How to seal sap leaks?

[NM_Shooter]

Am building a lofted bed for my kid.  One of the 4x4 posts that I have is seeping a little bit of sap in a few small spots.  This has two coats of minwax varnish on it.... Is there a way to seal these spots that are weeping, or are we just going to have to live with it until it fully dries out?

[Don_P]

That might take a few generations. Setting pitch is tough. There are many volatile compounds in pitch each with it's own set of freezing and boiling points and then each pitch pocket contains a different quantity of pitch. A kiln usually runs pine up to 180 degreesF for some amount of time to hopefully drive off all the volatiles that will flow below that temperature and anything that is left should freeze as soon as the heat is removed. Then as long as the stick doesn't see that temperature or higher again the pitch will not flow. That sounds great in theory and most often it works. The temperature has to be maintained for long enough to vaporize all of the volatiles for that temperature for this to work. When there are concentrations of resin they can still contain some quantity of the lighter volatiles and they can begin to flow at lower temperatures. I run into this with my air dried pine as well, when the house hits a new high my wood can sweat beads of resin, usually I'll brush them off when it refreezes, all depending the pitch can remain tacky if it came from a large gooey pitch pocket.

I'd try to get it as hot as possible for as long as possible first, then the old standby was shellac to seal it. If you go that route check compatibility of finishes.

I was working on a heart pine beam on one old cabin and had ripped it in half out in the sun on the porch. The beam had been installed in 1865. As we ate lunch the pitch began to bead on the old air dried timber in the sunlight.

[NM_Shooter]

Argh.  I was afraid of that.  OK.. I guess I'll wipe the spots down with mineral oil, and hit it again with polyurethane.  I tried to pick out the straightest and driest.  Should have bought the redwood :-(

[MountainDon]

Takes me a while to percolate some thoughts...

How about wrapping some absorbent material over the pitch pocket like a gauze pad bandaid. Then wrap the post with a heating pad or blanket and leaving that on for several hours to a day. Most of the pitch might flow out and you'd be way ahead of the game.