I know the subject of raising the boom has come up before, but I haven't found anything about having to shorten the mainsail. I raised the boom about 3" a couple of years ago. Of course I've never been able to get the mainsail as tight as I would like since I'm at the top of the mast. Has anyone done this and cut the mainsail a few inches shorter. My concern is, can I reuse the same headboard.
Cutting mainsail shorter
- Thread starter chp
- Start date
My mast is shorter than the stock one by about a foot and a half. I had to simply buy a smaller sail. That was ok because I didn't like the bolt rope anyway.
By the way. I have a Mac sail that needs a headboard if anyone is looking for one. Seems to be in decent shape.
By the way. I have a Mac sail that needs a headboard if anyone is looking for one. Seems to be in decent shape.
In the past, I cut about a foot off the bottom of a sail and converted it to loose foot. I did this "manually" using a speedy stitcher http://www.sailrite.com/Speedy-Stitcher-Sewing-Awl-Kit
I don’t remember the details.. but it was a big job and this was on a 15 foot boat so a smaller sail. That sewing awl works great for a job like this as it can go through many layers of sail cloth - which is necessary to get the strength in the mod. I ended up being happy with the results but I understand you have to be careful as you have a fair chance of screwing the sail up.
I did not check but maybe sailrite even has a video giving some idea how this would be done. I know someone who made a sail from a sailrite kit and it looked like a great sail.
I don’t remember the details.. but it was a big job and this was on a 15 foot boat so a smaller sail. That sewing awl works great for a job like this as it can go through many layers of sail cloth - which is necessary to get the strength in the mod. I ended up being happy with the results but I understand you have to be careful as you have a fair chance of screwing the sail up.
I did not check but maybe sailrite even has a video giving some idea how this would be done. I know someone who made a sail from a sailrite kit and it looked like a great sail.
I cut 3' out of an old shark sail and sewed it back together to use with my Siren 17.
I used the same foot. Just shortened it about 2'. So I had 3 pieces of sail that I sewed back togetther. First I joined the foot while keeping the bolt rope in it. I took the 2' out of the middle of it. Then I sewed the bottom to the top.
I had to do a little adjusting to the leach line but nothing over 3'.
I used my Singer Stylest sewing machine with a #18 needle and vinyl thread. It needs a little help getting going if you have over 6 layers of sail cloth.
I used the same foot. Just shortened it about 2'. So I had 3 pieces of sail that I sewed back togetther. First I joined the foot while keeping the bolt rope in it. I took the 2' out of the middle of it. Then I sewed the bottom to the top.
I had to do a little adjusting to the leach line but nothing over 3'.
I used my Singer Stylest sewing machine with a #18 needle and vinyl thread. It needs a little help getting going if you have over 6 layers of sail cloth.
So to get the foot part of the sail back to the right width where it joined the upper part of the sail did you cut it into 3 pieces (cutting a vertical piece out of it) leaving you with a forward and aft section of the foot part of the sail. Then sewing those together and then to the top part of the sail?
Sumner
[FONT=Arial, sans-serif]============================
Our Endeavour 37
Our MacGregor 26-S Pages
Our Trips to Utah, Idaho, Canada, Florida
Mac-Venture Links[/FONT]
It seems most have cut the foot or in Findings situation it sounds like the middle. I only want to cut the top. My concern is the headboard. Cutting the sail down makes it wider from the luff to the leach. I don't know if I should get a new wider headboard.
when I cut the foot of a main, the goal was to reduce sail area/ lower the center of effort. Sounds like your goal is more to minimize area loss by cutting at the top?
I was paranoid about cutting the top as this is where all the twist action/ backstay tension comes into play and by looking at how beefy that area is, probably a lot of stress. Seems complex enough (especially the twist characteristics) that it would be easy to screw up the sail but I am completely guessing. But.. if you cut the top, what about making the sail into a square top?
I was paranoid about cutting the top as this is where all the twist action/ backstay tension comes into play and by looking at how beefy that area is, probably a lot of stress. Seems complex enough (especially the twist characteristics) that it would be easy to screw up the sail but I am completely guessing. But.. if you cut the top, what about making the sail into a square top?
Sounds like the OP just wants to take a couple inches off the top, correct..?
If so drilling the rivits out and lowering the headboard you should still be well into the head "build up" and probably still be able to capture the leach tape in the headboard...
If it gets wider quicker than the head board can capture, add a wider piece of leach tape to connect with original leach and be able to tuck under head plate...
More than a couple inches off the top and your probably looking at a wider headboard to capture leach tape...
If so drilling the rivits out and lowering the headboard you should still be well into the head "build up" and probably still be able to capture the leach tape in the headboard...
If it gets wider quicker than the head board can capture, add a wider piece of leach tape to connect with original leach and be able to tuck under head plate...
More than a couple inches off the top and your probably looking at a wider headboard to capture leach tape...
Thanks squid. That's exactly what I was looking for. A couple of inches and I am still well into the reinforced part of the sail. I was debating on 2or3 inches off the top. I think at 2 I can still grab the leech with the existing headboard. At 3 inches its about 1 inch short. I'll try 2 and see how that works. All I want to do is get more tension on the sail when I hoist it up.
I wanted to raise my boom some to clear my Bimini. However the sail track opening is just above the stock gooseneck connecting re boom to the mast. Therefore I bought a gooseneck slide that runs inside the sail track in the mast. I took my mainsail to a sail loft and had them cut about a foot off the bottom of the sail, put in new reinforcing and grommets etc. Now my boom rides just above the sail track opening. I don't notice ant change in sailing. This worked great for me but might not for everybody.
I also might need another inch or two to possibly clear the solar panels that replaced the bimini and I'm wondering if I might just be able to sew in a pleat up by the headboard or down at the foot to do that. I don't see this really changing the sail shape and can live with that if it does. The sails are still way newer than the ones we sailed with at first.
I'm going to look at that option if I need it and I have the sewing machine down here if I need it. I had the sail up on the trailer and I think I left enough clearance but won't know until I get on the water and see what it is like underway,
Sumner
[FONT=Arial, sans-serif]============================
Our Endeavour 37
Our MacGregor 26-S Pages
Our Trips to Utah, Idaho, Canada, Florida
Mac-Venture Links[/FONT]
The issue of wanting to raise a boom is quite common for most (95%?) cruising sailors.
However this need, usually ~95% of the time, arises because simply that the boltroped dacron mainsail is not being correctly raised in the first place; proper sail raising will cause the aft end of the boom to rise several inches and with NO modification of the sail at all.
Unless a dacron mainsail is properly raised and the luff boltrope additionally 'stretched out' AFTER raising, the usual result is the aft end of the boom 'drooping' severely into the cockpit.
For the MacGregor series boats discussed, a 'properly' raised and set mainsail will have the aft end of the boom positioned nearly 3" higher than if you 'just raise' but do not properly and additionally tension that luff boltrope .... properly 'stretching-out' the luff boltrope causes the leech to tighten and which 'raises' the boom end into proper position!!!!!!!
When the head of the sail is forcibly raised an additional ~1 inch for every 10-11 ft. of luff length to 'stretch out' that boltrope, guess what happens to the leach and the clew position at the end of the boom ?????
Without setting and properly raising a boltroped dacron mainsail ..... the boat will aggressively heel over on a beat, can be vulnerable to 'skidding' off to leewards, be much slower and 'cranky', and will probably have significant 'weather helm' unless you (wrongly) rake the mast well forward.
So, before you rip apart your mainsail and change its 'as raised, designed shape' I would suggest that you first consider to follow the directions in: http://forums.sbo.sailboatowners.com/showthread.php?t=120970 (post #!) and properly stretch-out that luff boltrope AFTER raising the sail with additional halyard tension ... and which will cause that boom aft end to raise 'considerably'.
Go to any lake, bay or any other sailing venue and simply observe ALL the drooping-into-the-cockpit-booms on 'cruising' sailboats - probably 99% of all cruising sailboats you see with 'drooping booms', will indicate that 'most' cruising folks simply are unaware how to 'properly' raise a cross-cut woven dacron mainsail !!!!!!!
If you MUST alter the sail for more boom clearance, I would suggest cutting a sharp triangular 'wedge' from the un-cut tack and across the foot to a new higher clew position, with the apex of the triangle at the TACK and most of the depth of the cutaway increasingly from towards the leech section --- all to raise the aft end of the boom:
1. You will not disturb nor have to reinstall the tack cringle
2. You will not disturb the sailmakers (hand sewn) 'binding' of the boltrope to the sail/sleeve that sets the necessary 'preload' tension of the boltrope.
3. You will not (hardly) disturb the 'reinforcement patches' at the tack.
4. all the 'work' will be done toward the leech - new clew cringle or "D" ring, new foot edge seaming, etc. Just loft a straight line from the corner of the existing tack to the NEW clew position.
The problem with cutting the head and reshaping / tapering the leech at the top panels is that the sail may then, when fully raised, be 'too long' in the horizontal plane at the 'mid panels' and will cause the leech to be much longer than what can easily pass the backstay .... the sail'a leech will 'hang up' on the backstay in 'light' winds when tacking and gybing. Plus, you will undoubtedly have to cut away the sailmakers hand sewn boltrope binding to the 'luff sleeve' near the headboard ....and simply ruin the precise amount of boltrope 'preload' tension that the sailmaker 'designed' into that sail ..... leaving you with a VERY mis-shapen sail shape. A LOT of the sailing shape of that sail is dependent in how much 'preload' (purposeful shortening) of that boltrope was in relation to the sails 'unstretched' luff length.
99% of improper sail shape (including 'boom droop') is caused by improperly 'raising/setting the sail' ... by not additionally and properly 'stretching out' that luff boltrope with additional halyard tension, AFTER raising that sail.
Hope this helps. ;-)
However this need, usually ~95% of the time, arises because simply that the boltroped dacron mainsail is not being correctly raised in the first place; proper sail raising will cause the aft end of the boom to rise several inches and with NO modification of the sail at all.
Unless a dacron mainsail is properly raised and the luff boltrope additionally 'stretched out' AFTER raising, the usual result is the aft end of the boom 'drooping' severely into the cockpit.
For the MacGregor series boats discussed, a 'properly' raised and set mainsail will have the aft end of the boom positioned nearly 3" higher than if you 'just raise' but do not properly and additionally tension that luff boltrope .... properly 'stretching-out' the luff boltrope causes the leech to tighten and which 'raises' the boom end into proper position!!!!!!!
When the head of the sail is forcibly raised an additional ~1 inch for every 10-11 ft. of luff length to 'stretch out' that boltrope, guess what happens to the leach and the clew position at the end of the boom ?????
Without setting and properly raising a boltroped dacron mainsail ..... the boat will aggressively heel over on a beat, can be vulnerable to 'skidding' off to leewards, be much slower and 'cranky', and will probably have significant 'weather helm' unless you (wrongly) rake the mast well forward.
So, before you rip apart your mainsail and change its 'as raised, designed shape' I would suggest that you first consider to follow the directions in: http://forums.sbo.sailboatowners.com/showthread.php?t=120970 (post #!) and properly stretch-out that luff boltrope AFTER raising the sail with additional halyard tension ... and which will cause that boom aft end to raise 'considerably'.
Go to any lake, bay or any other sailing venue and simply observe ALL the drooping-into-the-cockpit-booms on 'cruising' sailboats - probably 99% of all cruising sailboats you see with 'drooping booms', will indicate that 'most' cruising folks simply are unaware how to 'properly' raise a cross-cut woven dacron mainsail !!!!!!!
If you MUST alter the sail for more boom clearance, I would suggest cutting a sharp triangular 'wedge' from the un-cut tack and across the foot to a new higher clew position, with the apex of the triangle at the TACK and most of the depth of the cutaway increasingly from towards the leech section --- all to raise the aft end of the boom:
1. You will not disturb nor have to reinstall the tack cringle
2. You will not disturb the sailmakers (hand sewn) 'binding' of the boltrope to the sail/sleeve that sets the necessary 'preload' tension of the boltrope.
3. You will not (hardly) disturb the 'reinforcement patches' at the tack.
4. all the 'work' will be done toward the leech - new clew cringle or "D" ring, new foot edge seaming, etc. Just loft a straight line from the corner of the existing tack to the NEW clew position.
The problem with cutting the head and reshaping / tapering the leech at the top panels is that the sail may then, when fully raised, be 'too long' in the horizontal plane at the 'mid panels' and will cause the leech to be much longer than what can easily pass the backstay .... the sail'a leech will 'hang up' on the backstay in 'light' winds when tacking and gybing. Plus, you will undoubtedly have to cut away the sailmakers hand sewn boltrope binding to the 'luff sleeve' near the headboard ....and simply ruin the precise amount of boltrope 'preload' tension that the sailmaker 'designed' into that sail ..... leaving you with a VERY mis-shapen sail shape. A LOT of the sailing shape of that sail is dependent in how much 'preload' (purposeful shortening) of that boltrope was in relation to the sails 'unstretched' luff length.
99% of improper sail shape (including 'boom droop') is caused by improperly 'raising/setting the sail' ... by not additionally and properly 'stretching out' that luff boltrope with additional halyard tension, AFTER raising that sail.
Hope this helps. ;-)
Last edited:
Thanks Rich. I do realize all that you said. The reason I raised the boom in the first place is I'm pretty tall and the boom of the mac is low. I was able to get the boom horizontal , even a little higher before. I can still get it horizontal, but I know I still don't have enough tension on the luff. Hence the reason for just a couple more inches to tension the luff.
The Mac 26 is a sweet sailing boat, comparable to the Cat 25 & 27, Hunters, and others from that design era. ... all with relatively low booms. Most of the 'hot racing' boats of that design era had even lower booms ... flush decks with the boom about 3 FEET above the cockpit seat and one must 'crouch under' to swing the boom or get 'bonked'.
If you have a sliding gooseneck and the main has a boltroped foot, another possible alternative and with minimal ripping and re-sewing, is to DIY install an old-fashioned flattening reef --- install new reefing cringles a few (6-8") inches above the foot at the tack and clew, add heavy sail twine binding of the luff boltrope to its luff sleeve AT the tack flat-reef cringle and simply flat-reef down. If your main already has a cunningham cringle, youre half-way there already - but add that sail twine binding at near the cunningham cringle.
Method: Tie in the flattening reef of the sail before raising, release the sliding gooseneck, raise the sail as far as it will go up, then pull down the sliding goose neck about 3" to tension the luff boltrope. (Best to use a low stretch halyard). You dont have to fully tension a flattening reef, the sail doesnt need mid-panel 'bunt' cringles. The sail/boom will/can be 6-8" higher; and best of all, this 'modification' doesnt disturb the initial boltrope tension/length nor does it disturb the careful 'broad-seaming' (panel edge curvature) near the luff.
An old fashioned flattening reef is dynamite for sailing in 'light and flukey' winds - helps prevent 'separation stalls' on the leeside of the mainsail ... and the jib's leech can be held closer to main for less so-called 'backwinding' and to better adjust the 'slot open' distance. Also good for sailing between 15 and 18kts with an unreefed main.
hope this helps.
If you have a sliding gooseneck and the main has a boltroped foot, another possible alternative and with minimal ripping and re-sewing, is to DIY install an old-fashioned flattening reef --- install new reefing cringles a few (6-8") inches above the foot at the tack and clew, add heavy sail twine binding of the luff boltrope to its luff sleeve AT the tack flat-reef cringle and simply flat-reef down. If your main already has a cunningham cringle, youre half-way there already - but add that sail twine binding at near the cunningham cringle.
Method: Tie in the flattening reef of the sail before raising, release the sliding gooseneck, raise the sail as far as it will go up, then pull down the sliding goose neck about 3" to tension the luff boltrope. (Best to use a low stretch halyard). You dont have to fully tension a flattening reef, the sail doesnt need mid-panel 'bunt' cringles. The sail/boom will/can be 6-8" higher; and best of all, this 'modification' doesnt disturb the initial boltrope tension/length nor does it disturb the careful 'broad-seaming' (panel edge curvature) near the luff.
An old fashioned flattening reef is dynamite for sailing in 'light and flukey' winds - helps prevent 'separation stalls' on the leeside of the mainsail ... and the jib's leech can be held closer to main for less so-called 'backwinding' and to better adjust the 'slot open' distance. Also good for sailing between 15 and 18kts with an unreefed main.
hope this helps.
I did a search of mast steps and found a mod by Trinkka some years ago. Hardware changes to me is easier than cutting and sewing sails.
http://forums.sbo.sailboatowners.com/showthread.php?p=963656&highlight=Mast step
Maybe your standing rigging could still be used with longer turnbuckles, just a thought.
All U Get
http://forums.sbo.sailboatowners.com/showthread.php?p=963656&highlight=Mast step
Maybe your standing rigging could still be used with longer turnbuckles, just a thought.
All U Get