Linseed oil definintions and characteristics

[Lynn]

I have researched linseed oil since there is so much talk about it as making a superior paint product, filler, etc and I did a search on this site, but did not see a full explanation of the positives and negatives of linseed oil. So here is a thread to work out definitions etc.

First I found on this site_(click_here) that boiled linseed oil is not really boiled, but has additives that give it the properties we find convenient--like the paint will dry. He quotes the label of his can of linseed oil:

Let me quote the warning label from a can of boiled linseed oil...

"Use of this product will expose you to arsenic, beryllium, chromium, cadmium and nickel, which are known to cause cancer; and lead which is known to cause birth defects and other reproductive harm."

That seems more than "boiled".

Also in the paint department of linseed oil use, it is said that linseed oil is food for mildew. This effect was minimized in the past with the heavy dose of lead paint had on board, but we don't add that to the mix now, so this could be a big problem in exterior paint applications. In fact a recent_thread complained about darkening of the linseed oil painted trim, but there was no suggestion that this could be fungus creeping in. Also it was suggested to help white wash stick to stucco one could add linseed oil. I'm very concerned that this might lead to growth of mold/mildew.

So there are the issues I see that need to be considered as you take the step into linseed oil in restoration projects. I hope the people using this will chime in with more/better information

 

[middi]

interesting observations Lynn, I am sure though, if they further refine the trace element checks , gold, uranium and star dust is also present.

We are not suppose to drink the bl**dy stuff.

 

[Nigel Watts]

Sounds like the manufacturer is coveining himself in case traces of any of these things is found.

I too have heard that boiled linseed oil has added driers. Driers often contain heavy metals, which can be toxic. Cobalt is contained in a driers often used by artists.

 

[biffvernon]

Boiled linseed oil is not actually boiled but has hot air passed through it. This promotes the oxidative polymerization - i.e. it sets faster. There should not be any additives in the form of heavy metals when you but a bottle of 'Boiled Linseed Oil'.
Tha commonest siccative, or drier, in paint is manganese oxide, which is not very toxic, though I wouldn't sprinkle it on my dinner.
The potential for mildew in linseed oil stems from the non-oil content of the proteins and other stuff. There are different qualities of oil - refined, cold pressed etc., a bit like with olive oil, and the impurities content varies. The Stuff that Holkham Paints sell may be better in this respect than what you find in the average hardware store. You can refine your own oil by repeatedy mixing and shaking with water, leaving to stand and pouring off the oil. Each time you do this the oil becomes purer with the proteins that feed mildew dissolving in the water. Fine artists do this as you get an oil which won't yellow with age.

 

[Lynn]

Biff I knew we needed a full airing of this topic. Very interesting onformation you bring out here. I think it is worth reading the can of oil you buy carefully. I haven't bought linseed oil, but from my reading on the web it seems in the US the label "boiled" is with additives and "polmerized" oil is what you describe.

Do you refine your own oil? or have you had good luck with the Holkham paint as far as mildew, etc?

Thanks for clarifying this stuff.

 

[NT]

Boiled linseed oil really means linseed oil that will polymerise/oxidise, or dry. How this is achieved can vary: heat or chemical driers both work.

I guess putting raw linseed oil in the frying pan would also make it a drying oil. Roasting olive oil encourages it to polymerise, and the result is very tough stuff.


NT

 

[L1zzy]

Can I suggest you call the folk at Holkham Linseed Paints (UK Distributors for Scandinavian paint I'm usuing) who know all about it and talk to them - its all a bit techie for me but their site has factsheets with techno data on their products. I can't fault it and although I admit I didn't drink the stuff its smells good enough to!

 

[Nigel Watts]

I am currently experimenting with making my own scumble glaze to create a woodgrain effect. The background is painted in a semi gloss oil colour (I'm afriad I'm using Dulux eggshell for this). The scumble glaze is a thick but semi trasparent layer you put on top before dragging various combs, bushes, pieces of rag-covered horn, feather etc through in an attempt to create the desired effect.

Parry's Graining & Marbling suggests making the glaze with raw linseed oil, turpentine (either 2:1 or 3:1 with the oil), pigment, and "liquid driers". Artists oil paint, which is just (unboiled) linseed oil and pigment, can take months to dry naturally, but it will dry eventually. I imagine any linseed oil paint with a much quicker drying time will have to have some form of driers in it. I have just bought a bottle of "Terebene" driers from my local decorators merchant. All it says on the bottle about its contents is that it contains "a special blend of chemicals".

 

[Penners]

Boiled linseed oil is not actually boiled but has hot air passed through it. This promotes the oxidative polymerization - i.e. it sets faster. There should not be any additives in the form of heavy metals when you but a bottle of 'Boiled Linseed Oil'.
Tha commonest siccative, or drier, in paint is manganese oxide, which is not very toxic, though I wouldn't sprinkle it on my dinner.
The potential for mildew in linseed oil stems from the non-oil content of the proteins and other stuff. There are different qualities of oil - refined, cold pressed etc., a bit like with olive oil, and the impurities content varies. The Stuff that Holkham Paints sell may be better in this respect than what you find in the average hardware store. You can refine your own oil by repeatedy mixing and shaking with water, leaving to stand and pouring off the oil. Each time you do this the oil becomes purer with the proteins that feed mildew dissolving in the water. Fine artists do this as you get an oil which won't yellow with age.

That's absolutely fascinating.

 

[middi]

Totally agree with your comment Penners and I am sure we are all enlightened on the subject.

.....( with the possible exception of Biff )

 

[Sue Wilkinson]

I have just bought a bottle of "Terebene" driers from my local decorators merchant. All it says on the bottle about its contents is that it contains "a special blend of chemicals".

Yes, that's the stuff that appears in modern day paints. It will have a VOC content, but then if you are using a Dulux eggshell paint behind it you will already have the chemicals present so I wouldn't worry about it.

I wonder what the Victorians used to help dry their glazes. They were big on effects as you know, and wouldn't have wanted them wet for months.

Have you got one of those rubber 3 sided blocks with various grains cut into them? They make graining a doddle. You use one of them first for the basic effect and then fiddle about with feathers and stuff for the fancy finishers. You have had a real experiement over the years on your house haven't you. Its great that you have risen to all the challenges.

Sue

 

[skier-hughes]

I have researched linseed oil since there is so much talk about it as making a superior paint product, filler, etc and I did a search on this site, but did not see a full explanation of the positives and negatives of linseed oil. So here is a thread to work out definitions etc.

First I found on this site_(click_here) that boiled linseed oil is not really boiled, but has additives that give it the properties we find convenient--like the paint will dry. He quotes the label of his can of linseed oil:

Let me quote the warning label from a can of boiled linseed oil...

"Use of this product will expose you to arsenic, beryllium, chromium, cadmium and nickel, which are known to cause cancer; and lead which is known to cause birth defects and other reproductive harm."

My Linseed Oil from Holkhams says,

100% coldpressed Swedish Linseed Oil.

Graham

 

[Lynn]

Two last questions... I think the last two anyway...

How does linseed oil paint age? On the Holkham site there is a red building that is shown as the aged look of that color.

http://www.holkham.co.uk/linseedpaints/p_brickred.html

Is there any set expectation on this or is it pretty individual to the paint and you have to expect to be surprised as time goes on. I know the maintenance recommendation of doing a light coat of oil after a few years to renew the look, but in general it sounds like this is going to be a changing surface and I want some info on what to expect.

Second I have read that it is very tough stuff to remove. I am thinking of using this paint with shutters and if ordinary stripper will not work well in the future, it might cause a problem for the next person. If normal strippers won't remove it what will?

I am thinking about making the shutters linseed blue and our metal work a dark brown or black shade. Comments on if the blue would be too bright or if it would fade unpleasantly would be appreciated.

for those needing a reminder of what my house looks like...

http://web.mac.com/chakoianfamily/iWeb/Site%205/Photos.html

I'll post more current photos since the aluminum is off now, wood repaired and it is starting to get pieced back together. Coat of white wash will help of course.

 

[NT]

Theres normally no need to strip off any paint thats well stuck.

NT

 

[L1zzy]

I have just used teh Linseed oil process a la Hlkham on my cottage windows and as readers will know I'm a convert! In answer to your question about removal of Linseed paints all I can say is that prior to renovating all my wooden window frames (two of which were original 18thC) i used a heat gun to remove the old paint. (Hokham advise not using chemical stripper) certainly the 2 oldest window frames had been painted using Linseed oil based paint/pirmer and I firmly believe this is why they have lasted such a very long time. The paint came off using the heat gun like sort of warm , thick wax - it was easy as pie to take off and compared with the more modern paints on the other frames took minutes instead of hours.I hardly had to scrape at all whereas teh other frames neede alot of scraping and sanding etc. So my advice is GO FOR IT.The Scandinavians can't be wrong.Holkham i think say that the surface will begin to look chalky after 5 years but I don't think it says the colour fades - leastways a single coat of Linseed will restore it. Its gorgeous to apply and easy to wash your brushes out in the Linseed soap (which is also brilliant for cleaning glass) End of sales pitch!! And as i'm now on my 3rd coat of it I can vouch that it can dry in 24hrs in warm weather!