After designing and installing a very high end hand selected custom milled rustic oak floor, I chose to go with a tung oil finish. I preferred the ability to repair any damage from daily use with ease, knowing the trade off was in regular maintenance. I totally saturated the planks with a 30/70 to 50/50 tung oil /mineral spirits blend. I then wiped off access until no more surfaced. I noticed that about a month later the floor began to blush white or polymerize where the sun passed over it from my skylights. But the kicker was when high humidity 75-80 set in. The entire floor blushed white. I can wipe down with mineral spirits, but once it dries the floor goes white again. Sanding or scrubbing with scotch brite only exacerbates the condition. It gets much worse. Wiping down with a 50/50 blend seems to take care of the problem, but only for a very short time, maybe a week or two. after all my planning this blindsided me. Do I have to install air conditioning? Any suggestions or experience with this issue would be greatly appreciated. Regards, and thanks in advance.

"After designing and installing a very high end hand selected custom milled rustic oak floor..."
"Do I have to install air conditioning?"

Seems like these two things are conflicting - you've put a lot of care and attention and probably money into this custom flooring project, obviously you've done your research into finishes and maintenance, yet you didn't plan for humidity control? One of the first conversations I have with any client, especially during a reno, is about climate control - the wood needs to be installed in the climate it is going to perform in, and that should be consistent all year round if you want the floor to behave consistently. This means monitoring your Relative Humidity all year round and using humidifiers or dehumidifiers as necessary. The goal range is 40-50%RH for most products and when you say humidity was in the 75-80 I really hope you mean outside and not inside the house! You'd be looking at buckling etc, all kinds of expansion related issues.

Short answer, YES get the AC going, that will help the circulation and may help your other issues. Most importantly however will be the dehumidifier - an AC unit will remove some moisture through condensation but not always enough depending on the house.

With regards to the finish - once you get your climate sorted, see if its still an issue - I know skylights and other concentrated areas where sunlight shines directly on the floor for long periods will lead to oxidization of fading/lightening of the stain over time. Sometimes a rug is the best/easiest solution.

Thank you, WestonKris for your reply.

Actually, I put a great deal of thought into humidity control. I reach humidity up to and over 75%. I designed the floor layout to arrange plank lengths and widths to minimize expansion and contraction based on the expansion values of the wood. I also deep saturated the planks with reduced tung oil to block moisture. So far, no buckling but I will have to open up some off the expansion joints. I can't run a dehumidifier because of my open house plan and the fact I have no central heat. I have been through the worst of the humid season and so far all is okay.

It is the issue of my tung oil finish bleaching out that blindsided me. I have not found anything on the internet that mentions this issue, and so no directions on how to resolve. I believe the culprit is a combination of sun and humidity. I am hoping someone may have been through the same and can advise.