How do I stop my underwater chainsaw from stalling when I hit creosote-soaked pilings?

Ran into the same thing demoing a railroad trestle a few years back, and the answer is basically you don't beat the gum, you plan around it. Creosote never really cures, so every inch of cut smears soft tar into the bar groove and drive links. No bar oil on earth stops that, so don't waste money chasing one. What worked for us was cheap oil and a rotation system: keep three or four old junk chains on hand, run one until it loads up, then swap it and drop the gunked one in a coffee can of diesel to soak. Fifteen minutes in the can and a wire brush takes 90 percent of it off. Scrubbing cold right after the cut, like you're doing, is the slow way because the tar sets up hard.

Did a seawall rebuild with old creosote timbers a couple years back and the thing that saved me was a bucket of oven degreaser from the kitchen aisle, not anything saw related. Let the loaded up chains sit in that overnight instead of diesel and most of the tar just wipes off with a rag after. Cheaper too and no fuel smell in the truck. Also found hot water helps, I'd rinse the bar under the marina washdown spigot while the wood dust was still soft. Anyone tried pressure washing the chain? Seemed like it'd blast the gunk out of the groove fast.

This whole thread makes me glad my mess was just one piling. Only tip I've got that hasn't come up yet is to cut a shallow kerf first, like half depth, then go back for the full pass. The second cut chews through cleaner since the tar's alredy been sliced. Slows you down overall but way less than stopping every few inches. Also, does anyone know if that gum builds up faster with a new chain vs a half worn one? Wondering if I should save my dull chains for creosote jobs.