Over the next days, weeks and months I'll document my experiences of Osmo, what preparation was undertaken, the application process used, the concerns, do's and do not's and anything else that other people may find helpful when trying to decide whether Osmo is right for you.

We're doing this because there is very little information or feedback from other users on the internet, and I think it is important to know as much as possible before committing to a certain product or method.

I am sorry if this turns out to be a long winded blog-like post, but I'm sure someone will find it usefull one day.



Background:
Kristin (my wife) and I are building a new home on Waiheke Island in Auckland's Harbour (Auckland is in New Zealand for those that don't know).

We are both environmentally aware and constanly try to do what is right. Our home is what we would like to consider Eco-Friendly. We've used an array of products that are sustainable, renewable and non-harmful to the environment either during the manufacture, transportation, use and effects.

Osmo (although transported from Germany) seemed the least harmful product available. It was not easy to track down in New Zealand, however once we were pointed in the right direction (http://www.goldenfields.co.nz/paints.php) the support and information we received was pretty good.

Phillipe at Goldenfields asked what type of flooring timber we were using (Tasman/Tasmanian Oak which is a Gum/Eucalypt grown in New Zealand) and he explained that because Tasman Oak is a Hardwood and does not absorb very well, we should initially use Osmo Clear Extra Thin.



The documentation on the can of Clear Extra Thin and on the Osmo Website is rather confusing and contradictory. One line says apply the first coat thinly and evenly, the second line says generously and evenly.

Somewhere else, the instructions are to sand the floor no smoother/finer than 120 grit sand paper on a belt-sander (professional floorsander) and another set of Osmo instructions say 100 grit.

It seems that the final sand should be done according to the hardness of the timber. Hard timber should be sanded to only 100 grit. This allows for better penetration, but a fractionally rougher grain. On softer floors or ones that absorb better, a final sanding using 120 grit is recommended.

As Tasman Oak (also known as Pilularis or Blackbutt) http://www.timspec.co.nz/Products-Sawn-Timber-Exotic-NZ/p1/Pilularis-Blackbutt-ifc19c9d2-6732-404a-bd9b-5b2c32e7960f-21170.htm is a very hard wood, we initially sanded to 40 grit, then filled the nail holes with a water-based filler that the floorsander supplied us with.

Once the filling was complete and had hardened (over night), we (the floorsander) sanded using 100 grit.

The idea was then to apply the finish ourselves, since Osmo state that it is designed for the DIY User.

We spent a great deal of time vacuuming the floor, removing all dust from the floorsanding and plastering that had taken place over the last few days. We were very careful to remove every trace of dirt, dust and loose gum (from the gum veins) as possible because we were afraid of making a big mistake and regretting it for years to come.

Once our final vacuum (2 hours to do a 2 bedroom house)(about the 3rd since the floorsander left) was done with all doors and windows closed to avoid other dust particles or contaiminates landing on the floor.

The instructions give an indication of how much Clear Extra Thin should be used per Square Meter (40ml which is 8 tea spoons), but that is a bit difficult to use in a practicle situation. Instead, we chose to guess it.

What really helped was someone's comment "think of Osmo as a Stain and not as a paint". I also read somewhere that one SHOULD initially apply the finish across the grain and then smooth it out going with the grain.

We bought the Osmo Application Brush below:


During application, we basically "scrubbed" the oil/wax into the floor. The doors and windows were kept closed, again to avoid dust blowing in or around.

Applying the first coat took three hours (120sqm home) and was back-breaking. Maybe it didn't need to be, but when I do something, I like to give it my all. I scrubbed and scrubbed for all of those three hours. I didn't just wipe it on and hope for the best. I took great care to ensure an even coat was applied and really rubbed into all nooks and crannies.

Once done, we waited for the floor to dry to a point where it was no longer tacky (around 3 hours). Then, we opened the windows and doors to allow some great air-flow.

Although the first coat is very thin (we should have used 3 pots of Osmo and only used 1 for the whole house) (because of the timber's poor absorbtion of the wax) it looks church goer amazing.

Tomorrow morning I'll very very very lightly sand using a 400 grit sandpaper on a pole, just to remove any timber-hairs and what-not.

I'll update this post after tomorrow's coat.

I've just finished applying the second coat. It didn't need to be scrubbed in like the first one and only took 1.25 hours compared with over three for the first coat.

This morning, before we applied the second coat, I sanded the floor using the 400 grit sand paper on a long broom-stick. That took only 10 mins, then a quick vacuum and away we went.

I must point out that some care is taken when walking on the dry first coat, as it is very slippery both in socks and with bare-feet. The light sanding removed any timber hair, dust and brush bristles that landed during the drying time.

The second coat glided on very easily.... basically just like mopping a floor. We used 25% more Clear Extra Thin wax than on the first which suprised us. Maybe I was simply more generous.

It has been drying for around two hours now and doesn't look patchy like some people have reported. Obviously there are still some shiney bits where the wax is still wet, but I invisage that will disappear over the next few hours.

The colour of the flooring has clearly darkened with this 2nd coat, so it will be interesting to see what the final coat does.

So far, the brush has been wonderful. We simply wrapped it in plastic last night and used it again today. I would urge anyone wishing to use Osmo to buy one. Not two. Have one person apply the wax and have the other located in a place in the room so that they can spot any missed areas.

Having a spotter is especially important on the second coat as it is very hard to see where the application starts and stops when one is standing directly above the area. Often it is best to stand back and review the coverage area and drying pattern.

So far, we have not had to wipe up any excess wax. Just letting the nice warm air and the timber to absorb as much as possible.

Tomorrow, we'll apply the first (and maybe the only) top Hard Wax using the same method, however we'll probably resand the floor prior to applying it (with a vacuum directly there after).

Once again, I'll report back as to how it works out.

Well, the floor looks great, however the wax is still tacky in a large number of places, which obviously means we have not sanded or started with the Hard Wax.

It is a bit concerning, because normal drying time is 12 hours, it has now been 30 hours in excellent drying conditions, and yet it is not dry.

Tomorrow is another day, and I would prefer to do things properly, so I'll keep my fingers crossed and pray to the wax-drying-gods.

Back soon.

Thomas,

I hope that this will turn out wonderfully for you. I have never used this product. My experience has only been a client that had a different contractor use this product and their experience seemed similar to your descriptions.

In the end the floor dried for the most part. However the finish scratched very easily. Their Brazilian Cherry floors were left with large white scratches in the wax all over the floors.

I chided them for not contacting me. The only contractor locally who used Bona Kemi, water based poly-urethane finishes. They are environmentally friendly and extremely durable.

I hope for the best for you and you floors.

Barquios, thanks for your wishes of good-luck.

Out of concern, I have contacted Osmo and explained:
a) the floors were still a little tacky in a few places
b) the coverage I have acheived (3 times what they suggest) worries me.

They explained that if the floors were still tacky, I've applied too much or the timber pores are saturated.

The solution they propose happens to be the same for both senarios: Lightly sand the floor, allow the newly opened pores/newly exposed wax to air for 12 hours. Then apply a VERY thin Top-Coat.

I have heeded their advice and initially sanded the floor using 400 grit sand paper, however that clogged the paper within a few moments, so I changed the paper to the only one I had, namely 120 grit (one extreme to another).

This took the sheen off most boards but still clogged the paper. I decided to change to fresh paper once for every room. Having said that, as the paper clogged, I brushed the dried wax off using a wire-brush.

Once again, I then vacuumed the floor as thoroughly as possible in preparation for tomorrow's top-coat.

I must admit, I am still feeling some trepadation. If the pores were saturated by the second coat, how can a little sanding and then a "VERY thin application of top-coat" not give me a candle-wax feel on the floor?

Tomorrow is the day.... I'll report back the results.

Thomas

OK, so, we did it. First thing this morning, we applied the first and only coat of the Hard Wax.

It was a mild spring morning, a bit cold, but not too bad. Maybe that is why the wax was rather thick and gooey. None the less, we applied it as thinly as possible.

The manufacturer states on the pot that one can should cover 60 square meters, we however covered the whole house and still had some left over (about a cup).

8 hours after application, the floor was only marginally tacky. I found a dry spot and scraped it with my finger nail, and very little white powder came off, and no scratch mark was left.

I know it is only early in terms of drying time, but the signs are good.

Now, all we have to do is wait the 2 weeks they say it will take for the wax to reach it's fully hardened state.

In the next few days (not sure when), we'll start to walk on it, but only with clean socks.... no more skidding on it like I did on the first 2 Extra Thin coats.

The smell is a little stronger than the Extra Thin, but a day or two of airing should eliminate that. I guess the fact that we kept the windows and doors closed during and after the application didn't help.

I shall provide further progress updates as new developments occur.

Regards,

Thomas Greve

Good luck with this project, hope all is working out for you.
These vegetable based oils and natural wax products are at the same time a throw-back to techniques from generations ago, and utilizing modern technology do indeed provide an environmentally conscious product to work with.
I have one concern about your project. I have worked with Tazmanian Oak on occasion and found it to be an easily finished wood following normal practices. Did you say your floor was first sanded with 40 grit and then finished with 100? Seems to big a grit spread to me to get a smooth surface.

Before urethanes and such, many floors in my area were finished by applying a couple of coats of shellac and when fully dry, a coat or two of carnuba pate wax. Dry shellac is a natural product but is thinned (cut) with denatured alcohol. Outside of the alcohol being flammable, shellac is a safe, non-toxic product. It dries very fast, adheres to just about any and everything, is known as a great sealer and imparts a nice color and tone to the wood. One needs to wax it as it isn't very durable. The carnauba paste wax does contain petroleum distillates however. But not so much as it is considered a pollutant. In my heavily regulated area, there is no VOC restrictions on carnauba paste waxes. And one uses very little when waxing a floor. I have refurbished floors finished this way that had the original stain, shellac and wax from the 1920's and 30's. After thoroughly cleaning them, I applied two coats of Trewax. The floors usually looked great again and was way less inconvenient and expensive than a full resand.

Two weeks on, and it is all good news. Everything has worked out so far. Nice hard covering of wax, no white scratchy powder etc.

I think we are all good.

So, hopefully this will help others and wasn't a waste of time.

Thanks for reading, and please give feedback if you find this helpful.

Also a big thanks to those that have followed our progress and given feedback so far.

Regards,

Thomas and Kristin.

I had tried OSMO on Ipe wood, and I had the same tacky problems, even with very thin coats. I could not get it to harden. I tried to apply the finish very soon after the final sanding, and also tacked the floor with mineral spirits to hopefully remove any excess natural oils in the wood, but still had tacky floors after a couple weeks. I think this has more to do with Ipe than anything else. I ended up removing all the OSMO and going with Waterlox, which has been great.

The only other problem I has was getting all the OSMO wax out between the boards. No matter what I tried, there was always some remnant of wax between most of the boards. Sanding this out seemed impossible. Perhaps there's a way to remove this wax, but I could not find one. I ended up sanding the best we could, then applying Waterlox. What we ended up with was a some "retreating" of the waterlox from the edges. As we applying more coats, there was less "retreating". In the end the finish was acceptable to me. Honestly, I wish I never heard of OSMO!

One important lesson I learned was that doing a "test sample" for looks is not good enough. Do a test sample on several boards, preferably on a substrate, where all the boards are together. Then spend a couple weeks walking on it to be sure it performs as well as it looks.