Hi Steve
No, the epoxy mastic is formulated to be painted on bare metal ( Bit like hammerite was in the good old days )
I bought the smallest size pack, so far have painted all of my wishbones, rear uprights & driveshafts, still have just under half a tin left
Had I not already painted my chassis with Galvafroid & Red hammerite
I would have got the larger pack & done the whole lot.
It doen't take that much thinners to thin it down .... Tis like treacle when first mixed but the addition of a little thinners really does the trick
Hope that helps mate
