Wood – How to stop a board from “leaking” sap

interiorwood

I recently assembled a shed and one or two of the board on the wall are "leaking" sap:

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I thought it might stop after I removed the first batch but a few days later, it came back. Is there anything I can do to stop this (while still preserving the natural wood look)?

I've already put three coats of polyurethane over the whole interior.

Best Answer

It's a pitch pocket.

Just give it time - "a few days" is not much time in this case - it might ooze for a year before it gets done. You could try heating it (to make it ooze out faster), but that might have detrimental effects such as checking, a.k.a. cracking; or in this case, cracking more.