As my chain boke, I can now try to fix my leaky timing chain cover.

Is there a best method of puting this gasketless cover back on without leaking. I don't think this thing ever did not leak. I think the previous owner has has an Atlanta Rolls/Mercedes dealer try several times. It has been gooped up with sealant.

I was thinking about using silk thread. Airplane engine rebuild shops use it to seal crankcase halves.

Has anyone tried using silk or is the fit on these parts to imperfect for this method?