Once upon a time I decided to put a door on my greenhouse to keep the wind out. Lynne and I went up the road to the hardware warehouse to get some materials. I alread had hinges, and I didn't want to spend too much on the door as we live in a rental property and it's all just going to have to come down when we move.
I looked at the prices of various timber - pine was about $2/m no matter which size you bought (well you can get cheaper large pieces because they tend to sell the poor graded timber in larger sizes). Dressed hardwood is about $5/m, green undressed hardwood is $2.7/m. For a door I wanted the whole thing to be lightweight and to allow as much light to enter as possible.
The timber merchant told me not to use pine as it rots too quickly, so I would have to use treated pine. I've fallen out of favour with treated pine (CCA) as it is full of elemental poisons like copper and arsenic - these poisons never break down and I think probably end up in the food chain. I think in 50 years time there are going to be some real problems due to the amount of CCA that's out there.
The hardwood prices and sizes put me off considerably, and I don't like the fact that much of it is cut directly from the small amounts of old growth forests left. I faced a dilemma. I could get wood from Tim at bowerbird, who cuts all his timber from farms and suburban blocks, but he's an hours drive away - I'd probably do as much damage to the environment getting it as using the hardware shop hardwood. So I wandered down to the garden section where Lynne wanted to check out the specials. There were 1.8m 25x25mm garden stakes for $5 a bundle of 6. That works out to 50c/m. What's more, the timber is made from the useless corners and lowest grade timber from whatever's handy. Finally, it's specifically designed to deal with outside conditions. There are also similar low grade large diameter(50x50mm) stakes.
$10 later and I headed out with my collection.
The result of that expedition is a nail and screw free door that has withstood the test of Sarah (who kicks the door open with her foot), the test of njh (who has bumped into it numerous times), the test of Charles (who insists on trying to open it outwards rather than inwards) and the famous test of Australian sun (which bakes with UV and cooks the wood).
The wood is joined with a simple routed out rebate with wooden pegs driven in.
The whole frame is then wrapped in clear plastic under tension and stapled on. The resulting door is very rigid for its weight (comparable to a solid metal screen door). It is mostly transparent (more so than a wire mesh door) and very light.
I owed Sarah a rabbit cage and decided to try using radially sawn timber for the frame. Other people have made her rabbit cages, but they have all been so heavy as to be basically immovable. My aim was to build a rabbit cage frame that weighed less than a rabbit. Enter radially sawn timber.
Just down the road is a company that sells radially sawn alpine ash (Eucalyptus delegatensis). The big advantage to me of radially sawn timber is that it is much more dimensionally stable and stronger than traditionally sawn timber. Sarah picked up a bundle of this timber and then I realised that it would be a serious challenge to join. You see, because it is sawn radially it has a trapezoidal cross section. Traditionally rabbit cages have a rectangular cross section.
Well after many abortive designs I developed the trapezoidal double triangle light weight low cost rabbit cage. The ends are made from triangles built using a simple router jig and garden stakes, the lengthwise pieces are radially sawn strips with amazing stiffness.
The previous two sections were really intended to lead up to the project I'm going to illustrate - a tallboy for seed raising. A tallboy is a piece of furniture popular in the 1700s in Europe consisting of a set of drawers built up on tall legs. A standard tall boy isn't much use for raising seeds in - it has enclosed sides so neither air nor light can get in, poor drainage and they are generally not rated for outdoors.
My tallboy aims to be as open as possible to maximise light, have good drainage, and to fit as many trays of seedlings as is reasonable in a small area. I'm also aiming to keep both costs and construction time to a minimum and to use sustainable timber. It also needs to be weatherproof.
The drawer rails are made from 17mm thicknessed garden stake, with a 'quarter lap' join (half a half lap join :) I used some scraps to make a spacer jig to ensure that firstly the drawers were evenly spaced, but more importantly that all the drawers are level (this is very important, despite the fact that the drawers are much smaller than the holes they are to fit inside). The quarter lap is used to provide some rigidity to the whole structure (It has no value for the rail itself).
The rails are simply attached with a blob of hot-melt glue (magic stuff! - water proof unlike PVA and sets in about 2 seconds) and a nail. The rails are certainly stronger than the drawers.
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Once all the rails are attached it is prudent to give the whole set up a trial run. Now you're probably wondering what I am going to use for drawers. Well I found that I had lots of nursery trays (the sort that you get little punnets and even full sized puns in). They are very light and yet quite strong due to the clever moulding of a fractal space frame structure on the base. I tested an edge supported tray to 5kg. These are also very cheap, often they are thrown out by nurseries.
As you can see in these pictures it is really important to get the shelves well aligned or the trays will drop straight through, probably dislodging the next layer etc. That is why I recommend a mock-up.
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I chose not to provide a rebate in the supports for each rail as this would weaken those stakes considerably compared with a nail, and the tray edges are the weak point here, not the rails.
Now I had some of that radial timber left over from the rabbit cage so I used that for rails at the back. Besides the little rebate for the rail I didn't bother with any joins for these. I think if I did it again I would put a rebate on the back rails to provide additional rigidity. Hot glue and nails seems to be robust enough so far...
Finally I attached 2 rails to the front to stop the rails pulling apart. For a finish I used Tung oil, as I have a large quantity sitting around congealing, and it apparently has good protective qualities. It's also non-toxic. Because the feet are narrow I simply put each foot inside a small tuna tin. Eventually I'll pour into each tin some cement to make the feet sturdy.
You can fit either 8 metric punnets or 10 imperial punnets in each tray (or 1 powersaw, or 3 cordless drills).
