Sealing my waterblock?
 

Hello all, this is my first post so please bear with me.
I was wondering how everyone felt about RTV Silicon as a waterblock sealant. Has anyone used this before or even read about people who have? My block design uses a copper base and aluminum block could I solder these two metals together?

I have soldered Al to Al and I have soldered Al to Cu....but its not easy. I used a aluminum brazing flux and silver solder. Its pretty wild to see Al tin up with silver solder.
I suggest using plumbers goop or Permatex as a sealant.... the Permatex sealed blocks I made were joined so tightly I had to use a torch to seperate the halfs.Cutting a groove all the way around the inside edge of the mating halfs will leave a nice bead of sealant even after clamping the pieces together.