Raised boom affecting mainsail shape?

[abiehl]

First of all I wanted to say thanks to everyone on the macgregorsailors.com forums for being so helpful! I'm a complete beginner, and have learned so much from these threads. Hopefully someday I'll know enough to be able to contribute, rather than just pick people's brains

I've had a 1994 Mac 26S for a month and a half now, and have taken it out 5 or 6 times. I've noticed that there is something very wrong with the shape of my mainsail - it is way way too slack. At first I thought it might be because I wasn't raising the sail high enough - maybe there was some sort of obstruction in the track that the sail slugs run in that was preventing me from raising the mast all the way. However, I checked for this the next time I set up the boat, and it wasn't the case. I also suspect that the age of my mainsail (original) is a factor in how slack it is (stretched out over time). Still, the sail seems to be way too slack for age to be the only factor. I realized the other day from looking at the mast that the previous owner had raised the boom in order to accommodate the bimini (picture attached). I have noticed from forum searches that others have raised their mast to accommodate a bimini. When you do so, do you also have to trim your sail size? I would think that that would be very undesirable, because it reduces the amount of wind you can catch... Am I missing something? Is there something else I can do to fix this problem? If I really have found the problem, I am considering moving the boom back down to it's original location, and cutting down the size of the bimini (a solution to the boom/bimini interference problem that I have seen others use).

I am going sailing on Monday, and will take and post pictures of my mainsail.

Thanks for the help!

[Nautek]

Abiehl

Do you mean you are not getting tension up the mast or do you mean the sail is baggy?
If the boom has been raised then you may need to reduce the foot of the main by the amount that the boom has been raised. This may be cheaper than altering the bimini
Check to see if you can raise the halyard block up the mast to compensate

If it is baggy then make sure you have slack in the topping lift

A better photo will help

Allan

[abiehl]

Sorry to be unclear, I meant that the sail is baggy. Is the halyard block just the hardware at the top of the mast that stops the mainsail from going any further up? It looks like it is just a pop rivet. I think I could probably replace it with another one an inch or two higher. But I don't think it will even come close to getting all of the "bagginess" out of the sail. If cutting the sail is my only option, I would probably prefer to just lower the boom back down. But it's definitely something I'll have to think through. I'll post pics after my sail on Monday. Thanks for the quick feedback!

[bscott]

If you hoist the main and there are no wrinkles in the luff then the main is fully raised. Chances are you're not fully raise AND your sail is blown (excessive draft) out. OEM sails have a poor reputation for longevity. It is relatively inexpensive to cut/sew the foot of the sail but if it is blown out you'll
be waisting your boat bucks.

Bob

[abiehl]

So I didn't end up getting any pics during my sail on Monday. But I noticed for sure this time that there are wrinkles in the luff when the mast is fully raised. I do not use the bimini frequently, so I would not be very concerned that lowering the mast would make it impossible to sail and use the bimini at the same time (and that is if I am not able to modify the bimini by cutting down the "legs" a bit).

As a new sailor, I am concerned most with getting my boat in decent "sailing shape" first - I'm fine with worrying about what I would consider peripheral stuff later.

Has anyone else changed the height of their boom before? To me it doesn't seem like it would be difficult. As the picture I attached in the first post shows, the holes from the boom's original position have not been filled, so I only need to drill out the 4 rivets, and re-rivet the plate that the boom attaches to. Is it that simple?

[bscott]

So I didn't end up getting any pics during my sail on Monday. But I noticed for sure this time that there are wrinkles in the luff when the mast is fully raised. I do not use the bimini frequently, so I would not be very concerned that lowering the mast would make it impossible to sail and use the bimini at the same time (and that is if I am not able to modify the bimini by cutting down the "legs" a bit).

As a new sailor, I am concerned most with getting my boat in decent "sailing shape" first - I'm fine with worrying about what I would consider peripheral stuff later.

Has anyone else changed the height of their boom before? To me it doesn't seem like it would be difficult. As the picture I attached in the first post shows, the holes from the boom's original position have not been filled, so I only need to drill out the 4 rivets, and re-rivet the plate that the boom attaches to. Is it that simple?

Drill an GO

Bob

[Terry]

When you raise the sail at the start do you loosen off the vang and mainsheet?? Sometimes beginners do not loosen these off so they do not get the mainsail pulled all the way to the top and therefore get a tight leech but loose luff. To get both tight you must let off the mainsheet and boomvang so that the main luff will pull tight down at the tack. Go back and try it again and I bet you will have a tight mainsail.

[ualpow]

To get both tight you must let off the mainsheet and boomvang so that the main luff will pull tight down at the tack.

I forgot to loosen vang once and spent more than a few minutes trying to figure out why my main wouldn't go all the way up.