Doing justice to jarrah
Above: Matching colour can be tricky: the colour range in jarrah will frustrate the maker every time.
Words: Evan Dunstone
Photos: Lisa McKelvie
Jarrah (E. marginata) has long been recognised as one of Australia’s finest and most versatile timbers. A native of south-west Western Australia, it has been used since European settlement for just about everything imaginable. Jarrah is hard, strong, beautiful, nice to work, sands well and takes a nice finish. Jarrah sounds almost too good to be true, right? Well, there are a few catches.
Jarrah is one of the better eucalypts to dry (but still touchy by comparison to many non-eucalypts). Unlike redgum, it will air dry satisfactorily if handled correctly. One could hardly ask for a better timber drying climate than where it grows, so I have no concerns with stock up to 50mm thick being air dried. Over 50mm thick, I’d have some reservations and be reaching for the moisture meter more than once.
Kiln drying jarrah has long been understood and the results can be excellent. Unfortunately, some companies are only interested in turnover and rush the process, resulting in checked boards. It infuriates me that the quality of such a fine timber will be knowingly risked for want of a little more time. It is wise, if possible, to develop a relationship with a local miller who understands what you want, but that is true of all timber buying.
There are significant industries based around jarrah and it has a grading system to match. Select (class 1) is the highest grade and basically guarantees one clear face and a few minor faults on the obverse face. Standard (class 2) allows for some minor faults such as gum veins, checks and marks left by borers. Feature (class 3) allows for all manner of gum vein, faults and nasties. There is also a relatively little used grade called Standard and better that allows for up to 80% of a pack to be standard with no less than 20% select. I have never been tempted by this grade, but I am assured by my supplier that it exists.
This detail of a cabinet made by Jamie Latham shows how well jarrah shows line definition.
As a general rule, I like to buy wide 50mm boards. A board 250 x 50mm by definition comes from a large old tree, and is more likely to have good colour and figure. I like my jarrah dark and (if possible) spotty. A 100 x 25mm could come from a mere sapling and be as pink and clear as my daughter’s cheeks (which look good on her but is not what I want for my cabinets).
If all eucalypts were as nice to work as jarrah, our nation would be truly blessed. Although hard and dense, jarrah is a pleasure to work with hand tools. It marks out cleanly off the knife, cuts well with sharp tools and keeps a crisp edge. I used to be a complete devotee of Japanese pull saws, but I now concede that a well tuned Western back saw is often better for joinery on jarrah: the timber is so hard that it can easily damage a Japanese saw’s teeth.
The dark endgrain of jarrah can be put to good use when designing.
Japanese chisels and Japanese or A2 steel plane blades are definitely the weapons of choice for slicing cuts. Unlike blackwood or the infamous Queensland walnut, there is no appreciable silica content to jarrah, so cutting blades do not wear excessively from that additional source of abrasion. However blades do chip or crumble because of jarrah’s hardness. If you want a laugh, test an ordinary hardware store carpenter’s chisel on a dense piece of jarrah endgrain; it will curl up its toes on the first cut.
Jarrah, even fiddleback jarrah, will cut nicely with a well tuned handplane or spokeshave. As with all our eucalypts, use a high (30 or 35°) bevel on your plane blade and keep it sharp! I know it is frustrating to be heading back to the waterstones all the time, but jarrah is not to be trifled with. A well tuned card scraper works like a treat, as does a scraper plane and you really can get a lovely ‘off the tool’ finish if you know what you
If, like me, you rely a lot on sanding, you are in for a pleasant surprise; jarrah is wonderful to abrade. It holds shape well, cuts quickly and uniformly and takes a beautiful polish. My normal grit sequence when sanding jarrah long grain is 100, 150, 180, 240 and finally 320 grit. There is not much point hand sanding long grain beyond 320 grit, as you really won’t see much difference. When using my air driven random orbital sanders (God bless Dynabrade) I always go up to 400 grit, but that is to remove the cross grain scratches of the previous grit of the orbital pattern. If you are a decent hand sander, you shouldn’t have any cross grain scratches! On endgrain I will happily hand sand to 400 grit and if I am after a super high polish, follow up with 600 grit wet or dry.
Because jarrah endgrain polishes so well and looks so great, you can play interesting games with the contrast between long grain and endgrain in your designs. Some timber, such as Victorian ash, doesn’t have very interesting endgrain (usually because it is porous) but jarrah’s endgrain can look like polished stone. Makers who use a lot of jarrah tend to design toward its strengths.
Jarrah veneers well and is readily available as commercial veneer. Traditionally sliced veneers are common and I am also aware of a few boutique mills that offer re-sawn veneers. I’m a big fan of re-sawing veneer, but I do it myself and have never bought any, so I cannot recommend a specific supplier. You could walk into just about any decent sheet material supplier and buy a 2400 x 1200mm MDF board with a pre-laid jarrah veneer.
The author’s Budawang Tallboy in jarrah, shows the rich colour jarrah can offer.
Dealing with faults
Jarrah is one of the easier eucalypts to fill. In my article on using redgum (AWR#56) I went into considerable detail on filling gum veins and other natural features. As most of the techniques described in that article are directly applicable to jarrah, I won’t repeat myself here. Suffice it to say that successfully filling and disguising faults is an art form and should never be rushed.
Jarrah takes a superb polish but there are a few things to watch for. If you oil jarrah you will need more coats than you are used to. I usually apply four coats of hand rubbed oil on blackwood but would put six on a jarrah piece of the same design. I like a ‘wet’ look to my oil finishes (the piece should glisten as if wiped with a wet cloth) with a low reflection. An oil finish is a good choice, especially as the oil emphasises the reds and yellows but it can drop back quickly if you don’t have enough coats.
Beware of sunlight I am famously anti lacquer and jarrah is one of my justifications for this stance. Jarrah reacts very badly to direct sunlight. It goes the most unsightly powdery yellow even from strong reflected light. It really is one of the worst timbers for sun bleaching and oxidization. You must ensure a piece of jarrah furniture gets only diffused natural light. Jarrah is good for bedroom furniture precisely because bedrooms do not normally get strong daylight. Lacquer would appear to exacerbate discoloration and makes fixing discoloration many times worse.
Years ago I supplied a retail outlet that insisted I lacquer my furniture. All their other furniture (made by another company) was sprayed and they didn’t want customers asking for an oil finish in those designs. The outlet put my jarrah table and chairs in the east facing main window (pride of place to their way of thinking) and sales were strong—for a while. After about 18 months I went to look at the suite as sales had dried up. The backs of all the chairs were an unappealing mustard colour while the fronts were still red. The suite looked appalling. I had two chairs from the same batch that I had oiled and kept in my own small south facing showroom and they had only darkened a little. Obviously the main culprit was the exposure to sun, but stripping and re-finishing those sprayed chairs was a horrible job and they never quite looked right again.
While we are on the subject of discoloration and oxidization, beware of the trap of leaving your precious half constructed jarrah project uncovered in the workshop. Many a forgetful maker has returned to the workshop on Monday only to discover they have made a shadow print of some object left over the weekend on their work. You will be distressed at just how difficult it is to sand out the shadow print of your Stanley 4½. Use an old sheet and cover it.
Jarrah presents no particular problem with respect to adhesion. Like most aspects of woodwork, preparation is everything. Ensure your joinery is clean, firm fitting and that you have not contaminated the surfaces with greasy fingers or oil. If, like me, you store components for a while, ensure you scuff the cheeks of the tenons with some 100 grip paper to remove that pesky oxidization.
The drawer on this open sided cabinet shows how light effects jarrah over time.
Jarrah is fantastic for accurate joinery. Whether you are cutting delicate dovetails in a drawer or dirty great lap joints for your barn, jarrah is the goods. Because it marks so cleanly with a knife, it is easy to mark out accurately. The timber is uniformly dense and the grain even, so you don’t have the short grain problems of redgum or the fibrous fuzz of blackwood. If you wished to make some wickedly complex Chinese joint, jarrah would be a great choice.
There is one thing to watch with jarrah joinery and that is not to make it too tight. Softer timber, such as blackwood, will compress a little if things are not quite right. Jarrah will not compress the same way. Consider a mortise and tenon where the tenon cheeks are ever so slightly too tight. When the joint is forced together, the tenon of a softer timber such as silky oak will compress and the joint will go. It is far more likely with jarrah that the mortise will split along the grain above and below to accommodate the tenon. This is particularly a problem when making chairs with small component section sizes.
The other allied problem of overtight joinery is glue starvation. You can actually scrape the glue film off the joint if things are just too damn tight. This is less likely with a more porous timber but quite possible with a timber such as jarrah.
The tones of jarrah left to right: light, light spotty, medium classic, medium dark, dark spotty, dark. These samples have been lightly finished with two coats of oil.
Careful colour and grain matching is the key to using jarrah. The range of colour variation over jarrah as a species is very broad and even colour changes over the length of a board can be dramatic. I have seen four metre boards that transit from dark and spotty at one end to light pink and clear at the other.
No other Australian timber takes up so much of my workshop time to colour match. Most of the big manufacturers get around this by putting a colour wash over the jarrah (to even out the differences) and using a lacquer finish (which tends to dull the colour, particularly reds and yellows). If you have access to a spray booth, prepare two identical pieces of jarrah, then spray one and oil the other: you will be amazed at how different they look.
The way to ensure the best colour match is to ensure the source of supply. If the boards come out of the same tree in a logical sequence, obviously you are more than half way to a happy colour match. Unfortunately, most of us don’t have the luxury of the whole sequenced tree in our woodshed.
Jarrah also has a distinctive grain, so you must match for grain type as well as colour. You can often have two boards that are the right colour but the wrong grain. This is exaggerated by the fact that it is quite common for backsawn and quartersawn boards to be liberally mixed in a pack. Many is the time I’d have perhaps two cube of jarrah to hand and still cannot find just the right last board to finish a tabletop.
When we receive a pack of jarrah in my workshop we always lightly skim the best face over the planer and then write a code on the endgrain. A code of LSF means light colour, spots and figure. The boards are then racked according to whether they are quartersawn or backsawn. This saves us a lot of time and trouble later.
And in conclusion
Colour match carefully, cover your work between sessions, fit your joinery just right, use a few more coats of finish and you will be a happy jarrah user.
Evan Dunstone designs and makes furniture in Queanbeyan, NSW. Learn more at dunstonedesign.com.au