Bolt Rope Track in a Wooden Mast - How To?

[upchurchmr]

I would like to build a wooden mast based on a birdsmouth mast construction and inclued an integral, internal bolt rope track.

To allow the sail to be hoisted similar to a commercial aluminum mast I have assumed I would need to make a similar shape - an open slot on the aft end which would retain a bolt rope.
To get the sail to slide I was thinking about some kind of tube embedded - aluminum or pvc slotted along the entire length.

Has anyone done such a thing or know of something similar?

I am assuming just a shaped wood slot coated with epoxy would have a lot of friction - hard to raise the sail.

Any help or comments would be appreciated.

The boat would be a small trimaran about 16', possibly starting with a kayak hull.

Thanks,

Marc

[Peerie Maa]

People have been putting luff groves in wooden masts for years before epoxy and without embedding any sort of tube. Mine was varnished, providing the clearances are OK there was not too much friction.
Birdsmouth would be an interesting challenge though as they are usually glued up out of only two blanks, with the luff groove and hollow routered out of the middle. It must be possible to make a stave with a luff grove for assembling into a birdsmouth. Just needs a little thought and planning.

[ChrisBen]

Round router bit. Start with a straight bit first.

[robert666]

I have a hollow wooden mast with a luff groove and internal halliards, its oval and made in two halves. It was made sometime in the 1960's as it is original to the boat. I have never sailed with it because the boat is still being restored. I did a few test hoist with the rig up on the trailer and found getting the sail up and down rather troublesome. on the way up the luff had to be very carefully fed into the start of the groove to prevent it getting stuck. Lowering the sail I had to let go of the halliard and haul the luff down with both hands. It was a slow process and the sail is worn and chafed on the luff of the sail from previous use. Its not a system that I would recomend for small capsizable boats where the sail often needs to come down quickly. If you do want to use this system then Glen-L boat designs publish a free guide to small boat rigging that includes mast and boom construction diagrams.

Robert

[JimD]

Bolt ropes are a pita. They tend to jam, you can't reef. Highly recommend that if you insist on using a luff groove that you use some sort of slug and not the rope itself: http://www.youtube.com/watch?v=QeVtm-N1EX4 unless you are racing and the minor improvement in sail efficiency using the rope is very important to you.

[Todd Bradshaw]

You can also buy Teflon luff tape, which has Teflon threads woven in where the rope will be. It slides up and down much more easily that regular Dacron luff tape.
http://www.sailrite.com/Tape-Dacron-8oz-Teflon-White-5

[Lewisboater]

If you do want to use this system then Glen-L boat designs publish a free guide to small boat rigging that includes mast and boom construction diagrams.

Robert

Where can I find these?

[smithb9]

Where can I find these?

google "rigging small boats glen-l"

[Jay Greer]

I have built several masts for Kites, a boat that is a close relative to the International Finn. This was prior to the advent of the bird's mouth form of construction. Masts were made of two book matched sides that were pre half slotted prior to creating the shape. This required an accurate jig for the router set up. The router bit used has already been posted by Chris Ben. I sould be noted that at least a quarter inch to 3/8" should be left flat on the sides of the slot in order to provide strength to the sides of the luff area. Otherwise, the groove will fracture at the outer wall. We did NOT varnish the slot as it would cause the sail to hang up. Parafin is a better choice and provides a bit of friction reduction as well as moisture resistance. At the tack an insert of hard wood such as Honduras should be let in to provide strength in that area. It should be noted that a pear shaped mast is better for this form of construction if fore and aft strengh is desired. We did this for the International 14's before synthetic masts were adopted. It will also insure a stronger slot. If a bendy rig is needed, then an athrwart ships elipse or round cross section is the ticket. I would strongly recommend that you practice a lot on scrap material prior to attempting to construct the actual mast as the process is a bit touchy to accomplish.
Jay

[robert666]

http://www.glen-l.com/free-book/rigg...sailboats.html

unfortunaetly it only refers to bermudan mainsails, and store bought stainless steel and plastic hardware.

Robert

[Dusty Yevsky]

Here's a link detailing how to build a mast for a DN iceboat. It's not birdsmouth but the construction process is straightforward and the mast is very strong. I built one of these for a DN and like it a lot. I'm going to tweak the design a little and build one for my CLC Triple Kayak/Sailrig trimaran. I'm hoping a wingmast will help a little with higher pointing. One change I would make to these plans is to use CPVC tubing instead of aluminum conduit. The slipperiness of the CPVC makes a raising and lowering the sail a snap.

http://www.idniyra.org/articles/mast_made_easy.htm

[upchurchmr]

Todd,

Thanks for the heads up, I had never seen this material. My experience is primarily with beach cats which all used the bolt rope.

Marc

You can also buy Teflon luff tape, which has Teflon threads woven in where the rope will be. It slides up and down much more easily that regular Dacron luff tape.
http://www.sailrite.com/Tape-Dacron-8oz-Teflon-White-5

[upchurchmr]

Dusty,

Do you know of any special issues with the CPVC tubing for bonding? I assume you used a bolt rope, not slides?

Marc

Here's a link detailing how to build a mast for a DN iceboat. It's not birdsmouth but the construction process is straightforward and the mast is very strong. I built one of these for a DN and like it a lot. I'm going to tweak the design a little and build one for my CLC Triple Kayak/Sailrig trimaran. I'm hoping a wingmast will help a little with higher pointing. One change I would make to these plans is to use CPVC tubing instead of aluminum conduit. The slipperiness of the CPVC makes a raising and lowering the sail a snap.

http://www.idniyra.org/articles/mast_made_easy.htm

[Binnacle Bat]

Bolt ropes are a pita. They tend to jam, you can't reef. Highly recommend that if you insist on using a luff groove that you use some sort of slug and not the rope itself: http://www.youtube.com/watch?v=QeVtm-N1EX4 unless you are racing and the minor improvement in sail efficiency using the rope is very important to you.

I'm surprised to hear you can't reef a sail with a bolt rope, as I do it often. There just has to be enough space between the bottom of the slot and the gooseneck. I have a hook on the gooseneck to take the luff reef cringle, and jiffy reefing led forward on the boom to about a foot abaft the mast. The only messy bit is that the foot of the sail has a boltrope in a slot on the boom, so the nettles have to go right round the boom, making it hard to get the sail into a neat bundle. My mast is alu, so friction is not a big issue, I like the idea of lining the slot of a wood mast with Alu or PVC or CPVC.

I use slugs on my storm trysail, which in its previous life was a jib. It was much easier to replace the jib hanks with slugs than to sew on a bolt rope. Cant say there is any advantage, as you have to feed each slug into the track every time you hoist.

Slugs make sense on a boat that lives on a mooring, as the sail will stack up much more neatly. On a boat like mine that lives on a trailer, and the sails a unbent most every sail, the bolt rope in slot is fine.

Allan

Reef early and often!

[upchurchmr]

Allen,

"Reef early and ofter!" didn't exist in my world. Never reef (cause I couldn't) and just cope! Lots more excitement that way. Luckily I survived the rush.

One of my best memories was sailing a Tornado Cat with a first time sailor friend on the trapeeze in 40 knots gusting. Took down the jib, but the speed was not to be believed and we never really had a control problem.

Never Reef! (Well I might of if I could of)

[Dusty Yevsky]

Dusty,

Do you know of any special issues with the CPVC tubing for bonding? I assume you used a bolt rope, not slides?

Marc

I was a little nervous about the CPVC bonding to the spruce. I figured if there were any issues I would back up the bond with small brass screws countersunk into the back of the tube through the slot, but this has not proved necessary. I scuffed the outside of the tube with 36 grit sandpaper and slathered on thickened epoxy. Two years of hard iceboating and no sign of delamination. Bolt rope on the sail.