Sanded floorboards .. now what ?

[Mike]

I have sanded down the floorboards and they look good. They are tight fitting and 3 inches wide. No one is sure how I should protect them ... wax .. varnish .. oil?

Reccomendations please

Mike P

[Gib Bogle]

Three coats of moisture-curing polyurethane. First coat slightly diluted so it soaks in, second coat gloss for toughness, third coat satin for appearance. Fine sanding in between coats. That's what we just got.

[Bruce]

It is very much a matter of personal taste, and you will get almost as many opinions as there are people offering them.

However, for what it's worth, I use OS Color from OSMO. It's an oil/wax based system that allows the wood to breathe, and is hard wearing.

In areas that are subject to wear, it is an easy job to re-sand lightly and reapply OS Color. It's available in a range of colours; my personal taste is for something that is near colourless to allow the natural features of the wood to show as much as possible.

I'm not a fan of varnish because it doesn't allow the wood to breathe.

[Stuart Noble]

Why moisture-curing out of interest?

[Tim S]

Mike coughed up some electrons that declared:

Next door neighbour, who knows something of wood, recommended Treatex to me the other day - some blend of waxes and linseed oil. I don't have any first hand experience, but I'm giving it consideration.

He liked it partly as it was fairly pleasant to lay, being devoid of stinky artificial solvents.

Cheers

Tim

[ransley]

Why would you want it to Breath, its dead wood!. Actualy it will oxidise and darken faster if it breaths and if you think it doesnt now just remember only the top is sealed to keep out damage. The Breathing argument is kinda dumb

[ransley]

Water base yellows the least over time, oil base is harder. Clear is the hardest since what is used to dull a fnish makes it softer. If a satin finish is wanted for the finish coat then only use it on the finish coat. Buy from a pro paint store that can direct you right.

[Bruce]

Like your opinions, you mean?

[The Medway Handyman]

Given that wood doesn't have lungs or gills, how can it breathe?

[The Medway Handyman]

[Gib Bogle]

All the poly-people we spoke to recommended it - they said the water-based stuff isn't as tough.

[Bruce]

You're obviously unaware of the benefits of microporous paint.

Poor you. ;-)

[ct]

Osmo Polyx Oil:

[RobertL]

This might be worth a read:

[mail]

Dear Mike Bruce, Stuart and Ransley (in particular) have it right. It is a matter of choice and personal preference What do you want aestheically and practically? Aesthetically, it is best to use a stain/oil/wax largely reversible minimal coating "slightly protective" application that often requires regular attendance and repair such as a wax polish next you can have a low build covering next a polyurethane single pack which you can put on as many layers as you like and when part of it becomes worn (like the bit by the kitchen sink) all that is needed is a light sand down and revarnish lastly a decant thick high build two pack (smells like Hell) which is hard as you like but brittle and a sod to repair when eventually it goes

Personally, I went for the one pack resin and four coats for a bedroom and 7 coats for a kitchen. The kitchen / diner is not 25 years on and has only been topped up once about 10 years ago

If i had the time and the boards were really nice I would eschew the resin and go for oils and waxes...

Chris

On the subject of breathing.... (risking dipping toes in boiling water here!) ... this is a colloquialism for the abilty of a material - in this case dead organic matter - to exchange air and water from the outside environment to the surface and some inner parts of the timber Softwoods are basically a series of hollow tubes like a straw bound together whereas hardwoods are mass material of solid fibres with the occassional tube and lots of "rays" going sideways outwards. The stuctures are rather different but the basic material, cellulose, hemicellulose and lignin are the same. The major component that goes in and out of timber when it "breathes" will be water as wood is naturally hygroscopic. This will dramatically affect the dimensions of the timbers. there is therefore a cogent argument to minimise this movement in floor boards by applying a vapour check such as a sealant once the timber has equilibrated to a summer mc in the normal house environment which I suspect will be about 10 or 12% w/w. I am very happy to be corrected but can see no advantage to a floor boad being exposed to its environment and only a very limited disadvantage (very minor seasonal changes in dimension which under normal condtions are not a problem). Can anyone out there advise me to the contrary?

[Stuart Noble]

But not all solvent based polyurethanes are moisture-curing. I thought that was for outdoor, low temperature applications where condensation might be a problem. TMH's Rustins suggestion is the varnish I've used. Stinks to high heaven but only for a short time. Calling it "plastic" doesn't help to sell it but it really is rock hard and totally transparent. The acrylics I've seen are less so on both fronts.

[Stephen Howard]

It might actually be advantageous to seal the upper surface of a floorboard given that there will often be a difference in air temperature and humidity between the upper and lower surfaces which typically results in the upper surface losing more moisture.

That 'dead' wood breathes and moves is without doubt - in my profession I regularly have to deal with the effects of such movement in exotic hardwoods, which don't have anywhere near the elasticity of softwoods. A significant and constant difference in the moisture contents between inner and outer surfaces can lead to splits and cracks - hence the need to treat inner surfaces ( AKA the bore ) of hardwood instruments with natural oils.

Softwoods, by comparison, practically get up and walk around the room

- so a sealed coat on the upper surface will help to slow down the loss ( and gain ) of moisture to that surface and provide a more stable counterpart to the lower surface, which will tend to remain more or less constant anyway.

That said, I prefer a finish that allows the wood to look like wood - but I do understand the practicalities involved when it comes to floorboards.

Regards,

[Stuart Noble]

Only that IME old boards don't expand and shrink seasonally to any great extent. There is obviously the initial shrinkage in new stuff (supposedly 4% of the width per 1% drop in moisture content for softwood) but thereafter it stays pretty much the same. I suppose that implies the relative humidity in our houses doesn't vary much. One thing's for sure, surface coatings won't stop any such movement.

[Andy Dingley]

Two or three coats of an acid-cure (two part) formaldehyde varnish. There's nothing else out there as tough. Rustins and a few others sell them as "Floorcoat" etc. Water-white and you can get gloss or semi-matt.

Dead easy to work with, although it stinks and you'll want to wear a mask just for comfort. Two hours later it's hard enough to stand furniture on, three or four hours and the smell has vanished.

If you want a really dull matt, apply gloss then cut it back a couple of days later with pumice or rottenstone.

[Martin Bonner]

Gentlemen, gentlemen! A little less sarcasm and a little more discussion of the actual merits of proposed approaches would stop this turning into a flamewar.

By "breathe", I think that Bruce means "can absorb and release water vapour from the atmosphere". Is that correct? What do you see as the advantages of that?