Boiled Linseed Oil - What to cook it in?

[Benedict]

I am in the process of getting set up to boil my own oil and have all the material but got to thinking about the pot that I will boil it in.  What should the pot be made of?  Is aluminum OK or should I use stainless steel or other steel container?  Or does it matter?

Thanks,
Bruce

[Dphariss]

Find an old deep fat fryer. Gallon of oil, some crushed limestone and some Japanese drier. Put fryer on high and cook the oil for about 15-30 minutes after it starts to smoke. Decant about half when cool then reheat the remainder to thicken it more. Thicker oil is better for the fill coats on  walnut.
Or you an use a camp stove and a stainless pot heat it till it starts to smoke then reduce the heat. More dangerous than the deep fat fryer.
There is a longer description of how to make the oil in several posts on the subject of BLO or stock finish.

Do this outside and keep anything living away from the oil.
Dan

[Benedict]

thanks Dan.  I read the earlier posts and other than mentioning a deep fat fryer, I did not see anything about what to cook it in.  You seem to think it should be stainless steel.  My plan is to do it outside on a small hot plate rather than an open flame.  I understand that this is a dangerous process so will be doing it outside with small amounts of oil.

Bruce

[Tim Crosby]

 Dan,
  You said "Thicker oil is better for the fill coats on  walnut." I thought you wanted it thinner to start with so it would penetrate better and then build up with thicker. Am I thinking/reading wrong?

 Thanks, Tim C.

[Stophel]

The oil I have been using for an oil finish is THICK.  Boiled for....actually, I forget how long...probably about an hour.  I use a little self-contained deep fryer thing with an enclosed element on the bottom.  It's aluminum with a teflon coating, which at first I wondered about, but found out it has no effect. 

Do it outside, far away from anything else, keep a fire extinguisher and the properly-fitting lid handy.  It CAN catch fire.  I've learned to not keep the lid on and then lift it off.  The heat builds up too much, and fire is a possibility.

For every pint of oil, I put in 1 tsp of lead carbonate, and 1 tsp of a burnt umber.  Both are drying agents.  Get it to a low, roll, and keep it there.  It doesn't need to really froth.  Just turning over.  Every now and then, dip some out with a stick, let it cool, and see how thick it is.  That way, you'll know when to stop boiling.  When satisfied, turn off the heat and let it cool, but not all the way.  It needs to be warm so it will flow, and pour it into Mason jars.  And there you have it.

[Stan]

Keep in mind that as the oil starts to boil it will increase in volume! Stan

[Don Getz]

While we are the subject of Linseed Oil, over the years I have good and bad things said about it insofar as a good waterproof finish.   I've heard tales of being out in the rain with a linseed oil finished stock and it turned white, or pale,
underneath the finish.   If I remember correctly, John Bivins did not like it as a stock finish.  What is the real scoop........
Don

[Dphariss]

Dan,
  You said "Thicker oil is better for the fill coats on  walnut." I thought you wanted it thinner to start with so it would penetrate better and then build up with thicker. Am I thinking/reading wrong?

 Thanks, Tim C.

For seal I use the thinner oil mixed with Turpentine that has been aged. Then the thicker oil for *fill*. Then the thinner oil mixed with Grumbachers Oil Painting Medium III for final finish. I used this mix with turp for the seal on maple recently and it works very well so I will surely use it this way in the future.

Filling of walnut is not the same as sealing it. The heavy oil, and it will get like molasses if left exposed to the air in a cloth covered jar, thick skin to break through, will fill Black Walnut quicker, with less work than anything I have ever tried, including the "fillers", wet sanding etc etc.
Another thing the BLO fill coats do not dry as most people expect. When its dry enough to not stick in the steel wool I take it off. It will stay rubbery for weeks since LO does not dry "hard". Its not supposed to.
This what makes it a good stock finish. Even the varnishes made from it are "soft" unless high levels of resin is used. This is why the varnish will not crack when  dented unless its very severely struck or the object cuts rather than dents. Hard finishes will break at the dent and "leak" moisture or they will not expand and contract with the wood, check or crack and will then pass water. When you see "flexible"used to describe a wood finish it means they can paint it on a metal bar, bend the bar and the film will stretch with the metal. This is not the same as elastic. Where the wood expands *and* shrinks the finish must follow.
Something that BLO or an oil varnish does very well.

There is no such thing as a waterproof finish for a gunstock.
The requirements are just too severe.
Water resistant is all you will get. Waterproof finishes just will not stand the temp changes and the abuse that a gunstock gets in use.
Yes straight BLO and some oil varnishes will turn milky if you hunt all day in rain or snow. Especially where the hands touch the finish.  Adding some resin to the oil to make a varnish will greatly reduce this. But the effect is temporary with straight oil and the BLO will return the moisture to the atmosphere when the weather  dries or the gun is moved indoors. Any wear to the finish is easily fixed with a little oil rubbed on to return the shine.
The average deep fat fryer will not "boil" the oil. I have used a propane camp stove to increase the temp but I cannot say I can see any difference in the oil. Overheating the oil can damage it. Something that can occur if making varnish with resins that require high temps to mix properly.
Lead will reduce the drying time in high humidity. Where I live this is not a great concern.
The darker oil gives a better look to the wood, stained or not, than transparent or even colored synthetic finished will. These often make the stock look painted with little "depth" to the finish. But with their rapid dry times they can be desirable where production in more important than looks.
This is where Permalyn, Tru-Oil etc came from.  It drys much faster then store bought "BLO" which is a painters product not a stock finish. When many people think of BLO this is what comes to mind. But it is not what was used for stock finish until recent times.

Dan

[Stophel]

While we are the subject of Linseed Oil, over the years I have good and bad things said about it insofar as a good waterproof finish.   I've heard tales of being out in the rain with a linseed oil finished stock and it turned white, or pale,
underneath the finish.   If I remember correctly, John Bivins did not like it as a stock finish.  What is the real scoop........
Don

Whenever you hear someone say something like "I put boiled linseed oil on a stock, and I was out in the rain once, and all the oil ran out, and the stain ran out too" (another reason to avoid aniline dye, by the way), it's probably because they took modern "boiled" linseed oil (which isn't), soaked the wood with it four or five times and said, "there, I'm finished".  Linseed oil, boiled or otherwise, must be applied EXCEEDINGLY sparingly with each application.  It must be allowed to dry THOROUGHLY.  Meaning each coat needs AT LEAST one full day of direct sunlight...preferably two or three.  I cannot emphasize that enough.  Otherwise, the surface may dry a little, but all that oil underneath there, that you soaked into the stock will be just as liquid a year later as when you put it on.  You may as well have used axle grease.

I have found that when linseed oil is thoroughly dry, it is utterly unaffected by water.  Now, water will pass through linseed oil, but it slows the transpiration to a rate that the wood can more easily handle.  Water will also sometimes spot the oil, but so far, I haven't seen it spot where it doesn't dry itself out and go away fairly quickly.  I've not really taken any of my linseed oil-finished guns out into the heavy rain yet, so I cannot honestly speak to the effects of a heavy soaking of water, but so far, a little water won't hurt anything.

By the way, I had to jerk out the thermostat in my deep fryer so that it would stay hot enough.  As soon as it got hot enough to turn the oil over, it would annoyingly kick off.  Now, the downside is that I HAVE to watch it carefully so it doesn't get too hot.

[Joe S]

I’ve found that there is a wide range of temperatures you can use to make lead/linseed oil drying oils.  At a minimum, you need to get the oil hot enough for the lead to disassociate from the carbonate and react with the oil.  This seems to happen at about 300-320 degrees, so this would be the lower limit.  At relatively low temperatures, you can produce thin, pale oil about the color of honey, but with a reddish tinge.   This oil dries in a day or so in the sun.

Kettenburg processes his oil at about 630-640 degrees.  Linseed oil auto ignites at 649 degrees, so this would be the upper limit.  At this temperature, you get oil that is nearly black.  He described his process in some detail in a recent post. 

Based on what I’ve seen, at about 400 degrees you start getting thicker, darker oils.   Longer cooking times of course result in thicker, darker oils.  I have not done careful controlled experiments on drying times, but it seems to me that for a given thickness of oil coat, drying time is about the same for oils heated from 320 to 450 degrees.  Kettenburg says the oil he makes at really high temperatures dries noticeably faster than oil processed at lower temperatures.

One source I found from the way back times said that the oil should be heated until it will scorch a feather.  According to my thermometer, this happens at 460 degrees.  I’ve tried it and it makes a dark, moderately thick oil.

[hyltoto]

Here is something I learned in my DCM days, a nice finish and very durable in weather. Culvers magic Paste:

I have a personal favorite that, (I used it to add weather proodfing to my 1803 harpers ferry_- combines the traditional hand rubbed linseed oil finish with the
weather proof qualities of the polymer finishes and looks like you spent your whole life working
on the stock. It consists of a mixture of 1/3rd Linseed Oil, 1/3rd Turpentine (acting as a solvent),
and 1/3rd Beeswax, gently melted together over something other than an open flame (an old-time
radiator used to work well). When it is well melted, it should be stirred and left to congeal... It
turns into a paste that makes a great (military style) finish that looks like it took a million years
to apply. Repairs easily, even in the field. Got this one from an old gent at Perry back in the Mid-
50s who looked like he had personally used it on his issued Trapdoor Springfield... I went home
and tried it, and have been using it every since.

[DutchGramps]

....It consists of a mixture of 1/3rd Linseed Oil, 1/3rd Turpentine (acting as a solvent),
and 1/3rd Beeswax, gently melted together ....

Raw or boiled linseed oil ?

[dipstick]

Try this if you want to thicken  oil,place raw linseed in a glass jar cover with a lid of open weave cloth & place in a warm sunny spot,This will take about six months , the process of oxidisation takes its time,the longer you leave it the thicker it becomes,years ago it was used to make a varnish for violins .

[Stophel]

This is basically "stand oil".  If you want to keep the oil relatively light colored.

[Dphariss]

Mad Monk needs to publish a booklet on making and using BLO.

Dan

[Joe S]

He did.  It's called Staining and Finishing for Muzzleloading Gun Builders,Methods and Materials from 1750-1850

[davec2]

Joe,

Where might one acquire a copy of Mad Monk's writings on finishes?

Dave C

[Dphariss]

Joe,

Where might one acquire a copy of Mad Monk's writings on finishes?

Dave C

I have a stack of paper 6-8" deep and a couple of CDs from Monk that has accumulated since the late 1970s including a draft paper he did for Dixon on finishing. I have never seen the booklet. Only heard of it when it is referenced here and there.

Dan

[davec2]

Dan,

It sounds like we need to track this document down!  Joe S, do you have a copy?

Dave C

[Joe S]

I do.  Try Dixons.  They have it from time to time.  The book covers a lot of interesting topics, but it is not really helpful on varnish.  If your interests are limited to making BLO and varnish, you can get all the information you need off of this site and the archives. 

[Gary Collins]

davec2  go to www.thealchemist.us at the bottom of page go to books let us know if this is it  gary

[T*O*F]

Maybe I'm the only guy in the world who's got a copy.
WHEN I got mine it was only available from Dixon's and they only had a couple left.........that was at least 5 years ago.

Now you can all have a race to call Dixon's and see if any are left.  As many of you guys who go to Dixon's Fair, I can't imagine there would be.

[Rayant]

No, I'm the second guy.

[hyltoto]

*

[Dphariss]

I do.  Try Dixons.  They have it from time to time.  The book covers a lot of interesting topics, but it is not really helpful on varnish.  If your interests are limited to making BLO and varnish, you can get all the information you need off of this site and the archives. 

No offense, please, none is intended but this is basically how things are *IMO*. I am quoting Joe but only because he sorta opened the door.
There is  silliness and misinformation concerning stock finishes. Some coming from high places in the ML builders community.
The problem with the use of true BLO is the superficial nature of the material *generally* available.
Most people don't care enough to make the effort to understand the process or to use the stuff in the manner that is needed to give the best result. This is another reason for the scarcity of material on the subject. It feeds on itself.
Most people want something that they can use like modern plastic finishes.
BLO is different. Its no harder and may be EASIER to use but you must *understand the processes and reasoning*. Aging turpentine for the seal coat mix etc.
I have several Maple stocked guns with 2 coats of BLO or one of my BLO mixes on them and they look good. Then I read of people working for a month to finish a rifle. Its not realistic.

The same can be said of ferric nitrate stains. Some feel its easier to put in 3-5 (more?) coats of various stain colors to get a vintage look than one or maybe 2 coats of nitrate stain. I just don't get it.


Apologies for any ruffled feathers. Really. This not pointed at ANYONE. But I see it as a problem that needs to be pointed out at least to those who want to make "traditional" guns. You can't make a traditional gun with synthetic stains and plastic finishes. Example, folks will maintain that the 18th century kentucky has to have a tapered/swamped barrel to be right. Then they use plastic stock finish?
7-9 times out of ten they LOOK like they have modern finishes on them applied, for example, with techniques meant for black walnut rather than maple (its two different processes folks).
End of rant.

Dan