polyurethane varnish on old softwood flooring

[makp]

having ripped up 30 year old carpets on the first floor we are thinking of coating the plain T&G softwood floorboards with a 'dark oak' (ronseal type) satin polyurethane varnish. As the board are quite old some of the boards will need to be replaced but most are okay if not a little stained with emulsion paint spots.

So as these are softwood, can we just sand with our orbital black & decker sander (rather than hiring a big upright sander)?

also a lot of boards have linseed oil (from putty) stains - will that affect the varnish as i dont know how to remove the oil stains?

 

[TheDec]

Well your sander may be up to the job, the staining caused by the linseed oil can be wiped with a cloth containing spirit. It is important here I think that you choose a solvent based polyurethane and you should thin the first coat with around 12% spirit.

That 12 should read 10.

Dec

 

[makp]

thanks for the info on the sander and spirit.

think i need to do some more research on polyurthane varnishes.......i read on another post its better (and cheaper) to use a separate wood dye then clear varnish rather than the more expensive all in one stain varnish (i.e ronseal / sadolin / sikken)....apparently rustins wood dye, followed by rustins clear polyurethane sati varnish will give a better finish (though not sure if its solvent based?)

 

[TheDec]

Cheaper perhaps better I would doubt, the determination of the final result in both colour and depth of colour will be greatly determined by the cut and grain of the timber.

You have said that some of the floorboards will be replaced so you will be applying your penetrating stain to both old and new timber, therefore you will in a sense be left with a rather patchy effect. Building depth of colour by using a stain of this nature is a very involved procedure, whilst doing so with a stain/varnish combination is far easier.

Dec

 

[makp]

thanks again for the advice - i also thought that stained varnish would be easier but was told that wih the mix of old & new timber using a dye first woudl give more contol of colour depth before sealing with varnish - i was told it was more difficult to control finsih with stained varnish ?

 

[TheDec]

I at first thought you meant the entire area, yes applying it to the new boards will help you build the colour.

Dec

 

[makp]

sorry i was talking about the whole area!

 

[TheDec]

Then all you can do try it and see how it looks.

Dec

 

[ic1927]

Be aware that if you use oil/solvent based wood dye, you can only do it once, more than one coat and the dye will never fully oxidize. After using the dye make sure on the following day you thoroughly wipe it over with a clean cloth to remove excess residue before varnishing.

 

[makp]

Be aware that if you use oil/solvent based wood dye, you can only do it once, more than one coat and the dye will never fully oxidize. After using the dye make sure on the following day you thoroughly wipe it over with a clean cloth to remove excess residue before varnishing.

am i right in thinking that only water based dye will allow you to try multiple coats of dye to get the correct colour depth?.....but as i've using white spirit to remove linseed oil stains then i cannot use a water based dye or stain...it should be a solvent or oil based dye or stain ?