Monday, 4 December 2017

The importance of humidity

Water has a profound effect on wood. When moisture content increases. wood swells up. And when moisture content decreases, wood shrinks.

When moisture content changes too much, joints can open up, the wood can bend, and it can split. And long slim pieces of wood such as jian and dao blades, are particularly prone to movement.

In order to minimise these effects, wood must be kept at an ideal humidity.

The drying room with jobs in progress

The recommended relative humidity for houses is 50%, with a recommended minimum of 40% and a maximum of 60%.

Some musical instrument manufactures are even stricter, and recommend that humidity should be between 45% and 55%.

To ensure that Tigersden jian and dao have optimum stability, the wood is first stored in the drying room until the moisture content has equalised. The wood is then worked in stages, and is allowed to rest in the drying room in between those stages. The above picture shows a number of jobs in progress, from sawn wood, to almost completed jian.

This extra resting time extends completion dates, but the waiting is well worth it for that extra stability.

Stored in an ideal  humidity of just under 50%

Humidity and moisture content are just as important for the Martial artist. Mudao and Mujian stored in very damp or dry conditions will be prone to warping or splitting.

Most houses will fall within the recommended humidity, but care should also be taken to keep mudao and mujian away from heat sources, including radiators and strong sunshine. Modern houses with central heating and no humidifier, have been responsible for causing irreparable damage to wooden furniture.

Shrinkage crack in oak furniture panel

When wood is exposed to very dry conditions, it can distort or split, and in extreme cases, shrinkage can become permanent. The picture above shows a wide shrinkage crack in a 1930s oak, desk panel. The split was caused by central heating, but even though it is now the correct humidity, the wood will no longer return to it's original size.

Some of precious woods in the drying room

The last pic is an enlargement of some of the exotic woods in the drying room. These come supplied with the ends sealed in wax to reduce the effects of humidity. Some of them are completely encased in wax. Similarly, oil finishes, and lacquers help to protect against moisture changes.

Wood is a living material, and when treated well, wooden objects last hundreds, and in some cases thousands, of years.

Tuesday, 21 November 2017

Chinese chisels

Using a Chinese chisel to Clean up a cramp pocket.

I have had these chisels for over six years now. Quite different from the British style of chisel that I am used to.  I wasn't sure about these at first, but the more I use them, the more I like them.

Easy to sharpen. Rather lightweight, and the steel is slightly softer than my other chisels.  The narrowest ones can bend when used to lever with, so they are not suitable for heavy duty work.  However, they are good for paring with, and they hold their edge for a surprisingly long time. The fishtail pattern is useful for getting into tight areas, so they are ideal for cleaning up these cramp pockets.

Fishtail pattern Chinese chisels

The handles could be a more ergonomic shape, and oddly they are all the same size. The size of a tool handle is usually proportionate to the size of the blade. But having said that, they seem to be fine in use, so I will probably not make replacement handles for them.

These Chinese chisels are very nice to have in addition to my regular chisels, and it would also be nice to have a more robust version of these for heavy duty work.

The cramp pockets finished, and the former in use, with a dandao laminate cramped up.......

dandao laminated blade- cramped up

Sunday, 12 November 2017

Chinese seal

Many thanks to my friend Jason Tsang, of White Horse Tai Chi, for bringing me this beautiful Tigersden seal back from Hong Kong. It was specially made by hand, and features a carved Tiger on the top!

The same characters as the Tigersden Registered Trademark that is branded onto the blades. Except that the mujian use a slimmer seal, because those proportions are more suited to a narrow blade.

Wen jian with seal

Although greatly feared in China, the tiger was symbolic of strength, courage and military prowess. It was also synonymous with protection, because the character for Tiger, Hu, has the same sound as the character for Protection. Tigers have been used as symbolic and talismanic images since ancient times, and have been particularly popular as talismans on hats and shoes for children. In the Ming and Qing dynasties the Tiger was used to denote the 3rd and 4th military officer ranks.

First prints of the new seal on Chinese rice paper

The second character on the seal is Xue, which in this case means den. However, it also means cave, so the name Tigersden, is actually a play on my own family name. This is quite fitting because Chinese culture has a long tradition of using puns, rebuses, and homophones.

Jason Tsang, and White Horse Tai Chi, can be found on facebook : 

Sunday, 5 November 2017

Brass inserts

The first post has a mujian with inserted brass balance weights and inserted brass seven stars decoration. However, achieving a clean tight join between the brass insert and the wood, is actually more difficult than one might imagine.

The ends of the inserts need to be chamfered in order to ease them into the hole, but an uneven handmade chamfer will cause them to skew to the side. The brass also needs to be inserted very carefully. Hammering a brass insert into a hole can force it to one side, compressing the wood and causing gaps to appear.

The quickest and most accurate method for truing up and chamfering the brass rod is to use an engineering lathe.

Chamfering brass inserts on engineering lathe

Not many woodworkers have engineering lathes, but brass is a fairly soft metal to work with, so if there isn't an engineering lathe available, it is possible to do this with the brass held in a woodturning lathe, and using a file to do the shaping.

Brass inserts - trued up and chamfered

Once trued up, the brass needs to be inserted into the wood. This is best done using an even pressure in direct line with the hole. Ideally, an arbor press would be used, but a drill press will do this operation adequately. I still haven't got around to purchasing an arbour press. In the following picture, the brass rod is pushed into the wood by a length of stainless steel bar. The masking tape is used as a depth stop.

Inserting the brass on a drill press

And a finished example of brass even stars inserted using this method :

Brass seven stars jian

Wednesday, 1 November 2017

Double cord grip wrap

I have been making mujian and mudao for well over 10 years, and I have been doing grip wrapping for almost as long, but this is the first time that I have had the pleasure of doing a double cord wrap.

This wrapping is done in the same way as a standard grip wrap, but it uses a narrower cord, twice as long, and folded in half. The cord in this case, is traditional Chinese braided cotton. Twisted cords are also authentic for these wraps, and can be found on antique Chinese jian and dao.

1mm round cotton cord

As one might expect, this type of wrapping is much more fiddly and time consuming to do, than a standard wrap.  As the wrap proceeds, the cords tends to wind around each other, leading to unwanted tension and crossed cords. So it is very important to be methodical and to double check each loop before continuing on to the next one.

Double cord grip wrap

The finished grip wrap feels quite solid to the touch and less compressible than standard wraps. As the the cord diameter is only 1mm, the crossovers have a fairly low profile. As well as being rather attractive, the wrap seems very serviceable.

Next, I shall try doing this style with larger diameter cords to see how that changes the feel of the grip........and if I'm feeling adventurous, maybe using two different colours in the same wrap.

Lightweight Tai Chi jian with seven stars brass inlay, grip wrapping, and solid brass balance weights