Well believe it or not, but I've gone and stuffed up and done the same thing !!!!! West Syatems 5:1 ratio. Hasn't set hard. Tried everything I could think of. Sun, heat light, hair dryer. Just made it softer.

In the end - used a Linbide scraper to shave it all off. Actually quite easy to do.

I noticed, that this dud mix, seemed to soften what was already hard glass underneath! Would that be correct?

Now all off, sanded, ready for a new correct mix.
David