What are the options to attach mainsail and jib to the spars and rigging of a sailboat? What track or slides or slug do I need my mast and boom?
What are slugs and slide, what types of hanks are there? Which ones are best? What do their tracks look like?
Should my main be loose footed or not?
Is roller furling wanted for jib or headsail or should it be freestanding?
As boat designers as well as sailmakers we can help work out options if there is not sufficient information from other sources. Other sources could be boat plans, club or class association, builder’s group, the designer, previous sails used by similar boats.
Also the various roller bearing batten car systems used on larger boats are out of the scope of this article.
If building the boat yourself the boat plans will provide the correct sizing of the mast track and standing rigging and may go through some of the options.
If the boat has a production mast with a track built into or onto the mast then we would need the diameter of the track to identify which attachment size was best.
Some sails don’t use tracks or wires for support. The various Lugsails, Gaff Sails, lateens, spritsails etc simply use lacing or rope loops to attach the sail to the required spars
We recommend Duralac or its equivalent. Where I’ve worked there is no equivalent actually and it is worth every bit of the somewhat hefty expense.
When I was professionally rigging dinghy masts and we had a repair or modification and we saw the telltale green/yellow smears of Duralac on the fittings we knew there would be little problem with disassembly. It is just that good.
When we couldn’t see any smears of duralac we knew that fittings would either be corroded into place and difficult to remove or the fitting would have set up corrosion that had already substantially damaged the mast. Lots of money in a mast and a lot less in duralac.
How do I attach the Mainsail to the mast
Lacing is the cheapest option to attach sail to the mast.
The first method we are looking at, Lacing, is usually used on freestanding mast. It is the oldest method going back thousands of years. It is also cheap. The lacing can be continuous or be a series of individual loops. Some use cable ties, but be aware that cable ties break down in UV light – also don’t overtighten them around the mast.
We are starting to see some use of soft shackles for attachment of the sail as well. Easy and quick to attach and remove and incredibly strong.
When used for attaching the sail to the mast it is not particularly good for reefing the sail. For other types of sail like lugsails, gaffs, lateens most or all of the lacing is semi permanent and these sails are reefed without altering the lacing on the spars.
Bolt Rope on Mainsail or Mizzen that slides in the mast track
A Bolt Rope is using a rope sewn into the front edge of the sail. It slides into a track built into the mast or attached to the mast. We talk about tracks below.
This system is preferred by racing sailors as it is the simplest, lightest and most aerodynamically efficient method. It is less convenienient for reefing as the sail below the reef is not under control as it is completely out of the track. It definitely can be reefed but slides or slugs that run in the same track do make reefing easier.
Normally with cruising boats a track that accepts slugs or slides is chosen as it allows the sail to be reefed more easily than using a bolt rope. The sails can be reefed without all the slugs being removed from the track – so the front of the sail is under control at all times.
The unused slugs or slides can remain in the track below the reef if the rigging is set up to do so.
There are a lot of different choices. But I will go through the main ones.
Sail slugs slide in a conventional sail track so fit most production boat masts.
Slugs can be fitted in a conventional mast track for a Bolt Rope. So are a perfect retrofit to change the sail attachment system to a more cruising oriented and adaptable rig.
Slugs are for use with the same sail track used by the bolt rope. They are different diameters so we need to know the diameter of the mast track on your project to select the correct size
Final is a mast with an built in track
For home built boats there are different round track options that can be attached to an aluminium mast with rivets. If the rivets are inside the track they need to be countersunk flat heads. Same with wood screws for wooden masts – they need to be flat heads and countersunk so the slugs or bolt rope doesn’t get hooked up on them.
Track is either aluminium or plastic fitted after the mast is built. For wooden masts a slot to take the slides is cut into the mast with a router before the two halves of a wooden mast are glued up.
One trick with tracks with centreline rivets is to either grind the nozzle of the pop riveter to fit in the track. Sometimes a soft wedge can be used to open the track a little.
Sail Slides for attaching the mainsail or mizzen to the mast track
Slides are for flat track that takes the slide internally and is screwed to the mast. They do not usually retrofit to production masts and the track is separate from the mast.
The sides can be internal or external.
Internal Sail slide Option to attach sail to a flat track
These are usually plastic because they slide well in the usual aluminium track.They come in different widths to match different tracks. Though they are reasonably easy to modify to fit unusualy flat tracks. We need to know the sizing of the track to fit the correct slides to the sail.
Normally an aluminium track these days but some older tracks can be stainless steel or even galvanised iron or bronze on really old boats.
External Sail slides Option to attach a new sail to a flat bar track
Slides that slide on stainless steel flat bar or sometimes aluminium extrusion on more. These are not easily modified and have to match the stainless steel bar fitted to the mast. The slide normally has a spacer underneath. On really old boats it is possible to see galvanised steel or bronze.
The external slides are much more critical to fit than other types and must match precisely
This one is to fit a flat track made from a bar of stainless steel or commercial track. The ones shown are 5/8 inch wide. There are other types and at least one other size.
How do I attach the sail to the boom
All the tracks used for the mast will work with the boom. But that is not the only option.
Track similar to the mainsail luff
The track type can be the same as for the luff or one of the other options. But having a loose footed sail is a more common option these days.
Loose Footed Sail is an option for finishing your sail
There are two things to know if selecting a loose foot on your sail order from us at Really Simple Sails.
Loose footed sails are a great option as they reduce the stuff you have to buy, they allow more control over the shape of the sail. There are a couple of requirements though.
- The boom has to be stiff enough.
- End boom sheeting booms can be lighter for loose footed setups as most of the mainsheet tension goes almost directly into the back end (leach) of the sail.
- Mid boom sheeting tends to bend the boom more.
For setting up end boom sheeting you need an outhaul to pull the sail out. to the end of the boom. This is an ADJUSTMENT rather than something you pull super tight. There needs to be some curve in the bottom of the sail. It can have a deeper curve (1 in 10 curvature) for when you need power but be progressively flattened as the wind gets stronger. When there are waves it usually pays to not overflatten the foot.
And IMPORTANT is for the back end of the sail – there needs to be a strop or line around the boom to keep the sail close to the boom. This stops the boom from dropping down and pulling the bottom of the sail flat in all conditions which is bad.
Specifying the attachment of the Jib in your sail order
There are four main options.
- One is that the jib has a wire built into its front edge – a Jibstay. Dinghies and yachts.
- There is no jibstay and the jib clips to an existing forestay. Dinghies and yachts
- There is a aluminium or plastic extrusion on the forestay and the jib luff is fed into a track. Usually only yachts.
- Zipper luff usually for higher performance boats like off the beach catamarans which only have one headsail or performance dayboats.
1/ Wire jibstay built into the luff of the jib for free standing or roller reefing.
We need to know the size of the wire forestay or the specified size of the jibstay. We can help you work it out if you don’t know.
This is the simplest system for a new sail. The built in wire is used in three ways.
- The built in wire permanently supports the mast. Once the boat is rigged the sail is UP. This is common on racing boats as it is the simplest and cleanest system for use and aerodynamics.
- Jibstay built into the sail permanently supports the mast and roller reefing is fitted. This is generally not worthwhile on very small boats but is great as the sail gets larger or if the jib is out on a bowsprit. With boats kept on a mooring UV light can be a problem and for medium or large sails we can add some cloth for UV protection for when the sail is rolled.
- There is a separate light forestay that supports the mast. And when the jib is hoisted the jibstay built into the sail takes the full load of holding the rig up with no tension on the separate forestay. It is really important for performance for the stay built into the jib to take the full load. A neat trick to stop the forestay flopping around is that as well as the normal rope lashing at the bottom put a shockcord/bungee loop to take up the slop.
2/ Using jib hanks to attach the new jib to the forestay
Unlike the free standing luff with build in wire, jibs with hanks are clipped to a permanent forestay. There is no jibstay built into the jib at all.
The luff of the jib can be very light. And the hanks stop most of the jib from falling in the water or sand when the sail is dropped. You can often just drop the halyard and the sail will fall down. Then when the jibsheet is pulled tight most of the sail will come aboard the bow. In an emergency you can tidy it up later.
There are different hank types and they do vary the price. I’ll start with the cheapest.
Twist hanks – don’t change the price of the sail. They twist onto the forestay. If the right size one might occasionally pop off but never all of them. So they are a fairly cheap and secure system that doesn’t increase the cost of the sail much. Correct sizing is really important so they do clip on.
Webbing Snaps for small to medium keelboats
We don’t only see these on one design keelboats that have a permanent forestay, but that is the most common place. In that case the mast is permanently in place and webbing snaps are a light and arodynamically efficient choice. They are conventional button snaps and the webbing is fastened around the forestay.
For heavily used cruising boats they may wear out and need replacement every few years or after a decade or so if the boat has light use. Not a big deal for a local sailmaker to change them over.
Piston hanks in plastic or brass for attaching your new jib to the forestay
Piston hanks in plastic or brass. The are the most expensive option. Piston hanks are secure and have long working lives. They are also easily replaced and locally available at good boating suppliers when the originally fitted ones wear out a long time down the line.
The brass ones have a very traditional look that some people really like. They will get a patina or can be polished regularly
The brass ones have the opening on the top tapped closed when the hank is fitted to the sail by us. The plastic and brass are just about the same price, but they will add cost to the sail.
3/ Aluminum or Plastic Extrusion with Track and a moulded tape on the luff of the jib.
There are different brands requiring different tapes on the luff. We need to know
- Do the Headsail/s have a luff track?
- What is the brand of the track (if possible)
4/ Zipper Luff to zip around forestay.
Note that there is often a hook at the top to catch a ring at the top of the forestay. And the halyard goes inside the zipped area.
This is usually found on performance multihulls and some racing dayboats.
It is not easy to drop the sail quickly using this method.
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