Plaster-like layer under paint?

I’ve just acquired an old mirror and have set about repainting it. Upon scraping a small patch of paint off there is a layer of something underneath. It seems like plaster? I haven’t heard mention of anything like this prior to now and can’t seem to find any information now. I have photos but am not sure how to upload them.
Thanks in advance for any help,

PuffinInTegel's picture

If it's the picture you posted on Facebook, I'd say it was a botched repair job covered with car body filler compound or whatever you call it. I'd try prising it off to see what's below.
Pictures have to be linked using an html tag, I'm afraid. There is a description* here on the forum, but I'm taking the liberty of linking your photo here.
odd filler under paint .
If you only want to sail the boat for a season, glassing over this might do. But if you wish to keep it for longer use, a wooden patch repair job involving the removal of rotten bits is to be recommended!
BTW welcome to the Forum!


PuffinInTegel's picture

Apparently Facebook changes the security hashes of the photos and the URL of the picture no longer works.
All I get is a message saying "URL signature expired" :.( .