I can attest to the taking months for the raw linseed oil to polymerize. In the 7th grade, for a school shop project, I refinished my dad's beautiful Remington 257 Roberts rifle stock. I carefully scraped the old varnish off with the edge of curved broken glass, sanded till it was smooth as..ahem...well...smooth. Then I applied the linseed oil...several coats over several days. The stock turned almost black...and took months to harden up...though it never seemed to get very hard. I finally had to take it home when school ended. My dad just looked at the stock, looked at me, blinked several times, and went back to reading his newspaper. Took years for the shame of that to wither away....