Sail Slug Strength

cowlum

Member I
Hi

I'm starting on a project to build a sailpack for my e27.

My main sail is currently a bolt robe that's slid into the boom track.
To facilitate a sailpack I'd like to sew a number of slugs to the foot so that there is space for the sailpacks slugs.
The slugs sewn into the main foot would likely be about 20cm apart.

Of the two slugs I have available at the local chandlery only the fully plastic one fits through the goose neck guide.
So my option's are,

1) Use the 10mm fully plastic slug.
2) Shave a portion of the gooseneck guide to allow the 10mm stainless slug into the track. The portion shaved is non structural and i'm sure I can do a tidy job.

I generally don't like cutting, drilling or making changes that are not reversible .

Does anyone here know if there is much of a strength difference between the two?
Any real advantage to the stainless slug?
Any advantage of one slug over the other?

Additional note:
I'd really like to go loose foot main but I don't think this is an option with the mainsheet gripping the boom at the centre. The boom would likely bend.
 

Attachments

nquigley

Member III
Is this useful at all?;

What I'd like to see are slugs with a ball-bearing race in them for minimal friction in the track. There are some available, but they only seem to come with expensive whole systems, like Tidesmarine. I'd like to fid them available as individual items, separate from a whole system. I guess if they existed, sailmakers would be using them.
 

Christian Williams

E381 - Los Angeles
Moderator
Blogs Author
Footed to loose-footed mainsail? No problem.

If the outhaul tends to rise at the boom end, my sailmaker suggests a simple Velcro strap through the clew and around the boom. The strap slides on the boom when outhaul tension adjustments are made.

( I don't know if you can just cut the slugs off a footed mainsail, but maybe somebody here has done it)
 
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cowlum

Member I
Footed to loose-footed mainsail? No problem.

If the outhaul tends to rise at the boom end, my sailmaker suggests a simple Velcro strap through the clew and around the boom. The strap slides on the boom when outhaul tension adjustments are made.

( I don't know if you can just cut the slugs of a footed mainsail, but maybe somebody here has done it)
Thanks Christian, The 'velcro strap with outhaul' is the setup on all the raceboats I crew on but all those boats have a mainsheet that attaches near the velcro strap. If the mainsail creates any upward forces its transferred directly to the mainsheet and would also create some compression through the boom to the mast. On an E27 the mainsheet is on the cabin top, any upward forces would be applied to half the boom, then the mainsheet.. At least that's how I understand it..

In the attached pic..
Orange = e27 mainsheet
Green = most loose footed mainsheets I am aware of.
 

Attachments

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cowlum

Member I
Is this useful at all?;

What I'd like to see are slugs with a ball-bearing race in them for minimal friction in the track. There are some available, but they only seem to come with expensive whole systems, like Tidesmarine. I'd like to fid them available as individual items, separate from a whole system. I guess if they existed, sailmakers would be using them.
Thats not a bad idea, not really an issue on an e27 where everything is so small. I have crewed on some much larger boats where we have to squirt lubricant in the track every couple of weeks to make things manageable.

My E27 is strictly cruising, adjusting the outhaul is rare :)
 

goldenstate

Member II
Blogs Author
Hi

I'm starting on a project to build a sailpack for my e27.

My main sail is currently a bolt robe that's slid into the boom track.
To facilitate a sailpack I'd like to sew a number of slugs to the foot so that there is space for the sailpacks slugs.
The slugs sewn into the main foot would likely be about 20cm apart.

Of the two slugs I have available at the local chandlery only the fully plastic one fits through the goose neck guide.
So my option's are,

1) Use the 10mm fully plastic slug.
2) Shave a portion of the gooseneck guide to allow the 10mm stainless slug into the track. The portion shaved is non structural and i'm sure I can do a tidy job.

Could you saw off or sand down part of the stainless slugs so they fit in the boom track?
 

Frank Langer

1984 Ericson 30+, Nanaimo, BC
We have a loose footed mainsail on our 1984 E30+, with a cabin top mainsheet that attaches about mid boom. I have sailed in 25 to 30 knot winds (with reefs) and have not had any issue with the boom bending due to strain on the mainsheet. I don't know how your boom compares, nor what actual pounds of strain would be exerted on the boom, but unless you have a flimsy boom (which I doubt), I would think you could go with a loose footed mainsail.
Just my opinion, though...
Frank
 

cowlum

Member I
I'm just going to take the advice given here and work towards a loose footed main with two or three plastic slugs at the clew. If I sail cautiously it wont take long to work out if the boom and slugs are up to the task. If so, onto sailing and other tinkering, if not, I'll reassess.
 

goldenstate

Member II
Blogs Author
FWIW the 2017 vintage main on my 32-200 has plastic slugs that have not been any problem.

I wonder if one could rig some strut cables on a boom. Probably too complicated.

941BB595-7413-4F72-BEB2-059622702BEA.jpeg
 

G Kiba

Member III
My E27 has had a loose footed main for the past 15 years. Are you kidding? Works fine. I have a spinpole sleeve that rides in the groove as well. Best thing about the loose foot... reef lines are free to pass under! Take your sail to a loft and have the bolt rope removed and converted to loose foot.
BTW, you won't need boom slugs! That's nuts! The main on the E27 is like 9'.
 

Christian Williams

E381 - Los Angeles
Moderator
Blogs Author
Regarding forces on the boom, I believe they are all on the boom-end in any case. That is, the foot of the sail exerts no significant force whether slugged or loose-footed. Mid-boom sheeting is therefore not an issue or problem.

The line of force on the sail runs close to the leech. Anything outward of that is roach, which would flop over without battens to support it. When we crank down on the main sheet when close hauled, it tightens the sail near the leech and alters the line of the battens. Crank down hard and the battens are fore and aft and the sail is efficient. Relieve tension and the battens splay out, allowing the upper sail to maintain attached flow in sloppy conditions or light air, when that part of the sail would otherwise stall. The rest of the sail retains its aerodynamics depending on the skill of the sailmaker. We can move the center of effort a bit with the cunningham, or ruthless tightening of the luff.

I don;t really know why modern sailboats typically had slugs on the foot. Dinghies didn't. Lateen rigs such as the Sailfish have the lower spar lashed, like the upper, but that's probably just for convenience against tangling. Slocum's mainsail was lashed to his very long boom, probably also for convenience and because it was heavy stretchy linen. New materials make sail handling much easier, even when the sail is very large. Today's replica J-class boats have loose-footed mainsails.

Come to think of it, I think the wooden cruising boats I grew up with had footed mainsails simply because roller reefing was the fad. It is necessary in order to roll the mainsail up around the boom, which was, in retrospect, an idea that never worked very well anyhow and the necessary hardware and cursing was fairly quickly replaced by the slab reefing we have today.

Yes, I should be doing something else right now. So, alas, back to it.

j Capture.JPG
 

frick

Member III
My old E29 Main had a bolt rope in/on the foot.
My new main is loose footed and works just fine.
I would go with the plastic slugs and sew them on so you can get around the bolt rope with ease. Then again, I same a walking foot sewing machine.
Rick
 

cowlum

Member I
Thanks for the replies guys.
I've decided to go loose footed main as per the suggestions.

Instead of slugs I'll go with the velcro strap assuming there's no hardware in the way.

This is completely different to my original plan. It's also simpler. So I'm glad I asked.
 
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