Re: Hardware Store Epoxy?
No all epoxy isn't the same, and every formulation will have different properties, work differently, and cost differences.
The real question is if hardware store epoxy is suitable for your needs. Without knowing what product you are talking about I couldn't begin to give you an answer. Other than generally for this you would want a thickened epoxy, where the thickening agent does not absorb water. Silica of some sort is ideal, but there are a lot of other options.