Gaff not fitting correctly

[cs]

I had some weekender sails donated to me, but now I'm having a little bit of a problem. These are pretty decent sails with ropes sewn in and all that. Problem is with the foot and the tack. The foot is 12" shorter than what the plans call for, this is not a problem.

The tack is where I'm having a problem. The plans call for the tack to be at a 80 degree angle and this one appears to be at a 90 degree angle. This causes the boom to be to low and sit on the cabin top.

Chad

[cs]

If I put in the aft most 3 reef points, the boom sits correctly.

Chad

[John B]

Chad,First evaluate as to whether the rake you have in the mast is correct. It looked like a lot to me when you had the mast set up in the drive.
then, if that is right, its a recut on the foot.

[cs]

The mast may have a little bit too much rake to it. I'll look into that some more. If so I may adjust at the tabernackle and see what happens. For sure the sail has the foot 12" to short, but hey I can live with that. Don't know if I can re-cut the foot. This sail has a rope sewn around the head, luff and foot and I wouldn't have a clue as how to sew it back on.

Chad

[Dave R]

Chad, I sent you a PM

[Todd Bradshaw]

Recutting a gaff sail's foot is a very complex procedure, not even including dealing with the roped edges. You can't just hack the bottom off if you ever want the sail to set well or have the proper draft and shape. It would probably be easier to make a new sail or mast. I haven't looked at the plan lately, but I would find it strange if they really did design the boat to work with an 80 degree tack angle because of the sail handling problems that sub 90-degree tack angles bring into the equation. If it does have an 80 degree tack you also may need to rethink your luff lacing/or hoops/or robands plan to keep the sail from jamming on the way up. I remember looking at that photo in the driveway and just figuring that you had stopped with the mast part way up to take a picture. If that's what it looks like with the mast stepped I'd bet something is wrong.

[Dave R]

FWIW, here are dimensions of the sails as per the plans:
http://img.photobucket.com/albums/v506/weekender410/WeekenderSails1.jpg

Here's a shot of my Weekender to give an idea of mast rake and so on. Ignore the throat wrinkles, please.
http://img.photobucket.com/albums/v506/weekender410/jksolo3.jpg

Todd, I'm curious about the tack angle thing. Could you decribe how you would design the sail and especially what you would do with the tack angle? Should the boom hang down aft?

I've never noticed any issues with raising the sail but I've never raised a gaff main on any other boat so maybe I'm having all kinds of problems and don't know it. :D

[cs]

Thanks for the illustration Dave. I was going to double check the plans tonight. Keep in mind that Dave raised the boom on his weekender for a little more head room.

Here is a shot of another weekender and a shot of mine.

http://www.stevproj.com/roughdraught.jpg

http://a5.cpimg.com/image/35/7D/57714485-3f1c-0200017F-.jpg

We may have a comedy of errors here. The sail may be cut wrong, I may have slightly too much rake and I probably ain't got a clue as too what I'm doing.

This afternoon if it don't rain I want to get out and un-bend the sail and lay it out on the ground and measure everything to see what is out. I do know that the foot is about 12" to short for sure.

Once I lay it out than I can make a decission on what to do. The wife thinks that she can re-sew the foot. The rope on the foot is external and not inside the seam. It is sewn on like what Todd shows in his illustrations.

I also plan on moving the shrouds up higher on the mast to allow me to raise the throat higher. May have to even add a spreader. I've heard that other weekender have had problems with the gaff jaws hanging on the shrouds and mine do.

I'm also thinking about getting some Tyvek and laying the sail out as per the plans and trying to bend that to see where any problems may lie.

The way I see there are four options.

1. Order new sails.

2. Re-Sew the foot on the existing main.

3. Cut the foreward bulkhead and re-set the mast to cut back on the rake.

3a. I could re-cut the mast at the tabernacle to change the rake.

4. Leave as is & sail with the last three reef points reefed and than finish the design on the DragonShip so I can start it.

Chad

[Dave R]

Chad, it does look like there's something funny with your mast. Does it already make a bit of a dogleg at the hinge? Maybe that's just a trick of the photography.

[cs]

No Dave, in that photo I didn't have the forestay tensioned and the mast is leaning a little too far back. With the forestay tensioned it is in line with the mast base.

Chad

[Dave R]

I see. Well from what I can tell from the stub mast, the rake looks like it ought to be close.

BTW, although you can't see the shrouds in the photo of my boat, they are hanging off the peak halyard block's eyebolt so you can see they are a fair distance from the jaws. You don't have the length on your mast to get them that high but moving them up as we talked last night ought to help.

[cs]

I recieved an e-mail and yes these sails did fit the other boat they came off of. Makes me wonder if maybe the other weekender had the rake in the mast adjusted to make these sails work.

Chad

[cs]

Some quick calculations.

For every degree of rack the end of the boom would be affected by 2.06".

For every degree that the tack is off the end of the boom would be affected by 2.22" (22" @ 10 degrees).

So if the rake is off a little and the angle of the tack is off a little this could be a big drop by the end of the boom.

The more I think about it the more I think I need to verify what the rake on the mast is and than look at re-rakeing the mast.

Dave do you know off the top of your head what the rake is?

Chad

[Dave R]

Sorry Chad, I don't know what the rake would be. I think the angle between the front of the mast box and the bottom of the boat just ahead of the box is 92°. I've got a drawing or two I've done of the Weekender. I'll see if I can figure it out from them.

[Joe ( Cold Spring on Hudson )]

The sails Chad is talking about are my old sails from my ebay purchased weekender ONE design. The design is about 20 years older than the current design chad is working on. There may be differences. Also as with all home built weekenders there is many ummmm personal modifications that take place ;) The sails themselves if I remember we well made and Chad is correct they have nice sewn edges. They were manufactured by Klepper if I remember. They more than likely are not exact to the existing weekender plans. If there is anyway to adjust the gaff or rigging I would attempt that before attempting to re-cut the sails.

I'm sorry I could not be of any more help.

[cs]

Thanks Dave & Joe.

The more I think about this, I think that I need to delay the launch, pull the mast base out and cut the forward bulkhead so that the base of the mast comes into the cabin and thus reduce the rake.:(

While I'm at it I may add a base to the bottom to raise the boom a couple of inches.

Chad

[Dave R]

Chad, don't get that saw out right away. Measure that angle up in the forepeak hold.

Here is a side view of the Weekender model I've been working on. Everything is drawn per the plans except the bowsprit which is drawn as I built mine. there really isn't a good place to measure the angle besides at the base of the mast. It is 93° as I said before.

I don't know how the boat sits in this drawing relative to a waterline so I wouldn't use the angle between the mast and dotted line at the bottom as a guide.

http://img.photobucket.com/albums/v506/weekender410/weekenderside.jpg

[cs]

After looking at several weekender photos and you're drawings I think that my mast may be raked a little too much. Before I do anything rash though I will check the rake and I will lay the sail out on the ground and stake the corners to actually check the sail.

Chad

ps I need to lay the jib out and check it also.

[clancy]

Joe said the sails were manufactured by Klepper. Klepper is a German manufacturer of folding kayaks. It could be that the sails you have were made for their line of boats as illustrated on this page.
Chad you said the peak angle was more like 90°, that's what gave it away.

http://www.klepper-usa.com/upwind.cfm

[cs]

You may be right. I'll know more when I lay it on the ground and do some field measurments.

Chad

[Todd Bradshaw]

Dave, when the tack angle drops below 90 degrees it generally means that there are places on the lower luff where the distance from the clew corner to the mast is less than the distance from the clew corner to the tack corner. If you take that clew-to-tack distance and draw an arc on a sailplan, a sub-90 degree corner will look like this one.
http://www.imagestation.com/picture/sraid129/p45e35bf1bffec17526bbdfc46ae99563/f7c37ead.jpg

Notice how the arc runs off the sail and laps onto the mast near the bottom three hoops, robands or whatever they are? These are the spots where clew-to-mast is shorter than clew-to-tack and they have a very high potential to bind every time you raise the sail, lower the sail or partially lower it, as when putting in a reef. This binding can often be bad enough that you literally can't raise the sail. The more your tack angle drops below 90 degrees, the taller the potential bind area along the lower luff gets. There are ways to deal with this (usually by using a jackline which allows the sail to temporarily pull back and away from those problem hoops while raising or lowering and then snug back up once in position) and you may need to use it to detach some hoops during the time the sail is reefed, but you don't just sew the hoops to the sail and hoist away. So, the problem can be remedied, it just surprised me that they would build it into a reacreational design aimed at home-builders, but I guess they really wanted that salty, raked mast look.

A tack angle of 90 degrees or greater avoids the problem because every mast fitting above the tack corner is at least a little bit farther away from the clew corner than the tack corner is. Like this:
http://www.imagestation.com/picture/sraid129/pe3747343aa036253426e66ac1281bcac/f7c37e94.jpg

The arc doesn't overlap onto the mast and whenever the sail is going up, coming down or being reefed these small extra distances create a bit of slack and allow it to move freely.

The whole thing tends to be a totally confusing concept that's hard to get your mind around, especially on paper - but it's very real out on the water when you can't get the main to go up. In the case of the Weekender, the saving grace is using the staggered lacing system to connect the sail to the mast. It creates a lot of slack in the lace any time the sail is only partially up and the lace line doesn't snug up tight until the sail is fully hoisted. If, however, you ever decide to switch from lacing to hoops, robands or similar attachments which don't automatically create slack during the hoist, you're in for a big surprise when you go to raise the main. In reference to the discussion we had the other day about whether to lace the luff to the mast or use some sort of hoop/roband/toggle system, I would suggest sticking with the staggered lace system. If you ever really want to switch to something like hoops, it can be done but keep in mind that it will take some extra rigging (most likely adding a jackline system) to get them to work.

Boom angle is purely up to the designer. A low boom, or one that droops into the cockpit is usually better aerodynamically because it allows less of your power-generating wind to sneak away under the boom (the end-plate effect). From a practical standpoint though, it may also be a real pain in the butt (or head) for those souls in the cockpit and not be much fun to live with. The boom may also drag it's tail in the water when heeled over, which can create several problems. For most recreational sailors, I wouldn't suggest going much below level on it unless you're really trying to wring every ounce of power out of the system and are willing to live with it's downside as well. Booms which are raised a little bit on their aft ends (and also raked masts, by the way) tend to raise the boom's tail when the sail is eased outboard, providing increased clearance between the boom and the water when the boat heels over. This can often be advantageous.

[cs]

Todd, what do you think of our plan for me to fix the problem?

Chad

[Dave R]

Todd, I think I understand your explanation of the problem. Perhaps, since I've always laced the sail to the mast I've avoided the problem. I suppose I might see a bit of this if I pay attention when raising the sail even so. Fortunately I've never had any trouble with it.

I suppose this would really be a problem if the sail was a piece of plywood or even slats.

Thank you for the explanation and the illustrations.

Without asking you to redesign the boat, would you see it working better with no rake at all? Problem is there's no waterline or other horizontal reference called out in the plans so it would be hard to know where vertical is when building the boat. I guess that's a good reason to build another boat. I wonder if my wife would buy that reason? :D

[John B]

Get ingenious and come up with a block mast step arrangement that allows you to take some of that rake out and take it for a sail. The worst thats going to happen is you'll have some lee helm. Get the boat sailing and see first.

[Todd Bradshaw]

I'm not sure I'd alter the normal rake (although I'm pretty sure I'd alter Chad's, because it looks like the mast is falling down). Some people dislike Weekenders because they find them over-done with the clipper bow, mast rake, bowsprit and other salty cosmetics - which they find out of place an a little pocket cruiser. Yes, maybe it's a bit cartoonish, but I think it's kind of a neat little boat and I like the look of the rake. The problems that the rake presents can be dealt with. Plumbing-up the mast (assuming it didn't screw-up the balance) might eliminate them, but I'm not sure I'd like the looks of the boat as well.

Chad, I think the gist of the problem is that even though the sails you have might have been built for a Weekender, they weren't built for your Weekender. Shortening an existing gaff mainsail without ruining it is a very tough job and the odds of pulling it off are very low. You would be better off selling them as generic sails to somebody who happens to own something that shape or who hasn't designed their rig yet and using the money and your time to build or buy some sails that really fit your boat. But get the rake issue figured out first because it really looks like something strange is happening there.

[cs]

Okay, I guess I better be honest here. I was hoping that I wasn't off, but I went out just now and laid the miter gauge on it and I guess I messed up putting the forward bulkhead in. This is what guides the mast base and sets the rake. I'm at 100 degrees instead of 93 degrees. For those that are weak in math that is 7 degrees too much rake.:(

The best choice I see here is to take the mast base out and cut a notch in the forward bulkhead so that the base of the mast comes into the cabin so as I can get the rake correct.

Major surgery, but I'm up to it.

I still think the sail is cut wrong and will lay it out to check. Guess I need to get started on dis-assembly.

Chad

[John B]

That explains that. 17 degrees ( you have a typo)would correct the issue and give you some lift to the boom eh.

[cs]

I did have a typo the angle measured at 100 degrees not 110. The rake is out 7 not 17.

Chad

[Dave R]

Chad, maybe that will take care of it. Did you lay out the sail, too? How does it look?

[cs]

Yes, here is a quick down and dirty diagram of the sail.

http://a7.cpimg.com/image/13/D7/57875987-cb0f-02000199-.jpg

As you can see it is not the same as what the drawing calls for.

Chad

edited to add some minor corrections. The head of the sail is 5'-9" not 7'-4" and the angle at the head is 135 not 130. I must have missed the angle at the leech. The tack is right and the other measurements are correct. I'll correct the diagram after I cook supper.

[Joe ( Cold Spring on Hudson )]

Chad, please do it in inches and do a side by side with the dia above.

[cs]

Let me make some corrections to my rough measurments and I will.

Chad

[cs]

Okay the revisied sketch posted next to the plans.

http://img.photobucket.com/albums/v506/weekender410/WeekenderSails1.jpg

http://a3.cpimg.com/image/D1/38/57878993-65a7-02000199-.jpg

Chad

My diagonal is about 161"

This sail has about 5 sq ft less of area than as per the plans, but that doesn't make up for me screwing up the mast rake. Been working on getting the mast base out of the mast box.

[Joe ( Cold Spring on Hudson )]

Chad you got problems :(

Sorry

[cs]

Not to bad Joe. I can make the sail work and I ain't worried about losing 5 square feet. I started tear out last night on the mast box. It will be a pain getting the mast out of the box, but after that is should go smoothly.

Chad

[Dave R]

Chad, did you attach the stub mast into the box? If not, just take the hinge off at the tabernacle and lift the stub out. I wouldn't take the rigging and stuff off. All you should need to do is get into the cabin and cut out a slot about 3 1/2" wide in the center of the cabin bulkhead.

[cs]

Dave, the mast stub is a tight fit, and I do mean tight. I had screwed the mast stub in and have taken the screws out. The moisture in the air has caused the mast to be even tighter. I started working on taking the front of the mast box out last night to relive some of the pressure so that I could get the mast stub out.

Chad

[Dave R]

Oh my. Sounds like a bit more work than I thought. I wish you success.

FWIW, I overlayed your sail dimensions on the dimensions from the plans. This is how they compare.
http://img.photobucket.com/albums/v506/weekender410/chadsails.jpg

[cs]

Wheh! That stub mast was a tight fit, but it is out. Required cutting the front of the mast box off and using a pry bar and than a mini-sledge, but it is out.

I decieded to take the mast into the cabin through the foreward bulkhead. Already have the rough slot cut and just need to do a little trim work and than re-set the stub mast.

Chad

[cs]

Just to update you a little. Last night I worked on cleaning up the new cut in my foreward bulkhead and epoxy all raw edges. I also epoxied a spacer block in the bottom of the mast box so as to raise the mast an 1-1/4". Tonight I will probably re-set the stub. This weekend I told the wife that we will need to start the final coat of finishes.

Chad

[cs]

Okay I have the main up. I know it isn't set completly correct. Just got it up to check. It now clears the deck. Went to set the jib and like the main it is off, but unlike the main I can't make it work. The foot should be 76" and is actually 104", 28" too long. To make it work I would have to redo the bowsprit and add 28" to it. I will cut the jib and re-sew it.

Before mast adjustment.
http://a5.cpimg.com/image/35/7D/57714485-3f1c-0200017F-.jpg

After:
http://a3.cpimg.com/image/3F/BF/58153023-6892-0200017F-.jpg
http://a6.cpimg.com/image/42/C0/58153026-3b13-0200017F-.jpg

Chad

[Dave R]

Chad, that looks much nicer. You'll still have to duck and when the boat is in the water the boom will kind of point down toward the rear but it should get you on the water until you can another mainsail.

[cs]

Dave, I'm used to ducking when the boom comes across. Here is a shot of me & Charles Gresham in my SH-14. Noticie how low the boom is.

http://a7.cpimg.com/image/4F/3C/20286287-555a-028001E0-.jpg


Chad

[cs]

It was mentioned in another forum that the jib with the bigger foot is a "lapper" and works great in low winds. You have to set it up with jib sheets instead of a clubfoot. Any details or photos of said set up?

Chad

[John B]

Chad,Interesting term?I see where it comes from but Genoa is the usual name for an overlapping jib.
just tie on a block.. to the rail to suit the sheet lead.This is something that takes quite a bit of fiddling to get right so don't do anything permanent until you've sailed it in a variety of conditions.
You can estimate it on land by setting the sail on the boat in some wind and holding the sheet until the foot tension and leach tension is about the same . DO NOT close off the leach, thats the boatkiller. Another way of estimating the lead is to tension the sail up when its off the boat.
Tie the head to the porch and the tack to a tree and firm up. Then pull the sheet until you have it even. holding say three feet of the sheet you sight along it and put some removable tape on the clew on that line. That lead will give you a starter position but it will need to be adjusted probably back on the rail.So don't make it permanent.

[Joe ( Cold Spring on Hudson )]

Hey chad don't feel so bad I finally figured out the proper position for the Gaff on Tidbit.

When Steven was out sailing with me he mentioned how the gaff saddle was not sitting on the spot on the mast designed for the saddle. I said yea I know I cant get the main to go up any more. We figured out if we loosened the sail where it is attached to the top of the Gaff the whole sail will slide down and you can raise the gaff saddle to where is is supposed to go.

http://www.imagestation.com/picture/sraid207/p2866e9ad021678adf1949a7db9c3f1d7/eeb49e23.jpg

Then I peak the gaff and the sail is set perfectly

http://www.imagestation.com/picture/sraid207/pcf80214917ca2975aa8324f0cc40cc59/eeb49dcc.jpg

I just figured it out today and I launched April 1 :o :o :o

[John B]

I had to rush off to the boys soccer...then fit an exhaust system clear the garage and cut up some wood.....
Further to the jib lead.. if you have a short tack lanyard... 6 inches perhaps adjustable, you can also shift the sail up and down to trim to the actual sheet lead( block) on the rail, so that gives you a bit more adjustment.

[cs]

Over at Frank Hagen's site, they said to put the blocks at the rear shrouds. I did that and by the time I put a figure eight knot in the jib sheet it had just enough room to work out perfect. I will need to put a horn cleat on each side of the cockpit to cleat off the sheet. I know a jam cleat would be better, but I already have horns cleats and there is not a West Marine where I can just go in and buy what I want.

Chad

[geeman]

CHAD, your having some problems with the final setup,but take heart,you DO have a WOODEN boat sitting in your driveway.Every time I go out and look at mine,its still glass.Your WAY ahead of me!.And you built a beaut.