Replacing Traditional Wood Masts with Alloy

[Pelagic]

Originally Posted by ingrid75

Replace wooden masts with alloy? Sir, you are a Phillistine.

Welcome to CF Ingrid75........

LOL.....I'm a Scotsman living in the
Philippines, ..... easily mistaken for a Philistine....

[Dougtiff]

So one of the issues not mentioned is using the hardware on a metal mast, their not designed for metal, so changes need to be done. The repairs that need to be done, i.e. scarfing do not need to be more that 8 to 1 and any glue joints needing repairs can be done by raking out the seam with a hacksaw blade and filled with epoxy, as far as timber surely you can find some fir there, been doing this stuff for many years for a living and no failyers yet.

[reed1v]

Originally Posted by chris95040

Nonsense.

Well you obviously have not been around boats much. Try putting a stainless winch next to an aluminum mast, or a bronze cleat on that mast.

[Terra Nova]

Originally Posted by reed1v

Well you obviously have not been around boats much. Try putting a stainless winch next to an aluminum mast, or a bronze cleat on that mast.

You have obviously not been around boats much. Everyone else uses aluminum cleats, not bronze, on an aluminum mast.

[chris95040]

Originally Posted by reed1v

Well you obviously have not been around boats much. Try putting a stainless winch next to an aluminum mast, or a bronze cleat on that mast.

I've been around them my whole life, some with aluminum masts, some with wood.

From the conviction of your response, I'd assume you had a lot of experience, too, which makes it even more bewildering that you've come to these conclusions.

Despite the melodrama, you do bring up a good point. The problem of dissimilar metals is certainly real, and certainly needs care (tef-gel, etc) when assembling the mast. And then if you're really concerned, maybe 20 years later you can treat it to a fresh disassembly/reassembly.

[Pelagic]

Originally Posted by Schooner Chandlery

...1 It is no big deal to scarf even quite large repairs in a wood mast. You likely don't require very large sections of wood to do this (even 12:1 scarfs) so you can have exactly the correct wood even MAILED to you from another location if you needed to. You are in the Philippines, right? The PI has good logistics for getting things in-and-out of country.

....2 About paint vs varnish--our 84 yr old mast was painted for most of its life. We have many varnished surfaces on the boat and I love the look of varnish but we decided to keep the masts painted for the good of the masts. We use a traditional oil-based paint that is nothing like a modern 2 part marine coating. We worry that if there is a crack in the paint and water intrudes, modern coatings hold the moisture in against the wood rather than letting it dry and rot will then happen.

Good luck with your inspection and repairs (if needed) of your spars.
Brenda

Thanks again for your great advice.... I am going to need some repairs.

Unfortunately I was away from the boat for the last 2 years and when I came back, I focused on wiring and upgrades first part of the year.

Gone again during this year's rainy Typhoon season and when I came back found that some minor cracks had expanded as I show below.

I just don't know how serious yet, so preparing for every eventuality in case I have ruined my masts..

This is really going to show my ignorance about woodcraft....BUT HOW CAN YOU DETERMINE A WOOD ORIGIN AND SPECIES from just looking at it?

On Old wood, most people just seem to guess and I don't know how critical matching wood repair is?

Thanks for the tip of using oil based paint vs 2 part.

From looking at the pictures below, my plan is a complete strip of 2 part paint (burn and scrape)... then prod and sound for sponginess?
Rout out to solid wood and assess.... Any comments?

I can now see that some of the stainless plates I was advised to put on by the spreaders, may have contributed to the problem....

It is going to be a nervous start to 2016.

[Terra Nova]

You won't be able to tell what wood it is through the paint. Where the boat was built might give a clue. But spruce is the most common. The cracks appear to have been caused by improperly sized fastener holes, some of which may have fallen on glue joints, and aggravated by improper bedding and lack of maintenance.

[Delancey]

Identifying wood species just by looking at it can be pretty hard if not impossible. Researching is a good way, like if you can figure out who the builder and asking them. The best way is to use a microscope and compare to known samples, which can be easy if you know what you are looking for and a lot of work if you don't.

Before you go down that route keep in mind that repairing with same species is prefered but not mission critical. First you need to strip the paint and see what the problem is. Maybe it's not so bad.

I see some checking but that doesn't necessarily mean rot. Even if there is rot, depends on how much. Even if there is a bunch and you have to replace some wood, not knowing the exact species isn't the end of the world.

People glue different kinds of wood together all the time. If it ain't broke don't fix it, so see what needs fixing first.

[Formosa Scott]

I would suggest asking this question here as well: The WoodenBoat Forum
I would also be interested in the correct method for checking for rot, how to deal with checking etc.

[Pauls]

Hi Pelagic,
First, as has been said above, it is not necessary to match the exact species of wood. Masts are commonly made from both spruce and fir. What you do need, if you are splicing in repair parts, is a good, high quality softwood, clear, straight grained, and vertical grained.

If you need to cut out and splice in pieces I suggest you build a fixture and make the cuts with a router. It is a quick, painless and very accurate way cut splices, and it eliminates most of the skilled hand work. The jig will ensure accurate, clean splice joints. 10 to 1 is considered standard.

I think that this can be a project that you will enjoy. Good woodwork is not that difficult to do, and the finished result can be quite satisfying.

[Schooner Chandlery]

Yes, it seems to be fastener driven and related to the lack of expansion of the paint (can't keep up with the wood) as well.

You've gotten some great advice. If using the most common woods for spars -- this would be spruce and fir, you'll be able to tell you've got one or the other. Other woods, maybe so, maybe not. The thing to match is the dimensional stability of the wood. You don't want to put in a wood that expands a lot more (or less) than the wood you've got in place because its that mis-match of expansion/contraction with moisture content that will mess with your glue seams.

Definitely use a jig and router and work with a 10:1 or 12:1 scarf on the edges of any bits that you may have to put in place. It is quite possible that you may only be looking at digging out a seam or a small crack (using a hacksaw blade for example) and gluing in literally a splinter of wood in those cracks. Or, you may route out a small dutchman that doesn't go all the way through -- this may be extremely superficial. Even so, don't be tempted to glop some thickened epoxy in there--do your repairs properly using wood and only resort to epoxy as your glue--not to fill a void.

Can't wait to see when you strip that paint off. Best of luck!

[Pelagic]

Thanks all for the reassuring advice on fixing my wood masts

Researching what kind of 33 year old wood I have will be a challenge as Dutch builder Van Hellerman is long gone .

Comment about oversized fasteners stumped me, as I was able to reuse the same that came off in 2009

[Delancey]

Originally Posted by Formosa Scott

I would suggest asking this question here as well: The WoodenBoat Forum
I would also be interested in the correct method for checking for rot, how to deal with checking etc.

I think general concept for repairing checking has been explained. As far as surveying for rot an awl is sometimes used as a probe for hull planking and framing, although this is a destructive technique that will leave marks.

For examining a mast a visual inspection is usually relied upon, hence varnishing spars has been suggested as a prefered finish. Spars are typically made from softwoods like fir, spruce, or cedar and an obvious discoloration (gray-black darkening) of the wood accompanies rot which is easy to identify.

Below I have attached a photo of an example of a scarfing jig using a router. If you look around the web you will find a dozen other flavors, some using pipe instead of wood tapers and even a few with circle saws instead of routers that are used for scarfing plywood.

Depends on the repair required but sometimes you might want to make a separate jig that fits on the mast and one for making the filler piece. Without a router a scarf in-place can be produced with simple hands tools which requires a little more skill. Scarfing lengths of lumber is easy, stack one board on top of the other and cut a taper with a hand plane or electric planer.

Whatever the method, an experienced pro knows enough to do a couple practice joints on some scrap wood before getting started on a mast repair.

[IolantheSF]

Doug Fir has the characteristic of getting harder as it ages. Most woods have near infinite fatigue cycle tolerance within their stress limits. Metal masts have actually exploded from resonant cycling. For finish, coat with slow setting epoxy (MAS is thin) so that it penetrates, then sand and paint a couple of coats. Bed everything in 5200. If you have to take anything off, warm it up to about 300 degrees F, and the goo melts.

[Schooner Chandlery]

Originally Posted by IolantheSF

Doug Fir has the characteristic of getting harder as it ages. Most woods have near infinite fatigue cycle tolerance within their stress limits. Metal masts have actually exploded from resonant cycling. For finish, coat with slow setting epoxy (MAS is thin) so that it penetrates, then sand and paint a couple of coats. Bed everything in 5200. If you have to take anything off, warm it up to about 300 degrees F, and the goo melts.

Sealing the wood is a good thing. You can use a thinned epoxy, Smith's CPES here in the states, or a water based product made by Wolner called Woodlife does the same thing--seals the cells of the wood on the surface so water can't reside there and rot things. Agree pretty much with all except suggest one stay away from the 5200 for bedding. It is more costly than it should be, it is an adhesive that doesn't have sufficient elasticity to compete with other non-adhesives for bedding, and it's more of a pain to get off of things because of its adhesive nature. We used a silicone-modified polyurethane (e.g. Sikaflex (spelling?) or Tremco) for bedding small objects to decks and used old-fashioned Dolphinite (more spelling?) for bedding anything on the wood spars.