Spar Varnish

Friend has a wooden spar and is wondering how many coats of varnish and how many years. I have suggested at least 15 coats (11 jet speed, 4 spar) and that he should get 7 years between varnishings.

I am looking for anyone who has some experience with this question of number of coats and length of time between applications that require stepping the mast. Any ideas and reason behind them?

 

This is a very well covered subject and my recommendation is to paint that mast, not clear coat it. I say this because of the 7 years between varnishings expectation which is wholly unreasonable, even as far north as you are.

With proper upkeep, you could leave the mast in place for as long as you want, though it does mean you'll have to haul yourself up the stick and touch up as required. This is the key, there's absolutely no clear coating that doesn't require regular routine maintenance. This means regular inspections, touch ups and periodic top coats, to preserve the sacrificial upper layers of the coating.

You have the right idea with many coats, though I'm not sure what you mean with "jet speed", I'll assume it's a fast drying brand, which is likely a polyurethane, not an alkyd varnish. I'd suggest, if you go polyurethane, you stay all polyurethane. While on the subject of polys, the latest catalyst born polyurethanes are very tough, durable and long lasting, but they are also difficult to repair and once you let it "get away" from you, it all has to be removed and you're starting over again.

Buy a copy of "Brightwork-the art of Finishing Wood" by Rebecca Wittman. This woman knows her stuff and though we disagree on a few points, her techniques are sound and you'll learn how and why, etc.

 

PAR:
Thanks for your reply. You are correct that all coatings require upkeep, it is the cost of stepping vs varnish, cetol or paint that is the question.

Jetspeed is an Interlux product that is quick drying. It is a varnish, however, it has no UV inhibitors and must be overcoated with a varnish that contains them. I was informed of these varnishes by my brother, a cabinet maker, who uses them all the time.

I will pass along the reading recommendation. Thanks, Tim

 

Jetspeed by Interlux, never heard of it. They have a line of single part polyurethanes, traditional alkyd varnish and an LPU, all of which I'm familiar. If it's a fast drying product, again, it's not an alkyd varnish, but a polyurethane. There's only one way to speed up an alkyd cure and there's only so much drier you can use, before it affects the finish. In fact an easy way to get a satin finish is to add too much drier to a varnish.

 

Ten coats makes sense. Fifteen is a bit much though no harm would be done.
It makes no sense to use two different varnishes though. Speed shouldn't be your goal until you've mastered doing it the slow way.
Take your time and keep things simple.
Your information about longevity of a varnish before re-coating is erroneous. I live in Maine and I have skipped a year on the spars before (which meant adding a coat for the missing year), but if you think you're going to avoid work by going several years, you are mistaken. The work will multiply instead.
Typically, the recommendation is to apply two coats each season. More if you live in the southern latitudes where the boat is exposed for most of the year.
Two coats are needed because you will have sanded off that much preparing the surfaces for re-coating.
PAR suggested painting the spar instead (a white or buff color is usual). God knows why I haven't painted mine because it makes so much sense. You can go three to six years between coats with paint and touch-up's a breeze, but I do like that golden honey color of natural wood so I go to the extra trouble year after year.
Varnish is a tremendous amount of work compared to paint. The alternative to plain varnish is to get into a two-part clear urethane but such finishes are absolutely impractical for the non-professional (and most pros around here use single-part varnish anyway!). Stick with regular tung oil-based spar varnish and become proficient at that before considering experimentation with more high-tech finishes.

 

Thanks Allan...the real issue is the cost of stepping the mast and not so much the work. The equation is the cost benefit ratio of how many years can one go between stepping the mast and revarnishing. In order to varnish the mast properly i.e. take the old varnish off, sand between each coat with stearated sand paper and applying varnish will require the mast to be stepped. That is a costly endeavor, and gaining the maximum amount of time between steppings and the maxim protection from the varnish is the issue. The amount of time to do the job once the mast is stepped will be incremental of the cost of stepping, that is the varnishing job once per year will not be that significantly less than every two years between varnishings, but the cost of stepping the mast is.

So fundementaly how many years can one go between varnishings, and is that interval expanded by applying more coats?

 

Unfortunately, regular spar varnish isn't going to do it for you if stepping the mast is so costly. No matter how thick the varnish, the surface will require an annual re-coating, so you are stuck choosing between painting and paying someone to apply a two-part clear coat (expensive).
If I were faced with such a decision, I look at buff-colored single part alkyd paint. The paint will cost $35.00 plus your labor (assuming a thirty foot mast, a day's labor sanding, filling, taping, and another coat the following day).
Others are welcome to chime in.

 

The answer is no. 10 coats of UV protected varnish is as good as you will get. The varnish breaks down, shrinks, and gets brittle with age and eventually cracks. More coats will not stop it from aging. That is why Wittman recommends a "touch-up" coat over all bright work every six months (probably a bit extreme, but once a year is a minimum). If the cost of stepping the mast is so high, go with paint. The cost of keeping brightwork looking good is almost constant maintenance.

Consider it is out in the weather, would you roof a house with vanished wood and expect it to last? But that is what exposed brightwork on a boat is like.

 

Thanks Alan...my friend is looking into that, however, he likes the look of the wooden mast, and on a Stone Horse (Edey and Duff) it does look nice to see a wooden spar. Some owners apparently paint them, but won't paint wear as quickly...not from UV damage, but running rigging, such as abrassion from the halyard?...my boat has an aluminum mast so I will pass on the words of wisdom from you and PAR and will let him figure it out.
Thanks,
Tim....former Peaks Islander, winter time...

 

Petros...Thanks, just saw your post, and I did send along the reference to Rebecca Wittman's book to my friend. I just may go get one myself.

 

Par, I am surprised you haven't invent a robot to go up the mast and paint it... It could be done....

 

I would offer to go up my friends mast, but I am too old and too fat....

 

Much could be said about a high quality LPU in this application, which is far superior to alkyd varnish in durability and UV resistance. Even a good quality single part polyurethane will out preform a good alkyd varnish.

Unlike some of the comments mentioned, varnish can be quite old and still good, if it's maintained. I have a fully varnished boat, that has base coats that are over two decades old. Yes, it's been touched up, well cared for and kept up, but the base coats are the same as when I built the boat in '88. Of course if you let it "get away from you" it will crack, peel, lose gloss, darken, etc. I have repaired 40 year old varnish that was darkened, but still acceptable. Clear coatings over wood, are about routine upkeep more then any other factor.

The idea is to have a few sacrificial top coats over a fairly heavy base. These sacrificial coats take the bulk of the abuse from UV (not all, but most) and if they are regularly renewed, typically based on you local environment, you can have many decades of enjoyment from a varnished piece.

If you wanted to limit the amount of un-stepping you have to do, use an LPU. Personally I don't think you need to un-step a stick to do a good job of clear coating. You also don't have to strip the old clear coating off unless the damage warrants it.

 

Actually I looked at that problem as related to the construction industry. A robot to go up a scaffold or side of a building is doable and could be adapted to a mast, the biggest challenge is applying paint with a robot. You would get unpopular very quickly if you sprayed paint all over the marina and a robot that can handle a paintrbrush would sink the boat ...

 

I think the main problem with a mechanical varnish delivery devices isn't the mast climbing aspect, but actual delivery in an acceptable fashion. Applying varnish is highly dependent on environmental conditions, which a machine can't compensate for without considerable complexity. A spraying shield could be arranged to keep the over spray to a minimum maybe a vacuum.