Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 14-10-2016, 17:34   #16
F10
Registered User

Join Date: Feb 2016
Location: Hawaii
Boat: S&S 34
Posts: 68
Re: Mast Bent While On The Hard

Quote:
Originally Posted by bsurvey View Post
if you rub your hands over the bent area do you feel any bulging or wow of the side wall? if so its probably shot.
There are no bulges any where. The bend is along the entire length, like a bow (as in bow and arrow). I can get rid of the bow by pushing (about 30 lbs force) in the middle of the mast. Also the bend is on the weak axis of the mast (port to starboard direction).
__________________

__________________
F10 is offline   Reply With Quote
Old 14-10-2016, 17:39   #17
F10
Registered User

Join Date: Feb 2016
Location: Hawaii
Boat: S&S 34
Posts: 68
Re: Mast Bent While On The Hard

Quote:
Originally Posted by neilpride View Post
One lower is going to be out of tune probably because that side need to compensate those 2 inches, in a single spreader mast maybe no problem , in a double or triple set of spreaders you can never reach a proper mast tune ...
Mine is just single spreader. What I am wondering is what caused the bend to begin with, seems the mast just creeped due to maybe heat effects of the sun. I am hoping once I tune the rig, over time the mast will creep back to its straight position again and would stay that way even if it were to be taken off the boat. Seeing it will take only 30 lbs horizontal force to correct the bend, should not be too much difference in the tuning tension on the wires as the lowers will be set between 800 and 1000 lbs.
__________________

__________________
F10 is offline   Reply With Quote
Old 14-10-2016, 18:28   #18
Registered User

Join Date: Oct 2016
Posts: 47
Re: Mast Bent While On The Hard

Sounds to me like Masts need truss rods, like guitar necks...
__________________
n13L5 is offline   Reply With Quote
Old 14-10-2016, 18:34   #19
cat herder, extreme blacksheep
 
zeehag's Avatar

Cruisers Forum Supporter

Join Date: Jul 2008
Location: furycame alley , tropics, mexico for now
Boat: 1976 FORMOSA yankee clipper 41
Posts: 16,639
Images: 56
Send a message via Yahoo to zeehag Send a message via Skype™ to zeehag
Re: Mast Bent While On The Hard

my yacht builder friend used to turn the mast over and support it in a different manner to straighten em out.
OR you can buy a new one for about 15000 usd, new.
your choice.
hanks masts that he turned over did not subsequently have any issues.
zeehag is offline   Reply With Quote
Old 15-10-2016, 06:51   #20
Registered User
 
neilpride's Avatar

Join Date: Jul 2009
Location: in the world
Boat: csy 44 tall rig.
Posts: 2,745
Re: Mast Bent While On The Hard

Quote:
Originally Posted by F10 View Post
Mine is just single spreader. What I am wondering is what caused the bend to begin with, seems the mast just creeped due to maybe heat effects of the sun. I am hoping once I tune the rig, over time the mast will creep back to its straight position again and would stay that way even if it were to be taken off the boat. Seeing it will take only 30 lbs horizontal force to correct the bend, should not be too much difference in the tuning tension on the wires as the lowers will be set between 800 and 1000 lbs.
Can you post a picture ? a bend mast is a bend mast, i mean there is no way back to OEM extrusion shape, 6061 alu grades are heat friendly but there is no way to straight the mast again to the original shape , saying that if you are sure there is no hard spots or kink spots it could be ok if the 50% of the bend lenght is at the spreaders lowers point, just check by the mast mainsail track when you finish the rigging tune if is straight,, i told you a example, some time ago a couple come to our dock by a rigging inspection , 2 spreader tall mast, all fine excpet for a spagueti form in the spar, several attempts in the d1 and d2, uppers lowers and no way to put the mast in column, after all we loose all and found the mast bent between the 1 set and and 2.

Yours could be fine if the bend spot is at the Lowers tangs, why is bend and why happen is a mystery for me, we have a sparcraft and selden bulletin to how store masts in the racks, we know by experience that masts need to be keep as straight as posible when they are stored or working on it, is not a big deal tow a long mast in the dolly for a while with a hig bend compared to store a mast with a huge bend for a long time.
Could be a manufacture defect and you notice it now?
Could be heat and long term storage?
Could be out of tune for long time?
Could be the yard throw someting or leave a heavy object in the mast?
No idea.
__________________
neilpride is offline   Reply With Quote
Old 15-10-2016, 07:50   #21
Moderator
 
HappyMdRSailor's Avatar

Cruisers Forum Supporter

Join Date: May 2008
Location: North Mississippi
Boat: 48 Wauquiez Pilot Saloon-C22 Chrysler Sunpiper- 19 Potter-Preparing to cruise w/my girl
Posts: 5,969
Re: Mast Bent While On The Hard

Just out of curiosity, where are your spreaders in relation to the maximum deflection???

Just an FYI

Running a quick calc on bending moment for your Rolly stick T11A, I get nearly 1/2 the yield strength stress in the middle if only supported by the ends lying sideways... This is a bare stick without your stiffeners/holes/bolted shiznit... It wouldn't take much extra to bend it! Like bird/paintbrush/mosquito...

I kid...

WAG is you're going to be fine tuning... but Neil is the spar guru here on CF...
I'd pay close attention to what he has to say...
__________________
In the harsh marine environment, something is always in need of repair...

Mai Tai's fix everything...
HappyMdRSailor is offline   Reply With Quote
Old 15-10-2016, 09:35   #22
Registered User
 
neilpride's Avatar

Join Date: Jul 2009
Location: in the world
Boat: csy 44 tall rig.
Posts: 2,745
Re: Mast Bent While On The Hard

Thank you happy, and just to end my little help here maybe, F10 , could be the bend a visual cheat?? I mean are you try to put the mast in a perfect flat surface and see if the mast retain the shape?
__________________
neilpride is offline   Reply With Quote
Old 17-10-2016, 12:20   #23
F10
Registered User

Join Date: Feb 2016
Location: Hawaii
Boat: S&S 34
Posts: 68
Re: Mast Bent While On The Hard

If all goes well, should be stepping the mast in a week. Yesterday I took a piece of weed wacker plastic line (that I can tension very tight) and stretched it from the mast base to the mast tip. The bend is constant along the entire length of the mast. At the mid point of the mast the deflection of the mast from the taught line is 1 inch. This 1 inch is located approximately at the spreaders which are close to the mid point of the mast (this is single spreader rig). This bend might have been there when I started the work a year ago, maybe I missed it. Applying about 30 lbs of force at the bend, and with the mast supported only at the ends, the mast will be straight, but will spring back when force is removed. Note the bend is in the weak direction, port to starboard. The bow to stern direction the mast is perfectly straight.

So if a mast is stored incorrectly, does it then creep and can get bent? I understand aluminum has no fatigue limit, is this a factor? Note I did a complete inspection of the mast and I see no bulges, dents or bends, no cracking, and very minor corrosion where some fittings were attached to the mast. All corrosion was sanded down and primed zinc chromate and then painted. The mast has been at my house and I helped take down and transport the mast- never left my sight.
__________________
F10 is offline   Reply With Quote
Old 17-10-2016, 12:48   #24
Registered User
 
neilpride's Avatar

Join Date: Jul 2009
Location: in the world
Boat: csy 44 tall rig.
Posts: 2,745
Re: Mast Bent While On The Hard

Quote:
Originally Posted by F10 View Post
If all goes well, should be stepping the mast in a week. Yesterday I took a piece of weed wacker plastic line (that I can tension very tight) and stretched it from the mast base to the mast tip. The bend is constant along the entire length of the mast. At the mid point of the mast the deflection of the mast from the taught line is 1 inch. This 1 inch is located approximately at the spreaders which are close to the mid point of the mast (this is single spreader rig). This bend might have been there when I started the work a year ago, maybe I missed it. Applying about 30 lbs of force at the bend, and with the mast supported only at the ends, the mast will be straight, but will spring back when force is removed. Note the bend is in the weak direction, port to starboard. The bow to stern direction the mast is perfectly straight.

So if a mast is stored incorrectly, does it then creep and can get bent? I understand aluminum has no fatigue limit, is this a factor? Note I did a complete inspection of the mast and I see no bulges, dents or bends, no cracking, and very minor corrosion where some fittings were attached to the mast. All corrosion was sanded down and primed zinc chromate and then painted. The mast has been at my house and I helped take down and transport the mast- never left my sight.
Do you try to see if the bend is still there with the mast resting in the floor, because with the mast supported just by the 2 ends a bend is a normal thing, the mast flex ... quite normal if you just support the 2 ends...
__________________
neilpride is offline   Reply With Quote
Old 17-10-2016, 12:51   #25
Moderator
 
HappyMdRSailor's Avatar

Cruisers Forum Supporter

Join Date: May 2008
Location: North Mississippi
Boat: 48 Wauquiez Pilot Saloon-C22 Chrysler Sunpiper- 19 Potter-Preparing to cruise w/my girl
Posts: 5,969
Re: Mast Bent While On The Hard

Quote:
Originally Posted by F10 View Post
If all goes well, should be stepping the mast in a week. Yesterday I took a piece of weed wacker plastic line (that I can tension very tight) and stretched it from the mast base to the mast tip. The bend is constant along the entire length of the mast. At the mid point of the mast the deflection of the mast from the taught line is 1 inch. This 1 inch is located approximately at the spreaders which are close to the mid point of the mast (this is single spreader rig). This bend might have been there when I started the work a year ago, maybe I missed it. Applying about 30 lbs of force at the bend, and with the mast supported only at the ends, the mast will be straight, but will spring back when force is removed. Note the bend is in the weak direction, port to starboard. The bow to stern direction the mast is perfectly straight.

So if a mast is stored incorrectly, does it then creep and can get bent? I understand aluminum has no fatigue limit, is this a factor? Note I did a complete inspection of the mast and I see no bulges, dents or bends, no cracking, and very minor corrosion where some fittings were attached to the mast. All corrosion was sanded down and primed zinc chromate and then painted. The mast has been at my house and I helped take down and transport the mast- never left my sight.
This all sounds like good news to me! Well... better news anyway... UNBENT is good news!

1" is far better than 2", AND max deflection is at the spreaders... I'm betting that you won't even have to tune it out... Meaning I'm guessing it will disappear under even shroud tension... I am HOWEVER... Not a professional RIGGER

According to Neil previously, creep can happen to improperly supported sticks... and YES, Aluminum DOES have a fatigue limit, as does just about everything...

The attached says 14ksi, albeit 50 million cycles of +/- 14ksi, but that's what it is... My prior quick calculation was that lying on it's side supported at the ends, the center saw 14.27ksi, but no way did it cycle +/- that... let alone 50M times...

Party on...
Attached Thumbnails
Click image for larger version

Name:	6061-T6 Fatigue Limit.jpg
Views:	33
Size:	127.2 KB
ID:	133029  
__________________
In the harsh marine environment, something is always in need of repair...

Mai Tai's fix everything...
HappyMdRSailor is offline   Reply With Quote
Old 17-10-2016, 12:53   #26
Registered User
 
neilpride's Avatar

Join Date: Jul 2009
Location: in the world
Boat: csy 44 tall rig.
Posts: 2,745
Re: Mast Bent While On The Hard

Yeah , so if you loose the side rigging like uppers and lowers and leave the forestay and backstay tensioned the mast bend , and if they are really tight the bend is insane , I guess you know what I'm trying to say, check with the mast all along well rested in a flat surface and maybe you found a surprise...
__________________
neilpride is offline   Reply With Quote
Old 17-10-2016, 13:08   #27
Moderator
 
HappyMdRSailor's Avatar

Cruisers Forum Supporter

Join Date: May 2008
Location: North Mississippi
Boat: 48 Wauquiez Pilot Saloon-C22 Chrysler Sunpiper- 19 Potter-Preparing to cruise w/my girl
Posts: 5,969
Re: Mast Bent While On The Hard

Another option is to store it for a year bow side up and see if you luck out in 10/17...

(sorry... that's not even funny as I type it)


maybe a little...
__________________
In the harsh marine environment, something is always in need of repair...

Mai Tai's fix everything...
HappyMdRSailor is offline   Reply With Quote
Old 17-10-2016, 14:10   #28
F10
Registered User

Join Date: Feb 2016
Location: Hawaii
Boat: S&S 34
Posts: 68
Re: Mast Bent While On The Hard

Quote:
Originally Posted by neilpride View Post
Do you try to see if the bend is still there with the mast resting in the floor, because with the mast supported just by the 2 ends a bend is a normal thing, the mast flex ... quite normal if you just support the 2 ends...
If I support the mast at two ends with the mast oriented in the strong direction (like a "I" beam) the mast will be straight in the vertical direction (no bow in the vertical direction), however it will be bowed in the horizontal direction. If I support the mast at two ends in the "weak" direction, even orienting so the "bow" is up the bow will still exist. If I now put about 30 lbs force in the middle of the mast (still supported at the ends in the "weak" direction with the bow up), the bow will disappear, but reappear when the 30 lb force is removed.
__________________
F10 is offline   Reply With Quote
Old 17-10-2016, 14:21   #29
Registered User
 
neilpride's Avatar

Join Date: Jul 2009
Location: in the world
Boat: csy 44 tall rig.
Posts: 2,745
Re: Mast Bent While On The Hard

Quote:
Originally Posted by F10 View Post
If I support the mast at two ends with the mast oriented in the strong direction (like a "I" beam) the mast will be straight in the vertical direction, however it will be bowed in the horizontal direction. If I support the mast at two ends in the "weak" direction, even orienting so the "bow" is up the bow will still exist. If I now put about 30 lbs force in the middle of the mast (still supported at the ends in the "weak" direction with the bow up), the bow will disappear, but reappear when the 30 lb force is removed.
What I'm trying to say is that if you support the mast at the 2 ends make no diference if you want to see if is bend or not, if tomorrow I get a spar and support it by the 2 ends probably I'm going to see one side wobbling...
its 40 ft long, I doubt you can see anything straight 40 ft long supported by the 2 ends.. because you are facing the mast in the supports in the strong direction, the flexing need to go somewhere , usually at the weak sides..thats why I suggest put the spar at the floor free of loads and tension and see if is bend or not, to be sure...
__________________
neilpride is offline   Reply With Quote
Old 17-10-2016, 14:41   #30
F10
Registered User

Join Date: Feb 2016
Location: Hawaii
Boat: S&S 34
Posts: 68
Re: Mast Bent While On The Hard

Quote:
Originally Posted by neilpride View Post
What I'm trying to say is that if you support the mast at the 2 ends make no diference if you want to see if is bend or not, if tomorrow I get a spar and support it by the 2 ends probably I'm going to see one side wobbling...
its 40 ft long, I doubt you can see anything straight 40 ft long supported by the 2 ends.. because you are facing the mast in the supports in the strong direction, the flexing need to go somewhere , usually at the weak sides..thats why I suggest put the spar at the floor free of loads and tension and see if is bend or not, to be sure...
To test for bending, I am taking a 40 foot long, thin weed wacker plastic line and tensioning it to 50 lbs. I can position this line along all sides to the mast to test for bending. In the strong direction the mast has no bend. In the weak direction it has the 1 inch bow bend in the middle. Makes no difference how the mast is rotated or how it is supported the 1 inch bend is always there. The bend is there no matter if the mast is supported at the two ends or supported equally every 10 feet, the bend is still present. The mast weighs about 200 lbs. I can pick up one end and rotate it (other end supported on the ground) and the bend is always present and in the same location.
__________________

__________________
F10 is offline   Reply With Quote
Reply

Tags
mast, on the hard

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Bent Mast Repair Fiveslide Deck hardware: Rigging, Sails & Hoisting 65 11-05-2016 17:30
Going up the mast while on the hard? marlinmike Construction, Maintenance & Refit 8 11-03-2014 06:41
Would You Worry About a Bent Mast ? Ocean Roads Deck hardware: Rigging, Sails & Hoisting 55 15-10-2010 13:18
Bent mast. TOM Deck hardware: Rigging, Sails & Hoisting 10 10-12-2008 16:27
mast slightly bent bobs Deck hardware: Rigging, Sails & Hoisting 9 05-07-2008 21:56


Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 21:42.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.