are there any hardware store thinners that are thesame? I assume that humbrol is mineral spirit but I am not sure. The reason I ask is that the price of a small bottle is usually the same as a litre of hardware bought stuff.

I just go to my local hardware/paint shop and buy 1 litre tins of generic 'enamel thinners'. I have had no problems with using it and it is a fraction of the cost of Humbrol thinners.

Cheers
Cliff