Hammerite has I am sure been health and safetied to the point where I have gone off using it. Personally I have taken to using blackfriar red oxide and then satin black, seems to have stuck to my bmw frame better than the hammerite I used of a few other bits and bobs, and is less than half the price from my local stockist. Thinners for either hammerite or the other stuff I use lidl cellulose stuff as it's cheap and cleans the brushes well enough, I've used it to thin smootherite for spraying too. I also have had smootherite react with itself between coats - annoyingly it was when I'd invested in the proper thinner too. The old finnigans hammerite was far better 20years ago, I used up all the odd ends of that in about 6 different coulours on my trailer a few years ago, the oldest paint has stood up better than the newer - all hammerite brand, applied on the same day, just bought across a 20 year timespan.