I have found Tiger Seal to be better than Grey Stripe, which kind of lifts off as you smooth it down. However, the Tiger Seal started setting in the tube after the first use and I ended up cutting the tube open to use the rest. This was despite wrapping it in clingfilm.
I have never used it as a weld sealer I normally just use a oxide primer then paint over that but that is on my 4x4 i might try that PU40 on my slider welds when i eventually stick them on