The Effects of Water – H20:
Everyone likes a drink, we certainly needed it to help write this article on how water affects wood and all things woodworking.
Water is often seen as a benign, essential substance, but of course it can be very dangerous too. Like wind or fire it has both its positive and also its negative aspects. Too little and we can die of thirst and crops fail, too much and we can drown. It is a Jekyll & Hyde molecule that we just can’t do without. Bizarrely, it is composed of two explosive gases, one of which is breathable oxygen, and yet we can drink it, wash our dirty hands in it and mix up all sorts of compounds and even use it to put out fires! So let’s look at how it affects wood and all things woodworking.
Rot, which can be of either the wet or dry variety, is caused by bacteria living in wood or other organic materials and gradually eating away at it. The cell structure of the host material starts to collapse and although repairs are possible, eventually the decay will win.
Most, but not all rot occurs in exterior timbers. Fence posts and similar ground ‘planted’ timbers rot in the area from just above ground level to well below it. The deadly combination of air, water and thriving bacterial spores will destroy the wood in this zone. Strangely though, the bottom end of a post may be completely intact underground, especially if it is sitting in clay.
Ways around the problem include treating the timber beforehand, opting for metal fixing instead or using a replacement concrete spur. Timber cladding on buildings needs regular treatment to protect it from
the alternating effects of sun and rain. No piles of leaves or grass cuttings, etc. should be left against the cladding as damp will attack it.
Slow oxidation of those ferrous metals that we call rust are always a concern, while other metals such as copper and aluminium also oxidise in the wrong conditions. It can be distressing to see on decent handtools because once it starts you cannot put back missing metal, only restore it as best as possible. Iron is a bit more resistant than steel to oxidation, however there are various treatments that can be used to stave off further damage.
Firstly, you can remove rust using a chemical agent or by electrolysis. Then you can apply another agent to retard rusting and/or apply a metal primer or paint. You can prevent the rust problem in the first place by using an anti-rust compound in an enclosed space such as a toolbox or cabinet which will keep the atmosphere safe for tools. Oils and other lubricants also help maintain tools in good condition and make any moving parts work more easily.
Various things can be ruined by the presence of even a small amount of atmospheric damp including metal as previously described. Beech (Fagus sylvtica) biscuits for jointing swell when wet, this is how they are designed to grip inside joints after applying water-based glue. Unfortunately, if they aren’t stored completely dry, they will swell up and be hard to push into joints. Store them in polythene containers to prevent this. Glues or other compounds that need water added, can be spoilt by the presence of moisture. Although not so popular nowadays, Cascamite and Extramite powder glues should only be bought in quantities likely to be used in a reasonable space of time to avoid degradation from damp. If you do restoration work then be aware that animal hide glue can rot especially in a humid workshop and produce the most disgusting stink!
Woodworking is potentially hazardous for a variety of reasons. Water is generally beneficial here because it can be used to wash off dangerous compounds like paint stripper, bleach, and for washing hands or even washing eyes if dust or dirt lands in the eye area. A note of caution though. Washing can cause splashes so be correctly protected with apron, chemical gloves and eye protection. Medical eye wash should be used, and only use clean water as an alternative. As we know, water and electricity don’t mix so switches and sockets need to be away from the sink and hands should be dried before touching electrical appliances and switches.
Water is an essential component of a number of things. PVA (polyvinyl acrylate) glue, acrylic paint, water-based dyes and wood finishes being some of the obvious ones. The down side can include drying times and lack of resistance to frost when stored as the raw material. However, in warmish conditions drying times compare favourably to oil-based finishes which can be quite slow to dry. There is a tendency for grain-raising as the wood fibres swell up especially with wood dyes. This means rubbing down afterwards which can leave an uneven finish. Better to wet the surface first and rub down before adding dye in the hope of reducing grain-raising. There are two adhesives that actually ‘like’ water – CA (cyanoacrylate) glue needs water for repairs to porous material like ceramic to block up the interstices (small spaces in between) while it cures. Likewise PU (polyurethane) glue which has expansion characteristics cures better in the presence of moisture and is the only glue that could potentially be used underwater.
Hand washing as we know is important, but we seldom do it often or long enough and the use of workshop chemicals or handling rotten or dirty wood can be enough to cause a problem. It also helps prevent spreading diseases too. Expert recommendation is that you should take as long as it takes to sing one verse of ‘Happy Birthday To You, etc.’ (seriously) using soap and water and then dry your hands thoroughly on
a disposable paper towel.