Can anyone suggest a suitable repair material for filling the minor grain cracks from expansion and contraction with the seasons in a south facing hardwood window ledge? It really gets toasted in summer sun and this year with so much water about it has taken a battering. It is about
30 years old and otherwise in reasonably good condition.The grain cracks are shallow and narrow mostly 1mm to 2mm max and their width varies with the humidity as the wood flexes in the sunshine. They are a bit too deep I think for just filling with wood stain but that might be what I do if I can't find anything better.
Also can anyone suggest a similar grain filler that will stand being on a south facing black firedoor (or in this case more a grain leveller since the problem is that the grain stands proud and sanding doesn't seem to help). Thanks for any suggestions.