Monday, April 22, 2013

The undercarriage

As promissed earlier today, some pictures of the undercarriage of the table. An overview, the mortise and tenon joints with drawbore pegs and the wedged tenons. Nothing is totally perfect, but for me it's perfect enough.

Large scale handplaning

The undercarriage of the table is ready. I finally found enough courage to do the glue up, and it wasn't very difficult after all. I will make some pictures for another blog.

So, no more excuses and onto the final part of the table, the top. I have selected two wide boards and one narrower one, which hopefully will make a nice looking surface. The only boards wide enough were cut from the centre of the tree. This of course gives plenty of shakes and knots and weird grain patterns. It also makes for some heavy cupping, bowing and twisting in the boards. They are 5cm thick and I want about 4cm, so I should have enough meat to reach a flat surface despite the crooked nature of the boards. This also means a LOT of handplaning.

As you can see, the boards are really overpowering my punny little 6 feet bench. Not only my bench looks small under these 2.10 meter long monsters, the shop reaches its limits too. I quickly learned to pull the bench out of its corner, so I can reach all around. First removing most of the bump on one side with the German scrub plane (agressive little beast). Then I follow up with the foreplane to get something like flat. Then turn the board over and flatten the show surface.

I spent most of yesterday to reach this point. In the picture it doesn't look half as good as in reality. That weird greeinsh streak through the middle is the centre of the tree, but it isn't so garish as it looks like here. Under a coat of oil it even looks nice!

One bummer. My elbows gave out. At night it was really painfull. So I give the project a rest for a while, maybe even seek some medical assistance. We are on holliday all next week, so rest shouldn't be too much of a problem.

Monday, April 15, 2013

Hide glue

Until now I have used "standard" Pvac glue for assembling all my woodwork projects. Overhere in The Netherlands know as the white wood glue. You can buy it everywhere, and it is rather cheap and easy to use. In the past, say until WW2, a natural glue made from the bones and skins of animals was the standard. Hide glue, or bone glue as it is know overhere. The bones and skins are cooked for a very long time, filtered and dried. You can still buy it, usually in the shape of small pearls. It's also pretty cheap, but not so easilly available. To use it you must dissolve it again in water and heat it around 60 degrees Celsius.

When I bought an old carpenters chest, I found a double cooking pot for glue inside this chest. Water is heated in the outer pot and the glue gets hot "au bain marie" in the inner pot. You put the pot on a stove and let it simmer slowly, all the time watching the temperature, because really cooking the glue destroys the adhesive properties. 60 to 65 degrees is ideal and higher not recommended.

Hide glue has its own pace. It's not like you  grab the bottle and squeeze some glue on your joint. First the glue pearls must be dissolved, which takes about two hours. Then you heat the glue pot to the required temperature. You stir a lot and watch the viscosity. It should be sirup like, not too thick, but also not watery. In the mean time you heat up the workshop and ideally also the wooden project, because you need warmth for the next step. Until now everything moves very tranquile and feels relaxed. But actually gluing your joints needs tremendous haste. Within a minute or so the glue cools and starts to gel and the joint shouldn't move anymore. For simple joints this is ideal. You don't need clamps, you just hold the parts together until you feel the glue grabbing. Complex joints are a bit stressy.

As soon as the initial gelling of the glue happened, it's time to relax again. The next phase is evaporation of all the water. This takes a much longer time. After a night the glue is allready very strong and the joints can be fully stressed. The strength will increase further, depending om the humidity of the environment.

So, why did I want to use hideglue? Good question. Probably because I just want to use that gluepot. And because it is new skill to learn. Some pictures. First the glue pot. I have added an extra pot, in this case a used glass  jar. This is a bit smaller thus better suited to my projects and it is easier to clean. A meat cooking thermometer to watch the temperature and a brush for stirring and applying the glue.

I did a lot tests this weekend to get familiar with the process, and to actually gain confidence in this glue! I didn't need to worry. It is slow, but when it dries it glues like crazy, stronger then pvac I think. So, on to my project. I did mostly one joint at a time, then letting it rest for a while to get a bit of initial strenght in that joint.  I glued the legs to the short rails and I glued the long rails to the very short rails in the middle. The latter with through mortises and wedged tenons. That was allready stressfull enough! I will assemble these parts together later this week when the glue is completely dry.

Clean up is easy with this glue. After a while the squeeze out is rubbery and can be pulled of the wood. A hot damp towel removes the rest, without a trace left. That is at least one big advantage of hide glue. The other big advantage? It's fun!

Monday, April 8, 2013

Drilling weekend

This was a boring weekend, as they say. Lots of holes needed to be drilled so I can attach the tabletop with screws to the undercarriage. The handtool equivalent of the electrical drill is the brace. My father used to be a big fan of the brace. He used it for years after he got his first electrical drill, while I wasn't much of a fan at all. So I took to the brace reluctantly, while I liked the handplane and handsaws almost immediately in my new found woodworking hobby. But my father never sharpened the bits, and that makes a huge difference.

So I started with some relief holes, where the bolt heads will be hidden. 24mm wide an about 2mm deep. They are so wide to give ample room for woodmovement. I cut these with auger bits. The first one seemed sharp so I made some holes in an offcut to get used to it. It was obvious this bit wasn't very sharp at all, and then something went wrong. The leadscrew broke off! Luckily I have accumulated quite a collection of bits, so I could move on to the next one. I sharpened it with a needle file, which made a huge difference. Drilling was very easy now, despite the large size of the bit. Here's a short video. Not really interesting to see, but it shows how good a sharp bit in a brace works.

After drilling all these holes, I drilled a smaller one inside all the way through, and started to elongate this smaller hole to give room for the screw to move. To elongate I drilled two similar ones next to the hole in the middle and then proceeded to cut out the remaining wood to create a mortice. This proved to be much more work then anticipated. Allthough drilling with brace and bit is fun, after 50 holes the novelty tends to wear off. And chisseling the mortices was also no fun because there is not much room and the chisel tends to get stuck. With hindsight, this is more a powertool technique, not quite suitable for handtools.

Having started this method for the short rails, I had to finish this chore. But I was reluctant to use the same method in the other short rails. That would have been 8 extra elongated deep holes. Because this is going to be totally invisable when the table is assemble, I used an oldfashioned technique, small blocks of wood with a lip, which fits in a groove in the rails.

This is much easier to make, and more fun. First I cut a rabbet in an offcut from another project. After cutting  the rabbet a lip remains. And it is good excuse to use one of my moving fillesters.

Then I had to plow the groove in the rails. I used a Stanley 45, because this one has all the cutters sharp and ready. After adjusting the plane it is a breeze to cut the grooves.

And then I only had to drill and countersink a hole for a screw, and saw all the little blocks from the rabbeted   board.

That's all the boring excersise this weekend. I cleaned up all the remaining boards with the smooth plane, and now I think everything is ready for the glue up.

Saturday, April 6, 2013

Video, chamfer plane

I am proudly presenting my Mosely chamfer plane in this video. It's being used to make nice and even chamfers along straight stock. Very easy to use, almost fool proof. The plane was made somewhere in the late 19th century in London.