lager under pressure?

i lager in corney kegs....my question is that I normally apply co2 pressure in order to keep a seal. after a while the beer is carbonated.....even though it hasnt finished lagering. is this a problem and if so can i lager without a seal on the keg....is this sanitary? can i also use finings on carbed beer....thanks

There is actually a closed fermentation technique that uses the end of fermentation to carbonate the beer in the fermentation Corney but it should be regulated with a spunding/relief valve setup.

It should not hurt at all to have a few psi for sealing the keg. Put some pressure on it, vent until the hissing almost stops, then leave it alone. You can vent just a bit each day if there is still some fermentation going on. Lagering under a little pressure is fine.