View Full Version : simple finishes
06-09-2001, 09:21 PM
Does anyone out there know of a finish that has the look and texture of oil yet protects a little better? Many of you probably rolled your eyes on an earlier post where I described finishing all my white oak brightwork with a homespun rubbing varnish made of spar varnish thinned 50% with mineral spirits. Yes, a few coats of this does seem to protect against water and dirt a little better than the linseed oil I applied the previous year but it also rubs away fairly easily from abraision of lines, oars, shoes, etc. I suppose it is like one coat of straight varnish applied in many thinned down coats. I am still resistant to the concept of six or eight coats of varnish on a vessel derived from working vessels, but there is no better protection for brightwork. (Yes I do realize that 'brightwork' and 'working vessel' look pretty dumb in the same paragraph)
I was wondering if there are any viable options in between. Do any of the Sikkens Cetol products work very well? Im trying to avoid the glossy encapsulated wood look. Is there another magical mixture that I can concoct? The linseed oil/turps/varnish mix I used last year looked ( and smelled) awesome but could not be built up thick at all without a gummy film. How about applying a couple of coats of varnish for its protective properties, sanding it flat and wiping a thin layer of linseed oil on top of that?
I would appreciate any comments or suggestions
06-09-2001, 10:54 PM
Got me... I can't think of a "flat" varnish or other clear coating that will stand up to the UV deterioration. You've got a couple of strikes against you also, given the oak. It will stain and weather quickly if it isn't protected. There's nothing wrong with varnish, even on a workboat. But, if it is really a type that wouldn't have varnish on it, what they used to do was paint the rails, etc., which would have been varnished with spar buff or dark brown paint. The paint was glossy, too, though. If you want a more subtle gloss in a good marine paint that will hold up, Kirby's is your best bet. Other than that, oil away. The oil will eventually darken your oak, though... a lot.
BTW, try tung oil... it is thicker and can be rubbed in well. It won't have UV protectant in it, but will protect better than thinned linseed and turpentine. Thinning expensive varnish as you suggest works, but since tung oil is what varnish is all about, you may as well go to the source and forget about paying for brushing solvents and the rest of the additives in varnish formulated for brushing and high gloss.
[This message has been edited by Bob Cleek (edited 06-09-2001).]
06-09-2001, 11:10 PM
Make a sample board. I did one today for a client. Taped eight squares for seven products and a neutral. Won't bore you with the details, but tried SeaFin and ProFin in the tung oil department, two different Minwax products, a West product, traditional Cetol and Cetol's gloss product. Don't go out and buy a bunch of stuff, walk around your marina with a handful of foam brushes. Folks gladly dive into their dock boxes.
This doesn't tell you how long your products will last, but it'll be an education in gloss, ease of application, how many coats you'll need, etc. I am in no way shape or form a Cetol fan, "Ten coats of Epifanes or the world's going to Hell in a handbasket" is my motto, but Practical Sailor's annual maintenance report gave acolades to Cetol again this year. Umteenth year in a row...
06-09-2001, 11:39 PM
I'm gonna jump in here and suggest picking up a small can of "Deks Olja" to test. Used it for years on a schooner I used to run where we never wanted to ever have to scrape varnish. Provided pretty good protection if kept up with fairly frequent "refreasher" coats. Didn't darken too badly. Use just the "Number 1" and you'll avoid the high gloss look of yacht varnish.
06-10-2001, 10:13 AM
Thanks for the inputs. I figured it was an either or proposition. My understanding about varnish is that it is a mixture of tung oil and phenolic, alkyde or polyurethane resin cooked together to create not a mixture of the two but a completely different sort of polymerizing compound with a purpose of creating an actual coating on the wood. Nothing but nothing seems to actualy "penetrate" hardwood more than to simply fill or bulk out the outermost fibers which is why its so hard to create an effective moisure retardant with it. I was hoping for something which formed a coating without looking like one. I'll play around with your suggestions trying tung oil or deks olja part one to see how it does. But for now, I'm going sailing!
06-10-2001, 01:47 PM
Jack...if you want a coating which does not look like one, there is actually a technology of that, and here is how to do it:
First, put on as many coats of the clear finish of your choice as to have enough UV absorber within that film thickness so as to protect the color appearance of the wood. That is the big secret of maintaining color and protecting the cellulose of the wood from UV degradation: Enough of a film thickness of something UV-protective.
Second, Put one one last coat of the same stuff, only flatted to where there is no glare from the surface. The film thickness is not visible, and it looks as if there is nothing there. If your "semigloss" or "satin" finish still looks as if there is something there, then get a flat version of that finish, and blend it with gloss as necessary to the point where a dry coat just begins to look like there is something there, and then back off with more of the flat. The whole idea is to have it flat, which means it does not reflect light off the top surface, but only the wood surface below. "military flat" coatings are like that, but with wear will develop a semigloss sheen, and the appearance will quickly become patchy. A little less flat from that and you will have what you want. The two-component polyurethane finishes will have the best toughness and wear resistance. Find one that comes in gloss as well as flat, or has a separate flatting agent available.
06-10-2001, 08:34 PM
Does anyone know the origin of the word varnish? Is it derived from the Sanskrit word for colour - Varna ?
06-11-2001, 09:46 AM
LazyJ, I suspect the linseed you used was boiled. (Either that, or too much varnish.) If these other recipes don't appeal, try using raw instead, thinned with turps as before. I think you'll be pleasantly surprised.
06-11-2001, 10:36 AM
I've been using versions of a mixture of varnish, turps, boiled linseed oil and pine tar on my spars and brightwork. It does darken the wood a bit - depending on the amount of pine tar. It gives a nice flat finish. I use this on a glued lapstrake canoe which is stored outside most of the time and it holds up well.
For reasons that are not altogether clear to me, sometimes I mix up a batch that doesn't go off, leaving me with several square feet of unwanted flypaper.
06-11-2001, 02:40 PM
Hey Mike, Tell me more! It was indeed 'boiled' linseed oil that I used in the origional mix because it has the added metalic salts which make it kick quicker. What is the advantage of the raw stuff in the mix?
Thanks for the info. That approach, though lots of work, adds up best with everything I have learned on this forum and elsewhere about the application and longevity of film type finishes. Using a flatted version of the same finish didn't occur to me for use as the final coat. I know that polyurethane is one of the toughtest resins out there from which varnishes are made. You specified a two part polyurehane finsih. What is the molecular difference between that and single part. Is the two part stuff brushable/ buildupable by hand? Can it be knocked down flat with sandpaper before the final coat is applied? If I decide to use a film finsh I'll go with your approach.
Someone on another active thread says they've been using straight tung oil wiped over everything farily frequently. Sounds like a lot less work in the long run. Maybe I'll try that approach next year.
[This message has been edited by Lazy Jack (edited 06-11-2001).]
06-12-2001, 05:27 PM
Originally posted by Lazy Jack:
Does anyone out there know of a finish that has the look and texture of oil yet protects a little better?
Try Varnol. It's a Scandie finish. Very popular in Scanihoovia. Varnol is basically a mixture of varnish, oil and pine tar. Depending on how many coats you put on, you can get anywhere from an oiled wood look to full-on gloss.
You can read more about Varnol at http://www.eastsystem.com/nvonfo.htm and you can see a picture of a deck done in Varnol at http://www.eastsystem.com/deck.jpg
Here's what one UK web site says about Varnol:
"VARNOL is a traditional Norwegian varnishing oil - half oil, half varnish - based on a formula of refined pine resins and raw (gum) turpentine. Uniquely, VARNOL gives a durable oiled - wood finish and a high gloss from the same can, feeding, stabilising and enhancing the appearance of all timbers. Protecting the wood initially with a few wet - on - wet coats is fast work, while final finishing can then be left for better conditions if necessary. Owing to VARNOL's forgiving nature, patching up and maintaining the finish is also easy, with no rubbing back between coats or "minimum drying times". Find the finish you've been looking for by signalling:
06-12-2001, 07:00 PM
Jack......there are "polyurethanes" and there are polyurethanes.
The one-component varnishes are made from oilseed resins [the oil is cooked, with air blown through it sometimes, to partially polymerize it]. Sometimes other things are added to it to give the film better hardness, and/or better flexural/tensile properties. Some of those things are long strings [molecularly speaking] derived from the polymerization of an isocyanate with something else, to give a molecule with the urethane[ -O-CONH- is what it looks like, a carbon with a couple of oxygens and a nitrogen stuck to it, a hydrogen stuck to the nitrogen, and two linkages to connect with other things] linkage or urethane group.
The long string does not react like a urethane; it is pretty inert, but it can give good mechanical properties when mixed in with other resins.
The two-component polyurethanes have no oilseed resins or other funny-business mixed in with them, if they are the highest-quality aerospace-grade polyester polyurethanes. Below that in quality are [two-component] acrylic polyurethanes, and below that are the ***New! Improved! Now with Polyurethane!*** finishes.
All of these things hold their gloss more-or-less well depending on the level of UV absorber and antioxidants in them. These additives are expensive, so manufacturers have to compromise between retail price and additive levels. Further, varnishes cure by oxidation, and so one cannot add antioxidants, thus UV will embritle them sooner and they will lose their gloss sooner.
This is a perenial problem with conventional varnish...one can add some UV absorbers (not too much...cost is an issue..) to protect the color of the underlying wood, but they will lose their gloss noticeably in only six months...less if you have a sharp eye.
Tung oil and some others have a high percentage of linolenic acid in their molecular makeup...an eighteen-carbon chain with three double-bonds. These things never fully cure, as the structure is too hindered for them to all find each other. The remaining unreacted double-bonds function as a crude UV absorber, but also cause darkening of the film with age.
Most oilseeds ahve some linolenic acid in tehm. Aint' much ya can do about it......Mother Nature and all that.
Only the two-component polyurethanes have the compatibility with both UV absorbers and antixoidants, both of which are needed, and have the most UV-stable molecular structure. Go look at the tests in The Practical Sailor [Belvoir publications...also does Powerboat Reports...they are sort of like Consumer Reports...tests products and says what they think about them]. The top life expectancy winners for gloss retention and color stability are all two-component polyurethanes.
06-14-2001, 10:50 AM
I went to the web site and read the application directions. It seems that the diluted Varnol is used as a sealer. Is this correct, or would it be wise to use something like CPES before applying any Varnol?
Originally posted by nicholasc:
06-14-2001, 01:53 PM
Originally posted by Norm Harris:
I went to the web site and read the application directions. It seems that the diluted Varnol is used as a sealer. Is this correct, or would it be wise to use something like CPES before applying any Varnol?
I wouldn't glop up good wood with overpriced epoxy thinned with acetone (what CPES largely is, judging from the MSDS) But YMMV.
One thing about trad. finishes is that they are easy to repair. Unlike epoxy. Why not try applying the finish according to the directions?
If you do feel a need to 'seal' the wood (that's what the finish does, doesn't it?) before applying a finish, try thinned varnish or freshly mixed shellac. Both are easy to repair. And no, *fresh* shellac doesn't turn white when water gets on it -- old shellac that's been dissolved in alcohol for a while does because the alcohol esterifies the lac resins over time.
You could even try a commercial vinyl sealer -- designed for use as a tie coat between materials that might have adhesion problems (eg, oily woods like teak).
06-14-2001, 09:47 PM
Nicolas, have you actually used this stuff, or are you just passing on somebody else's advertising? I've used gallons of CPES and I've also used a fair bit of "over-priced epoxy" (isn't it all? LOL) thinned with alcohol and with acetone, and even with vinegar (that was an experiment, granted... slowed the cure. The vinegar is much better for hand washing...)
There is no comparison between epoxy resin thinned with acetone and CPES. I don't profess to know why, Chemist can tell you, maybe, but anybody who has used CPES under paint or varnish on good wood can attest to the fact that it creates a coating that last maybe three times longer than without. Moisture doesn't penetrate and lift the finish.
Your varnish, pine tar and turpentine product has been around for a looooong time. It works find and as advertised. However, it will likely darken the wood considerably and it will not produce a fair, glossy brightwork result. People have been canning a "better" varnish for as long as they've been inventing "better mousetraps." They still make your basic quality traditional varnish and it consistently out-sells the super-goops ten to one against anything else. What does that tell you?
06-15-2001, 09:26 AM
I question the notion that traditional finishes are "easy to repair." If you have an oil finish that needs to be recoated twice a year and patched everytime it gets bumped or dinged, and then wooded every few years because it turns black, you call that easy? Regular varnish is easier than that. Regular varnish over CPES is even easier, as you may not have to recoat for several years and fixing dings and scratches is as easy as buying a 50 cent disposable brush and opening the can of paint. If you use a super-duper polyurathane, then you might get five to ten years without having to recoat. That's what I call easy. Apply it the way Chemist says, and it should look pretty nice.
How'm I doin' Chemist?
06-15-2001, 09:42 AM
Sounds to me, Scott, that you have a good point. I'll probably make do with the oil aproach until next spring when I put another coat of paint on the interior and use the Chemist approach for the brightwork (which I should probably minimize.) I built it under the assumption that it is easier to swabb another coat of oil over the wood then it is to do prep a surface and apply a coat of paint. I didn't consider the weaknesses of an oil finish.
Why do I always feel a need to re-invent a well established wheel?
Do have one question, however. My origional linseed oil mixture began to show signs of mildew when I pulled the boat out this spring. What is the fungicide added to marine oil finishes?
06-15-2001, 03:17 PM
Do-It-Yourself fungicides are not an option. These things are sold in 55-gallon drums [where are you going to put ten thousand gallons of varnish?] and the manufacturers of these toxic things are all into Responsible Care, which means everyone is trying to get into cradle-to-grave responsibility for your stuff...so you just can't have any of that because you are a civilian, so-to-speak.
Mildew under varnish comes from moisture in the wood under the varnish, which means the wood was damp when varnished, and/or you didn't us a moisture-dissolving primer such as CPES.....that stuff will not allow mildew to form in the interface because there is no interface, just a wood-resin-topcoat sanwich with no air gap...a fungicide in the varnish might only help if the wood was dry enough that the varnish properly impregnated the wood. In your case there was air right at the surface, and you are trying to make a dried-oil-finish with no film thickness to speak of, and so this thing will be as fungally nutrient as wood itself. You started off looking for simple finishes, and the fact is that simple finishes have liabiliities, mainly that they do not last, due to UV and other environmental degradators, and that is why varnishes and other finishes were developed. The consusmer demanded it.
You can have a simple finish, but you have to live with all her warts and blemishes.
As for the mildew, strip it and start over. You will never get the mildew spores out of the wood, so [if not CPES and varnish] maybe you are one of those who needs to soak their wood in antifreeze, forget about varnishes sticking well, and live with what you have.
Scott, you are doing fine.
07-08-2001, 10:52 AM
You might check Iain Oughtred's book on clinker boatbuilding. He talks about his preferences for finishes. After reading it, I bought some Varnol and am satisfied with it. Time's a factor for me. Varnol is easy to maintain.
07-08-2001, 05:29 PM
I've used Cetol Super 7 on a ply deck with very long lasting results [3 years].
Not a hard finish so it doesn't take knocks and chafe very well but it is very UV stable.
The stained variety I used built up to quite a dark finish after its second coat though - maybe re-coat with a clear version.
Varnol and Deks Olje No.1 are very good and easy to maintain - a quick wipe over with some spirit and then re-coat.
Ordinary varnish works well as long as you varnish 1-2 MONTHS before you use it so that it hardens.
Tried thinned epoxy as a primer and it seems to work ok but never tried CPES yet.
Tried a varnish 'enhanced with silthane' once and it was a disaster to re-coat - when I rubbed the odd patch down to feather an edge and the old varnish produced a 'fluffy' surface so bad that the whole lot had to be rubbed off. Nightmare.
07-09-2001, 11:02 AM
Here in SW Florida, where mildew is everywhere, oils go green-black in nothing flat. So do some acrylics. Cetol does not. Linseed oil well thinned with turpentine and applied boiling hot, then sealed with varnish, also holds up well. The best fungicied appears to be mercury. Unfortunately it is also a humanicied. Tributyltin, sold as anti-mildew additive under the name "Die-All" also works, but I don't want to rub skin up against a surface coated with it. As boiling hot oil is a dangerous pain to work with, I'm sticking with Cetol. I'll just skip reading the data sheet too close.
07-09-2001, 01:23 PM
Re: Etymology of varnish?
From the American Heritage Dictionary, through www.dictionary.com: (http://www.dictionary.com:)
[Middle English vernisshe, from Old French vernis, from Medieval Latin veronix, vernix, sandarac resin, from
Medieval Greek verenik, from Greek Berenik Berenice (Benghazi), an ancient city of Cyrenaica.]
A slightly different etymology from Webster is:
[OE. vernish, F. vernis, LL. vernicium; akin to F. vernir to varnish, fr. (assumed) LL. vitrinire to
glaze, from LL. vitrinus glassy, fr. L. vitrum glass. ]
No Sanskrit that I found, but interesting anyway!
The fishermen here in Eureka use a mixture of Linseed oil, Tung oil, and Stockholm tar on the parts of their boats where the wood grain shows through. It results on a dark brown almost black finish, but seems to hold up well. They all seem to have their own secret recipe but it is something like 60% 30% 10%
07-10-2001, 10:09 AM
Speaking of simple finishes, I decided to make up a test board with a variety of oil finishes to see how they hold up to weather. One of the mixes I'm testing is the Pacific NW Boat Sauce referenced in WB and here on the forum. It is a mixture of Daly's Seafin Teak Oil, varnish, and pine tar (8:1:1). I suspect the Seafin oil contains a lot of linseed oil because it has the usual cautions about disposing of rags in water, spontaneous combustion etc. Here's my question, on the can of Seafin oil it says that the product will last for years in the can until it's opened. But, after opening, any unused portion should be disposed in accordance with local hazwaste regs etc. etc. What gives? Is this for real? Why should this be? Who can afford to throw away the unused portion? I just went ahead and mixed up the whole can into boat sauce and hoped that would somehow preserve the "sauce".
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