What are you using for pickling solution? Sodium bisuphate is not harsh on most plastics. Heavy gauge copper can be used to make a pickle container and eventually it will have to be remade as the copper gets eaten away. If trays are not a large volume of your work, you might try different plastic containers for your pickle. pour it back into your 5 gallon bucket after you use it so it does not break down the other plastic. Good luck on your trays.