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Has anyone converted to a one piece mast?
http://www.hobie.com/forums/viewtopic.php?f=69&t=40619
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Author:  tonystott [ Wed Feb 22, 2012 5:12 pm ]
Post subject:  Re: Has anyone converted to a one piece mast?

I tend to oversimplify things, but couldn't you just insert the strengthened epoxy into the joint and then stand the mast vertically to eliminate any side forces?

Author:  kayakman7 [ Thu Feb 23, 2012 9:06 am ]
Post subject:  Re: Has anyone converted to a one piece mast?

reconlon wrote:
J,

Did you just glue the two sections together, or did you also fill in the center to strengthen and reduce flex?

Did it add much additional weight?


I only glued the two sections together, (imho) decreasing flexiblity would remove a major safety component of the boat.

tonystott wrote:
I tend to oversimplify things, but couldn't you just insert the strengthened epoxy into the joint and then stand the mast vertically to eliminate any side forces?


yes that would likely have worked but i wouldn't have been sure the it was straight. since i have the levels, it seemed logical to use them.

i should have some results this weekend and i'll report how it works out.

j

Author:  KayakingBob [ Thu Feb 23, 2012 10:35 am ]
Post subject:  Re: Has anyone converted to a one piece mast?

The reason I was asking if you reduced the flex in your mast is that I think that is most of the problem with my TI in winds above 15mph. With my AI's, I can reef the sails even in 30mph winds at all points of sail by just releasing some sheetline and then reefing in (or or out). On my TI, I cannot reef except when in irons above about 15mph winds, even with the 3 to 1 setup. My mast flexes too much causing difficulties with reefing, sometimes even when strait upwind! Having to turn into the wind for every minor adjustment in reefing compared to the AI is not good (IMO).

Author:  kayakman7 [ Thu Feb 23, 2012 1:34 pm ]
Post subject:  Re: Has anyone converted to a one piece mast?

reconlon wrote:
The reason I was asking if you reduced the flex in your mast is that I think that is most of the problem with my TI in winds above 15mph. With my AI's, I can reef the sails even in 30mph winds at all points of sail by just releasing some sheetline and then reefing in (or or out). On my TI, I cannot reef except when in irons above about 15mph winds, even with the 3 to 1 setup. My mast flexes too much causing difficulties with reefing, sometimes even when strait upwind! Having to turn into the wind for every minor adjustment in reefing compared to the AI is not good (IMO).



i had a lot of trouble with furling before i did this:
kayakman7 wrote:
Joker wrote:
How do we rig an easier purchase for the furling line, such as 2 to 1? Joker


Hi Joker,

it's almost impossible to rig the furling line for 2:1. There is just not enough length to accommodate the extra line you would have to gain the mechanical advantage. 2:1 will double the amount of line necessary.

I used some cheek blocks to improve the direction of pull, reduce friction loses when furling, and i actually moved the line to the rear seat.

See my post:
kayakman7 wrote:
My front seater isn't quite strong enough to furl in heavy weather, so I added three cheek blocks, a new harken cam cleat, and a longer furling line. I also replaced the sheet with a higher quality line and found it runs much smoother, which was a problem since I switched to 3:1.
See pics...

Image

Image

Cheers,

J



adding just the "front and center" cheek block will make furling easier because you are pulling the line directly, not wearing onthe eyelet guide mounted on the cam cleat. however, be sure to locate the cheek block to optimize the direction of pull for you use.

cheers,

j


the higher quality line seems to help almost as much as the additional pulleys.

if you wanted to keep the furling control in the forward cockpit, i would add just a single cheek block. that reduces a lot of friction and reduces the chances of the furling line getting under the furling drum.

i'm able to furl under all conditions now, just releasing the sheet slightly. i hope the one piece mast should help too.

j

Author:  kayakman7 [ Thu Aug 02, 2012 4:47 am ]
Post subject:  Re: Has anyone converted to a one piece mast?

So I recently found out why I was having issues with the mast top and bottom sections spinning. It actually was not the joint between the two sections, it was the mast topper.
Image

So I will sand, clean, and epoxy it back together. I wonder when my furling drum will separate. What a pain in the @$$!

cheers?

j

Author:  Tom Kirkman [ Thu Aug 02, 2012 6:46 am ]
Post subject:  Re: Has anyone converted to a one piece mast?

1. Clean (alcohol)

2. Sand (degloss with grey Scotchbrite or 600 grit wet/dry paper)

3. Epoxy

This is the correct procedure for obtaining a "water-break-free" surface before epoxying. Although you may not require all that it offers, it is the optimum condition for obtaining the greatest bond strength possible.

http://www.rodbuilding.org/library/waterfree.html

Author:  kayakman7 [ Thu Aug 02, 2012 5:34 pm ]
Post subject:  Re: Has anyone converted to a one piece mast?

Thanks Tom,

I had already finished the glue up when I saw your post. I learned a few things from that article: like using scotchbrite over sandpaper and which solvents are best. I thank you, the info should be helpful in future glue ups.

Should be bombproof in 24 hours!

cheers!

j

Author:  sun E sailor [ Fri Aug 03, 2012 8:02 am ]
Post subject:  Re: Has anyone converted to a one piece mast?

kayakman7 wrote:
.....
So, now I'm thinking of epoxying them together w west systems epoxy. Will this void my warranty? Is there any other reason why I shouldn't? Only thing I can think of is if the mast broke, I would only have to replace half...
J

A mast for the TI in the Hobie Catalogue is listed as: Pt.# 88991121 MAST-TDM ISLAND 550CM $716.00. At that price I assume (like the akas) that it is not sold separately.

J. I'd be curious to hear how yours is holding up, now that you've epoxied it together.

These other conversations about the sail spinning or twisting so that it doesn't completely furl is most interesting. I found this was happening to my sail a while ago as well, quite often in fact and so much so, there was a dark stain on my sail right where the mast joined :x. At the time I just didn't understand what was causing it or how to fix it.

When I installed my new crossbar I re-epoxied my Furler Drum to the mast because it was no longer staying fixed to the mast. I also wanted to line up the plastic loop on the Furler Drum (that the down haul line goes through) so that it was in line with the sail's web loop at the top of the sail where the web folds into the Mast Top.

By doing this, the unfurled sail would then be straight to the mast. I too duct taped my mast together and it has stayed put ever since :).
I've also noticed that my sail unfurls much easier now than it did before.

J. Thanks though for pointing out that the Mast Top could also be the culprit in terms of allowing the sail to twist. I'll have to check mine :wink: .

Author:  Tom Kirkman [ Fri Aug 03, 2012 9:15 am ]
Post subject:  Re: Has anyone converted to a one piece mast?

By the way, that article was written by one of the people who helped Boeing develop their epoxy systems in the 1950's. The guy is in his late 80's now but still involved in the adhesives formulation field.

Author:  NOHUHU [ Fri Aug 03, 2012 3:09 pm ]
Post subject:  Re: Has anyone converted to a one piece mast?

It is supposed to twist. Hobie ships it this way.

Author:  kayakman7 [ Fri Aug 03, 2012 4:18 pm ]
Post subject:  Re: Has anyone converted to a one piece mast?

NOHUHU wrote:
It is supposed to twist. Hobie ships it this way.


please explain.

Author:  NOHUHU [ Fri Aug 03, 2012 8:29 pm ]
Post subject:  Re: Has anyone converted to a one piece mast?

These tips are not glued from the factory and so not intended to be. On a stock, mounted sail, you can probably twist the end cap 15-20º in either direction by hand.

From what I can tell this allows a slight luff rotation at the top and helps create a better sail contour and possibly a smoother reefing pattern.

On the boats where the tip is epoxied, I have been seeing a noticeable deformity or wrinkles near the upper batten. It's most obvious on the TI's and when slightly reefed/sailing close to the wind.

I have gone through a couple new sails on my AI and never glued this joint and have never been told too, so I don't know where the concept came from that it's supposed to be a fixed/bonded connection. Unless you are bracing it for a jib, of course.

Is there Hobie documentation out there that recommends this end cap be bonded in place?

Author:  kayakman7 [ Fri Aug 03, 2012 9:14 pm ]
Post subject:  Re: Has anyone converted to a one piece mast?

NOHUHU wrote:
These tips are not glued from the factory and so not intended to be. On a stock, mounted sail, you can probably twist the end cap 15-20º in either direction by hand.

From what I can tell this allows a slight luff rotation at the top and helps create a better sail contour and possibly a smoother reefing pattern.

On the boats where the tip is epoxied, I have been seeing a noticeable deformity or wrinkles near the upper batten. It's most obvious on the TI's and when slightly reefed/sailing close to the wind.

I have gone through a couple new sails on my AI and never glued this joint and have never been told too, so I don't know where the concept came from that it's supposed to be a fixed/bonded connection. Unless you are bracing it for a jib, of course.

Is there Hobie documentation out there that recommends this end cap be bonded in place?


other than the hardened epoxy which that I cleaned off the tip and which had clearly failed to bond to the mast, no, there seems to be very little documentation about the specifics on anything on the boat. for instance, torque specs for the x-bars? no one knows. i can say that the epoxy bond failed because there was absolutely no sanding or surface prep done before the mast tip was inserted. the epoxy broke cleanly off the mast tip and off the mast. i assume it should be glued because it left the factory glued!?!

i would disagree with the assumption that it shouldn't be glued for another reason: the mast tip and the downhaul are the only reasons you can furl the sail. if the mast tip spins, then quite a few sailors wouldn't be able to furl, since quite a few sailors don't have the downhaul installed. mine didn't have one and the dealer set mine up, i had figure it out on my own. the dealer actually said not to use it, but i could if i wanted to when i asked about it later.

also, recall how many furling drums have failed, perhaps the same thing has happened to the mast tips? i tried to spin the tip before gluing the mast together and couldn't. i had to remove the sail and really grab the tip before it spun easily. i am confident that the mast tip has been spinning all along and i needn't have glued the mast together.

when the downhaul and mast tip work together, the sail furls neat as can be but when they are out of sync, i get folds and bunches of sail.

sun E sailor wrote:
I'd be curious to hear how yours is holding up, now that you've epoxied it together.

it's doing great, in fact, i can't tell the difference. i'm happy that i glued the mast together, i still haven't found a reason not to. i expect to find that the sail furls better and cleaner now the tip is secured. we shall see.

cheers,

j

Author:  kayakman7 [ Sun Aug 12, 2012 7:59 pm ]
Post subject:  Re: Has anyone converted to a one piece mast?

NOHUHU wrote:
Is there Hobie documentation out there that recommends this end cap be bonded in place?


quoting my dealer, "I would put a couple of spots of 2 part quick epoxy on the cap and put it back in the mast."

j

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