: Actually, linseed oil seems to be a problem even when used only in
: salt water.

I dunno, my frames are still looking bright, no black anywhere. There is some blacking on the canvas in the cockpit area. I'd say that was from moisture rising from the ground beneath the kayaks as the ends are free of mold. I store them outside.
I think the type of wood has a bearing on mold development, the coaming edge I used was hazel on one and willow on another, the risers are red deal (probably Scots pine?). Both oiled with linseed. The hazel got moldy and crumbled after two years or so, the willow lasted longer but went brittle rather than moldy. The risers are undamaged.
Hazel is a high starch wood, willow a bit less so but has an acidic nature, red deal (whatever it is) is a resinous wood, could probably make turpentine from it.

I also had a frame from my first (very poor) attempt at a baidarka which was left on the ground, after dismantling, for about four years. Red deal and linseed oiled and it only bleached from weathering, no mold. I don't use any wood preservatives. Tis a puzzle.

Mike Savage (puzzled)
South West Cork