What he said...
Plus, here is a tip that will save you money and gives excellent results.
For INTERIOR seam sealing...consider using LIQUID NAILS - right from the good old hardware store.
You can use some mineral spirits to slick it and smooth it...and it will stand up to anything else out there you can get from the auto body store.
I actually picked this tip up from a fellow that does six figure restorations.
He puts masking tape on his finger, dips it in mineral spirits, then uses it to press and flow the material into tight joints.