Poly over French polish

Has anyone tried putting a spray-on polyurethane layer over a French polished tabletop?

I'm not just talking about painted on shellac, but a full-blown mirror polish - the kind that takes hours of faff with a rubber. Will the poly actually stay on, or is there nothing to bond to without sanding the shellac?

I'm hoping the answer is that the finish will still look quite fancy, and the poly will bond fine and protect it from spilt drinks etc., but that sounds a bit optimistic. Thoughts?

I would be sanding back.

If it's a great finish leave it alone and treat it with care. Put poly on it and it will look like poly and you will lose the beautiful finish to a plastic look that will degrade the look of the piece. YUCK. :yucky:

If you want to make it more durable try Polish Reviver over the French polish. It will make it harder to damage with water, alcohol, heat, etc.

For what it's worth the poly can also be damaged with heat and alcohol, etc and it's a lot harder to repair than French polish.

From Polish Reviver info sheet:
Polish Reviver has the ability to protect or retard the time it takes for water, heat and alcohol to damage most polished surfaces. i.e.:If it takes 5 minutes for a unprotected surface to mark it could take from a number of hours to a number of days for the same marking to occur after using Polish Reviver.

For what it's worth:
Many years ago I had a cedar table top (top table from a nest of e tables) that I would mark up sections of, with water, heat, alcohol, etc to show how well and easy the Polish Reviver worked. After redoing the whole top over time I tried to damage it again with the same things and couldn't.

I had a cup of boiling water sitting on it which I kept filling with more boiling water and letting some to spill over the top of the cup. did this for around 2 hours and couldn't mark the top with the water eventually the only damage done was that the constant heat slightly melted the shellac so that when the cup was eventually removed there was a very slightly indented ring where the heat had been concentrated from the base of the cup. I also poured whisky, red and white wine, brandy and finally metho onto sections of the top and none of them made any mark.

Hope this is of some help.

Cheers - Neil :U

Oh wow, thanks, I'll check it out. It would be a shame to change the finish, it does look nice.

Thanks for the tip,

Sam