What's the best process for sanding/finishing reactive stained oak floor with hardwax oil to leave the best surface?

Question

I have raw oak floorboards which are being individually stained and finished before being laid. For context - this is my first time doing anything like this, so apologies for my lack of technical knowledge. After many experiments I have decided on a reactive stain which is a combination of two brands that I mixed together to produce a really nice darkish desaturated brown.

During the experiments I found that water popping the grain massively enhances the stain absorption and looks far better and more professional. My problem is in dealing with the raised grain. If I sand after staining (even lightly), this pulls some stain off. If I sand to 120 before applying the stain, the colour actually is still good (I would have thought the pores would have closed up slightly again) but the grain still raises again after staining (although to a lesser extent) and the texture still feels quite rough to the touch.

Ulimately I am looking for the best workflow in going from raw oak to achieving a nice smooth floor finish. Currently my process is this:

1. Water pop the boards.
2. Without sanding, apply one coat of reactive stain then egalize with a dry brush to remove any excess stain
3. Very lightly sand with sanding sponge around 320 grit to remove popped grains, nibs etc.
4. Apply thin coat of Osmo Polyx with microfibre roller.
5. Repeat step 3.
6. Apply thin second coat of Osmo.

That's it. I'm getting a decent finish with a nice colour, but texturally it just feels like it could be softer, smoother, and less 'plasticky' which is part of the reason why I went with a hard wax oil over a polyurethane varnish. I've tried all kinds of application and sanding methods, including using red buffing pads, maroon pads, white pads for application etc. and so far the process above is the best I have. Applying oil with white pads over water based stain is not a good idea btw.

Could anyone suggest where I might be going wrong, and how I might get the best finish with this combination of reactive stain and hard wax oil? I'm a complete amateur and have not made things easy on myself by choosing such an awkward combination of finishes! Yet I love the colour and this could be an awesome floor.

Bonus yet related question: The Polyx oil I bought is called semi-matt 3055, as I wanted barely any gloss- just slightly more than matt. However the final finish appears quite a bit more reflective than the sample I had seen. My guess is because of the darker colour of the wood, stronger reflections are visible. Is there anyway to dull the reflections or will they reduce as the oil cures, or with wear? Or are they stuck like this forever? I regret not buying the matt now.

Thanks!

Answer 1

I don't think there's an ideal solution here, and it's possible you're already getting close to the best result you can given the constraints.

But as I read it there is still something to try, and that's doing the usual amount of sanding after raising the grain.

Which is, just enough.

TL;DR raise the grain with water, sand lightly, then proceed.

The goal of pre-raising grain with water is generally to stop grain rising when something based on water is applied afterwards, but it only works right when you only sand off the raised grain and don't go any deeper. As a result a very light sanding with fine-ish paper is what's called for; I can't stress the very light enough here, you're ONLY looking to take off the whiskers. You must force yourself not to sand any further after they're gone..... trust me, this is harder than it sounds :-)

If you look up in finishing guides in books and online how to pre-raise grain you'll see there is (rather inevitably!) no absolute consistency in recommendations of how to do this, although the general principles are the same. But a fairly typical routine would be:

• Prior to this sand only to 120-150 and no finer.
• Dampen the wood. You don't need to saturate for this to work, just dampen the surface so it doesn't take too long to dry and you minimise the chance of boards warping; think damp rag rather than wet sponge.
• Wait for the wood to dry; drying can be accelerated with fans, a hairdryer or heat gun (used carefully).
• Sand very lightly, by hand, using reasonably fine paper, e.g. 320. Some people use 280, still others use 360 or occasionally even finer.

Remember to sand just enough to remove the roughness and no more.

Note 1: use fresh paper. You need the paper (or cloth/film/mesh) to cut efficiently for this to work, and except for some of the newest meshes/screens that last approximately forever this means using very fresh or brand new paper. Dull paper cuts less efficiently and tends to have a burnishing effect on the surface of the wood.

Note 2: do not use steel wool as a substitute for abrasive paper here. Similarly, don't use Scotch-Brite (or any equivalent). None of the conformable abrasives cut quite the same way that paper/cloth/film/mesh does, even the ones like Scotch-Brite that contain abrasive grit.

I should mention that some people report that raising the grain twice, sometimes even more times than that, is the only way to ensure that you get zero raised grain after applying your waterbased finishing product.

---

Re. your bonus Q, I would normally encourage you to ask this as a separate Question, but it's too quiet here and if you need an answer in real time I would encourage you to ask on one of the woodworking forums with a large, active membership. Given the popularity of Osmo products in recent years — to the point where any finish-recommendation question would result in Osmo being mentioned at least once if not multiple times! — I'm sure you'll find a large number of people willing to help.

I suspect you'll find out that this Osmo product just isn't as matt as you'd like, even after very thorough shaking/stirring of the can to ensure proper distribution of the matting agent. And unfortunately I think you'll discover over time that usage may make matters worse — it's broadly the case that more-matt finishes get buffed slightly with use, increasing the sheen, and where abrasion is highest they can end up actually quite shiny. While I'd be critical of Osmo for a couple of reasons this is just the way it is with wood finishes in general. From what I've seen firsthand even more-matt ceramic tiles buff up with use (and a shockingly small amount of use in some cases!) and the glazed surface of tiles should be a couple of orders of magnitude tougher than any wood finish.