The only method of finishing balsa I take a more "dim view" upon than water-based priming/filling is coating it with paper.
Yechhh.
VOC-laden solvent-based ALL-STEPS finishing of wood or NOTHING for me.
Works the BEST and has the added bonus of PI$$ING-OFF enviro-whacko nut-jobs.

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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, and HAVOC !