Mahoney Walnut Oil

Re: Mahoney Walnut Oil

robo hippy

I use the Doctor's Woodshop walnut oil, but same process. I get it sloppy wet and apply with one of the grey synthetic steel wool pads while spinning on the lathe. I sand out the next bowl and oil it, then go to the first one and wipe it down again, leaving it very wet. Let it soak in at least over night, and wipe off with a rag. It takes a week to 2 weeks for the oil to cure. Sunlight helps, and some times if I am in a hurry, I will stack them on wire shelves and put a 60 watt light bulb under them for a few days.

robo hippy

Re: Mahoney Walnut Oil

mjonesrdg

All of the nut and seed oils rancidify over time. The oxygen molecules that are in the oil, will attack the lipids, and phenols and formaldehydes are formed, breaking down the oil...little by little. Walnut oil that has been in inventory for an extended period of time will take much longer to dry (polymerize) than fresh walnut oil.

Woodturners would be well advised to check for freshness before using the oil on wood. Look first for a ..."Best-used-by.....(date).." stamp on the label, and secondly, taste a bit of the oil. If the oil has begun to rancidify, it will have an unpleasant flavor that lingers in the mouth.

Re: Mahoney Walnut Oil

John C Lucas

I apply Mahoneys e ery day until i get the sheen i want. Thats usually overnight for the first coat and 24 hours thre after

Re: Mahoney Walnut Oil

David Walser

Stuart -- Part of the answer to your question depends on how you apply the oil. I wet sand with walnut oil, using a paper towel to remove the excess oil and sanding grit in between grits of sandpaper. Sanding with the oil forces the oil deeper into the wood and the heat from drying the wood in between sandings (the lathe is on) helps to "friction cure" the oil. By the time I've sanded up through 400 grit, the item typically has had enough walnut oil that additional coats are not necessary. In effect, the item has already had 3 or 4 coats.

If I'm not wet sanding with walnut oil, then I apply as much oil as the item will absorb, wiping off any excess after about 15 minutes. I'll apply another coat in about 12 hours, repeating with additional coats every 12 hours or so (or once a day) until the item has the "right" sheen.

Re: Mahoney Walnut Oil

Jim Barbour

By way of a disclaimer, I am an economist, not an organic chemist so some of this may not be absolutely correct from a chemist's point of view, but it fits my experience and conversations I have had with chemists.

Tangential to the topic of prepared walnut oil based finishes such as Mahoney's, if you purchase walnut oil directly you will find that some will dry fairly readily and some will not dry in anything like a reasonable amount of time, taking as much as several months to set up. The difference is whether the oil is refined or raw. If the oil is refined for food use, one thing they want to accomplish is to retard any tendency to set up in the bottle. Thus the refining process removes the dryers from the oil.

Raw, filtered oil will set up fairly quickly - a matter of a few of hours to a week or so depending on temperature and humidity. Refined oil is treated for cooking so that it will (ideally) never set up, maintaining it's liquidity for as long as possible.

If you are an organic chemist, and if I have misspoken, please correct me. I have tried both and have had these results. I then asked why and was told it was the refining process.

Re: Mahoney Walnut Oil

David Walser

Jim -- I think you got the effect, if not the cause, correct. Mahoney's Utility Finish cures more quickly than walnut oils from the supermarket. On his website, Mike says that this is because he heat treats his oil.

Re: Mahoney Walnut Oil

Jim Barbour

David, I suspect you are correct.

My note is based on never having used Mahoney's product. I have, however, used several gallons of raw, filtered walnut oil directly, without heating or any thing else, and have never had it not set fairly quickly, even after storing it for a couple of years. One time I inadvertently got a bottle of refined oil and it never did set up. Thus I may have conflated correlation with causation.

I tend to apply the raw oil, let it dry for a day or so, and then buff the item. It may be that the heating when I buff is doing the same thing as Mike is doing when he heats his. The problem I had with the refined oil is that it never got hard enough to buff - perhaps if I had buffed it wet, heating it, it would have set.

It seems to me that if you are buying walnut oil directly, not after it has been treated to make a finish, refining makes a difference. But I could be wrong.

I don't like any version of walnut.......

JamieDonaldson

.....oil, and suggest this whole discussion could be avoided by problem simply switching to Minwax Wiping Poly finish!

Re: I don't like any version of walnut.......

Jim Barbour

Sometimes I wish I was a flat worker. Those guys agree on everything! 😜

Re: Mahoney Walnut Oil

mjonesrdg

Walnut oil comes to market as either "refined" or "cold-pressed". Either refined or cold-pressed might have a wax, a dryer, or a thinner added, but pure 100%walnut oil whether refined or cold-pressed, will act the same if made from the same harvest-year nuts.

Heat and UV light can speed up the polymerization process, but no amount of heat or UV light will reasonably expedite the process if the oil is degraded by excessive age.

The purpose of refining the oil is to extract the maximum yield i.e. the most product possible to sell. Cold pressing losses some oil in the process, but provides a more flavorful product. Typically, a plant that produces cold-pressed oil, will date stamp theirs and a vendor of refined oil will not. Cold pressed, this year's harvest, with date stamp, will always be a better bet for our use.

Remember the taste test. Taste it at the store before you take out of the store. The price differences, I have found to be negligble.

Re: I don't like any version of walnut.......

john lucas

Jamie I use it on my user bowls. I don't want a finish that builds and stays on the surface because it wears out and chips. Mahoney's Walnut oil has been changed to remove the alergen. It hardens in the wood and holds up quite well. It does get dull with usage but is easily rejuvinated by a new application if that's the look you need.

Candy dishes and things that won't be washed a lot I do use wipe on poly.

Re: Mahoney Walnut Oil

robo hippy

Mike Meridith, the Doctor, as in PHD in Chemistry, of the Doctor's Woodshop gives an excellent demonstration when talking about his oils. The walnut oil used for bowls, and some times oil painting, is processed differently than the oils sold in the supermarket. Both are heat treated, but I have no idea what the exact differences are. The process can vary a lot from brand to brand. I have never had his, or Mike Mahoney's go sour on me like the vegetable oils can, but this is never certain. The going sour seems to be related to leaving excess on the surface, and that means food as well as oil.

As far as solvent based finishes go, I don't put anything on my bowls that I can't eat straight out of the container. While the chemical driers do cure out, they still leave traces, and after talking to one person who was very sensitive to them, I will not use them again.

You can go to Mike Meridith's web site, and I am pretty sure he explains it better than I do. He does dumb it down for us non-PHD's......

robo hippy

Re: Mahoney Walnut Oil

Doug Ladendorf

Which product do you guys recommend, Mahoneys, Dr's Woodshop or other? Is there a difference and do both have allergens removed?

Doug

Re: Mahoney Walnut Oil

David Walser

Doug -- I've used both and cannot tell a difference. Mahoney says he heat treats his, the Doctor's website is silent on whether its heat treated, or not. Both claim that their oil has been filtered and treated to remove any of the walnut proteins that cause a reaction in some people. (Doctor's says he's tested his oil using his lab's mass-spectrometer and cannot find any trace of the offending particles.) However, both warn that they cannot guarantee no allergic reaction to the use of their oil.

In his Youtube videos, Mike Meredith (the doctor of Doctor's Woodshop) explains that once the oil has cured, it becomes a polymer -- which should make the protein unavailable for causing allergic reactions.

HTH

Re: Mahoney Walnut Oil

Bill Neff

If I remember correctly (from my life working for a pet food company) when the walnut oil is heated it doesn't remove the allergen. What the heating (hydrolyzation) does is break apart the protein molecules so that they cannot connect the "contact points" that cause the allergic reaction. Think of a ball with protrusions sticking out around it. If you drop a piece of metal that hits at least 2 protrusions you'll get a reaction. If the metal is too short to make contact there is no reaction. This is a very simplifed explanation but that's how it was explained when the company I worked for developed an allergen free pet food. Similar process used for baby foods.