Just finished a project made with reclaimed pine. - high benchtop rack for slo-cooker, microwave, toasters/breadmaker and all those rarely-used but space-occupying things - pasta folders, thermos flasks, tinned anchovy puree with chives etc.
Leaving it unvarnished (it's quite "antique pine" dark anyway) for a while until I'm sure I don't need to alter or add anything but put into temporary service but thought I ought to do something about the old screw holes, knife marks and stuff even though I had no good quality filler to hand.
Took scoop from tub of brilliant white cellulose filler (poundland !!) and added a few granules of nescafe. Result - extremely close match, no mixing-in problems or unwanted dilution and the left-over makes a delicious and filling snack spread on a piece of cardboard.
I've used wrung-out tea bags and/or wood stain in the past, but it tends to make the mix a bit too wet if I'm trying to darken the filler appreciably. The coffee keeps it stiff (!) and the granules dissolve completely and almost immediately
I doubt the colour will fade, but I wondered if anyone else had experienced problems with their own beveragely-enhanced projects? (how about THAT for a feeder line?)
I know unvarnished pine tends to darken but I have no idea if this is an ongoing process once it has obviously changed. Experience?
er... don't try the snack thing.