I want to seal the end grain on several redwood Adirondack chairs and planter boxes to slow down the rotting process and other moisture damage. Didn’t want to buy expensive sealing epoxy just for this. Tested System Three Epoxy with #2 Hardener on the end grain of four different species.
Fresh mixed epoxy is quite runny and it kept soaking into the end grain of all samples for about an hour or so; I applied more epoxy of the same mix a few times over an hour. After about two hours the epoxy gelled. The samples were cured for a day and then split on the TS to reveal the cross section.
Here is what I saw.
Cherry: the epoxy penetrated about 1/32” deep, with some streaks going deeper.
Poplar: epoxy barely went inside, about 1/64” deep, at most.
Douglass Fir: epoxy barely penetrated the late wood, can’t see much; however, went 1/8”-3/16” deep into the early wood.
Redwood: wicked in quite a lot of epoxy—about 1/8”, late wood didn’t soak up much.
Maroon stripe above samples mark the area where the epoxy was applied.
Overall, I guess System Three Epoxy with #2 Hardener works for my purposes and I’ll be sealing the end grain on the outdoor woodwork with it. Alternatively, #3 Hardener gives even a thinner epoxy, it would be interesting to see if it would go deeper. However, it requires long curing times at relatively warm temperatures.
-- "If you're not counting the ripples when throwing pebbles in the water, you're wasting your time."