The training of the pro will always dictate the level the product will perform. Loba products are very expensive. As soon as a pro uses it exclusively then you are working with a HIGH END pro with outstanding training. No one voluntarily works with **EXPENSIVE product if they can't get it to work. The hardener is the stuff that makes things cure quickly. The faster it cures the faster it becomes 'tough'. In theory, Loba 2K Supra AT can be used without the hardener but it takes over 1 MONTH to reach final hardness (2 coats = 30 days; 3 coats = 60 days or more). If someone believes they can make something 'go further' by mis-managing the LABRATORY produced mixture is often considered a pretender. That being said, there are MANY uses for the products without the hardener...but only the very well educated high-end pros (the one's who made it through College or University but chose to work with their hands) will grasp the subtleties of 'off-label' uses.

Ciranova ? Pink Blocker can be used with any competitors brand stain. I have not experienced any issue. You do need to buff with a maroon pad prior to applying a stain with other manufacturer's WB PU. I have not applied any other WB except for Ciranova's own WB PU over Pink blocker. No time for experimenting. Pink Blocker is a reactive stain. It is water soluble. Ciranova has a binder in their invisible line finishes : Ecofix plus, Woodlook Plus and Oculto. It helps prevent reactivating the stain and moving the color around. Reactive stain can be applied after pink blocker. Still needs buffing with maroon pad. You can use the regular reactive stain on red oak. It will not be as intense as if, it was applied onto white oak. Aquavintage is a two part reactive stain. hardwax oil , oil poly or wb poly can be applied. If, using WB poly, use one of Ciranova's invisible poly. Ecofix for light natural colors. Woodlook for whites and grays and Oculto for dark tone reactive stains. It is water soluble, competitors WB PU will move finish around. If, you want a WB system that looks like a oil finish. Ciranova's invisible line is what you want. It will look as natural or raw as can be with the protection of a WB system. For added protection, you can do two coats of their invisible finish and two coats of Fortico. Fortico is comparable to Bona Traffic HD and Loba's Supra AT. You can top coat Ciranova's invisible finishes with competitors WB finishes. That will help keep cost down. Only downside, if, you run into issues. The tech support will not help you. Use your own discretion. Unico is the same as RMC. It's a single coat oil system with the added benefits of being able to apply a WB PU over it. It's soft, top coat with one coat of Titan or two coats of Fortico for the added protection. Titan is better than RMC. Note: every manufacturer alters their binders slightly in their finishes to make it unique. It creates issues with other manufacturers products. You would need to test samples to make sure there are no finishing issues. I have used Ciranova's reactive stain with RMC and Pallmann's oil with no issues. I have tried applying a competitors WB PU over Ciranova's reactive stain with no success. It moves the color around. But when used with Ciranova's invisible PU, no issues. You can apply dewaxed shellac over the reactive stain and apply a competitor's WB PU or just apply oil base poly. Keep in mind oil base poly will turn yellow. For aged look, it does not look good. If, you want the aged look use Ciranova. you won't be disappointed, unless your guy does not know how to use it. For a stained look, you can use any other brand. The colors are all the same, besides Duraseal, which has more colors available than anyone.

I have to agree that these were preexisting but almost invisible because of the sanding. The top pic looks like "old finish" was left in place. Considering how thin your boards are and how old they are, this is not unexpected. And to be clear, old floors can have 80 years worth of contamination (ie. wax, shoe polish, Pledge, Murphy's Oil soap, soap, hairspray, hair dye, etc) on them. These products can, and will, get past the original finish and contaminate the wood. Just like old urine stains pushing all the way through a board (the dark gray stain is most like an old urine stain...cause that's what they look like after many years), these contaminants can go several millimeters into the wood. Especially things like cooking oil, Murphy's Oil soap (anything oil based really) or even melted wax from a candle. After sanding, you wouldn't have 'seen' these things. But a quick swish of a slightly damp mop (make it wet to give some depth of colour) and all of these things would have been evident within moments of the water touching the wood. And that's why you can see them now. The clear coat is like water hitting the wood. It gives the colours depth...and definition. But unlike water, the finish is permanent. At this point, I would keep going with your plan = 2 more coats of Loba 2K Invisible. And You will want to hurry. To get a good 'stick' the next coat should be put down within 24 hours of the previous...or else the flooring guy has to abrade the floor again to get a mechanical grip rather than a chemical stick. Keep going. Know that you are getting 20 years more out of these floors that probably should have given up the ghost 20 years ago. That means you are extending the life by 40 years. For an old hardwood floor, that's impressive.

Thank you so much! I appreciate the expert advice. I'm definitely not an expert! I think I used the wrong term earlier - when I said 'raw'. What I meant is that that ideally the colour looks like natural wood, as close to white oak as possible - vs. something that turns pink, yellow or orange. We do want some shine, and are leaning toward a satin finish. So, in that case, would you still recommend Loba invisible? Concerned about durability, as we don't want to be fretting about the floors. These floors are rather yellow, which is why I asked about the UV blocker or stain. Edited to add: we also have the option of delaying this work and waiting until someone that can do both Bona and Loba is available. So, if Bona might be a better option, that's something we can consider. Quite possible I'm overthinking this ;)