On my LM27, I discovered that the forestay only was fastened to the deck with two bolts. I had a new rearstay installed this spring and tightened the wires up to maximum, with the result thet my anchor cover could not close - the deck was lifted a little. On the part of the forestay, attached to the deck and below deck, a little hook can be seen. This is for installing a kind of extra reinforcement as no futtocks with chainplate is mounted in front. I simply bought a 8mm turnbuckle, fastened it to the hook on the forestay in one end and in the other end to two 10mm bolts drilled through the front. Now it is steady as a rock.
Hi Jandane, I would like to make this improvement also. How have you fixed the bottom end of the turnbuckle. From your photo it looks like you have drilled through the front of the hull and fitted an anchor point of some sort. Although I want to make this improvement I don't fancy drilling a couple of holes through the front of the boat. Your advise would be welcome. Many thanks. John. Siren
I indeed drilled two 8mm holes through the front. The bolts were given a lot of Secumastic and an anchor plate fastened on both sides of the holes. No water will ever penetrate and if, it will leave via the bottom hole in the anchor locker. The fibre glass in the front is around 20 thick so no worries there
thanks for the advice. while adding a bowsprit outside my LM (which required some additional bolts,screws and metall plates anyway), I followed your advice inside the anchor locker and added the fix for the forestay you suggested almost the same way. As a result I'm no longer afraid to 'peel of the deck and superstructure' ;-) .
Hi All, I can indeed confirm that the forestay attachment is a somewhat baffling weak point in the LM27 design which is not at all up to the standard of the backstay and shroud attachment points.
At some point a previous owner had fitted a double forestay on my boat which it was obviously not designed for and due to this weakness the whole fore part of the deck stucture had begun to lift which I first noticed as slack in the forestay. It required a substantial structural GRP repair and I have added a tang down the apron in order to fully consolidate it.
If done before this sort of damage occurs Jan's reinforcement should suffice to prevent it happening but it is a surprising weakness in an otherwise bullet proof design. Forestay tension can be very high especially if a backstay tensioner is employed to give the mast pre-bend - beware!
Mick
Last Edit: Aug 31, 2017 19:22:04 GMT by oceandancer
For the first time ever today (shame on me!) I tried to set up the rigging correctly on my LM 27, following the written instructions that I inherited with the boat and that had been provided to the first owner in 1981. Having tensioned the fore-and back-stays and cap shrouds, I tried to create some pre-bend in the mast by slackening the aft lower shrouds and tensioning the forward lowers. By the time I had achieved a barely visible pre-bend the deck had risen appreciably at the point of attachment of the port forward lower shroud. I then stopped, hand-tightened the after shrouds and locked all the turn buckles. Questions: - is there a real risk that when beating to windward the port forward lower shroud will tear its mounting out of the deck? - should I slacken the forward lower shrouds, or will that achieve nothing at this stage? - what should be done to reinforce the lower shroud mounting points? Advice welcomed Charles
See Jan's "Reinforcement of front innerstay on LM27" This seems like a neat solution, although you will have to cut a flap in the headlining material in the cave locker. MKII boats came built with reinforcement of the lowers stays. The deck can bulge alarmingly, I have even seen star crazing around the pad eye.
Many thanks Mick. (You have had a busy 24 hours, sorting out the worries of us less experienced owners - much appreciated.) More questions if I may: - How has Jandane attached the lower end of the turnbuckle with which he has reinforced the forward lowers? (Perhaps Jandane himself might like answer that one.) - What is your advice regarding my first two questions above: is the mounting liable to tear out of the deck while beating to windward and would it help to slacken the tightened forward lowers? Charles
For the first time ever today (shame on me!) I tried to set up the rigging correctly on my LM 27, following the written instructions that I inherited with the boat and that had been provided to the first owner in 1981. Having tensioned the fore- and back-stays and cap shrouds, I tried to create some pre-bend in the mast by slackening the aft lower shrouds and tensioning the forward lowers. By the time I had achieved a barely visible pre-bend the deck had risen appreciably at the point of attachment of the port forward lower shroud. I then stopped, hand-tightened the after shrouds and locked all the turn buckles. Questions: - is there a real risk that when beating to windward the port forward lower shroud will tear its mounting out of the deck? - should I slacken the forward lower shrouds, or will that achieve nothing at this stage? - what should be done to reinforce the lower shroud mounting points? Advice welcomed Charles
In case it is any use to anyone I have posted on this forum a copy of the rig tuning instructions you mention. They are in a thread in this 'Ideas for Sharing' section called 'Trimming of rigging - LM 27 and LM24' and dated May 2017.
I don't know much about LM27s, but from my observations and reading about similar problems in other boats I think it is most unlikely that the lower shrouds would tear out of the deck (though it's not impossible and I offer no guarantees!). What is much more likely to happen is that the deck flexes upwards. This can result in - creaking from the deck as you walk in the vicinity of the shroud mounting points (these are also known as known as chainplates) as the deck works up and down, - cracks in the gelcoat surface of the deck in the vicinity of the flexing (the glass fibre sandwich, the structural bit of the deck, is much more flexible than the rigid and brittle gelcoat finish to it), - (less likely) some separation of the hull deck joint, and/or - loss of seal between the chainplates and the deck, allowing water to enter and rot the (presumably balsa core), eventually leading to decks flexing over a wide area and serous loss of strength.
I think some have mentioned in previous threads having the cracks and creaking.
I am no expert, but if I were you I would slacken the forward lowers again a bit to reduce the flexing of the deck, and accept that you will not achieve optimum setting of your mainsail (it will be too baggy, especially in higher winds, resulting in less drive forward and more heeling).
I've got a bit of the creaking on my boat, which curiously has previously had tie rods (in the form of stainless steel tubes) installed to take the tension of the aft lower shrouds down to the hull, but not for the forward lowers which are under significantly more tension (if the rig is set up as per the LM instructions).
Installing tie rods for the forward lowers and for the forestay is on my list of jobs to do, but is, sadly, a long way from the top of that list at present!
Many thanks for this clear and comprehensive response; very reassuring! I took Marguerite out today before I had read your advice, so sailed her with the forward lowers still tight. The wind was a fluky force 4 and when sailing close hauled the speed through the water was good while there was appreciably less weather helm in the gusts than before, so that is a positive outcome. As far as I can see, the bulging of the deck at the chainplates has not increased at all. So what I propose to do is leave things unchanged for the rest of this season but keep an eye on the shape of the deck, and next winter install the reinforcements suggested by Jandane. Charles
Hi Paul, Re the locker tops. I would go for 18mm ply rather than 12mm as the bracing required is much less and you can more easily attach a simple rolled edge using glue with counterbored screws and wooden plugs. This is an easy way to attach the edge strips and can look quite tidy. Just remember to keep the scews quite low in order to allow for the radius of the rolled edge(see drawing attached in MS word) Don't go for very exotic ply veneers as these are expensive now and will get more so. When I fitted my locker tops (24 years ago) teak veneer was easy to get but now it's like hen's teeth!
Thank you Jan for this post. The Riggers arrived to replace the genoa roller reefing, and said the front of the bow was lifting and would need reinforcing, which they left with the marina staff to sort. Luckily I recalled this post, found it and told the staff we wanted the same fix, which they duly did. They were complimentary on the idea. Just waiting for the Riggers to finish the job
Thank you Jan for this post. The Riggers arrived to replace the genoa roller reefing, and said the front of the bow was lifting and would need reinforcing, which they left with the marina staff to sort. Luckily I recalled this post, found it and told the staff we wanted the same fix, which they duly did. They were complimentary on the idea. Just waiting for the Riggers to finish the job
And did it work well? Last summer I did around 1000NM and have noticed, that when the mast trim is good on a LM27, she goes very well against the wind and in addition, on all other directions, I feel the ship much more “sailing” and not wobbling/popping
. . . when the mast trim is good on a LM27, she goes very well against the wind and in addition, on all other directions, I feel the ship much more “sailing” and not wobbling/popping
Do you have a backstay tensioner, Jan? I've always wondered how much difference that would make.