 |
|
20-08-2022, 15:33
|
#1
|
Registered User
Join Date: Aug 2022
Location: Loreto BCS
Boat: Lagoon TPI 42
Posts: 5
|
Lagoon TPI 42 sugar scoop cracking
hello,
My husband and I are new live aboard sailors with some previous day sailing and charter experience before purchasing our first boat a '96 Lagoon TPI 42, Namaste, in Baja.
We have started to notice leaking under our aft cabin port lights after washing. I originally thought I didn't shut the port lights tight enough but we then noticed cracks running the width of both sugar scoops and what might be water damage behind the vinyl wall finishing around the port lights.
We are hoping it's nothing serious but would love more opinions or thoughts from more experienced sailors or anyone who has experienced the same problem.
I have attached some pics.
Thank you!
|
|
|
20-08-2022, 16:00
|
#2
|
Registered User
Join Date: Sep 2009
Location: Houston
Boat: ‘01 Catana 401
Posts: 9,628
|
Re: Lagoon TPI 42 sugar scoop cracking
A crack like that is typically just a gelcoat crack, nothing to worry about. The age of the boat suggests that it may be time to rebel the port(s).
|
|
|
20-08-2022, 16:01
|
#3
|
Registered User
Join Date: Nov 2007
Boat: Seawind 1000xl
Posts: 7,507
|
Re: Lagoon TPI 42 sugar scoop cracking
Have you tried pulling the ports and re bedding them? I’m guessing the cracks are probably in the gelcoat and probably haven’t compromised the laminate, but that’s a guess. I’m pretty sure the core on your boat is balsa so either way a good idea to stop the leak.
|
|
|
20-08-2022, 16:02
|
#4
|
Moderator
Join Date: Nov 2011
Location: aboard, in Tasmania, Australia
Boat: Sayer 46' Solent rig sloop
Posts: 30,226
|
Re: Lagoon TPI 42 sugar scoop cracking
Welcome aboard CF, SailWithNamaste,
Sorry for your problems. In your shoes, I would ask around to find out who is a good fiberglass repairer in your area. Then consult with him or her. Perhaps get 3 quotes on the repairs. Your goal will be stronger sugar scoops, plus a dry boat. Your boat has cracks which leak into the interior and has been doing so for quite a while. Salt water, wash water, and it always travels, pulled by gravity, and any wood it gets to will rot. In addition to your own thread here, they may be some information on the Lagoon Owners thread.
Sometimes you can keep costs down by doing the work yourself under the tutelage of a paid (or barter) proper boatwright.
Ann
__________________
The only thing necessary for the triumph of evil is for good men & women to do nothing.
Who scorns the calm has forgotten the storm.
|
|
|
20-08-2022, 16:38
|
#5
|
Registered User
Join Date: Aug 2022
Location: Loreto BCS
Boat: Lagoon TPI 42
Posts: 5
|
Re: Lagoon TPI 42 sugar scoop cracking
Thank you! we definitely plan on asking around for some professional help and get it fixed sooner rather than later. We wanted some opinions before we started ripping things apart if we didn't need to. We will also look into pulling the ports and rebedding them. We appreciate the help.
|
|
|
20-08-2022, 17:30
|
#6
|
Moderator
Join Date: Nov 2011
Location: aboard, in Tasmania, Australia
Boat: Sayer 46' Solent rig sloop
Posts: 30,226
|
Re: Lagoon TPI 42 sugar scoop cracking
Unfortunately, at the moment, it is broken enough to allow water ingress. Most simple gelcoat stress-cracking doesn't, unless the cracks are too deep. But one of your pictures definitely shows the water intrusion. So, to me, who has a different boat, and not my own heart into yours (as yours may be), it is easy to say it is broken, just not all the way, as yet.
It is going to be a big job, if our fiberglass cracks are any indicator, because in our case (previous boat), we had to glass in new floors to stiffen the hull. Yours is not that bad, but one always has to go back to fresh, solid glass, and scarf in at about a 10:1 distance ratio, to make things as strong as new. Do you happen to know if the boat ever hit something in reverse? Any ideas as to cause?
Ann
__________________
The only thing necessary for the triumph of evil is for good men & women to do nothing.
Who scorns the calm has forgotten the storm.
|
|
|
20-08-2022, 17:34
|
#7
|
Registered User
Join Date: Nov 2007
Boat: Seawind 1000xl
Posts: 7,507
|
Re: Lagoon TPI 42 sugar scoop cracking
Quote:
Originally Posted by SailwithNamaste
Thank you! we definitely plan on asking around for some professional help and get it fixed sooner rather than later. We wanted some opinions before we started ripping things apart if we didn't need to. We will also look into pulling the ports and rebedding them. We appreciate the help.
|
Pulling the ports and re bedding is a simple inexpensive job, and may quite possibly cure your leaks. If not then maybe further investigation into the gelcoat cracking.
|
|
|
21-08-2022, 03:59
|
#8
|
Registered User
Join Date: Aug 2009
Location: Lake Macquarie NSW
Boat: Chamberlin 11.6 catamaran
Posts: 1,024
|
Re: Lagoon TPI 42 sugar scoop cracking
It could be gelcoat - but it might be more.
Gelcoat is thick and weak, so it often cracks when a corner is under some extension that does not cause issues to the glass. But if the glass is damaged then so will the gelcoat.
If it was my boat, I would get out a little dremel tool and work away on the gelcoat crack, opening it up. Hopefully when you get through it you will find nice, green/grey looking fibreglass laminate. Hopefully there will be no white parts or cracks. If there are not cracks then you can get some flowcoat (which is gelcoat that will set in air) and fill the vee of gelcoat.
If the glass is damaged then you really do the same thing - work away at it until you get good stuff and then reapply new glass. BUT, the new glass will have to be chamfered onto the old glass and so there will need to be a lot more removal of gelcoat to reinforce the glass so it doesn't crack again.
Post some photos of the sugar scoops if you want comment on them
cheers
Phil
|
|
|
21-08-2022, 07:01
|
#9
|
Registered User
Join Date: May 2015
Location: edmonton alberta
Boat: 1992 lagoon 42 tpi
Posts: 1,747
|
Re: Lagoon TPI 42 sugar scoop cracking
We have a sistership, 1993 tpi 42, SV purrfect.
I would guess the water is coming from the port itself. It isn't too hard a job to remove and rented. At the very least it will give you a better insight into what's going on inside there
The other possiblity is the deck seam above, where the deck meets the sugar scoop top side. I've attached a picture, we had leaking along the side into the engine room from this so I scraped it out and resealed it with 5200.
If you haven't found it yet, there is a FB owners group.
https://www.facebook.com/groups/Jean...ans/?ref=share
|
|
|
21-08-2022, 07:15
|
#10
|
Registered User
Join Date: Nov 2007
Boat: Seawind 1000xl
Posts: 7,507
|
Re: Lagoon TPI 42 sugar scoop cracking
Quote:
Originally Posted by chris mac
We have a sistership, 1993 tpi 42, SV purrfect.
I would guess the water is coming from the port itself. It isn't too hard a job to remove and rented. At the very least it will give you a better insight into what's going on inside there
The other possiblity is the deck seam above, where the deck meets the sugar scoop top side. I've attached a picture, we had leaking along the side into the engine room from this so I scraped it out and resealed it with 5200.
If you haven't found it yet, there is a FB owners group.
https://www.facebook.com/groups/Jean...ans/?ref=shareAttachment 263180
|
If that’s a picture of your Lagoon it appears you have the same gelcoat crack below your ports?
Would it be possible for water to enter the balsa core if the ports are leaking? And is there a core where the gelcoat cracks are? I would think solid glass at the radius.
|
|
|
21-08-2022, 07:28
|
#11
|
always in motion is the future

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 20,485
|
Re: Lagoon TPI 42 sugar scoop cracking
This is a typical fault from TPI. The problem is caused by their choice of gelcoat, their way too thick application of gelcoat and incompatibility with the vinylester laminate.
The good news is that it’s just ecstatic, no water ingress. The laminate was done using the SCRIMP process, which is very good.
Our Sundeer is also built by TPI and we have the same problem. You need to grind the crack out a bit (even with just a Dremel and small ball shaped bit), refill and sand flush.
The water damage is due to the portlight bedding.
__________________
“It’s a trap!” - Admiral Ackbar.
|
|
|
21-08-2022, 18:11
|
#12
|
Registered User
Join Date: May 2015
Location: edmonton alberta
Boat: 1992 lagoon 42 tpi
Posts: 1,747
|
Re: Lagoon TPI 42 sugar scoop cracking
Quote:
Originally Posted by smj
If that’s a picture of your Lagoon it appears you have the same gelcoat crack below your ports?
Would it be possible for water to enter the balsa core if the ports are leaking? And is there a core where the gelcoat cracks are? I would think solid glass at the radius.
|
Yes, pic of my boat, and yes it has similar gell coat cracks. They are pretty common throughout the boat.
I would assume it's solid glass on the radius, but can't guarantee it.
Our surveyor did a pretty thorough job of sounding three years ago. Very few (Small )soft spots were found. None were near the gell coat cracks. I still periodically tap these area to keep confidence(and catch problems early) So far so good.
Ours is quite solid by this port, which is why I suspect the OP's is leaking at the hatch itself.
|
|
|
30-08-2022, 16:12
|
#13
|
Registered User
Join Date: Aug 2022
Location: Loreto BCS
Boat: Lagoon TPI 42
Posts: 5
|
Re: Lagoon TPI 42 sugar scoop cracking
Quote:
Originally Posted by smj
Have you tried pulling the ports and re bedding them? I’m guessing the cracks are probably in the gelcoat and probably haven’t compromised the laminate, but that’s a guess. I’m pretty sure the core on your boat is balsa so either way a good idea to stop the leak.
|
So we did some experimenting and it does appear to be the ports and we will be rebidding them soon. As far as the crack, any suggestions on a product or proper procedure we should use to close/seal it?
|
|
|
30-08-2022, 18:21
|
#14
|
always in motion is the future

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 20,485
|
Re: Lagoon TPI 42 sugar scoop cracking
Quote:
Originally Posted by SailwithNamaste
So we did some experimenting and it does appear to be the ports and we will be rebidding them soon. As far as the crack, any suggestions on a product or proper procedure we should use to close/seal it?
|
Yes, use a Dremel with this bit: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
And grind the crack down until you get to solid glass that doesn’t show the crack anymore. Lengthwise, make sure you go all the way to the end of the crack, don’t leave a little piece, better grind a bit longer. If you don’t, the crack may start creeping further.
After that you need to fill it. If you’re not painting it anytime soon, use white colored MarineTex. Fill it with a tool that fits the curve like a tongue depressor. Try to overfill it just a little bit, because it will shrink. Let it cure.
If it shrank too much, fill a little more, until it is cured proud. Now sand it flush. You can put sandpaper around a hose to fit the radius.
__________________
“It’s a trap!” - Admiral Ackbar.
|
|
|
30-08-2022, 23:34
|
#15
|
Registered User
Join Date: Mar 2011
Location: Panschwitz, Germany
Boat: Woods Mira 35 Catamaran
Posts: 4,801
|
Re: Lagoon TPI 42 sugar scoop cracking
Quote:
Originally Posted by s/v Jedi
Yes, use a Dremel with this bit: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
And grind the crack down until you get to solid glass that doesn’t show the crack anymore. Lengthwise, make sure you go all the way to the end of the crack, don’t leave a little piece, better grind a bit longer. If you don’t, the crack may start creeping further.
After that you need to fill it. If you’re not painting it anytime soon, use white colored MarineTex. Fill it with a tool that fits the curve like a tongue depressor. Try to overfill it just a little bit, because it will shrink. Let it cure.
If it shrank too much, fill a little more, until it is cured proud. Now sand it flush. You can put sandpaper around a hose to fit the radius.
|
Terminate the inner end of the crack with a drilled round hole, slightly larger than diameter of the dremeled crack.
No need to go deeper than the dremeled crack.
The round hole distributes stresses better and stops the cracks from continuing further inward.
Regarding Gelcoat. Use a designated Topcoat or add a small amount of Stearine.
The Stearine allows the Gelcoat to cure tackless in air.
Standart Gelcoat is not exposed to the air with its finished side when layed down in a mold hence it does not have Stearine added and would cure tacky on air.
|
|
|
 |
|
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
|
|
|
|
Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
Vendor Spotlight |
|
|
|