invisible finishes.

[Rich Engelhardt]

What did Krenov use on his cabinets?

I have no real idea - but - since he began his ww'ing career in Sweden there's an excellent chance he was taught the use of soap finishing.
A soap finish is both nearly invisible and extremely durable.

[Scott Holmes]

Rich,

Extremely durable or easily renewed? Doesn't water dissolve soap?

[Rich Engelhardt]

Scott,
Yep - sure does.
Thing is it doesn't dissolve it 100%. Water just takes off a very small portion of the film.
Dirt and stains wipe off with a damp cloth. While the surface is still slightly damp, a new coat of soap is applied.

Unlike wax, soap doesn't get tacky and attract dirt and dust. Nor will it change color as some solvent waxes do. Nor will it impart any sheen.
It's also a very hard finish - according to some as hard as varnish.

Soap is a traditional Scandanavian finish. It's been used there on interiors, furniture, tool handles (unlike wax or other film finishes a soap finish won't raise blisters), floors and just about anything and everything wood for a long long long time.
("Soap" is probably the most ancient of man made wood finishes known.)

Almost all high end furniture made in Scandanavia has a soap finish. It's considered a mark of fine craftsmanship - akin to dovetailed drawers.

One big drawback to it these days is finding the right soap.
Gimme a second here.....
Drat.. I can't find the old link I had for sourcing soap flakes. AFAIK, IIRC,,, there's only a single source for them based out of the UK.
Since I can't find the link I have to go by memory so forgive me if I'm not 100%.
The soap has to be pure and contain no additives, oils or perfumes. I
IRC, home made lye soap is the closest you can get here in the US.

I first heard of soap finishes from my old friend and mentor - "Old" Floyd.
Floyd and I worked together in the late 1960's and again in the early 1970's.
In the time between, Floyd had been trasnferred to Upper Michigan and heard about it up there from his customers.
I'd forgotten all about it until I saw someone here mention it a few years ago.

[Prashun Patel]

"...unlike wax or other film finishes a soap finish won't raise blisters..."

But it may dry yr hands out !!!

I'm going to research this further, but my non-pro instinct is that the Scandinavians used soap for the same reason many people used linseed oil: it was available. Modern finishes and glues tend to be superior in just about every way to their traditional counterparts.

Soap, by definition, is designed to make water and oil co-soluble. Because of this, I would venture to guess that a soap finish would do a GREAT job of attracting dirt and wax from anything it came in contact with over time. On the other hand, it probably cleans up very easily.

[Rich Engelhardt]

Modern finishes and glues tend to be superior in just about every way to their traditional counterparts.

Pre- VOC lock down,,,,,I'm w/you 100%.

W/the way things are being regulated these days, I'm not so sure.