Ooops!

I spent the last two years milling, curing, hand planing and custom fitting together a wide slab scarlet oak floor in my treehouse.

After a solid month of work hand planing the planks, installing and applying 4 coats of tung oil (mixed with citrus solvent – 1:2, 1:1.5, 1:1 and 2:1) I left on vacation for a few weeks to let it dry. 

My dear 83 year old father then took it on himself to apply another coat of what he thought I had been applying – but what was in fact a 1:1 mix of dark tung and spar varnish. 

It made me sick to my stomach to hear the news.

After years of thinking about and crafting every board for this floor, hand planing (about 6 hours a board) etc, I was so excited to have an all natural tung oil finished floor that would last a lifetime and develop a patina and wear as the tung oil finished floor wore over the years. 

Does anyone have any advice for stripping the varnish without ruining/sanding down the hand planed finish of the boards? 

Any ideas appreciated.