Trugs, bird houses, dovecotes, etc are all designed to be used outdoors and subject to everything Mother Nature can throw at them. Bare timber left in the weather develops a grey patina; it happens to all timber although some take longer to go grey than others. It is part oxidation (like rust on steel) and part as a result of exposure to UV. There are other elements involved but those two are the main ones.
For many people that ‘grey’ look adds character to the piece; bird houses and trugs are often left to go grey and crack to give them an ‘aged’ or ‘rustic’ look. The great thing about timber is that it can always be restored to how it was when made. Generally a light sand will remove the patina and then it is just a matter of applying protective oil or wax.
If your house gets seriously weathered and you want to return it to its original look then you’ll need some course sandpaper (like 60 or 80 grit) and a bit of work. After using the course sandpaper, gradually move to the finer stuff (like 240 grit). This will give you a nice, smooth finish, then re-apply linseed or tung oil and finish with some beeswax polish (or similar) rubbed in using 000 or 0000 steel wool. Finally, buff the excess wax off with a soft cloth.
You can apply a varnish or polyurethane finish to freshly sanded timber; we don’t like it much but in some situations it can be good. From experience, varnish tends to flake and peel off after a while (especially if it’s in a sunny area), so there is no real advantage over a plain oil finish.
We use an exterior PVA glue for all joints (pretty strong) and sometimes dowels or screws – it would be unusual for joints to split and come apart but it can happen and this is no different to the timber itself – it’s can also crack. Generally, there is nothing to worry about unless the integrity of the item is affected – in these cases it’s a good idea to contact us for advice on the best course of action.
Blue Swallow Designs 