Fcers, need some help on an (imaginary?) issue. i use an o-ring like that in the pic below to make the operation air tight. if the o-ring is heated and close to the air path, am i being anal in asking myself whether it's safe ie will it off-gas or something? For those who do use o-rings, would you use silicone from china http://www.dhgate.com/store/product...mm-thickness/176155772.html#se1-1-1|607377440 this seems a lot more quality but if it's viton. is it as safe as silicon? http://www.ebay.co.uk/itm/METRIC-VI...t=LH_DefaultDomain_3&var=&hash=item337c929cb7 Anyone with o-ring experience could chime in?