Mr T":329lpqhr said:
I'm not sure if you are criticising the use of the reviver, as I specified, or just the use of boiled linseed oil.
The boiled linseed oil is the questionable element Chris.
If you want to clean a dirty piece of furniture the boiled linseed oil serves no purpose. To clean a dirty surface all you need is something to loosen the dirt and wash it away. White spirits and a mild abrasive, eg, wire wool or nylon pad is one method.
If you want to strip old dirty and crazed shellac then alcohol and an abrasive do that effectively and take you down to bare wood. Adding boiled linseed oil to the mix puts linseed oil on the wood. The question you have to ask is, "Do I want to apply linseed oil to this wood after I've stripped the shellac?"
Similarly if the reviver contains linseed oil and is used to clean up an antique that has a couple of hundred years of wax on it, you need to ask the same question, ie, do you want or need to add linseed oil.
Linseed oil doesn't add anything useful to the cleaning properties of the solvents and astringents in the mix you mentioned containing white spirits (turps), alcohol (aka meths) and vinegar.
Linseed oil remains after all the astringents and solvents have evaporated from the surface. It remains on the surface of a film forming polish that's not dissolved by any of the solvents in the mix. What useful purpose can a thin gummy film of linseed oil serve over an oil based varnish or lacquer is a fair question.
If the old polish was an oil, a wax or a shellac in some form, then the solvents strip the old finishes or polish away and the linseed oil remains on and in the fibres of the wood. Then the question has to be, "Do I want to replace the original finish that was on the wood with linseed oil?"
In this last scenario the original finish, now replaced with linseed, may not have had the colour changing characterists that linseed oil has. Boiled linseed oil darkens the wood. Another characteristic of linseed oil is continual darkening over time.
So, let's say the original finish on an old piece of furniture was a shellac of some sort over wood(s) coloured with natural vegetable and other dyes available 200 years ago. Naturally the original colours have changed over the years as the dyes have faded and the wood has oxidised and reacted to UV rays. Linseed oil in the reviver will immediately darken any wood it comes into contact with as the shellac is stripped away by the alcohol in the mix, and it will continue to darken over the years.
In this case has the reviver done the job intended, or has it unintentionally altered the nature of the piece entirely? And is this what was intended by the person doing the 'reviving'? Or would a different reviving technique be an altogether better method, eg, simply strip the old shellac with alcohol and re-polish the job with new shellac. Slainte.