A friend has a small piece of concrete from the Israeli/West-Bank Barrier, which was significant to him. As he had been keeping this in an envelope, and since concrete fragments are actually not that robust, I decided to build a small case to store the item securely, transport it safely, and display it elegantly.
To make things easier, I intended to use solid timber with a void removed from it to provide the housing. This would be easier and faster than building a jointed box, and would also allow the void to conform to the shape of the object for protection.
Given the significance of the piece of concrete, I also included a suitable bible verse in the lid.
This 'Ible uses scrap timber and a bit of juggling to get things to fit, so please modify to your tastes. And please post if you do anything similar.
Step 1: Design
A previous box to accommodate a random shape had just used a large circle, sized greater than the largest dimension. This would not work in this case as the recycled timber which I was planning on using had flaws which would have been apparent in such a large piece.
As the sample of concrete was roughly in the shape of an isosceles triangle, I built a similar shape from two different sizes of circles which matched holesaw diameters in my toolbox and joined them together using straight lines, to give a triangle with rounded corners which was slightly larger than the dimensions of the piece.
The rough shape is shown as a .GIF above. Also attached are the LibreOffice drawing file for this, and a PDF, which was needed to get a copy-shop to print it out onto thick card stock.
Once I had the shape drawn and printed onto normal paper, I cut it out as a template and confirmed that the pieces of nail-damaged timber which had would allow the shape to be placed with clear wood all around.
Step 2: Prepare the Wood
Someone very kindly gave me their old kitchen, and most of the timber from that is spoken for in other projects.
Some pieces of Heart Rimu and Sap Rimu which were used as bracing in the old kitchen are not involved in those projects, so they were available for this one.
I removed the screws which held the bracing to the back of the door, then broke the adhesion from the nails and varnish with a small wrecking bar ,and then drove the nails back through the wood to remove them.
Once this was done, I painted over the varnish with a dichloromethane paintstripper, left it to soften the varnish as instructed by the tin, and then scraped the gunge off.
After that, washed the pieces of timber with methylated spirits and left them to dry.
When dry, I went over the two flat surfaces of the wood with sandpaper from 40 grit down to 120. The edges of these boards would be cut off and discarded during the construction, so there was no need to spend time getting them looking nice.
Step 3: Drill Body and Lid
The two key decisions on layout were for the top layer of the base (Heart Rimu) and the thickness of the lid (Sap Rimu). I chose a location on the wood where no nail holes would be visible and there was the maximum clearance around all sides, and then laid the paper template there.
Using a bradawl, I marked through the template to leave a dot at the center of each circle.
I cut the large circle out using a holesaw mounted in my drill press.
Once all three pieces had their large hole cut, I cut the smaller holes in the top layer of the base, and then used that as a template to make sure that the smaller holes in the other pieces of board were aligned.
The net result is the three boards shown in the last photograph. I will not use the words "Mickey Mouse" to describe that.
Step 4: Form Final Void Shape
To ensure that the void for the double-thickness of the base was smooth-edged, I stacked the two boards for the base and clamped them together, before marking the straight lines tangent to each pair of circles and cutting along those with a jigsaw.
The lid was treated similarly, and then the two layers of the base were aligned together, glued and clamped.
A day later, after the glue had cured, all three layers of timber were clamped together, the final shape of the outside of the box was marked and then four cuts were made with a handsaw.
This gave three pieces of wood, two glued together, which formed a rectangular prism, with a rounded triangular prism cut from the middle.
Step 5: Assemble
To seal off the ends of the void, and to provide a final top and base to the piece, a scrap of thin plywood was found which was just wider than the box.
Lid and base were glued to this, taking care to make sure that the "good" surfaces of both were the ones still visible.
After the glue had cured, the excess ply was cut off with a handsaw and the lid and base were oriented correctly and clamped hard together.
All four outside faces of the sides of the box were smoothed off against a fairly coarse grit on a belt sander. This left the ply layer flush with all sides and the four edges of the box square.
Step 6: Finish
Once the two pieces were the correct size, they were sanded down through the grades by hand.
After getting them to 120 grit, they were coated with Danish Oil. Follow the instructions of your particular oil, but they are usually going to be something along the lines of "wax on, wax off."
Since the base of the box was going to be covered by felt, it did not need to be oiled, which meant that the lower portion of the box could stand on a block of wood for the oiling. The upper surface of the lid did need to be oiled, but since the blind end of the void would be covered in felt, the lid could be oiled and then supported on a piece of wood which contacted only the blind end while the oil went off.
After the first coat had dried (eight hours), I gave all the oiled surfaces a quick polish with 240 grit paper before applying a second coat.
Step 7: Adding Lining and Fittings
I used a scrap of paper to make a liner for the side of the void in the body. Once that was sized up and cut correctly, I copied the piece onto self-adhesive green felt, cut that out and stuck it in place. The end of the piece started with the corner closest to the catch, so that the join would not be very visible. Rubbing over the joint with a finger to merge the fibers after completion meant that the join was pretty much invisible anyway.
Repeat the process for the vertical portion of the inset in the lid, remembering to make the join at the other side, and then repeat again for two pieces to stick at the blind end of each void.
I printed out a variety of suitable verses relating to walls and cut one of them out to insert into the lid. The fibers of the felt provide a margin-for-error in the cutting.
The base was covered with some black self-adhesive felt so that the finished box will not scratch any polished surface on which it is placed. The base was covered with two pieces of scrap felt as it will not be seen, but again, teasing the felt fibers across the join leaves it pretty much invisible.
Lastly, the hinge and catch were fitted using the appropriate screws.
Step 8: Crimes Concealed and Future Advances
There were two obvious flaws with the final object.
The first is that catch which I had intended to use broke during installation, as shown above. This did not happen until I had installed the lid piece using two screws. The replacement catch slightly narrower, which means that the old screw holes are _just_ visible peeking out either side of the catch on the lid. I could have avoided this by checking the integrity of the planned fitting before starting the installation.
The second is that the lid opens all the way to 180 degrees. If the hinge had been mounted backwards, it would have held the lid just past vertical, which would look neater, and keep the text in the lid in clear view.
An additional leaning is that cutting through two layers at the same time with the jigsaw was hard and slow. Since the felt will cover a lot of problems, I should probably have just cut the upper layer nicely, and then transferred that marking to the lower layer and cut it separately.
On the positive side, I was amazed at how well the Rimu, especially the Heart Rimu, took the oil. It was the easiest timber I have ever oiled, and it looked amazing. This experience has definitely settled a discussion I was having about how to finish another project using other pieces of the recycled wood.
The first pieces of green felt which I applied to the inside of the void did not stick. On close inspection, it became clear that the self-adhesive backing had perished while in storage and there was only a dry, crusty residue where the glue should have been. I scraped that off with a sharp knife, and then used double-sided tape to adhere the felt to the timber, but it is concerning that the glue had decayed in storage. For future projects, I may just use plain felt and either contact cement or double-sided tape.