|
|
14-02-2017, 14:00
|
#1
|
Registered User
Join Date: Dec 2008
Location: Nr WINCHESTER IN UK
Boat: HUNTER LEGEND 456
Posts: 7
|
HUNTER 456 (2002) - PROBLEMS WITH HULL GLASS FIBRE DELAMINATING
A Recent survey of the yacht identified a reasonably large area of the topsides hull suffering from delamination of glass fibre layers and balsa core layers internally with no external visual evidence.
Water ingress appears to have been through defective deck to hull joint in way of aft master cabin both on port and starboard sides.
Has anyone experienced this rather serious form of osmosis and what is the best permanent cure? There is a school of thought that it is possible to drill small holes into the hull in way of and inject a 'liquid' epoxy to reinstate strength to the affected areas.
Any advice and or knowledge/experience would be appreciated.
|
|
|
14-02-2017, 14:35
|
#2
|
Registered User
Join Date: Sep 2014
Location: Fiji Airways/ Lake Ontario
Boat: Legend 37.5, 1968 Alcort Sunfish, Avon 310
Posts: 2,750
|
Re: HUNTER 456 (2002) - PROBLEMS WITH HULL GLASS FIBRE DELAMINATING
If the core is drenched, the epoxy method won't supplant the water. I question how much stronger it will be. Now, some will drill holes and hope the core dries out. I question how successful this can be.
I've seen this done on boats I was looking at. It tells me that a previous owner neglected the boat then later decided to do a patch-up. How did they dry out the core? Or did they just squirt in epoxy?
|
|
|
14-02-2017, 20:45
|
#3
|
Registered User
Join Date: Mar 2012
Location: Michigan/Bocas del Toro Panama
Boat: Corbin 39
Posts: 265
|
Re: HUNTER 456 (2002) - PROBLEMS WITH HULL GLASS FIBRE DELAMINATING
I successfully dried out about 30 square feet of deck on a Saber once without filling it full of holes. Once you drill all of those holes you'll get a case of the polka-dots that will show forever. Things will look fine for a season before they show up though.
I used a large infared heater for curing auto paint to evenly heat about four square feet at a time, while pulling a vacuum on it with a large vacuum pump. Under Vacuum the water has a much lower boiling point. I can't fully remember but i think I shot for 180° to 200° Fahrenheit on the surface of the deck. As hot as I could go without scorching the gel. Used aluminum plate as heat sinks to protect things like toerail.
took a whole winter to do it. I had to check on it daily and it cost the owner about $6,000 by the time, everything was re-bedded. Now that deck had very little delamination. It just peged the moisture meter everywhere when it was surveyed for a sale. Chain plates and bow pulpit were the culprits. It passed the following season when I was done.
Usually I would cut the skin off from the underside, but this boat had too elaborate of a molded headliner and bulkheads in the way so I had to think outside the box. It took a lot of time but when I was done there was very little evidence that I had been there. Managing the heat and vacuum was a lot more pleasant than reglassing and shaping the deck I might add.[emoji3]
|
|
|
14-02-2017, 20:52
|
#4
|
Registered User
Join Date: Jun 2008
Boat: Tartan 40
Posts: 2,490
|
Re: HUNTER 456 (2002) - PROBLEMS WITH HULL GLASS FIBRE DELAMINATING
Quote:
Originally Posted by toddedger
I successfully dried out about 30 square feet of deck on a Saber once without filling it full of holes. Once you drill all of those holes you'll get a case of the polka-dots that will show forever. Things will look fine for a season before they show up though.
I used a large infared heater for curing auto paint to evenly heat about four square feet at a time, while pulling a vacuum on it with a large vacuum pump. Under Vacuum the water has a much lower boiling point. I can't fully remember but i think I shot for 180° to 200° Fahrenheit on the surface of the deck. As hot as I could go without scorching the gel. Used aluminum plate as heat sinks to protect things like toerail.
took a whole winter to do it. I had to check on it daily and it cost the owner about $6,000 by the time, everything was re-bedded. Now that deck had very little delamination. It just peged the moisture meter everywhere when it was surveyed for a sale. Chain plates and bow pulpit were the culprits. It passed the following season when I was done.
Usually I would cut the skin off from the underside, but this boat had too elaborate of a molded headliner and bulkheads in the way so I had to think outside the box. It took a lot of time but when I was done there was very little evidence that I had been there. Managing the heat and vacuum was a lot more pleasant than reglassing and shaping the deck I might add.[emoji3]
|
How did you pull a vacuum without drilling holes?
|
|
|
14-02-2017, 21:11
|
#5
|
Registered User
Join Date: Mar 2012
Location: Michigan/Bocas del Toro Panama
Boat: Corbin 39
Posts: 265
|
Re: HUNTER 456 (2002) - PROBLEMS WITH HULL GLASS FIBRE DELAMINATING
I used existing holes in some spots. Some places i drilled a hole from bottom, and some spots i had to drill in the deck. You don't need a very big hole to suck through, 1/8 " will work.
|
|
|
14-02-2017, 21:16
|
#6
|
Registered User
Join Date: Mar 2012
Location: Michigan/Bocas del Toro Panama
Boat: Corbin 39
Posts: 265
|
Re: HUNTER 456 (2002) - PROBLEMS WITH HULL GLASS FIBRE DELAMINATING
Your not moving a lot of air volume to dry it out. Your building a vacuum to boil it out slowly as steam.
|
|
|
15-02-2017, 08:35
|
#7
|
Registered User
Join Date: Jan 2011
Location: Now based on Florida's West coast
Boat: Pearson 34-II
Posts: 2,713
|
Re: HUNTER 456 (2002) - PROBLEMS WITH HULL GLASS FIBRE DELAMINATING
Capt,
If you're looking to buy the boat, walk away. There are, perhaps, hundreds of these boats on the market without delamination issues. The problem is not osmosis but ingress of water into the core. The only failsafe way to repair is to remove an outer/inner skin, replace the core and re-glass. Hope this helps. Good luck and safe sailing.
__________________
"And those who were seen dancing were thought to be insane by those who could not hear the music."
Friedrich Nietzsche, Thus Spake Zarathrustra
|
|
|
15-02-2017, 08:47
|
#8
|
Moderator
Join Date: Jul 2009
Location: Sxm , Spain
Boat: CSY 44 Tall rig Sold!
Posts: 4,367
|
Re: HUNTER 456 (2002) - PROBLEMS WITH HULL GLASS FIBRE DELAMINATING
Run away!! if your description of the problem is what you say,, a large área of the topsides delaminated, is going to be a expensive repair, there is only one way to cure the problem, cut the skin and dry or replace the core , reglass the área and Paint the whole boat or worst, spend a huge amount of money machting gelcoat and redoing gelcoat...
|
|
|
15-02-2017, 09:21
|
#9
|
Moderator Emeritus
Join Date: Oct 2013
Location: Jacksonville/ out cruising
Boat: Island Packet 38
Posts: 31,348
|
Re: HUNTER 456 (2002) - PROBLEMS WITH HULL GLASS FIBRE DELAMINATING
I think he owns it, and needs to fix it.
At least his signature has that boat in it.
|
|
|
15-02-2017, 11:08
|
#10
|
cruiser
Join Date: Jan 2012
Location: Lake Ontario
Boat: Ontario 38 / Douglas 32 Mk II
Posts: 3,250
|
Re: HUNTER 456 (2002) - PROBLEMS WITH HULL GLASS FIBRE DELAMINATING
Quote:
Originally Posted by captpsmith
A Recent survey of the yacht identified a reasonably large area of the topsides hull suffering from delamination of glass fibre layers and balsa core layers internally with no external visual evidence.
Water ingress appears to have been through defective deck to hull joint in way of aft master cabin both on port and starboard sides.
Has anyone experienced this rather serious form of osmosis and what is the best permanent cure? There is a school of thought that it is possible to drill small holes into the hull in way of and inject a 'liquid' epoxy to reinstate strength to the affected areas.
Any advice and or knowledge/experience would be appreciated.
|
Im a little confused by your terminology. Are the high moisture readings in the hull, between waterline and toerail, or in the deck.
In either case there are viable repair methods short of removing skin and replacing core, under certain circumstances.
Before doing anything, get a reputable glass guy to evaluate. Surveyors with moisture meters have been known to be wrong. He may charge a couple hundred bucks for consultation, but will likely save you thousands, by advising Pros and cons of various repair options, if any are required at all.
|
|
|
15-02-2017, 11:36
|
#11
|
Registered User
Join Date: Oct 2011
Boat: Valiant 42
Posts: 6,008
|
Re: HUNTER 456 (2002) - PROBLEMS WITH HULL GLASS FIBRE DELAMINATING
Moisture meters don't measure moisture. They measure capacitance. Because water is more than ten time the capacitance of fiberglass the meter can detect water. But lots of other things like metal plates next to the inner hull or even embedded in the hull can affect capacitance too.
Did they do a plastic hammer tap test to map out the area with water saturation? If not do that next.
|
|
|
15-02-2017, 20:53
|
#12
|
Registered User
Join Date: Nov 2012
Location: Swansea, MA
Boat: CLC Skerry
Posts: 260
|
Re: HUNTER 456 (2002) - PROBLEMS WITH HULL GLASS FIBRE DELAMINATING
Ditto on the moisture meter. A surveyor once found "moisture" in the solid glass hull of my old Tartan, right in the lazarette area. Right where the spare anchor and chain were stowed against the hull... Time to get out the little plastic hammer.
|
|
|
16-02-2017, 06:16
|
#13
|
Registered User
Join Date: Jan 2011
Location: Now based on Florida's West coast
Boat: Pearson 34-II
Posts: 2,713
|
Re: HUNTER 456 (2002) - PROBLEMS WITH HULL GLASS FIBRE DELAMINATING
Apologies are in order to CaptSmith when I failed to notice in his avatar that he owns the boat in question. Sorry. So, with this is mind, I would second RamblingRod's suggestion to get a quote from several fiberglass specialists. Do not tell them your potential issue but rather that you need a written evaluation for your insurance company. It is important, at this point, not to panic and be absolutely certain that the problem does exist. Surveyors are like athletes: some fair, some good and some great. If you do have delamination, there is only one fix: remove one skin, re-core and re-glass. On a large area like a hull, the drill/dry/fill method is not appropriate because of the torsional stresses on the hull while sailing. I hope this helps. Good luck and safe sailing.
__________________
"And those who were seen dancing were thought to be insane by those who could not hear the music."
Friedrich Nietzsche, Thus Spake Zarathrustra
|
|
|
16-02-2017, 06:31
|
#14
|
Moderator Emeritus
Join Date: Oct 2013
Location: Jacksonville/ out cruising
Boat: Island Packet 38
Posts: 31,348
|
Re: HUNTER 456 (2002) - PROBLEMS WITH HULL GLASS FIBRE DELAMINATING
Are you where the weather gets below freezing?
If so be sure its not close to freezing when you do the tap test, it will pass with the core frozen. The 356 I bought that failed survey was a Great Lakes boat, and in one or two places you could see fine cracking in the deck where it was wet, I'm guessing that was from the freeze expanding the wet core, and that has to accelerate the damage I think
|
|
|
16-02-2017, 06:47
|
#15
|
Registered User
Join Date: Sep 2014
Location: Fiji Airways/ Lake Ontario
Boat: Legend 37.5, 1968 Alcort Sunfish, Avon 310
Posts: 2,750
|
Re: HUNTER 456 (2002) - PROBLEMS WITH HULL GLASS FIBRE DELAMINATING
Quote:
Originally Posted by toddedger
I used existing holes in some spots. Some places i drilled a hole from bottom, and some spots i had to drill in the deck. You don't need a very big hole to suck through, 1/8 " will work.
|
That's an interesting approach. I'd always wondered how one would get the water out if it's end grain- your heat/vacuum trick would do it.
1/8" shocked me though. All the boats I'd seen this done on had at least 1/2" holes. Interesting. I suppose that 1/8" would be just fine.
Now, you said it took all winter, but it's not clear if this was 24/7 or on-and-off. For an example, let's say I have one wet spot 8" square. How many holes would you drill? How would you create a sealed vacuum over the hole(s)? How long would it take to dry out that spot?
Thanks for the tip!
|
|
|
|
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Rate This Thread |
Linear Mode
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
Advertise Here
Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
Vendor Spotlight |
|
|
|
|
|