Adhesive Sealers first option
Below a photograph of the sealers we have been using and they are the ingredients needed to make RF.5 which was developed in house.
The silicone creates a good double wedged or hourglass shaped seal while the RF.5 is used on the outer seal (It has a very nice appearance if you remove the excess thoroughly.
Silicone RTV and AB glue
(Available in China)