Some pics of fatwood or resin saturated fir.
First, a chunk of heavy pitch-saturated fir I cut from a snag that was mostly red rot. Door frame gives a size reference. It is so heavy I do not think it would float, though I did not test that. It is totally dry and non-sticky. Any pitch balls etc. on the outside will crumble.
Close up of the inside of the same pice of wood. The outside is weathered.
After cutting the large piece into 4 or 5 inch long chunks, I split it with a big knife into slabs as thin as possible. The straight old growth grain splits easily going one way or the other so try it each way. I think it is from the top end of the tree toward the roots that splits straight without splittling out to the side, but never can remember.
I wrap a small handful of these slats in a paper towel, put that bundle in a zip loc and carry it always with my small fire making kit. The paper towel protects the zip loc from being shredded by the sharp ends of the wood, and it also burns. A large bundle of this stuff is under the seat of my 4x4 and another in my cook kit tub, etc.
Scraping the resin wood with a knife blade or sharp rock produces a fuzz. The fuzz scraped up in this photo ignited on my fourth spark stroke, and I am not very good with the fire steel yet. In previous tries, it ignited on first or second stroke. The slat is less than 1/16 inch thick and burning fuzz starts the slat on fire, which then works like a magnum match.