hi,
In the past I've tried doing washes using oils with pure turpentine and white sprit
even though I've sealed the paint with varnish or clear the tank has started to take the leaper route with bits falling off ect, that was using clear with the varnish it went very , very sticky for a few days, any ideas were I'm going wrong! as it puts me off weathering

I never understood why, but both clear gloss and matt often drive you mad. Once I was using Valleyo Matt Cote (acryl) and in half an hour time in the same painting session it gave me a nice matt finish and after a while a sticky glossy one!!! I usually (like many other fellas here) use Future (in the UK is marketed as Klear and you can buy it at the household dept of Tesco's or Safeways, etc.). I spray it just out of the bottle and let it dry overnight before starting with washes. I never experienced problems with it apart that it looks to darken a bit the base colour. Once you're done with my washes I usually give a coat with Testor's Dullcote...
Ciao

I've tried spraying klear on leaving it to dry completely it was using this with my crusader which was my last bash at washes it caused the wheels to come off track skirts to crack ect how much klear do you use on a kit I've covered mines in it till you can see a good layer on the surface but still to no joy

I experied the same problem as yours on a few models. I think it has to do not with the coating itself, but with the thinner/glue reaction and the kind of plastic. In that case I solved it not "flooding" the model but doing a selective wash. Another tip coming from other Armorama fellas is to use Zippo lighter fuel to thin the oils fot the wash, it seems to be less aggressive than white spirit or other specific thinners and dries much more quickly...
Ciao

Why not try 1 bottle of humbrol enamel thinner as your medium for washes. Works well with both oilsa and enamels. i have been using this for 2 years now and never had a problem. I have washed over humbrol and model master enamels, various oils and tamiya acrylic and have never used a clear coat or future or anything else. But one thing I do belive in is, giving the paint time to dry properly before adding the wash ........ 72 hours to be sure. If you have problems after this with humbrol, you are one unlucky chap. Dont worry about the long waiting time ..... thats why i have several projects on the go at the same time so i can have something to do while I am waiting! I have used white spirit and turpenoid as thinners before without lifting problems, but they dont give the results of humbrol. It might be that bit more expensive but its worth it. No worrys and no mess-ups is worth the bit extra!!
Something that alot of people use is balsamic turps..... supposed to be very good ...I havent tried it though. Available from good craft stores or art supply shops!!
Good luck