Do not overestimate Tamron's weather sealing. My recent experience tells that both sealing against dust and humidity are close to none.
Did you have a problem with this lens? Will you elaborate?
6D, Fuji X-T1, X-E1
Tamron 24-70 2.8 VC, 70-200 f/2.8L IS II, 400mm f/2.8L II, 100mm L IS Macro, Sigma 85mm, & 35mm f/1.4's, Rokinon 14mm f/2.8,
Fuji 23mm 1.4, 35mm 1.4, 56mm 1.2, 14mm 2.8, 18-55, 55-200