I recently purchased a Hunter 35.5 (1995), I feel the mast back rake by the previous owner is excessive, does anyone has any suggestion about how much (if any) is proper for this boat?
Thanks

-------------------------

Gene,
I am in the midst of a project to determine the optium mast rake for my Hunter 35.
Your fractional rig is the same as on my Hunter Legend 35 (circa 88).
As I understand it, mast rake for a fractional rig is determined by forestay length - and only forestay length.
The Hunter factory folks told me that they set up the 35 and 35.5s with 10 inches of rake.
The 10 being measured on the top of the boom - that is, using the main halyard as a plumb bob, measure 10 aft on the boom from the trailing edge of the sail track lips on the Isomat mast and draw a line on the boom.
To determine the factory spec rake you need to release all of the backstay presure to the top of the mast. That is - all pressure - tension on the back stay - it is free to flop.
With the back stay pressure released, the mast is just about as streight as an arrow as you sight up the sail track.
Using the main halyard as the streightedge as it drops down from the top of the mast and you will see that there is little if any bend in the Hunter 35/35.5 mast. If the mast is on the ground there are no adjustments to set the pre bend.
Now check or set your side shrouds to the recommended settings. Brion Toss, in his video on tuning a Hunter 35.5 uses the tap the shroud and listen to how tight it is. The tuning fork approach.
The boat stores sell (expensive) tools to test the amount of stretch in the shroud. In any case as you carefully tighten up on the 6 shrouds the mast will center up and with the slight of amount of back pressure provided by the swept back spreader bars you will put a slight strain on the forestay.
Remember this is a fractional rig. The back stay does not pull the forestay tight as in a mast head rig. The fractional rig back stay, is used to set the prebend and the bend.
At this point, measure the amount of rear drop movement as a weighted plumb bob on the main halyard drifts aft. The heavely weighted main halyard is acting as your taunt plumb bob to determine mast rake. The 10 mark on the boom is about 1 degree of rake provided the mast is streight with no back stay pressure. The mast will not fall over if the back stay is in full release.
If you have more than 10 of plumb you will have more than the recommended factory rake. Less of course is less.
To set the rake, if it is out of kilter - you need to release the side shrouds - all six- reset the forestay trunbuckle and then retighten the side shrouds to the recommended tension.
Once your rake is set (10 or so) your mast will still be as streight as can be.
Now you set your prebend with the backstay. How much prebend ??
Most sailmakers sew in about 4 of prebend in the main sail for the Hunter 35 series.
Again using the main halyard as a plumb bob streight edge - hold the halyard tight to the mast at boom level, sight up the sail track and estimate the amount of prebend you have induced in the mast with the back stay at a point about 25 feet above the deck.
This is an exact science if you have someone in a cherry picker bucket move in on the mast at about 25 above the deck and measure the prebend. If not - estimate the 4 inches of prebend at about this point.

If you go back and measure the rake it is not the correct rake. Your main halyard plumb bob will show more aft movement of the halyard on the boom because the very top of the mast has been pulled (bent) back by the back stay as it induces the prebend.
Mast rake is measured as the total aft movement of the full length of the mast and not just the top tip of the fractional rig.
One under sail, if you have an adjustable backsty you will induce bend to flatten the main sail.
Once under sail you will have head sail sag on the jib or genoa that will effect your abillity to point.
The back stay in a fractionl rig does not reduce head sail sag. More back stay pressure only causes more bend in the mast.
To reduce head sail sag and point highter, you will need running back stays - the subject of another discussion.

Trust this rather long procedure will help your and other HL 35 sailors sail better.
My mast rake project is to determine the exact rake for my particular boat for racing purposes.
Mast rake loads up the rudder and the keel. Commonly caller weather helm. Weather helm is good as it translate sail forces to the water. How much is good - dont know yet.

Sail on.

RD
Fl