Brodybreaux,Agree with both above^
As long as it isn’t pressure treated your good to go. I recommend the select pine 1x2s. They are always straight, strong, and come pre-sanded for a decent price.
I prefer FlexSeal but it is expensive. Dryloc is cheaper and will get the job done. Both in HD Paint department. Whichever one you decide to use keep in mind that both of them work via chemical reactions and therefore produce fumes, this is called off-gassing. It’s agood practice to allow everything to air out for at least 3-4 days before adding your Cham. 1 week would be preferable.
My most recent build with FlexSeal: