Polymerized Tung Oil and Shellac

Kevin Wilson

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Location
North Texas
I'm normally a lurker but after reading a thread on Woodweb http://www.woodweb.com/knowledge_bas..._Coatings.html several questions come to mind. If Tung Oil (the real stuff not just a small portion of the formulation) is so wonderful why don't we use it more? Has anyone ever used products from SutherlandWelles http://www.sutherlandwelles.com/ ? Twisp http://www.twispenvironmental.com/ ?

Also in a previous thread on SMC about shellac, the topic of premixed vs mix your own was discussed. It was pointed out that shellac degrades as it absorbs moisture once the can is opened. In the above thread at Woodweb, one contributor states that shellac begins to "polymerize" the moment the solvent dissolves the flakes and that even though the can is unopened, its qualities are degrading as the can sits waiting to be purchased by you and me.

Thoughts?

P.S. Now that I've come out of my shop to post I promise to be a better member of the community in the future!

P.S.S. Sorry for those who read SMC as this is a cross post!
 
Hey Kevin, welcome aboard. :wave:

To answer your first question, I think one reason not a lot of people use pure tung oil is the slow drying time. I believe many people (including me) want more instant gratification.

On your second question, I'll defer to someone who knows finishes better than I do. ;)
 
As mentioned, a disadvantage of pure Tung oil is slow drying. An advantage of pure Tung oil is slow drying. :doh:
I have only used it on walnut gunstocks. The slow drying allows additional coats to be hand rubbed onto the wood. When dry, it is nearly moisture impervious. That is the main feature I like about it. It is also very durable.
I believe Tung oil has not found widespread favor is because of the confusion with pure and adulterated products labeled 'finish' or whatever. Or some with the additives only mentioned in small print on the back.
Do try pure. You may like it. Easy to use. BTW, it does darken the wood. At least, it does walnut.
 
I do think I will use it on 1200 sq/ft of white flooring I need to refinish. I'm leaning towards the SutherlandWelles products but not sure which product. They seem to have three products from a pure oil finish to a pure urethane/alkyd resin/oil product. I like the pure oil product for it's repairability. Time to give them a call!
 
Although tung oil offers a bit more protection than does boiled linseed oil, neither offer much in the way of protection against water or chemicals or anything else. One other small benefit of tung oil over boiled linseed oil is that it is not as photoreactive as BLO, so doesn't darken as much.
They are both easy to repair when damaged where-as some other finishes are difficult to repair.

Linseed and Tung Oil are what are known as drying oils. Polymerized Tung oil simply has been heated and/or had driers added to make it dry faster, but still quite slowly. Boiled Linseed oil is no longer boiled, but has metal driers added. They were used by folks in the olden days because it was what they had.

If you're buying your shellac as dry flakes and mixing it yourself, it is best to mix only as much as you need because it does go bad on the shelf. The Zinnser ready mixed products have stuff added to give it longer shelf life. The containers should have a manufacture date on them and I wouldn't buy any that was more than 6 months or so old.

Just read the last post concerning using it on flooring. You would be much better served to look for a product specifically designed for floors. You want something that dries to touch fairly quickly and has the hardness/flexibility to handle the stuff floors are subjected to. Stuff for furniture is not the stuff you want.
 
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Kevin...

I'm a fan of polymerized tung oil. But I don't make my living with my craft, so can afford to deal with the long drying times.

If you've discovered Sutherland Welles, then you've probably discovered their site. Lots of good information there on pto. Lee Valley also sells their product, private-labeled for Lee Valley. You can only get gloss finish from Lee Valley, but it's the one I'd recommend anyway. As Jerry said, pto is tung oil that has been "cooked" in a very controlled situation to enhance cross bonding.

SW is expensive, but their site explains why. I've used it both as a brush-on with no thinning, and a wipe-on (some thinning required). In my view 2 coats of brushed on pto, rubbed out with pumice and rottenstone cannot be surpassed. It takes 24 hours to cure prior to the second coat, and it should cure a few days before rubbing out. Lot of work, but to me it's worth it. One advantage it has over polyurethane is that the second coat actually cross-bonds with the first, whereas polyurethane is just a layer on a layer (it's a tough finish, though). I've only used it on woodworking pieces, never on something like a floor that gets a lot of wear, although SW will point you to users who think it's great even for that (of course they would).

I've also used Moser's pto from Woodworker's Supply, and have no complaints with it. It's not pto in the same sense that Sutherland Welles is, though, because it has phenolic resins added...it's more like varnish. It has a shorter curing time than SW.

One thing about the slow drying times...lots of time to collect dust nibs. I have a small room that is dust-free (filtered air), and until I did that dealing with dust nibs made me a little crazy. Don't how you would fare with a floor. You might try getting a half pint from Lee Valley (15.50 plus shipping) and try it on something that you leave in the same area as the floor...see what happens.

Good luck with that. Let us know how it works out.

Cheers.
 
SutherlandWelles has 3 products designed specifically for floors and several products for each finish product. I was trolling for others who may have used their products. Looks like I'll be the freshman on this one. I refinished the floors with a water-based poly product (Varithane and Cystalac) about 7-8 years ago and with heavy traffic, pets, and nothing but daily dust mopping (I now use my CT22) weekly damp mop, it's no wonder they look as they do. The bedrooms and hall still look ok but I would like a repairable surface and not have to sand the finish off every 10 years. I would do well with concrete.

I've used a number of products with Tung Oil and plenty of shellac in the past. As suggested, I prefer to mix my own. It requires little time, effort, or skill (as noted that I can successfully do it) so I see no advantage to buying ready mix unless it's in another product like Kilz.

Thanks for all the feedback!
 
I used Varathane waterbased when I installed my son's hardwood floor in his family room. That was 3 years ago, and so far it's holding up. I know what you mean about the stripping and sanding though...very unfun. I have a hunch they'll move to another house before I have to deal with that. It dries very quickly, as you know...dust isn't an issue.

I know Sutherland Welles puts it out there that their finish is easily renewable. Would like to know what you find out about that (maybe I have to wait 10 years??).

Good luck.

Cheers.
 
Well I decided to purchase a quart of the Millie's from Sutherland Welles. It's cheaper than Tried and True that I use occasionally. I've got some white oak strips I'm gonna nail up top a piece of plywood and give it a try and see how I like the finish. Maybe I'll set it at the kitchen door where it will get lots of wear (until I trip over it one too many times). I'll keep you informed!

Kevin
 
Well I decided to purchase a quart of the Millie's from Sutherland Welles. It's cheaper than Tried and True that I use occasionally. I've got some white oak strips I'm gonna nail up top a piece of plywood and give it a try and see how I like the finish. Maybe I'll set it at the kitchen door where it will get lots of wear (until I trip over it one too many times). I'll keep you informed!

Kevin

Just curious, you could tape off a small section on the floor and finish just that couple of square feet. You haven't mentioned adding any stain, just the tung oil. It couldn't hoit to try, beats finishing the whole floor only to find out it might not wear like ya want. It's an idea, whether it's a good or bad idea...?:wave:

Ted
 
Hi Ted,

The only problem with that suggestion is that it would force me to hurry up and finish the project and not allow me to procrastinate for another 6-12 months!

I do have some 2 foot pieces of flooring that I'll install on a piece of plywood. I'll let ya'll know how it turns out.

Kevin
 
I completely agree with Jerry. I had to look twice to be sure I hadn't written it. If nothing else is added its still oil and can't offer much protection.

Regards

Jerry
 
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