Return to Hobie.com
Hobie Forums
It is currently Fri Mar 29, 2024 4:10 am

All times are UTC - 8 hours [ DST ]




Post new topic Reply to topic  [ 14 posts ] 
Author Message
 Post subject: pylon shoe hull crack
PostPosted: Sat Apr 03, 2021 5:34 pm 
Offline
Site Rank - Deck Hand

Joined: Sat Apr 03, 2021 4:43 pm
Posts: 5
Looking for experienced advice before I cut a hole in my beloved, original owner, 1986 boat.

As I was getting her ready for sailing season, I noticed a 6 inch horizontal crack centered directly below the forward pylon on inner side of starboard hull about 4-5 inches up from the keel bottom. The crack is centered along a ridge that runs approx. 12-15 inches mostly ahead of the pylon post. This ridge is not visible, but a very slight pushed out deformation can be felt by moving a hand up and down from the keel to the deck. There is additional gelcoat crazing along the ridge, but no other cracks. A little forum research and the Hobie Hotline article from sept/oct 2009 indicates this may be a pylon shoe problem. However, the pylon itself does not feel loose (cannot move up/down or sideways with aggressive handling), there are no leaks around the pylon/deck seam or from the offending crack (used soap bubble hull pressure test), and there is no noticeable depression or gel coat crazing on the deck in front of or behind the pylon. The port hull has no visible issues. So....

1. Can this be a symptom of something else, e.g. old age, bad trailer tie down technique, freezing water in the hull, other? There are no soft spots anywhere on the deck or hull sides.
2. Is an inspection port the only way to confirm the diagnosis? What to look for and how? I read about a 'split shoe' as well as a detached shoe (from one or both hull sides).
3. Can pylon shoe repair be done through (1) 4" inspection port placed aft of the pylon (between the pylons to avoid weakening the foredeck)? How far aft should it be placed to still reach the entire repair area? Is a 6" inspection port better or worse? I am not sure how to get the materials, my arm, and a light to see what is going on to fix this through a 4 inch inspection port. Any special tools needed?
4. Has anyone tried to fix this by drilling holes through the hulls opposite the shoe location in an attempt to inject epoxy between the inner hull surface and the shoe, sort of like fixing a delaminated deck?
5. What is the risk of sailing her like this another season? Will it fail catastrophically, or just make a bigger and bigger crack, until it fails catastrophically (the boat gets sailed hard and usually carries too much weight).

Temporarily, I have sanded out and done a simple crack repair of the gelcoat. Planning to monitor for re-emergence of the crack.

Any and all sage advice appreciated. Thanks in advance!


Top
 Profile  
 
PostPosted: Mon Apr 05, 2021 10:47 am 
Offline
Site Admin

Joined: Tue May 27, 2003 12:44 pm
Posts: 15027
Location: Oceanside, California
Maybe this will help?

https://www.hobie.com/forums/viewtopic.php?f=20&t=44471

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)


Top
 Profile  
 
PostPosted: Mon Apr 05, 2021 2:17 pm 
Offline
Site Rank - Deck Hand

Joined: Sat Apr 03, 2021 4:43 pm
Posts: 5
Thanks for the quick response Matt. I reached out on that old post and have not received a response. Looks like the potential for a bad day and answers my question #5. Hoping to get feedback from someone that can confirm a successful repair and details on where to cut the inspection hole(s).


Top
 Profile  
 
PostPosted: Mon Apr 05, 2021 2:46 pm 
Offline
Site Admin

Joined: Tue May 27, 2003 12:44 pm
Posts: 15027
Location: Oceanside, California
Did you download the article mentioned on the repair?

http://www.w1dm.com/projects/HOTLINE/09-09-10%20HOTLINE.pdf#page=16

Something stuck with me from years ago. One of our designers who was also on the America's Cup effort in 1988... Told me that you can fix anything in fiberglass. It is just a balance between weight and cost.

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)


Top
 Profile  
 
PostPosted: Mon Apr 05, 2021 7:47 pm 
Offline
Site Rank - Captain

Joined: Sun Aug 12, 2018 10:49 am
Posts: 26
Check out a You Tube called, "Anatomy of a Hobie 16"
They use a sawzall to cut open a shot Hobie 16 hull.
You will get to see what your up against.
Good luck.

Greg 1984 H16 Tequila Sunrise


Top
 Profile  
 
PostPosted: Tue Apr 06, 2021 3:37 am 
Offline
Site Rank - Captain

Joined: Mon Jun 16, 2003 4:40 am
Posts: 88
What you are describing are the classical symptoms of a pylon shoe failure. The article cited outlines the repair process. If you fix it now the hull can be saved. If you wait a much bigger problem will be the result. Patching the exterior crack will not remedy this you have to fix it from inside. Lots of ways to get access but the easiest is to install a port kit behind the pylon. No specific location for the port kit but it needs to be close enough that you can actually put your arm in and reach the pylon shoe.

Keep in mind the curved port kits are no longer available so you have to use a flat one and you can search on this site for posts about making the flat port kit work. The work can be done without using a port kit but that requires more advanced fiberglass skills. Regardless you have to get inside to do the repair.

Take care of this now while it's a small problem. Left unrepaired the hull will fail catastrophically.


Top
 Profile  
 
PostPosted: Thu Apr 08, 2021 5:12 am 
Offline
Site Rank - Old Salt

Joined: Mon May 24, 2004 10:33 am
Posts: 686
Location: Clinton, Mississippi
My 2 cents...
It's very hard to confirm a loose shoe just handling the hulls with boat on trailer......much different story when everything's being forced back and forth under load on the water. FWIW....I've done this repair and can't imagine doing it through anything less than a 5" port (even bigger hole before port is actually installed) in FRONT of the pylon. I'm no expert, and I ain't sayin' it can't be done, but.....

_________________
Jerome Vaughan
Hobie 16


Top
 Profile  
 
PostPosted: Thu Apr 08, 2021 8:22 am 
Offline
Site Rank - Deck Hand

Joined: Sat Apr 03, 2021 4:43 pm
Posts: 5
Thanks everyone. Now I just need to decide if I will be adding the 5" port in forward or aft of the pylon. I read discussion about the potential for issues with a port in front of the pylon. My deck is solid, no soft spots. If the work area will be accessible from behind, i would prefer that.

I plan to remove a 1/2" or so of foam core around the rim of the cut and replace with reinforced epoxy to help prevent water intrusion into the deck and provide a solid bearing surface for the port through bolts.

Any recommendations on 3M 5200 vs silicone to bed and seal the port?


Top
 Profile  
 
PostPosted: Thu Apr 08, 2021 3:16 pm 
Offline
Site Rank - Deck Hand

Joined: Sun Sep 01, 2019 7:24 am
Posts: 6
I just added a port on my 18 and went with 3M 4200. It is an adhesive sealant but is not as permanent as 5200. I've always been told with 5200 that once it's on there it will never come off.

4200 was recommended to me by some folks at West Marine because it is technically an adhesive and not just a silicone, but it can be removed with a little bit of effort if you ever need to swap out the port for any reason or temporarily remove it for additional repairs.

Some people may disagree with me, but I try to avoid 5200 unless it's to glue the deck joint or something highly structural that you would never want to come apart.


Top
 Profile  
 
PostPosted: Thu Apr 08, 2021 5:28 pm 
Offline
Site Rank - Admiral

Joined: Wed Aug 08, 2007 10:20 pm
Posts: 295
Location: South Boardman, Mi
The work area is accessible from either side. The repair seems scary because there are many steps and you have to cut a hole in your boat. Thankfully the individual steps are easy and the end result is bomb proof. I repaired my 16 back in 2008 and it is still going strong.


Top
 Profile  
 
PostPosted: Sat May 01, 2021 8:02 pm 
Offline
Site Rank - Deck Hand

Joined: Sat Apr 03, 2021 4:43 pm
Posts: 5
Thanks again everyone. I cut 5 inch inspection ports behind both port and starboard pylons, about 7 inches back from the pylon. The problem is the starboard pylon shoe has cracked in half in a jagged line vertically from top to bottom. This crack is allowing the pylon shoe to push inboard at the bottom when applying weight on top of the pylon. I notice the crack will open and close approx 1/16 inch with approx. 1/16 inch separation at rest. The crack runs completely through the shoe and is visible on the front, back and top of the shoe. Both halves of the broken shoe are firmly attached to the sides of the hull.

My current plan is to fill the crack with thickened resin using a spatula to force the material into the crack. I am concerned that i won't be able to completely fill the gap through the entire depth of the shoe. I also plan to fill and level a normal manufacturing gap that exists between the pylon and the hole in the shoe that receives the pylon. After the crack and gap are filled, I will lay 2 layers of resin soaked glass across the crack on the front, back and top of the shoe. I may attempt to run a strip of glass under the shoe across the crack. Tabbed and wrapped similar to the Hobie article above.

Questions :

Is this repair appropriate for a cracked shoe situation?
What is the best way to fill the gap created by this crack in the shoe foam?
Is thickened epoxy the best crack filler appropriate or would low expansion construction foam be betterf?

I was able to visualize the front of the pylon shoe using 2 iphones and the facetime app. One phone in the boat to look around and the other used as an external monitor.

On a related note, i did take this opportunity to remove 85 pounds of water logged floatation foam from both hulls. I plan to replace the foam with pool noodles. I was surprised as i thought I was adequately draining the hulls after each sail. Does anyone know how many cubic feet of pool noodles are required to provide floatation?

Thanks!


Top
 Profile  
 
PostPosted: Sun May 02, 2021 6:05 pm 
Offline
Site Rank - Admiral

Joined: Wed Aug 08, 2007 10:20 pm
Posts: 295
Location: South Boardman, Mi
Polyester resin is the best repair material. Epoxy works but it doesn't bond to the original resin quite as well. Foam just mucks things up.

While it may seem wise to leave the damaged material and just patch over it the repair will be much stronger if you sand/cut away all damaged material. Generally speaking leaving a resin filled crack creates a stress concentration that can cause interlaminar cracks to form (repair delaminates). Specific to this repair the issues are worse. The crack you described is likely located just below the bottom edge of the foam core. Any patch you apply will rely on the strength of the fiberglass layer on the inside of the foam. This is a very thin layer of glass and it likely won't handle the loads. To get around this you will want to lay a patch on the outside as well. Unless you want a bulging scab you will want to sand down through the damaged material to make room for a flush repair.

TLDR: follow the hobie hotline and don't take shortcuts.


Top
 Profile  
 
PostPosted: Mon May 03, 2021 3:21 am 
Offline
Site Rank - Old Salt

Joined: Mon May 09, 2005 10:25 am
Posts: 4176
Location: Jersey Shore
speed633 wrote:
Polyester resin is the best repair material. Epoxy works but it doesn't bond to the original resin quite as well.


I would tend to disagree. For internal, structural repairs, epoxy is the preferred material IMO. It is stronger and less brittle than polyester and with proper surface prep, it will have no issues bonding to the existing fiberglass or foam. For external repairs that will need to be gelcoated, I would use polyester. But for a pylon shoe, that’s not the case.

Not sure if you have enough space to work with this inside the hull, but for gap/crack filling, I have found West Six10 epoxy to work well. It is a pre-thickened epoxy that comes in a caulk gun style tube with a self-mixing nozzle. Just pull the trigger to apply it where you want.

sm


Top
 Profile  
 
PostPosted: Tue May 04, 2021 12:33 am 
Offline
Site Rank - Deck Hand

Joined: Tue Mar 30, 2021 6:30 pm
Posts: 17
sail_indy wrote:
Thanks everyone. Now I just need to decide if I will be adding the 5" port in forward or aft of the pylon. I read discussion about the potential for issues with a port in front of the pylon. My deck is solid, no soft spots. If the work area will be accessible from behind, i would prefer that.

I plan to remove a 1/2" or so of foam core around the rim of the cut and replace with reinforced epoxy to help prevent water intrusion into the deck and provide a solid bearing surface for the port through bolts.

Any recommendations on 3M 5200 vs silicone to bed and seal the port?


Lots of opinions on the hull ports. I added contoured ports to my 16 (I think they were 6") so the boat could be "dried out" after races. Boat was A fleet raced for 4 years or so with lots of SF Bay, Monterey, Ocean etc and I never had an issue with the ports. Just install them correctly, seal the cut edges and all should be fine. My ports were installed just forward of the front pylon. Had ports in both of the 16's that I raced. Then again, the boat lived in a garage so didn't have the uv issues some have with the ports. I had both white ports and black ones....neither seemed better or worse. Both were the old contoured ports from the local Hobie dealer.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 14 posts ] 

All times are UTC - 8 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Jump to:  
© Hobie Cat Company. All rights reserved.
Powered by phpBB® Forum Software © phpBB Group