Finishing with Oil over Shellac
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I was wondering how well it might work to put a few coats of linseed oil (cold-pressed) over a shellac finish for e.g. a table top in order to make it less prone to damage by water and other liquids. Anyone got hands-on experience with this? I might just give it a try and see how it works.
David
26 January 2016 at 12:34 pm #134208no it’s not possible as shellac dries hard and the oil will not penetrate it. Besides oil has very little protectant properties anyway.
@salko Thanks for your estimation. My thought was that linseed oil will polymerize and thus form a layer on top of the shellac. Do you mean the layer will not stick to the shellac? Have you tried this particular combination for yourself or is that what you expect from your experience? As far as I know linseed oil can be used to create quite water repelling finishes.
David
28 January 2016 at 8:04 am #134278This is an unconventional approach and one that won’t work and I do understand what your trying to achieve but if you want water repellent finish wax will do that job.
You have though answered your own question yes it will polymerize and look darn ugly, when people go overboard with their application of any oil eventually it builds up to a thick like too waxy appearance I’m sorry I cannot find the right words. Oils really is there to pop the grain and provide a small amount of sheen and some level of protection. If you apply subsequent coats of no more than 3 you will get the right level of sheen but what I usually like to do is apply one coat of oil let it dry 24hrs if need be longer depending on the weather and then apply the shellac over it again no more than 3 coats upon which you can apply the wax. Marketers have led people to believe because it sounds good that oils penetrate and protect the timber from within, this is untrue, they also like to claim that it nourishes the timber which is also untrue.
If your adamant in giving it a go then experiment on some scrap, you will never know the results until you see for yourself what will happen. I would suggest in your experimentation to apply a thin coat as you would normally but don’t wipe it off and let it dry overnight. On the second scrap apply the same coat let it sit for about 20 mins and then wipe it off and compare the results between the two. If it looks good and water beads off of it then go for it you will be the first person in history to have done it this way that I know of.
I’ve heard of putting oil *under* shellac to change the appearance of the grain under the shellac finish, but never heard of putting it over shellac. Be careful because some woods, like cherry, can blotch from oils alone even without stain/dye.
My finishing teacher hates linseed oil. He took an array of finishes, applied them side by side, and tested for how long it took them to dry and for how hard the finish was (as well as tendency to yellow). Linseed oil basically never dried. It just got gummy. I think he waited weeks. There are so many better finishes, I don’t know why people mess with this stuff. My teacher refers to it as misinformation spread by modern web-experts that really don’t know what they are doing, just as Paul refers to nonsense about tools and methods.
I started to learn french polishing from the web and books, and one thing to note is that french polish is applied with a fad as shellac plus occasional drops of oil which lubricate the polishing. When you are all done, one of the final steps is to “clear the oil,” meaning to get the oil off of the surface, generally because it is unpleasant and dulling. Seems to me that is enough of a hint to not take a nice shellac finish and smear some oil over it in the end. 🙂
David,
I think you’ve gotten some good advise.
Attached is a link to Amazon UK for Bob Flexners book on finishing:
Bob goes beyond just”use this, don’ use that” to explain in very understandable terms the Chemistry and rational behind all the typical options in finishes.
You don’t have to reinvent the wheel.BTW Dieter Schmidt has an excellent staff that can be most helpful in selecting the best product for your application.
Best,
Craig -
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