Raw linseed oil is not a furniture or joinery finish

Repeat after me.....

Raw linseed oil is not a furniture or joinery finish
Raw linseed oil is not a furniture or joinery finish
Raw linseed oil is not a furniture or joinery finish

Raw linseed oil, if it dries at all, dries very very slowly over many months. You might be lucky if you apply it and then rub it all off, but most of time it will linger on the surface, gradually becoming stickier and stickier.

Nor is it temperature or UV resistant. In areas under windows or near stovetops, it will break down or blister. On furniture, it will darken over time til it's almost black, particularly on areas where the piece might be handled such as the back of chairs.

And it will be sticky. And extremely difficult to remove later on.

Oil finishes either have to rely on the oil being modified during its manufacture with the addition of driers or being able to polymerise themselves. Polymerisation means that within hopefully less than 4-6 weeks, the oil's solvent has evaporated, it's oxidised (taken up oxygen molecules) and the oil is now hardened into a coating that is a matrix of interlinking molecules.  Unfortunately most plant derived oils don't polymerise - they have to be added to or modified in some way.

And the point about oils needing to take up oxygen is why oils will remain sticky inside cabinets, blanket boxes or any interior of an object - there's not enough air circulating to ensure the drying process even of oils such as danish oil (which is actually a thinned varnish but hey). Use shellac. It smells sweet and has a beautiful feel under the hand after a couple of light wash coats and a denib with #600 grit sandpaper.

Walnut oil will polymerise but it's one of the few plant oils that does. However it's not suitable for furniture as it doesn't stand up to the harshness of UV or handling.

Raw linseed oil most certainly does not polymerise. Or even really oxidise properly as it often forms a skin on top that stops gas exchange. It just goes sticky, trapping dust and getting duller and duller.

Sure it looks great when you first apply it to your raw wood - so does water. Any liquid will show off the pattern and colour. Think about why do you want a finish on the piece. Is it to protect it from scratches, stains, water marks, kids crayons - all the usual stuff living in a home throws at it? Raw linseed oil won't do that. Nor will it show off the timber in a few months' time.

Recently I refinished about 8 square metres of kitchen benchtops. The maker told the client to just apply fresh coats of raw linseed oil every so often when it looked a bit tired.

Which they had done for ten years and the result? It was discoloured, stained, affected by UV near the windows and in the corners under shelving, black and sticky like molasses.

It took a combination of cabinet scrapers, oil and wax degreaser, white spirits, acetone, scrubbing, swearing, methyl chlorine stripper, methylated spirits, more scrubbing and a lot more swearing to remove it all.

You can't leave traces of raw linseed oil under your new finish. It won't dry and harden, and may even fry as you apply it.

And if you are refinishing something that has had raw linseed oil on it previously, I wouldn't even consider using a finish such as two packs or anything with lacquer thinners as a solvent. There be dragons.

In this case I wanted to go with Livos Kunos countertop finish - this is a plant based oil finish with non-lead driers. I've used their floor finishes previously and been really impressed. The Kunos finish dealt with spots of fisheye during application without a hitch. It's a terrific finish which shows off the colour and pattern of the tallowwood.

Now if you don't believe me about the perils of raw linseed oil, check with Bob Flexner, resident finish guru at Popular Woodworking and the author of the best book published on finishing in the last 50 years, Understanding Wood Finishing.

Yes I know raw linseed oil was used by Grandpappy Joe when he was french polishing - if you're after a dark polish, yep, you use it when cutting with pumice at the later stages though most french polishers, including me, use white oil. If you leave any trace of raw linseed oil in the timber's pores, it can blister up months later, leaving either pinpricks or tiny little blisters.

I make my own grain filler using raw linseed oil, whiting, pigment, driers for artist colours, dash of varnish and white spirits as solvent. But I use it only under shellac after scrupulous cleaning down, buffing, drying and sealing with wash coats of shellac.

And sure Grandpappy Basil used it for years as his go to finish without any problems. Good on him - he probably sanded his work properly, put little on and took more off, and buffed the bejesus out of it for weeks afterward.

But 99% of you don't use it like Grandpappy Basil, and will instead leave a terrible sticky mess for someone else to clean up. Buy a tin of danish oil instead. It might be a couple of dollars more but at least you'll be putting a finish on the work instead of salad dressing.

Repeat after me.....

Raw linseed oil is not a furniture or joinery finish.