Would anyone have concerns about using an old bottle of low viscosity Hy-Gard (J20D) that was opened (and re-capped) many years ago? Has been stored in a shed exposed to extreme summer and winter temperatures.
I wouldn't hesitate using even a 10+ year old opened and tightly sealed bottle at all. Done it.
Thanks for your input. I wonder if the same holds true for a 5-gallon bucket of Hy-Gard, due to the additional surface area of oil exposed to air inside the bucket, and also the questionable seal on those buckets with the pour spout on top.