need stepping the masts HELP

[weheritage]

As mentioned earlier the mast were stepped on LEEWAY last Wednesday. Didn't have time, light or experianced help to complet the task. Went back this morning to put in the wedges and............ While the masts are set in tight they are also aginst the partners to the rear leaving a wide gap in the front of the holes. not sure how to tackle this prroblem. It appears as though wedges should be 360 degrees around the masts? How much rake would be desirable? Any sugestions or help appreciated.

weh

[JimD]

How much rake would be desirable? How much rake do the plans call for?

[weheritage]

Do not have plans...........built in 1942??????
I would think 6 to 8 degrees but do not know.

[Nicholas Carey]

Mast should be wedged 360 deg at the partners [usually]. Partner wedges fine-tune rake only. Gross rake adjustment done [usually] by sliding tenon at base of mast forward/aft as needed and securing with shims.

Cut shims from relatively thin stock (1/4 ins. ply or vg hardwood works well — figure shims likely to be under no small amount of compressive load.

Compute difference between forward/aft dimension of mast tenon and forward/aft dimension of mortise in mast step. Divide by rhickness of shim stock to get total number of shims needed. Adjust number of shims forward/aft of mast to set gross rake.

Fine tune rake with partner wedges and/or rig adjustments.

Generally speaking, rake should be adjusted to give a bit of weather helm whilst sailing.

[Figmental]

How about raising the sail if it still has a nice shape and adjusting the rake till the boom is level? That has worked for me once as a starting point when there was no clue.
David

[Ian McColgin]

The mast likely has a little rake and just laid back with gravity overnight. Most likely, you'll want to wedge it more evenly in the partners, but take your time.

It would not hurt to know what size of rig you're setting up, but here are some thoughts that go through my mind when I'm rigging a strange boat.

I like to get the mast up and even in the partners with just hand pressure stay tensioning - no fids and wrenches. If this means well lubed turnbuckles, so be it.

What sort of step have you? If it goes in only one way, that suggests that the designer figured the rake already and you'll meet those intentions if you just go straight up the middle. Even with an adjustable step - like maybe a square tenion at the mast heel and a longish slot with wedges to anchor the mast fore and aft - the designer usually means for the mast to wedge symmetrically in the partners, though different owners with different loads and trims will end up departing from that over time.

Now we squint up the aft side of the mast to see if the track makes a nice straight run and if not, why not.

Take the main halyard as a measure devise and, checking from chainplates port and starboard, determine if the mast is centered athwartships. It probably will not be, which is fine as only the slightest error at the partners could put the truck several inches out. What you're really looking for is to ensure that the partners and mast step are not seriously out of alignment. Boat that are really suspect are best checked with level and plumb bob before launching and stepping.

If there is a little athwartships problem you must choose one of two solutions. If the mast sights gunbarrel straight and the truck measures centered athwartships, then make asymmetrical wedges and go with that. More likely, you can wedge symmetrically and adjust the stays to make the mast straight.

If the truck is centered and the track bows, you'll need to fiddle it straight. If you've lowers, use them to bring the center of the mast under the truck. If no lowers, you move the truck directly and the middle by spreader compression, which means that every time you tighten the stay on the convex side of the bow you both push the bow out by the spreader and move the truck a little off. Trim to half way, then trim the other side and thus move in.

If you have double lowers, leave the forward lowers utterly loose till you have the mast nicely set, then use the forwards to either take out any reverse bow or to put in a little desired bow.

If you've not made the wedges yet. Try making seriously over-long wedges that at their middle are about the thickness of partners diameter minus mast diameter. If the mast and partners are not circles, adjust accordingly by you get the drift. Have the wedge taper from double that mid-wedge thickness to about nothing over a wedge length at least 4 times the partners' thickness. This will give you lots of room for asymmetrical wedging and you can cut them all off even later.

Label or number the wedges so you can get them right quickly again and again and again.

Anyhow, this will get you started. How much do you know about the actual tuning?

[Thad]

The above posts say all that probably needs to be said, but.... Every design differs and most designs show the designed rake. If you have the plans for a boat you should be able to read or calculate the designed rake. Most boats are built with the partner center set at the design rake over the step center, with little adjustment allowed. But...there are quite a few designs for boats with long steps and/or long partners that allow for adjustment, These are mostly racing class boats where experience and experiment lead to shifting the rake for effect. Most masts are set plumb or with a few degrees rake aft, but there are a few designs (like the Town Class) that almost always sail with foreward rake. As was said, usually one is after a light weather helm, for safety ("weather helm" so the boat will tend to round up and not jibe in moments of inattention, and "light" to keel turbulence drag at the rudder minimal). But for racers the main thing is winning so boat speed would be the prime factor with control a close second. In one design racing the class rules would usually specify limits to changes in rake. In classes like IOD where all sails are identical the only benefit of changing rake, if allowed, would be to balance.

[Ian McColgin]

By the way, the partners are part of the structure for a keel stepped mast. You want to get the mast wedged before sailing at all, actually before even tightening the stays beyond the very lights "hand taught." If you don't, you'll just induce a compression bow in the mast that will negate other aspects of tuning.

It is ok to have a bit of induced bow in many masts, hollow and solid. A good general rule is to start with the sail track or (gaff rigs with hoops or lacing) aft side of the mast nice and straight to the sighting eye. Like squeeze your eye against the mast just above the gooseneck fitting and see clearly all the way. This clear sight will actually establish a very slight bow in the mast unless your eye is an inch or so off the mast. It's like the subtle curve in the steps of the Acropolis. But straight or such a shallow bow are usually equally good.

Dynamics of tuning to follow if you have the questions, if you describe the rig and boat a bit, and if you don't have a local wizard who can more directly guide you along.

G'luck

[weheritage]

Thanks again to all. Could not get this information locally.
Both masts have a key way on the bottom and the fit nice and snug.

http://www.gulftel.com/boomer/Step1.jpg

should the mast be in the center of the hole? These are not.
Mizzen
http://www.gulftel.com/boomer/Miz1.jpg

Main
http://www.gulftel.com/boomer/Main1.jpg


weh

[Thad]

Looking at you pictures I'd say to wedge the main in the cented of the partner unless you use an equal line to chainplates either side to square it up. Then work to get the mizzen parallel and alligned to the main. You don't have much play at the partners to play with, but at least it should look good.

[Ian McColgin]

Lower section of main is octagonal fitting into round partners?

Is that mizzen going through a large hole in a cabin sole and down to a step, or is that a large hole in the cockpit sole and also the mizzen partners?

Even with a solid mast and much depending on the size of the rig and how it's stayed, I'd feel better about three wedges per surface on that main - the two on each side tapered/rounded to a partial wedge on the short section as well. Or 8 very cool wedges flat on one face and rounded to fit the partners hole on the other.

What type of boat and any pix of the whole?

Looks like fun

G'luck