Bigpoppa3346, thank you!
M21 is the easiest sealant I've ever used and durability is top notch (so I've read). It comes off so easy which is what I love. I actually read a thread that said if you apply M21 to a plastic zip lock bag and wait until it cures, the M21 will actually be able to peel away from the baggy...now that is a true barrier!! I ordered a gallon from a local distributor and they accidently ordered me two...but I took it anyways...Im glad I did!