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Gabe,

I was not aware of Groves. It is a very interesting site indeed. If I'd have found that years ago I'd probably have a dozen kids by now.

I basically agree with what he says. For example, I stated I more or less expected the sun bleached oil to yellow again. It starts out clear but dries yellowish. I don't bleach for that, but the better drying that I get with sun bleaching. I hate yellowed finishes. I think some folk find them attractive though.

But going back to the beginning, with raw cold pressed oil, I hedge my bets and husk and wash anyway. I first learned the habit of washing oils when making biodiesel for giggles, but that is not the main reason why I washed my linseed. It was simply to experiment with the old ways and see what worked.

I think the oils actual gross mucilage present will be mostly dealt with by the presser along with most of the residual moisture in the pressing. But I also note the raw oil is still slightly cloudy, and there are substances in there I know are deleterious to the finish in various ways. When I wash it I eventually get a nifty and bizarre crystal-like jelly-water forming in the "water" or layer that is under the oil that separates out on the top slowly. The washed, Cold Pressed Linseed Oil (CPLO) seems superior to me, so I use it. I generally sun bleach some and keep a fair bit aside for later uses.

As you know there are many ways to "wash" the oil. I simply take boiled rainwater passed through a ceramic filter, add it to the oil and blend buggery out of it for a while to thoroughly emulsify it. One blending is as good as two to four hand-shaken washes, and it's quicker and much easier than shaking. I let it sit in a cold dark place with no air in the jar and wait until it separates out a bit. That is, the oil separates from a milky bottom layer and sits on top. When I deem it ready, I can siphon the cleaned oil, or freeze the bottom layer and pour the oil. I prefer to siphon not freeze. I wash it again then, and the amount of crystals varies from pressing batch to pressing batch. I wash 2-3 times until the crystals reduce right down. This of course, takes months on end, and I have left a few tidbits of info out. Then, if you sit the washed oil for years, yet more scum drops out of it that doesn't happen in unwashed oils in my experience. This can be reduced by dropping the washed oil into water which is just past simmering and giving it a gentle boil for a few hours. Let it settle a few days and much of the scum drops out and the oil stays cleaner and clear for years if stored well. My use of the term mucilage is pretty loose, and probably incorrect bad habit and confusing, but in part it includes the strange crystalline sludge i speak of. Impurities. My unwashed oils go rancid, but my husk/wash/boil combo I have never had go off. If I had more time, I'd look into distillation of the washed and boiled oil. Note when I say boil here, I do not mean boiled or HT oil. Finish made from washed oils has a different film quality to the unwashed oils in my application - to the naked and magnified eye, but I have not tested nearly all permutations - I am not completely crazy. If I was a wealthy squire I might just do it, though, but I'd offer some nerd chemist nee stockmaker the job while I tried to wear out all the good guns I could find caps and loading gear for. Making whiskey would be more fun.

So now I have my fully washed oil. Right or wrong - doesn't seem to harm it. Some of it then gets sun bleached. Some of it gets left as washed CPLO (base reference washed oil), and some I do indeed heat treat, to get a better polymerisation and lighter dry finish that doesn't yellow so much. I used to experiment with all the "likely" different permutations but that was then ago........stopped that when my sheds went down.

Very interesting Mr Groves is using heat treated walnut oil. I will be reading up on his walnut oil.

He is very probably right on the washing, I have thought the same, but I have not tried HT CPLO that has been made from unwashed oil. I have made Heat Treated (HT) from sun-bleached CPLO and that was fine stuff indeed, and from straight washed CPLO, and from walnut oil. I have tried several heat treats and some have been eye openers. So, where does the term "boiled linseed oil" has it's roots?

Hehe. Like I said, this is starting to get complicated. I have a headache trying to write what has become habit and I have probably omitted some important stuff. I believe I am NOT a full bottle on it, but my results have been encouraging at the great expense of time.

So why the hell do it? I wanted to reduce metallic dryers to a minimum. I wanted to get the purest, cleanest coat possible. An oil finish with a classy slightly glossy hue. It goes much deeper than that, because my oil based finishes are mostly oil/natural resin "varnish". These are not oil finshes to me, but traditional varnishes and outside your topic. I prefer that as a finish, to straight oil with dryers, for several reasons. But I still use drying oil finishes, and also several ways of filling pores. The reason is the variability of walnut. And then the complexity rises to whole new heights. I'm probably doing things wrong, or overdoing some things like the washing before HT. Also, if you want a true gloss and the customer won't pay for sanding way past 400 grit........ain't going to happen is my experience - yet more TIME.

It would perhaps be much simpler to experiment with some of Mr Groves oils, and maybe some varnishes, but whilst I think there is much to learn from the oil painters, I keep in mind we are also dealing with wood so recipes probably will not interchange well between the two fields (?). Still, the art community provides some info I have never seen written about in the gun books.

On the alkanet root comment of mine........I've been roasted for that in the past, but I have met more than one very good stocker who agreed. It's maybe worth a try if you can get the whole roots, but I'd also bet the quality of the ground stuff varies a lot and I haven't tried them all. I leave it sitting for as long as possible, shake and sit, no air and in the cold. I don't like red oil to set hard quick so the oil soaks into the wood well. Once that is done, I can harden it by several means including the finish oil. I don't see the point in trying to get more red through a previously hardened coat. I don't like boiling alkanet in turps, or extracting with alcohol - red oil is my choice.

There is some walnut I just will not oil finish, but much of that is not real good stock wood anyhow.

I'd better get to bed.

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