I have a really hard time finding a D-Limolene supplier in Europe (D-Limolene is a solvent that dissolves HIPS plastic used as 3D printing material ) so my next best option is ABS . I want to print a mold core and after lamination to dissolve it , if i print in ABS i have to use acetone to dissolve it . I  must soak my core in acetone for an hour max , would this be enough to ruin my part ? I dipped a small part i made in acetone for couple of hours and i notice some small softening of the surface part but nothing major ,as far as i can see. Since i want my part to take loads i don't feel really comfortable using acetone . What is your view on this?

Rob is talking high end F1 applications, so using pre-pregs. If your max Tg is 90 then you dont want to take it up to 160.

Acetone is commonly used for this 'lost core' sort of application, however immersing epoxy in acetone isn't really ideal. If it is the only way, then it probably wont suffer TOO much with only an hour, but I would want to make sure the epoxy is thoroughly cured - which realistically means giving it a post-cure up to your max Tg.

Thank you so much Hanaldo for your honest view you really want to help someone like me .
Acetone is my last resort solution .I am thinking of test print in PLA that has deform temperature of 55C and then purring some hot water through.
I f  this doesn't work i print in ABS and  dissolve with acetone.