Boiled linseed oil, - so far so good

[Rolf]

I boiled the oil to today. I took a pint of cold pressed raw linseed oil, added crushed eggshells from 8 eggs and about 1-2 teaspoons of home made leadwhite.


I heated on a hot plate outside in a sand bath.


Around 80^oC it started to steam and bubble and some white waxy blobs started started churning in the oil.


At 110^oC it started to foam . I had to wrap insultation around the pot to get it hot enough.


After three hours it stopped foaming and steaming and the temperature rouse rapidly to 210^oC.
I turned off the hot plate and wrapped the pot in insulation. I removed the insulation after 45 minutes. The oil was still 210^oC.


I let it cool for a couple of hours and strained it through a piece of cloth. The oil is dark coffee colored. I tried it on a scrap of maple with the stain I'm using. Looks good. The oil does not feel sticky at all. Now I have to wait and see if it drys.


Best regards
Rolfkt

[Jim Kibler]

You may want to thin it some with turpentine if it's too thick.  Also, when testing to see if it dries, rember the sun.  It's amazing the difference it makes in curing the finish.  In my experience, a couple hours in good sun might be the equivalent of several days inside out of the sun.

[Rolf]

It's nice and sunny here in Norway , but the maximum daytime temperature was 30^oF .
Should I still put it outside to dry?

Best regards
Rolf

[Kermit]

Sunshine/UV is the key. A chemist once told me that it actually catalyzes the stuff, and it won't happen without the UV--it just dries, doesn't harden. He colulda been blowing smoke for all I know!

BTW, glad to see that fire extinguisher. Bummer to need one and have to try to remember where the nearest one is! 

[bgf]

Sun is good, but at 30dF (already? its 80dF here!), you might be better off putting it in a sunny window of warm house.  I would count on a minimum of 24 hrs., although you may be pleasantly surprised.  Sometimes thinning will speed things up, I think by depositing less varnish and evaporating quickly, but it will take more coats.  In the case of a house, I've found stuff dries quicker, not surprisingly, with dry heat sources (e.g. electric) as opposed to ones that keep humidity up.

[Joe S]

That looks like a good batch Rolfk.  It won’t be very sticky because it’s just oil.  If you add resins to make a varnish, then it will be plenty sticky.  Jim is right about the sun.  The polymerization of linseed oil is catalyzed by UV.   Higher temperatures are good, but even well below 0 UV speeds things along.

[Bill of the 45th]

Rolfkt, don't worry about the temp, it's the UV of the sun that cures it, and a window glass, even with untreated glass will affect the results.  Out doors is best.  Here in Northern Michigan in the winter it's almost impossible to get enough sunlight to make it work well.

Bill

[A.Merrill]

    If its UVs you need how about a tanning bed?       AL

[Mad Monk]

Rolfkt,

You really should have waited to add the egg shells until after you cooked the lead into the oil.

When you heat the oil with the lead compound the organic acids in the linseed oil will break down the lead compound and convert it to lead linoleate.
If you neutralize the organic acids before the oil gets a chance to react with the lead compound you get very little lead incorporated into the oil as a dryer metal.

Then once the oil's organic acids react with the lead you would add the egg shells to "kill", or neutralize, any excess organic acids left in the oil.
Any excess of organic acids after cooking in the lead will slow the drying rate.

The boiled oil film, on the wood, "drys" by absorbing oxygen from the air.  With a lead dryer metal oil this rate will be influenced by temperature and the presence of ultra-violet light along with air flow around the surface of the oil film.

Once the temperature starts to fall below 60 degrees F the rate of drying slows down.  If the air is not moving over the surface of the oil film it will initially pick up oxygen but then when the oxygen content of the air in contact with the film falls it will be starved for oxygen.

Ultra-violet light acts as something of a catalyst in the drying of the oil.

Manganese dryer metal oil films are very sensitive to relative humidity when it comes to speed of drying.  With a manganese, or cobalt, dryer oil film is subject to a relative humidity in excess of 60% the drying rate slows in proportion to the amount of humidity over 60%.
Lead based oil films are not sensitive to relative humidity.  The level of relative humidity has no real effect on the drying rates with a lead based oil.

Manganese and cobalt oil films are commonly called surface drying films.  The surface drys first and then drying proceeds from the surface to the base of the oil film.  Lead based oils are known as "through" drying.  The film drys relative uniform from the surface to the base of the film at the same time.

If you can find it in an artist supply store you might want to think of Venice Turpentine if you must thin the oil at any time.  This would be in preference to the use of "Gum Turpentine".

If you make any more batches of boiled oil.  When the oil begins to foam, showing a reaction with the lead during heating, you should skim off any scum that forms on the surface of the hot oil.  If the scum forming in cooking is incorporated back into the oil it will slow drying and sometimes give sticky films on wood.


E. Ogre

[Rolf]

monk, thanks for the advice. I've started a new jar of lead white. In a month or so I should have enough leadwhite to try again, if this first batch does not work.

Best regards
Rolfkt

[Mad Monk]

monk, thanks for the advice. I've started a new jar of lead white. In a month or so I should have enough leadwhite to try again, if this first batch does not work.

Best regards
Rolfkt

How are you preparing the "lead white"?

E. Ogre

[roundball]

Couldn't you just get a UV 'grow light' from a hardware store and do it indoors?


And forgive for not knowing, but does BLO not exist already made up?

[Rolf]

Monk, lead sheet metal in a jar with vinegar. I described the prosess here. http://americanlongrifles.org/forum/index.php?topic=12442.0

Best regards

Rolfkt

[Mad Monk]

Couldn't you just get a UV 'grow light' from a hardware store and do it indoors?


And forgive for not knowing, but does BLO not exist already made up?

The indoor UV light would work.  This had been used in linoleum factories late 19th and early 20th centuries in high towers that prepared the linseed oil as a gel.

Yes one can buy BLO at hardware stores and home centers.
But there are those who would do it the old way to see what it was like.

E. Ogre

[roundball]

Yes one can buy BLO at hardware stores and home centers.
But there are those who would do it the old way to see what it was like.

Wasn't questioning that at all...literally didn't know if "BLO" was commercially available

[Mad Monk]

Monk, lead sheet metal in a jar with vinegar. I described the prosess here. http://americanlongrifles.org/forum/index.php?topic=12442.0

Best regards

Rolfkt

The process you show goes back to the ancient Greeks and then Romans.

You should suspend the lead sheet over the vinegar.  Not in it.  It is the acetic acid fumes that "corrode" the lead to form lead acetate.

When the sheet lead forms the white crust, lead acetate or sugar of lead, you may remove it and brush off the powder into a jar.  Then put the sheet back into the jar for more time in the fumes.

Lead acetate, or sugar of lead, is not stable in air.  That is not to say it would catch fire or blow up.  Simply that the acetate of lead is not the environmentally stable form of lead.  When lead acetate has contact with air and a little bit of humidity it will convert to lead carbonate.  But not a real problem with oil boiling.  Lead carbonate works as well as lead acetate.

The old "Dutch" process for making lead acetate was to use wine vinegar which is about 8% acetic acid while cider vinegar is only around 4% acetic acid.  Plates of pure lead were placed in crocks.  Held above the surface of the liquid by using an inert block in the vinegar.  The crocks were then covered and "luted" (sealed).  Then placed in wooden racks which were then covered over with fresh manure.  The manure providing heat to speed up the reaction between the acetic acid fumes and the lead sheeting.

(I would also point out that this same proess was used with copper plates to produce copper acetate which was used in dyeing fabrics, leater, horns, etc.)

 
E. Ogre

[Mad Monk]

Yes one can buy BLO at hardware stores and home centers.
But there are those who would do it the old way to see what it was like.

Wasn't questioning that at all...literally didn't know if "BLO" was commercially available

I thought you were wondering why anybody would bother doing it when the linseed oil found in hardware stores and home centers is already "boiled" unless marked as "raw oil".
When you tell somebody you boil your own linseed oil that look at you like you are crazy. 

E. Ogre

[bob in the woods]

I don't suppose that it is necessary to point out that sugar of lead is very very bad for you!  Definitely NOT for your coffee 

[Mad Monk]

I don't suppose that it is necessary to point out that sugar of lead is very very bad for you!  Definitely NOT for your coffee 

I should have pointed out that you do not want to breath any dust of this.  One should wear rubber gloves when handling it.

But I consider it acceptable in coffee for a house guest if they happen to be a liberal anti-gun  Democrat!!!

I assumed that since we shoot lead projectiles and use percussion caps containing a lead compound we all understood the dangers of ANY lead to human health.

E. Ogre

[bob in the woods]

Yes, lead can be very dangerous to human health. Especially if it's traveling at 1200 ft/sec or so.

[Rolf]

The batch seems to have turn out okay. It takes about 2 days for an undiluted coat to dry with out sun ligth. But its alot softer that the finishing oils I've used on furniture. Is there a simple way to had some resins to the oil?

Best regards

Rolfkt

[bgf]

I'd add a little polyurethane and some thinner .  Don't take that seriously -- it should dry hard enough that you don't need to be concerned about it.  My guess is either there isn't enough drier or it hasn't completely dried, perhaps because you put on too thick a coat?  I was under the impression (from reading posts here, esp. DPhariss's) that boiling with lead as you did results in more of a varnish than an oil, so it should be plenty hard for gunstock use.  Hopefully he'll see this and give you some advice.

[Ed Wenger]

Rolfkt,

I just finished a walnut stocked rifle with boiled linseed oil.  I did the lead ball method that melts into the oil, and yes, it flashed and stank to high heaven, etc...  but turned out nicely.  I had the best luck with thin layers.  Just a drop spread out as much as I could, rubbing vigorously to produce some heat.  I applied 4 or 5 coats, letting it dry in the sun as much as possible between applications.  It built up nicely, filled the pores fairly well, and produced a nice finish.  I've done this before and applied too thick of a coat, and it didn't work as well as thin coats...


                           Ed

[keweenaw]

Those halogen work lights, with the glass cover removed, are a much better source of high energy UV than are grow lights or black lights.  They also generate a lot of heat so perhaps shining them on the piece to dry for relatively short periods of time would work or perhaps with a fan blowing other air across the work to keep it cooler would combine the UV, heat and air movement....Germicidal UV lights are still better, don't make much heat, but they can do serious eye damage and give "sun burns" with very short exposure times.  One would want to have them in a cabinet and not turn them on until the cabinet was closed.

Hardware store BLO is not really boiled, it just has driers added to it and these days the driers are not lead based.

Tom

[Dphariss]

Yes one can buy BLO at hardware stores and home centers.
But there are those who would do it the old way to see what it was like.

Wasn't questioning that at all...literally didn't know if "BLO" was commercially available

The oil that can be bought is either paint thinner, the BLO from the lumber yard or its artists stand oil. Neither is heated or really stock finish as would be found in the 18th or 19th century. Stand oil must be very pale to avoid darkening colors added to it and its made by a different process than boiled oil was back in the day.
The BLO is not really heated since heating the oil causes a loss of volume. So they add the driers cold and for paint it seems to work OK its just not the same as recooked oil. The heating process changes the oil in a couple of ways, darkens it and thickens it somewhat and if properly done reduces the drying time. The darker, natural oil adds a lot of character to the wood, especially walnut.


AND.
Mad Monk needs a thank you from all of us. Having known him through correspondence and telephone since the 1970s. He has sent me a great deal of information over the years and for this I am thankful. Its all been very educational and every time he posts here I learn something new.

Dan