Page 1 of 2

Bow in Mast.

Posted: Wed Apr 29, 2020 11:45 am
by adudinsk
Just wondering,.. I was working on the mast of my 2007 26M, and noticed a bow to it from top to bottom
I have read that this is not uncommon, and you gan tension the rigging... others say to bend it gently and straighten it out.
It appears to be from the base to the spreaders, about 1-2" out.

Will tweaking the rigging help? Should I put it on saw horses and gently flex the bend out?
I did not notice it when the mast was up when I bought the boat. (p.s. Its the 5" mast.. and no foam in it at all.)
Have watched many online videos of straightening the mast... only pain will be removing the rigging,.. and taking it all apart.

Comments/Suggestions?


Thanks
AD

Re: Bow in Mast.

Posted: Thu Apr 30, 2020 1:49 am
by neleus
I have just bought a 2007 26M and have absolutely no experience with the boat or mast tuning. However, I notice the manual that came with the boat has something to say - quoting from the manual:

"Ideally, the mast should have about a 1" bow. In other words, the centre of the mast should be about 1" forward of a straight line drawn from the top of the mast to the base of the mast. The downwind wires will be somewhat slack when sailing hard. When sailing into the wind, the mainsail takes over the task of supporting the mast from the rear."

Coincidentally, my sail maker has just asked me whether I can get a 100mm (4") bend into the mast to accommodate my elderly mainsail. So I am interested to see responses to your question from those with more experience.

Cheers,
Richard

Re: Bow in Mast.

Posted: Fri May 01, 2020 12:18 am
by adudinsk
my bow is side to side.. bows to stern .. from base to spreaders.. a few inches

Re: Bow in Mast.

Posted: Fri May 01, 2020 12:20 am
by adudinsk
I have talked to other non-macgregor sailors, and the did say that tuning can remove a bow.. or create one.
will have to raise the mast (a newbie too .. like yourself) and see what the tension is on all the rigging.

Re: Bow in Mast.

Posted: Fri May 01, 2020 5:01 am
by Tomfoolery
adudinsk wrote: Fri May 01, 2020 12:18 am my bow is side to side.. bows to stern .. from base to spreaders.. a few inches
You lost me. Bows to stern, or bows to starboard or port?

Re: Bow in Mast.

Posted: Fri May 01, 2020 5:49 am
by Jimmyt
Corkscrew? :D

Re: Bow in Mast.

Posted: Fri May 01, 2020 6:07 am
by adudinsk
That would work.. but need a big wine bottle then...

LOL

Re: Bow in Mast.

Posted: Fri May 01, 2020 6:12 am
by Russ
Mine, when turned sideways will bow with the weight if not supported in the center. I have a block of wood that I stick on the mast step to support it in the center.

My mast wants to rotate and likes to turn sideways where it has less resistance to bowing.
One winter the woodblock popped out and it rotated on its side. The tarp was heavy loaded with snow. and the mast bent touching the deck.
When I saw it my thought was "I'm buying a new mast".
After removing the snow/tarp and rotating it, the mast straightened right out.

I would raise your mast and re-evaluate. It might sort itself out once verticle.

Re: Bow in Mast.

Posted: Fri May 01, 2020 9:16 am
by BOAT
If the mast is bent sideways it sounds like a damage from an accident. Most likely a baby stay malfunction during a mast raising process went awry at some time in the past life of the boat. How does the mast tabernacle look? Any signs of repair to bending or rebending or a replacement?

Re: Bow in Mast.

Posted: Fri May 01, 2020 2:15 pm
by adudinsk
No signs of repair.. heating.. welding..bending..etc.

Maybe the rigging popped?

I will gently try to flex it back, as per a pile of YouTube videos.. and then good enough.
Its a 5" mast.. the wider ones.. so cannot get that.. would have to change over to the smaller diameter mast..
I am sure it will be fine for the lazy sailing I will do.
(going to put my $$ into an Axiom 7 multi-function display first)
(Mwahahahah... evil laugh...)

AD

Re: Bow in Mast.

Posted: Fri May 01, 2020 2:38 pm
by BOAT
When the mast is up see if you can tell where the bend is:

Stand behind the boat and look at the mast - if the bend is above the forestay I would consider trying to fix it.

If the bend is below the forestay Tom might know which side stay to crank on to straighten it out. I suspect he will want to know how close the bend is to the lower stay connection on the mast. The lower stay can put an S curve into the mast if it's set improperly, thus maybe it can make a curved mast straight too?

Tom might know - he knows a lot about bending metals and pressure and math stuff.

I have read posts here on the site of people that have added sections and put splices in their masts. The MAC19 had a two piece mast. It seems like an easy and reasonable solution.

Re: Bow in Mast.

Posted: Fri May 01, 2020 4:41 pm
by adudinsk
Thanks for the advice will do..

Re: Bow in Mast.

Posted: Fri May 01, 2020 9:41 pm
by neleus
Sorry, typical newbie, didn't read the initial post thoroughly enough. :(

Re: Bow in Mast.

Posted: Sat May 02, 2020 3:40 am
by NiceAft
I have a question for adudinsk. What does this mean?
(p.s. Its the 5" mast.. and no foam in it at all.)
I am not aware of the :macm: having a mast without foam. Did you remove the foam :?: Is this the mast from an :macx: :?:

Re: Bow in Mast.

Posted: Sat May 02, 2020 12:08 pm
by adudinsk
Nope. did not remove foam.
Changed the bearing.. looked up it.. no foam for a few feet (until darkness.. anyway).

A Hard Vang was added.. (big $$ upgrade) to add that a good section of foam would HAVE to be removed for the tracking..

The bend is right starting at the spreaders.. and a light curve from there to the base.
Bet It will straighten up easy... leaned on it.. while on the mast holder.. and it did straighten a bit.. will see what she looks like with the rigging up.
(fingers crossed...)

AD