Trinket boxes, trays, furniture, etc are protected from most of the things that affect timber outdoors; the exception is sunlight. Window glass filters some UV but anything left in a sunny position in the house will suffer the effects of UV – and heat.
Heat by itself is not a big deal (unless you throw it in the fire – then it is) but the effect heat has on the moisture content of the wood does have an impact. There is more about moisture in wood here but, briefly, as wood dries it also shrinks. This shrinkage can cause joints to open up and cracks to appear; this is not so bad – many old pieces of furniture will have imperfect joints even though the craftsman who made it would have done a decent job of it.
The only guaranteed way to ensure joints don’t open or a flat piece of timber doesn’t buckle or warp is to seal it in a humidity controlled room (a complete vacuum is even better). Aside from that, regularly applying oil or wax will help as it leaves the surface fibres slightly moist and adds a layer of protective ‘film’.
There are many commercially available wax-based finishes that can be applied at regular intervals. We use our own recipe beeswax finish which works a treat (recipe available here if you want to make your own) but any waxy polish is fine. If the surface of the timber is still nice and smooth then the wax can be applied with a soft cloth and buffed off with another cloth. You can also apply the wax using a 000 or 0000 grade steel wool; all this does is add a very fine abrasive element – just like polishing a car.
If the timber is starting to get a little rough you may have to give it a light sand with a fine grit sandpaper (available at most hardware stores). We finish all our interior designs with 400 grit sandpaper but, really, that is getting pretty extreme – 240 grit (or thereabouts) is fine. Once you are happy that the surface is nice and smooth and any old finish has been removed then you can re-apply a wax polish – keeping in mind the use of fine steel wool.
If sanding, try and keep sanding in the direction of the grain. Sanding across the grain in wood can leave ‘scratchy’ marks – not so good.
In the worst case scenario (thinking damage) remember we are are here to help out; simply contact us and we’ll do what we can to sort it out.