danish oil

[user 19915]

Does danish oil go off'' as mine as all curdled as to speak any idea why
Alan

 

[marcros]

yes it does. I think, typically 12-18 months in the wrong conditions. heat probably is the biggest accelerator, and opening the top regularly.

 

[Ttrees]

Good to know .......What about boiled linseed oil ?
Tom

 

[Phil Pascoe]

Doesn't seem to - I'm still using some I bough about fifteen years ago at a boot sale, and I don't know how old it was when I got it. That said I use it only for soaking my bench top, wooden handles, knobs and mallets, not for polishing or anything more delicate.

 

[bugbear]

Good to know .......What about boiled linseed oil ?
Tom

Seems to thicken and darken with time - but it's a lot of time.

BugBear

 

[Argus]

From my own experience Danish Oil does deteriorate over time in two ways:

First, it contains solvents and even with a tight-fitting cap, once opened there are fugitive losses which reuslts in it getting thicker in consistency.... but we are talking about several months.

Secondly, if it is left on a shelf for long periods I've noticed that it tends to get thicker at the bottom. One solution to this is that when I open a fresh tin, a handful of old screws goes in which helps to dislodge and disperse the sludge at the bottom with some vigorous shaking.

I should say that I tend to use Liberon by choice, but all good quality Danish Oils tend to behave in the same way.

 

[Paul200]

I'm an infrequent user of Danish Oil so have seen it thicken up over a few months. I've tried loosening it with a drop of white spirit - which works - but only temporarily, and I've no idea how this may affect the finish in the long term - if at all.

One idea that I haven't tried myself, but intend to when I get back into making boxes, is to decant the oil into small, airtight jars when you buy it and use them one at a time. It might work but I suspect that the one time exposure to air may start the thickening process off so you just end up with a whole load of jars of unusable oil :?: :?

It's annoying, that's for sure.

Paul

 

[ED65]

Alan, as you probably know Danish oils are generally a mixture of a drying oil and varnish. What has happened is the same as what regularly happens in opened tins of varnish, the varnish component has begun to set due to exposure to oxygen.

If the tin is full and the lid is airtight there's no reason why Danish oil can't last years, and I've shaken unopened bottles of it from the 90s and earlier that still sounded like they were the same viscosity they were originally.

But once you open a tin you introduce fresh air, and each subsequent opening exposes the contents to more and more oxygen so it becomes an accelerating process. There are two simple fixes for the problem though.

The first is just to transfer leftover Danish oil to smaller and smaller containers so there is minimal headspace above the liquid and this works well if you have suitable containers. The second is adding something to the original tin to raise the liquid level, glass marbles used to be recommended for this purpose but they're not as easy to come by as they used to be.

Good to know .......What about boiled linseed oil ?

Drying oils also oxidise over time but it's less of an issue. While it will slowly thicken it can take many years to get to the point where it actually gels and it's usable all the way up to that point (many users would hold to the view that it's actually improved, in the same way that all pre-polymerised oils are an improvement over the base oil).