DIY Stew":1d9sum6i said:
I have some Canadian Maple and would like to change its colour, I am not sure whether to use stain or dye, what is the difference? I would like to be able to sand the wood after it is stained or dyed, so which would be best to use? Stew
Yours is an interesting question because when I started in this game back in the 1970s dyes and stains were different concoctions. Dyes were made of fully soluble colouring agents. In other words, if you bought a powdered dye and put it in an appropriate solvent, eg, water, spirit, or oil, what you got was a liquid where the colouring agent was fully dissolved colourant at a molecular level. Each individual unit of a dye is a molecule. The dye penetrates the cells of the the wood fibre thus colouring the wood.
Stains on the other hand contain finely ground solid pigment that do not fully dissolve in the liquid carrying them, although there may also be dye in the mix. Pigments are opaque and can be made into paint, but with paint there's a lot of pigment, as well as other things to make the pigment lock together in the film. Stains therefore are a liquid carrying just a little solid pigment (as compared to paint) that largely colour the wood by lodging in crevices, pores, sanding scratches, etc. Stains need a binder in the mix to help them stick to those crevices, etc, and commonly the binder is either a little linseed oil or varnish type additive.
I don't know when or why it all got confusing here in Great Britain-- sometime in the 1990s I guess when I was living in the USA. Nowadays, if you go and by "stain" it's no longer obvious if what you are buying is a dye or a stain. The Americans, on the other hand have kept pretty strictly to the definitions I gave above and mark their colouring agents as either dye or stain, so you know exactly what you are buying. Here in Great Britain everything used to colour wood now seems to be labelled stain, even if it's not. The only way you can tell what you are buying is to look carefully at the label. It might say "dye stain", so now you can hazard a guess what you're buying is probably a dye. It might say "pigment stain" which tells you that there is solid pigment in it, but there may also be dye in the mix too. The label itself may not be particularly informative and it just will say "stain", and the only clue to it being a pigment stain will be instructions on the can saying something like, "stir thouroughly prior to use, and stir regularly during use to prevent settlement of solids".
As to which you use to colour your maple, you can use either dye or stain. Both can be sanded after their application if that's the look you want, but you'll get different results. You'll need to experiment to see which you like. One bit of advice though if you go with a stain containing pigments is to perhaps not sand the maple too smooth. You are probably best to sand to no more than about 150 or 180 grit so that you leave striations for the pigment to lodge in-- you may not like this appearance, especially if you sand with a random orbiting sander; it generally looks better (in my opinion) following hand sanding. Maple is a fine textured wood so there aren't a lot of natural places for pigments to lodge, hence the suggestion to finish sanding at a somewhat coarser grit than you might normally, eg, 220 or 240 grit. Stains tend to be prefered on coarser textured woods such as walnut or mahoagonay which are both medium textured, or on oak, ash, chestnut, etc, which are all coarse textured. Slainte.
