Woodfinish Man":3cx36ozc said:
Never heard of 'pre-stain conditioner' any more information?
I came across this stuff when I lived in the US. It was, for example, part of the Minwax range of finishes, mostly aimed at the DIYer rather than professionals. Their oil based stains are dye with a pigment element and a binder, eg linseed oil or touch of varnish, to lodge in open pores, hence the name stain as opposed to dye.
Minwax sold a pre-conditioner that you applied prior to putting the stain on and you applied the stain within about 1/2 an hour. The pre-conditioner's main job was to reduce or prevent blotching in blotch prone woods, eg, maple, cherry, pine, etc. As far as I could ever work out this pre-conditioner was mostly white spirits (mineral spirits as the Americans call it). The idea I think was that because the wood grain was partially choked with white spirits, particular the exposed ends of vascular tissue that hit the wood surface at an acute angle, the stain wouldn't absorb into those parts so well, thus leading to a more even colouring up job.
The truth is that I don't think this pre-conditioner is essential. You can get a similar blocking effect by applying a thin (or even very thin) coat of shellac and sanding it back pretty well leaving those severed ends of the vascular tissue partially blocked. Thus, when you apply the colourant, dye or stain, the uptake is reduced in those partially choked spots.
On a side note, one good element of finishing products and writing in the US is that dyes are dyes and stains contain pigment and a binder-- easy to tell apart which is unlike here in the UK where the manufacturer's terminology seems sloppy nowadays as is, I suppose, those writers that discuss finishing subjects in books, magazines, etc: it didn't used to be when I started because in my mind dyes and stains have always been different formulations to achieve different end results. It just seems to be that the manufacturers here in the UK no longer differentiate between the two and everything is labelled 'stain'. You have to look really hard to determine if it's pigment stain with or without dye and a binder, or dye alone without either the pigmentsor binder. Slainte.