Wood spreader question.

[Wind River]

I hope there are some riggers here with wood mast and spreader experience.

I am getting ready to fabricate some new spreaders for the masts on my Hudson Force 50 Ketch. I have purchased two long lengths of mast grade Sitka Spruce. One for my mast repair and the other for my spreaders. My question involves the grain orientation of the wood. The grain on these lengths of Spruce is reasonably straight long ways down the length. I can cut out the shape of a spreader following this grain straight down the length but that would leave me with a lot of wasted wood. If I were to angle the spreader across the grain slightly I could make much better use of the material but I don't know the effect that would have one the strength and dimensional stability of the spreader.

Can anyone help here or should I be looking to find a wood boat forum and pose this question there.

Also what are your thoughts on this spreader tip. New vs. old. The new one clamps onto the stays and the old one used wire and cable clamps. This is on the lower spreader of the main mast.

[Manateeman]

The spreaders are almost all compression so I think you answered your own question. You don’t want to start a split and it’s like planks...you know when the grain runs out you loose strength.
I began Boatbuilding in wood when the biggest glass sailboats were 19’. All the yachts in my home town of Dartmouth were wood. The closest I came to being seriously hurt in a boatyard was when a wood spar cracked while I was up in the rigging. Sorry but I’ll never trust a wood spar or spreader again.
Could you accept a wood veneer over carbon or glass or aluminum?
I have a good friend who builds inspected passenger schooners. The masts are carbon with a thin wood in epoxy veneer. They look beautiful.
Please just think it over.
The manatee crew.

[Oeanda]

My spreaders and mast are also homemade from Sitka spruce. I can’t claim any real expertise on the subjects of masts or spreaders, but they’ve held up well so far.

I have made quite a lot of bows and arrows though, and many of the same factors apply.
Look at it as a sandwich of parallel layers of wood. The areas that have full-length layers or growth rings do almost all of the bending. Any parts of the entire sandwich which are compromised or cut shorter than the rest, can be looked at, to some extent, as somewhat useless (or even disruptive) baggage, slabbed onto the sides of the useful part.

It’s a bit more complicated than that of course. But ideally- you’d be looking at a section of wood in which all layers are full length and parallel from end to end. So I wouldn’t be looking to save on wood by cutting cross grain, in this particular application

[thesaltytar]

'lo Wind River.

My boat is entirely made of wood and I also have a set of spreaders made from spruce. Manateeman is spot on about the grain orientation. Don't cut corners with this one. Nice straight and true grain and yes, there is unfortunately some waste, but this is where it's important.

That being said it looks like if you pattern out the two spreaders next to each other, kind of how you have then laid out (big end next to little end) the waste may be minimal.

As for the spreader tips I prefer just lashing them on with wire because I'm a minimalist. The pieces you fabricated look lovely and are a nice improvement so please don't misinterpret my personal preference.

Here are the things you need to think about the spreader tips: bed the hardware really well. End grain is susceptible to rot and anything that holds moisture against the wood will exacerbate that, so make sure there's no way for the moisture to get in. Good topcoats on the spreaders and I use Dolphinite for bedding something like this.

Next, what are the end screws going into? Are those machine screws or are those wood screws? If machine screws, I would recommend Loctite to stop them backing out, because that may be a potential point of failure (you don't want to look up one day and notice the end cap is gone). If they are wood screws, bed them also, because fasteners are a favored ingress point for water.

Also what holds the spreader cap itself on? If it's the two screws on the end, consider that screwing into end grain isn't the most structural choice (thankfully everything is under compression so this probably won't be a game changer).

Over all I think you will be fine and the use of wood in the rig doesn't bother me provided it is maintained and inspected - like any rig - you will probably have less chance of galvanic failure with this one. [emoji6]

You mentioned a mast repair?

[Rucksta]

Consider cutting strips and laminating the spreader.

[thesaltytar]

PS: I was referring to the first photo, the leftover wood will get used. You will need a couple pads to mount the lights on that are visible on the underside of your spreaders, and maybe a couple strips to cover the wire ways, point is I don't think the offcuts will be unusable scrap. One day they'll come in handy.....

[thesaltytar]

Originally Posted by Rucksta

Consider cutting strips and laminating the spreader.

That's a clever way to use the material to it's fullest. I don't know what the data is on laminate vs. solid wood for compression but it's certainly viable.

It does require a bit of technical skill for the layup process because of how important it is for proper epoxy handling. I've had bad batches fail on me and for this project might recommend the KISS method.

[Rucksta]

Originally Posted by thesaltytar

That's a clever way to use the material to it's fullest. I don't know what the data is on laminate vs. solid wood for compression but it's certainly viable.

It does require a bit of technical skill for the layup process because of how important it is for proper epoxy handling. I've had bad batches fail on me and for this project might recommend the KISS method.

Epoxy wouldn't be my first choice for a timber laminate as the fit will be good and no gap filling properties are required.

Polyurethane, hide glue or PVA would be among the choices.
The first two will produce a timber bond stronger than epoxy.

Laminates do well for applications where compression, twist & flex are present.

You are correct that some skill would be required to produce the laminate.

[Wind River]

Originally Posted by Manateeman

The spreaders are almost all compression so I think you answered your own question. You don’t want to start a split and it’s like planks...you know when the grain runs out you loose strength.
I began Boatbuilding in wood when the biggest glass sailboats were 19’. All the yachts in my home town of Dartmouth were wood. The closest I came to being seriously hurt in a boatyard was when a wood spar cracked while I was up in the rigging. Sorry but I’ll never trust a wood spar or spreader again.
Could you accept a wood veneer over carbon or glass or aluminum?
I have a good friend who builds inspected passenger schooners. The masts are carbon with a thin wood in epoxy veneer. They look beautiful.
Please just think it over.
The manatee crew.

Thank you for your input.
While I love the idea of making wood veneer spreaders it is not in cards for me right now. I may pattern all my spreaders and keep this idea as a project for another day though.

[Wind River]

Originally Posted by thesaltytar

'lo Wind River.

My boat is entirely made of wood and I also have a set of spreaders made from spruce. Manateeman is spot on about the grain orientation. Don't cut corners with this one. Nice straight and true grain and yes, there is unfortunately some waste, but this is where it's important.

That being said it looks like if you pattern out the two spreaders next to each other, kind of how you have then laid out (big end next to little end) the waste may be minimal.

As for the spreader tips I prefer just lashing them on with wire because I'm a minimalist. The pieces you fabricated look lovely and are a nice improvement so please don't misinterpret my personal preference.

Here are the things you need to think about the spreader tips: bed the hardware really well. End grain is susceptible to rot and anything that holds moisture against the wood will exacerbate that, so make sure there's no way for the moisture to get in. Good topcoats on the spreaders and I use Dolphinite for bedding something like this.

Next, what are the end screws going into? Are those machine screws or are those wood screws? If machine screws, I would recommend Loctite to stop them backing out, because that may be a potential point of failure (you don't want to look up one day and notice the end cap is gone). If they are wood screws, bed them also, because fasteners are a favored ingress point for water.

Also what holds the spreader cap itself on? If it's the two screws on the end, consider that screwing into end grain isn't the most structural choice (thankfully everything is under compression so this probably won't be a game changer).

Over all I think you will be fine and the use of wood in the rig doesn't bother me provided it is maintained and inspected - like any rig - you will probably have less chance of galvanic failure with this one. [emoji6]

You mentioned a mast repair?

The entire spreader and especially the tips and end grain have been sealed with epoxy. I actually put epoxy in the spreader tip and then pushed the spreader in. I let it set up, knocked off the tip and the end of the spreader was completely encased in epoxy.

These particular spreaders will likely be sacrificed anyway to make the mizzen spreaders as these were not made correctly to begin with and are a bit undersized for the main mast lowers. They were installed for a few years and look as good as the day I installed them.

The screws on the end cap are machine screw. No penetration's into the end grain. The caps are also sealed with 3M 4200. A tight fit, 4200 and the tension of the shrouds is what is holding them on.

[Wind River]

Originally Posted by Rucksta

Consider cutting strips and laminating the spreader.

Interesting. Are you suggesting cutting vertical or horizontal strips in relation to the the way the spreader is installed?

How is this better than solid wood?

[Wind River]

Originally Posted by thesaltytar

You mentioned a mast repair?

This is the next project.

There was only a small split showing originally. this is what it looked like after scraping away the rot that could not be seen. I have cut this side of the mast off at the glue line from the spreader block to the top of the mast. Other than the internal block at the spreader, most all of the rot was in this one side of the mast. The glue appears to have kept it on that side.