Man o' War wood finishing

Re: Man o' War wood finishing

Dick Coers

Curious why you felt the need to make the home brew? What were the expected results of mixing the 3 over using a commercial product?

Re: Man o' War wood finishing

eliot feldman

My only replay is that I favor this kind of blend of a varnish, an oil and the appropriate thinner for the varnish when I do it on the lathe. For example, I often use shellac, linseed oil, and alcohol -- or perhaps, lacquer, tung oil and lacquer thinner, for turned objects.

Why varnish is diluted with oil....

Bill Tindall, E.Tn.

...escapes me. Dilute the varnish with solvent if necessary for good flow out and brush it on. That is how varnish was used for the past 100+ years. Diluting with oil results in a soft film. I cannot think of any benefit from the oil dilution.

curious finishing chemistry

Bill Tindall, E.Tn.

It makes no sense to me to mix incompatible finish materials. How mixing shellac with linseed oil would result in an improved finish property escapes me. I would expect them to separate after application.

Shellac cures by evaporation. Linseed oil by oxidation and crosslinking. I am surprised that linseed oil is even soluble in 50/50 methanol/ethanol solvent sold as "alcohol" in stores.

To answer your question....

David Yoho

The mixture you are using so far is destined to result in a softer and thinner finish, therefore requiring more coats to build a finish. My thought is to start using just the straight Man o' War spar varnish until done.

A spar varnish is already a softer finish usually for outdoor items. The addition of oil makes it softer still. I know there are those that subscribe to "brewing" their own finish but I figure the companies that make wood finishes have done the research and testing to provide a product that works as is. Other than occasionally thinning a finish, I pretty much use them the way they came with excellent results.

Re: To answer your question....

eliot feldman

Well, I said that I didin't think I knew just what I was doing -- except that these mixtures seem to work beautifully on the lathe. Perhaps the really fast rotation of the object on the lathe and the resulting heat does the trick.

Given that I now have some build up of this "soft" Man o' War varnish on this end table, are you saying, after it dries, that I could do all right by continuing with just the Mano' War? I don't particularly want to sand it all off and start over. But I could. As I said, it does look pretty good so far, even though it's slow-going.

Also, I believe the are so-called "long oil varnishes", which presumably have more oil in them. They must be good for something, no?

Re: To answer your question....

David Yoho

Seems you already have some build at this point. By proceeding with the full strength varnish it will build quicker and require fewer applications to get you where it needs to be. Just be sure to allow what you've already applied enough time to dry.

If it feels like it needs smoothing between coats, I always use some 600 wet dry very lightly.

Amen

Re: curious finishing chemistry

eliot feldman

Why do you say these are incompatible? ALL varnishes are a mixture of a resin, an oil, and a solvent. In the case of shellac, the resin is the stuff the lac bug secrets, and the solvent is alcohol. Most oils will do. I've been using it on lathe-turned objects for years. It's a kind of easily-applied French polish.

Apparently, what I have concocted is simply a (perhaps too much oil) long oil varnish. So others a telling me that it will be on the soft side, which doesn't matter much for most turned objects, but may less than optimal for a table.

Based on what others have said, I'll continue with pure Man O' War with very light abrasive between coats.

Varnish in not a mix of oil, resin and solvent

Bill Tindall, E.Tn.

Traditional varnish is made by chemically reacting esters of glycerin and fatty acids (oil) with resin of one kind or another at high temperature w/wo oxygen. The result is a new chemical species not like either of the components. This material is then dissolved in solvent and a chemical added (drier) that will promote crosslinking (cure) of the varnish. Simply mixing these components does not make anything resembling varnish.

I never heard of a varnish being made from shellac, but it is possible. I have no idea the chemistry involved in modern varnish made from vegie oils, and synthetic resins.

I just tested and as predicted linseed oil is insoluble in alcohol, and I suppose insoluble in shellac dissolved in alcohol. Indeed you are making a sort of French polish. In the lathe buffing the linseed oil the blooms to the surface and is wiped off.

Re: Varnish in not a mix of oil, resin and solvent

eliot feldman

Well, you obviously know more about it than I do. So,please tell me again(your last sentence didn't read right) why I have been so successful applying shellac and linseed oil to lathe turned objects. I'm 79, but I still remember Mr Done, my junior high school shop teacher, applying shellac and linseed oil to lathe turned pieces. And I remember him saying that it was a kind of French polish( even though we know French polish is a method -- not a finishing material.)

Also, for what it's worth, the concoction I mixed up for my end table seem to work well -- except that it seems slow to build up. It looks good too.

Re: Varnish in not a mix of oil, resin and solvent

Bill Tindall, E.Tn.

It is common in French polish to add some sort of "oil" as a lubricant for the pad. The oil is insoluble in the shellac solvent solution and blooms to the surface and keeps the pad from sticking. I am sure the same is happening on the lathe. As the shellac builds on the wood the oil comes to the surface and lubs the rag you are applying the mixture with.

I shellac things on the lathe, and probably faster than your method. Depending on the piece I either saturate a brush or a piece of upholstery foam with shellac and touch it to the piece as it spins very slowly (like what is done with CA glue when used for a finish)

Re: Man o' War wood finishing

eliot feldman

After learning some things from this thread, I thought I would do a bit of research, and I found an interesting result on my first internet try.

There's a guy, Scott Sidler, on a site: thecraftsmanblog.com/how-to-make-your-own-wood-finish/. He advocates exactly what I concocted for outdoor projects. For indoor stuff, he uses polyurathane instead of spar varnish.

Go figure!

Re: Man o' War wood finishing

Don Stephan

It would be useful to this discussion to learn what is in commercial shellac-based friction polishes. Anyone have a label they could study and report back?

Even if the linseed oil works only as a lubricant, does it matter? That would mean the resulting finish is pure shellac.

Re: Man o' War wood finishing

Karl_TN

Capt. Eddie Castelin is a big proponent for O.B. Shine Juice:

Mix in equal parts Bull Eyes Shellac, Boiled Linseed Oil & DNA

Instructions:

http://eddiecastelin.com/yahoo_site_admin/assets/docs/shinejuice.54184110.pdf

I doubt Eddie is a chemist so it's possible the linseed oil is only acting as a lubricant vice catalyst. Regardless, he does seem to get good results with this mixture.

Re: curious finishing chemistry

TMStock

Varnish is a pretty broad term that includes spirit varnishes and oil varnishes...shellac would be a spirit varnish by most definitions of that finish, but not an oil varnish. So no - all varnishes are not made with an oil, a resin, and a solvent.

Re: Man o' War wood finishing

TMStock

Shellac has very poor solubility in oil, so likely some of these recipes are an attempt to increase solubility of that resin in oil and to get a tougher, more durable film by reducing the dried resin's solubility in alcohol and increase flexibility.

Bowed instrument makers use these sort of home-brew finishes all the time, as both spirit and oil varnishes are used on violins, cellos, etc. Once dry, it's very tough to tell whether the finish is a drying finish (solvent evaporated drying) or curing finish (cross-linking, polymerized cure), as both types of varnish may see both drying mechanisms at work, depending on the formulations.

Short oil versus long oil varnish formulations have been discussed...adding more oil will increase flexibility and likely reduce surface hardness of the film. Adding solvent will make brushing easier (to a point) or allow padded or spray application, and build film thickness more slowly, but the final film is similar to the unthinned finish, assuming the same dry film thickness is achieved.

Finally, Rule 1 of Murphy's Laws of Woodworking is in play here: if it looks stupid, but works, it's not stupid.

Re: curious finishing chemistry

eliot feldman

I don't claim to be any kind of export. But isn't shellac basically a resin -- the stuff excreted by the lac bug?

Re: curious finishing chemistry

TMStock

Resin with a solvent is usually a spirit varnish - like shellac. Add an oil that will dry (whether through cooking or chemical treatment) and you get an oleoresinous varnish...aka, oil varnish. Lots of resins besides shellac - phenolic, urethane, amber, sandarac, copal, dammar, kauri gum, rosin (pine resin), sandarac, balsam, elemi, mastic, etc.

Re: Man o' War wood finishing

eliot feldman

Well, maybe I'm not so stupid, after all because my "curious" spar varnish works beautifully. It's interesting that after what many on this site told me, I switched back to simply painting on pure spar varnish. But that resulted in a finish that had a million shiny spots and lots of tiny pinholes. I hated it.

What I tried next was to sand with 600 wet/dry grit and then sort of polish on my "curious" mixture using oooo- steel wool. By the time I got back to it , though, my odd spar varnish mixture had gelled a lot. But the polishing after the sanding did the trick. I believe that what I stumbled onto is a weird kind of French polish with, of all things, the 000-steel wool acting as a kind of rubber.

Thanks for your input.