I know the subject of oiled wood has come up within construction threads, but I think it deserves its own subject. I started a similar thread over on Rod’s Paipo Forum several months ago. Ideally I’m hoping for a thread that deals with what has actually been tried and tested. Sure we can get off on oily tangents, but whenever possible I’d like people to post about real experiments. Myself I’ve only tested Watco brand teak oil…but first some oily tangents…
To oil or not to oil? That is the question, of course it raises even more questions. What sort of oil and why? I’ve been doing a little searching on the internet. No luck with oiled paipos or lamaroos. Some recent mention of linseed oil on alaia replicas. Several mentions of kukui nut oil on surfboards and canoes. One site said old Hawaiian surfboards had a base coat of kukui oil, and were periodically top coated with coconut oil. One bit of trivia that I found interesting had to do with the immensity of the internal surface area of wood. Supposedly the internal surfaces of a cubic centimeter of wood can be equivalent to the surface area of several pages in a magazine. A factor of thousands.
Some oils dry better than others. Without getting deep into the chemistry, there is a test using iodine that allows oils to be ranked by their ability to dry or polymerize. Linseed, tung and kukui have high iodine values and dry well. Coconut, palm and cocao butter have low iodine values. I should also note that oils aren’t a single substance. They are made of numerous fatty acids, some of which aid in drying more than others. Follow this next link, then scroll about half way down the page to get to an iodine value chart.
Is your paipo oil already in your house? I’m talking about the kitchen, not the garage. Here’s a website that shows iodine values for some cooking oils. Walnut oil looks promising. I’ve heard some boat guys use it.
Pure tung oil thinned with citris looks like a promising surfboard finish. I haven’t tried it myself, but certainly merits some experimentation. Especially if you don’t like the danish oils that contain mineral spirits and cobalt drying agents. Here’s a source I found on the web for both tung oil and citris solvent. I don’t know how good or bad their prices are.
Myself I’ve only tried the Watco Teak finish. I wanted to experiment with something that was easily available to other folks. Plus it’s meant for exterior wood. It has both UV and antifungal protection. I used a burnishing technique where secondary coats of the oil are worked in with wet/dry sandpaper. Supposedly the wood dust/oil slurry clogs up the minute pores in the wood even after you wipe and buff. Here’s a website where the guy talks about burnishing the oil finish with sandpaper.
I am so happy I checked Sways tonight and found your question about oil! I have been making lots of alaias and I have been pretty happy with the mix of gum turpentinbe with raw linseed oil. I found that if I start with 2/3 gum turpentine (not mineral) and 1/3 oil for the first coat and wait 24 hours, and then 1/2 and 1/2 for the next 3 coats over the next 48 hours, I get a really good finish that lasts for weeks of hard surfing. It seems that the gum turpentine sinks into the wood an goes hard like a resin. The wood gets harder and more resistant to scratches. Then, after a bit of surfing, just a light rub of linseed oil on the bottom of the board is just right.
The raw linseed oil is much better than the boiled linseed oil. Without the gum turpentine, the linseed oil doesn’t seem to dry and wears off more quickly.
I use paulownia wood which is soft, but not as soft as balsa.
I haven’t tried much else except orange oil. It didn’t dry very well and cost a fortune.
I have stuck with the linseed oil and gum turpentine because it is easy to get, cheap, and works.
I would like to try tung oil as well as any other oils out there. This has been an untested realm for me.
Thank you for putting this thread and doing so much research already. I will check the links you listed and try to keep in contact with it.
One concept that should be cleared up first is the drying process of the oil. It’s not an evaporation process, but chemical changes that begin with the oil reacting to oxygen. Yes, solvents are used to get the oil to penetrate deeper in the wood, but the evaporation of the solvent is a different process from the curing of the oil. This Wiki thread covers it pretty well:
Probably worth noting that Tom Wegener’s brew is an organic solvent from a tree and an organic oil from a plant. A noble concoction for sure, and readily available. The addition of plant resin could (big maybe) make the oil/solvent mix into a simple varnish. Tom, if you haven’t tried it already…I suggest some experimentation with adding some paulownia tree sap to your turp/linseed mix (for the 3rd and final coat.) It won’t be as durable as commercial spar varnish, but I think there would be a sort of “chemical correctness” in returning some of the paulownia sap back to the shaped board. Possibly even a “spiritual correctness” if the sap and the board came from the same tree. Is there much sap in those trees? You wouldn’t need much to experiment with. Maybe a brew where the paulownia sap is 5 to 10 percent of the total volume. Anybody here ever make their own pine tar varnish?
Here’s another oily tangent…why would you intentionally use a non drying oil, like coconut oil as a top coat? I found several references on the internet about coconut oil on top of a base coat of kukui nut oil. That’s a non drying oil on top of a drying oil. Someone on another forum told me they use coconut oil as a speed coat. That it dissolves in salt water and reduces drag. I’m still dubious about the coconut oil. I tested some expeller pressed organic coconut oil on the bottom of one of my cubit boards that had a well cured (and burnished) Watco finish. I didn’t coat the whole bottom. Just a circular area near the tail. Then I wet the board with ocean water. The coconut oil beaded the water. It’s my understanding that it’s better to have an even film of water on the board. That water slides best over water. This is supposedly why a wet sanded board is faster than one that is glossed and polished. The wet sanded board maintains a film of water that rides along with board. If the coconut oil was dissolving in the ocean water, then I would expect it to bond with the water, not repel the water. Maybe coconut oil does have its uses, like the hull of an outrigger canoe. Something that has to be gripped, like a paipo…I’m still dubious. Perhaps Tom Stone can help us with that one when he gets here.
What you describe sounds like a variation on the theme of danish oil…commercially available stuff has an organic solvent, linseed oil, and some sort of varnish. I like the idea of using turpentine, pine tar, and linseed oil better. Or, as many (Surfoils, Dale) suggested to me, using a wax like canning wax, and a little heat to get it to get into the pores. Or, you could use the turp/tar/oil, then overcoat with wax. Many options.
I have a nice butcher block dining table. I put Tung oil on it 5-6 years ago, still holding up fantastic. Super easy to brush on, and I believe it’s also a self solvent.
Haven’t tried paraffin as a sealer. The simplicity is tempting. Higher temperature waxes like carnauba and palm wax might be worthy experiments in warmer climates, like the trunk of your car. Most car waxes probably have a high melting point.
When I used to do antique furniture re-finishing with my dad, we saw some pieces that had been done with a bees wax finish. The wax ends up turing almost black with oxidation and all of the dust/dirt that sticks to it over time, hiding the woods beauty and effectively ruining the finish. (Made it tough to strip too!)
And this is in a colder climate. …well part ofd the year anyway.
I’d be wary of wax finishes. When I used to do antique furniture re-finishing with my dad, we saw some pieces that had been done with a bees wax finish. The wax ends up turing almost black with oxidation and all of the dust/dirt that sticks to it over time, hiding the woods beauty and effectively ruining the finish. (Made it tough to strip too!)
Canning paraffin and beeswax are different materials.
There are many waxes, sealants and finishes, oils, lacquers, water base, etc. As well as various methods and combinations of applications. Type of wood and its condition, range of exterior/interior exposure, useage and maintenance… all affect long term durability and appearance.
In my experience, paraffin has proven to be a fairly benign substance, and I’ve never seen any darkening. Hot weather/sunshine only serves to wick the paraffin deeper into grain. Once it has penetrated below surface, it cannot be stripped.
Remember, I advised it for quick, one-off wooden surfcraft.
Not for fine furniture or display quality, high gloss
wall-hangers.
I’ve had best results when it’s applied molten, water thin/low viscosity. It’s a fast, inexpensive, lightweight, waterproof application. Easy to scrape and buff smooth, easy re-application. Excellent for sealing the end grain.
That is the challenge…sealing those tubes somewhere near the surface without putting too much work and material into it.
Degradation of a finish could be an interesting tangent here. Some finishes darken over time, but that could increase your UV protection of the wood. Maybe I’ll have to surf the web a bit to find out more about the actual mechanics of oil degradation. Any experts here?
Historic methods must have included the use of plant juices to stain the wood. Perhaps some of those plants are endangered and can’t be mentioned. I’ve been wondering if finely ground charcoal (from tree wood not the BBQ stuff) could be mixed into the oil mix…perhaps in the first coat. With the goal of both clogging the pores and adding some UV protection.
Hemp oil is a possibility for making either an oil or oil blend finish. The iodine value is close to that of linseed oil, and was used in varnishes and paints in the US before the era of Reeefer Madness. I’ve just only started looking for a cheap supplier of non food grade hemp oil. Here’s a Canadian source I found that has it on sale for $2 per liter.
I have a nice butcher block dining table. I put Tung oil on it 5-6 years ago, still holding up fantastic. Super easy to brush on, and I believe it’s also a self solvent.
Poobah, Dale and crew, Thank you for writing in. Poohbah, it is a great relief to hear that gum turpentine is an organic solvant! About wax vs. oils, my good friend Jacob Stuth has been using a mix of beezwax and oils to seal his alaia. it has a different feel to the turps and linseed oil, but it really seals the wood. It works good on paulownia but I think it would be an essential mix for other wood. Especially on the end grain (as Dale mentioned) so the wood does not suck up water. Paulownia does not suck up salt water so sealing it is not so important. I have not seen any signs of the wax turning dark, but if I let even an oiled bit of paulownia out in the rain, it will eventually mold.
I surfed an alaia that needed a coat of oil and then put it on the beach, oiled it, and then paddled it out again. There was a sincere difference. The freshly oiled board caught waves easier, but did not hold in when going across the wave as well. I really had to focus more on digging in the rail. The oil did wash off much faster than it I had oiled it two days earlier. I like the oiled feeling. From this little experiment, I could feel how a very slippery olo would be easier to ride because the biggest difficulty with surfing them is just sliding into the wave.
When I have taken wood out that has not been oiled well, the wood furs up and becomes ruff. This must be water getting into the open grains and expanding. It seems wax would make this stop easier than multiple coats of oil.
Tom, your experience with the freshly oiled board opens up a whole new can of questions, like what if you only oiled a stripe down the middle of the bottom? Or just the tail half of the bottom? What if you waxed the end grain and rails, but left the rest an oil finish? If and when the old Hawaiians put coconut oil on top of kukui oil, did they apply it selectively to parts of the board?
Maybe worth mentioning that a solvent with turpentine in the name could be synthetic, like mineral turpentine. It would still technically be an organic chemical, just not “organic” in the natural and renewable sense. Also worth noting that natural isn’t always eco-friendly. When you buy a can of turpentine, you don’t know if it came from plantation pines that were well managed or old growth forest that was devastated. I was reading some History on the subject, and was dismayed to read, “In approximately two generations, from 1870 to 1930, most of the original stands of long-leaf pine, covering 130,000,000 acres, were consumed.” That was in the Southeastern United States and the business was more nomadic then. Now most of the production is in China and Indonesia. So you can’t guarantee the your can of natural turpentine is eco-friendly, but you can have the satisfaction of knowing that it didn’t come from an oil well. I think I remember reading that Roy Stewart made his own turpentine. Not everybody has that option though.
We can’t talk about oil finishes without mentioning other things like wax or varnish. Latex paint on top of an oil-based primer is a worthy option. Maybe not historically correct, but certainly something to consider. Especially for people playing with plywood. It’s my understing that there are a lot of cracks you can’t see in the veneer…until they start to swell up.
I’ll throw out one more question tonight…anybody ever try to deal with the end grain problems by gluing on a tail/nose block of denser wood?
Regarding wax vs. oils… it’s useful to define terms. Waxes can be natural or artificial. Paraffin wax comes from crude oil. Beeswax, carnauba, and paraffin all occur naturally. In general, “wax” refers to a substance with properties similar to beeswax:
malleable at normal temps
melting point above approximately 45 °C (113 °F)
relatively low viscosity when melted
insoluble in water
repelled from water
BTW, tung oil is great stuff. It’s a “drying oil” sort of like linseed. Very resistant to water. Be aware that there are various tung oil blends, and some are really thick, others quite thin for penetrating deep into the wood.
I prefer to apply warm to a warm surface, in multiple applications. The first coats are the lowest viscosity, the final ones are higher viscosity. All the tung oils I’ve used have had slight yellowish/ golden tint, do not seem to darken much with age, as does linseed oil.
anybody ever try to deal with the end grain problems by gluing on a tail/nose block of denser wood?
Covering one end grain that way adds two additional ones, i.e. the opposite end grains of the tail/nose block. Be careful not to solve one problem by creating two more
...hiding the woods beauty and effectively ruining the finish...
Well, remember the natural appearance of exterior exposed wood is usually muted, bleached gray/ brown shades. Or greenish- brown/ blackish from mold and mildew.
Beauty is in the eyes of the beholder. From latter 1800s: