Boiled Linseed Oil and dry wood

[Player33]

Hi all, complete newbie on here, so please excuse the coming straight in with a question and apologies if it’s been asked before

I have a question about BLO finishes and dry wood that I hope I might get some advice on.

I’ve done rifle stocks before, so mainly walnut, but I am working a bit of elm for an experiment with a local chap who makes stuff out of it, including clocks. He waxes them, and it looks lovely, but I wondered if I could get an oil rubbed finish on it, so have been trying to do a hand rubbed BLO finish.

I have a problem with a section of the wood, on one side is a bit that just seems to drink oil. I can pour a puddle on, leave it, not rub it in or anything just leave it, and in 10 minutes it’s sucked the lot in and the wood is still drier than a dry thing. I’ve given it at least 6 good soakings so far, and it hasn’t flinched. The rest is fine, 2 coats and it was pooling, so that’s done, it’s just this 2 inches or so on the edge that was directly under the bark. It’s just an offcut I’m practising on so it’s not the finest piece of wood ever.

Anyone seen this before? Has anyone got any tips, or is it just pick a better a bit of wood?

Have attached a poor picture to illustrate.

 

[Jacob]

I'd try it on a finished item without sap wood etc. I use raw linseed oil. Has to be brushed on thin and then rubbed up after a day or so. Then a week or more later do it again. And again!
If you put too much on it pools on the surface or soaks in if it's porous, and won't harden.

 

[Sgian Dubh]

As Jacob has alluded to, the oil is soaking in to the much more porous sapwood than has soaked into the less porous heartwood. I suspect you're aware of the oil soaking in the most on the right hand side of your picture, and less so on the left. Given time and enough coats (hard to say how many) you'll be able to build up a surface of oil on the sapwood too, but it's probably not the best use of time and effort. Best advice is to try and avoid using sapwood if you're going to oil it. There are other reasons to try and avoid using sapwood that are related to durability, strength and stability issues, but those considerations aren't properly relevant to your specific question about the oil finishing. Slainte.

 

[Player33]

Thank you folks for your prompt answers. Avoid using pieces with the sapwood included seems the most logical thing to do.

 

[David C]

Please be sure to dispose of oil cloths very carefully.

They can burn very easily.

Cloths can be stored in sealed jars , water or spread out over the side of a bucket.

After spreading oil liberally and waiting ten mins or so, remove all excess from the surface.

If you don't do this a horrible sticky film will form.

David Charlesworth

 

[D_W]

if oil can travel through long grain, it will go far with gravity before it stops moving (maybe capillary action?).

Typical in wooden planes (sap beech) if they're being made and a little light to block the mouth and put linseed oil in the mortise. It will run to the far ends of the plane overnight (I have pictures of this as someone told me that would occur and I didn't believe them - so I took pictures/video the next morning).

Beech is an exaggerated case because moisture leaves the ends very very fast.

If you want to slow down the absorption of oil, use a drying linseed oil and a wax mix (if wax is OK) and allow coats to dry before applying more, or they will just continue to push the oil through the wood.

for planes, we normally use raw linseed oil to encourage maximum movement through the wood before drying.

On a 24" plane, I've gotten half a pint of oil into the wood just overnight, originating from one place (the center going out). To stop the moisture on planes at the end of the process (to keep the ends from checking), we normally wax and oil at once until there's no "air space" open.

Old planes often look like this, too - the end grain bits have been waxed pretty heavily to inhibit moisture movement. Once they're like this, they won't absorb oil, which is info for you - not that you want to make planes, but they are stopping oil and moisture transfer in a wood where it occurs most easily.

My other suggestion is this - if you don't want wax on the wood, then do a poor man's french polish process - mix a little bit of shellac in the oil and hand rub it until the shellac starts to form a barrier, but don't do this until you're happy with the amount of oil involved. As david C says, if you use BLO for the lubricant, after you have some shellac applied, wipe the oil off or it will dry into sticky yuck.

 

[David C]

Spontaneous combustion was the phrase I was searching for! Workshops have been burned down.

If anyone has the patience and the time, the long oiling process described by Alan Peters in his book, gives wonderful results.

We did this a number of times on oak and Elm. Students were with me for 40 weeks so there was plenty of time.

One slight difference, we used raw oil, Turpentine and a teaspoonful of driers. Turps has a slight oxidising effect but Alan thought white spirit worked fine.

David Charlesworth

 

[Player33]

Thanks everyone for your detailed answers!

I think the easiest solution is just to avoid the sapwood! It’s just a practice piece on an offcut this one, so I’m just working on the heartwood bit to show my colleague what it can look like. It’s coming up OK, the elm seems to like a hand rubbed process.

And the rags are stored hung up with clothes pegs! I’ve heard about the rags self-combusting, there’s enough YouTube videos about it as well.