Hi all, I have two projects with Tung oil. One is a beech wood kitchen worktop, where I’ve did some testing and can apply the pure tung oil with it easily absorbing and be finished in 3-4 layers.
My question is on the second project, which is a chestnut parquet floor. The tung oil does not readily absorb into the wood, so I’m considering diluting the oil, with either turpentine, d-limonene or naphta. Does anyone have any experience with what works best? How would penetration be affected by either of these agents? Would drying times differ? Would polymerisation speed be affected? What percentage solvent would one add and would one do that only to the first layer, or first two?
Is sanding in between layers required? What does it do?
Thanks in advance for any help!
Replies
Not sure why you wouldn't get absorption into a floor. Presumably this floor is stripped and has been sanded? If so, how even does the floor look after you apply oil on a spot?
Turpentine or limonene will be very very aromatic if you thin tung with them and do a whole floor.
Assuming pure tung oil is just raw tung, I'd get a glass jar and measure and start with 1 part thinner 1 4 parts tung and low the parts tung in the ratio until you have a consistency you like.
typical varnish thinners in the past, at least similar to what we can get now:
* turpentine
* some fraction limonene (though it might've been called dipentene) and mineral spirits. You'd want odorless. The limonene is a much stronger solvent than mineral spirits but when it's cut like that, it does make applying even odorless mineral spirits more pleasant. I'm fond of 1 part limonene and 3 parts mineral spirits.
* a mix of naphtha and mineral spirits - still as far as I can tell used in stuff like arm r seal ("stoddard solvent" and naphtha)
Naphtha alone would flash, but naptha can mean a lot of things. the stuff sold as VMP naphtha is kind of a mid flash off. you'll have a whole lot of flammable vapor in the air quickly if you splash out a lot of it, but it'll work to thin tung.
None will affect polymerization after the solvent is gone. They just solve the finish and delay it until they're gone, but once they're gone, the same thing happens.
You can use a japan drier, like Klean strip at 1% for your lower layers to greatly speed up the cure speed of the tung. Anything you see about tung not resopnding to driers is false. It may not respond as well, but 1% klean strip japan drier based on the volume of the oil will give you a pretty well dry result the next day and I see no effect in tung, even when testing layers put on top of wood. it's still flexible and functionally immune to water. that's starting with raw tung. If you have an aversion to driers, you could take advantage of that and apply the last coat or two without, but they will get you along well in getting the first deep layers dried.
there are three driers in klean strip's japan drier. I use it not because of a preference for any brands, but it's what I can get off of the rack and it works well with every varnish or oil I've put it in. It has manganese, zinc and cobalt driers as far as I can recall. cobalt at least in varnish is regarded for getting through drying in a film or finish layer. I mentioned concern about cobalt to a retired eastman chemist and he sort of brushed it off as not a concern in finishes. he has spoken up any time I mention something with varnish that's legitimately unhealthful. You're applying oils in this case and not bathing in japan drier daily. I wouldn't be surprised if the effect of the solvent vapors is worse than cobalt in drying agents in terms of health.
Is this an old true wood parquet floor or a newer floor, like this century? If a old floor it's would have likely been finished ( sealed) with shellac or a varnish of some kind or maybe both. Possibly waxed many times over the original finish. If you dont know its full history it may have been refinished previously and then with what? There is a finite number of times that a floor can be sanded by the way.
If it's a newer more modern parquet it's most likely a laminate and, a don't try this at home,bullet proof factory finish applied.
Not taking oil in either case would indicate that it is sealed and your probably better off not even considering oiling, even if you go rent a sander and take it down to barewood your likely to end up with very patchy looking floor( more absorption in some spots than others. If it's a modern laminate sanding is very risky as the veneered surface is likely not very thick.
If I were you I would call the floor guys for a refinish estimate. Even if your intending to do the job yourself you can maybe get an idea on how to approach the floor that you have. If you do refinish you can go old world ,shellac, varnish, like that-- or consider there are some really good finishes out there that are easy to apply, fast to dry, and easy to maintain such as Bona products.
I have old school parquet floors -- tens of thousands of individual pieces, but oak. I've sanded and refinished my floors and I think I'm at about the last sanding it can take. I used Bona Traffic and after maybe 10 years I scuffed and recoated again.
I agree with the above comments. Floors, especially old floors, can be a pain because of previous sealers / finishes.
I have had good luck thinning tung oil (which I love by the way) with mineral spirits. My projects have been shop made items which can be easily finished outside. Tung oil stinks when curing and especially when thinned. I’ve read that it can take up to 30 days for tung oil to fully ‘cure’, so be prepared.
I would not sand tung oil, probably a waste of time. I apply tung oil with a ‘Scotch Bright’ type material which mildly abrades the surface as you go. I finish with regular wax which slight dulls the otherwise too glossy finish.
Good luck.