknessing, ripping and cross cutting it. Although my tools are sharp so that might be why it was no problem. Apparently they won't stay that way if I use a lot of Karri.

The Triton workcentre got red sawdust everywhere so now I feel like a real Australian woodworker. Unlike most machines, I don't move the workcentre outside so that one makes the most dust in the shed. I still don't have enough juice to run the dusty. (Working on it).

I've been doing various mouldings on this project with the Karri. I've learnt that I need a track to fix a feather board to my router table. I won't scare you with the various temporary setups I used to clamp a feather board and various undersized push shoes I made. But I still have all my fingers and got the job done.

Sanding. Mmmmm. I've found pine is often too soft for machine sanding, in that it's easy to remove too much material. This Karri is the opposite extreme. Unfortunately in this design I've had to do most sanding by hand. Sanding, sanding, Sanding to remove a very small amount of material. Which is why I lost patience and tried to force some parts that really needed yet more sanding. However the good thing is that after the machining the wood doesn't need much sanding because it is close grained and dense. The ripping blade was really the only machine which left uneven blade marks. The router work will mostly not be visible on my finished project anyway. My little ol' 3 blade jointer and my segmented thicknesser gave excellent results on this timber. My SCMS has an 80 tooth blade which always gives excellent results anyway. The sanding is mostly to remove the glue residue and then to remove the marks left by the courser sand paper etc. Note however that I lack patience with sanding so others might argue more sanding is required than I thought. However I did spend all Sunday afternoon sanding and I'm not quite finished yet, so I think I'm not too lazy.

My wife wants to add some metal trimmings to the stands so I'm trying to figure out how to accommodate that before applying a finish. I think I'll just mask off those areas so that there will be bare wood to glue those metal parts on once they are ready. So I can now apply a finish everywhere else.

In terms of finish, I'm not sure what to use. I am hoping the timber will look good after a finish is applied. I was thinking shellac, which I have 'in stock'. Should I oil it before shellac? If so, which oil?

I'm thinking I'll make some little thing out of offcuts and try out the finish, rather than my usual approach of just slapping it on and hoping for the best.

Then there is just the electrical and the shades to fit.

The ants have decided that the nice new cream lampshades I have kept clean, in the shed cupboard is a great place to establish their nest! I'm laying poison but I might run out of time for that to be effective. I might get frustrated and spray them, but I'd much rather kill the queen. I hope they don't leave behind a mess on the shades but I guess they will.

Once I've finished this project and done some other things, I'll do another furniture project with Karri and see if my impressions thus far hold up.
It is a relatively cheap timber in Australia. It has it's advantages and disadvantages. I certainly wouldn't want to use it on every project. For me it's all about learning as I go along and so it's nice to also explore various types of timber. Another aspect of the journey.

I have worked with Karri in the past and found that it was nice to work with. I have used shellac for the flat work that was made from Karri and the small pieces that I had were turned on the lathe where I used a wipe on poly.

The pieces that I had worked with were lightish is colour and after applying shellac they came up a little darker. The turned pieces that I had I think remained the same colour but I can not recall as it has been so long ago. I never used an oil on this timber so can not comment on what the results would be.

I also checked the wood database and they state that the colour tends to darken with age. Karri | The Wood Database - Lumber Identification (Hardwood)

As you had these piece for a while you might be able to advise better than I.