I've had my mast back on for a week and a bit and got it very tight.
ive basically used the loos gauge which is a calibrated tool to tighten the stays evenly.
for eg, the stays are at a maximum of 14% of their breaking strain. Lowers are 10. Back stays are 8.
uppers are 12.
Ive got a rake on the mast, which really only shows from the top spreaders and up. It would be about a mast width but it's def noticeable.
The rake scares me a bit. On a 9 m mast it looks a bit like too much rake and I'm worried that it could be.
On the other hand the boat is sailing very very well to windward. Much better pointing ability.
before removing the mast I photographed the screws and threads. The forestay and the back stays are tighter than before.
ive fired this question, concern over to the Tophat forum as well. the concern is regarding the rake and tightness. Could iit be too tight although the gauge tells me , and pro riggers tell me(YouTube!) that 14 % of a wires breaking strain is ok?
iwill be sailing to jervis in 2 weeks so I guess a few trial runs are in order. With maybe some lesser tensions. Looks gauge is a must have tool imo. So handy And great for taking some guess work out if you wanna tension rig prepping for a blow etc.

If you can not open the heads door it's too tight! I'm not sure of my rake, it's probably about 6 inches or more



.

Steve,
don,t confuse mast rake with mast bend,
Your main sail cut or curvature along the luff will determine the correct bend of the mast which can be easily measured off the sail.
Same goes for the heady. you can watch the sag in the headsail luff whilst tensioning the forestay to help determine the correct forestay tension for the sail cut. Sometimes the two need to be juggled a bit to come up with a good average.

Mast rake helps going to windward, most boats should be set up with it, mine has 700mm of rake plus preset bend which helps your main shape.

Rake is controlled by forestay.

For a cruising boat your tensions sound about right, I have mine higher for racing. Do you use an adjustable backstay? If not can you increase the tension for windy days?

It's a bit of a shock isn't it. Ive just gone from floppy rig to 8% aft lowers, 10% central lowers and 12% on the uppers. It feels way tight on my compass 28. Not much rake.

The backstay adjuster blew a pulley at 3%! That's what 6 years of sun without moving does. I'm going to apply sensible backstay tension and have a look from the side.

All the advice says that this is nowhere near too tight. Let us know how it goes.

You are right. The Loos is great.

Bristle

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Jolene said..
Steve,
don,t confuse mast rake with mast bend,
Your main sail cut or curvature along the luff will determine the correct bend of the mast which can be easily measured off the sail.
Same goes for the heady. you can watch the sag in the headsail luff whilst tensioning the forestay to help determine the correct forestay tension for the sail cut. Sometimes the two need to be juggled a bit to come up with a good average.

so is rake just a tilt back and a bend - a bend?
In that case my mast in slightly bent!
Some good advice ther thanks alot.
My main is really easy to put up and has great shape.
I still think the rig is a bit too tight though and after rewatching the youtube video where the rigger said 11-13% is what you want i could be over by a few percent.
I will loosen it all slightly on Saturday.

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blackswan said..
Mast rake helps going to windward, most boats should be set up with it, mine has 700mm of rake plus preset bend which helps your main shape.

Rake is controlled by forestay.

For a cruising boat your tensions sound about right, I have mine higher for racing. Do you use an adjustable backstay? If not can you increase the tension for windy days?

come to think of it , id say i have Rake and mast bend. a slight rake and about 100mm of bend.
I dont have an adjustable backstay - only by the screws and actually i will replace these. Theyre the oldest parts of the fairly new rig.
Its easy enough to adjust/loosen the tension using the screws and now that i have some idea, i will do this.

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Bristolfashion said..
It's a bit of a shock isn't it. Ive just gone from floppy rig to 8% aft lowers, 10% central lowers and 12% on the uppers. It feels way tight on my compass 28. Not much rake.

The backstay adjuster blew a pulley at 3%! That's what 6 years of sun without moving does. I'm going to apply sensible backstay tension and have a look from the side.

All the advice says that this is nowhere near too tight. Let us know how it goes.

You are right. The Loos is great.

Bristle

my back stays are only on about 8-10% and are at the end of the screws, so cant tighten anymore, but its way tighter than pre mast lift.
I will need to have a test run in a good 30knots. Im going to relieve my (mastS) tension about 2% and i reckon she'll be perfect.

My shrouds are really tight. I have not adjusted them, they are as they were for SH races. The backstay has a wheel adjuster and I adjust that so that on light days there is a slight headsail sag, tighten it as the wind freshens. With the Currawong the keel stepped mast sits of a steel girder that crosses the boat and the shrouds attach direct to that via a SS strap. This enables the use of very tight shroud tension. Hard on the wind in a good breeze the leeward shrouds are still fairly tight. I would suggest keeping the shrouds as tight as you can, at least use the Loos gauge and set what ever the Selden mast tuning guide suggests for your particular version of a mast head rig. Ease off only if your boat is bending and the doors wont open! Sloppy rigging wears out.

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Sectorsteve said..

Jolene said..
Steve,
don,t confuse mast rake with mast bend,
Your main sail cut or curvature along the luff will determine the correct bend of the mast which can be easily measured off the sail.
Same goes for the heady. you can watch the sag in the headsail luff whilst tensioning the forestay to help determine the correct forestay tension for the sail cut. Sometimes the two need to be juggled a bit to come up with a good average.

so is rake just a tilt back and a bend - a bend?
In that case my mast in slightly bent!
Some good advice ther thanks alot.
My main is really easy to put up and has great shape.
I still think the rig is a bit too tight though and after rewatching the youtube video where the rigger said 11-13% is what you want i could be over by a few percent.
I will loosen it all slightly on Saturday.

have a look here:

joecoopersailing.com/mast-rake-versus-mast-bend/
joecoopersailing.com/mast-bend-and-mainsail-shape/