Hull Damage Question

Hi everyone , I need some guidance on a cored hull problem . I have a 2018 boat with a cored ( some type of foam i am told ) that has 2 lengthwise cracks , port side , 12 '' long . We believe these where from blocking . The crack closest to the keel is split open like someone took a can opener to it . We believe the crack had water in it and froze .
I am having a hard time having this repair quoted as there is no access to the inside of the hull to look at it , and tanks are above the cracks . There is delamination 40 '' forward and 60 '' back . Some say cut it all out , some say not . I am in Ontario Canada and there are few repair companies in the area , most are gun shy of repairing it . Some in Michigan will , but with Covid the boarders are closed to non commercial travel . I thought this hull was solid fiberglass , not cored .
Has all builders went this way now ? Are others having problems ? I was thinking there could be hull construction problems that contributed to the soft keel ? The plant told me that their process is 110 % . Thanks

 

Is it a core, or is it flotation foam?

 

Give us some photos. Really hard to understand or comment without seeing anything.

Also, are you in Toronto?

 

Well the plant is full of $h*t, because 100% is as good as it gets.

As for your damage:
You'd have to start digging and see what you find.
Then go another 12 - 18" beyond into seemingly good material.
Have a reputable shop dig in and give you an estimate.
They may charge you for the estimate but it's part of the work that needs to be done anyway.
If it's really bad, pay the bill and run!

Good pictures would really help.

No Fallguy, he's in London, a two hour drive west of Toronto. Why?

 

here are some pictures

 

I might be slow on the uptake, but in whose custody was this boat, when these cracks appeared ? If someone else has damaged your boat, you need to go after them. So far as the repairs are concerned, you at least need to know the construction details of the boat, in the damaged areas, and the boat's maker should be able to provide that.

 

Yes , i am going after the dealer ( boat had water in V birth when shipped to me ) . Factory was to supply me with a repair procedure ( which they did not ) . It is a long story . The dealer and factory have told me to go away . Pictures of a Ranger hull cut out , are under the ''sources '' page , and the full story on www.rangertugtruth.com

 

OK, watched the video. So how did you establish there was delamination ? The opinion of a prospective repairer, or surveyor ? If you stick a pointed object like an awl into the crack near the centreline, how far does it penetrate before bottoming out ?

 

There are some real good people in Toronto area is all.

So, a couple thoughts.

But first, I, accept no liability for attempting to help you.

A core could be a blessing in disguise.

First, verify you have a cored hull. Cut a 2 square inch hole near the keel with an oscillating tool. Only cut through the glass. Then dig out the core with a sharp chisel, being careful not to cut the likely next layer of glass.

I expect there is a core.

To repair, I'd say cut back at least 12:1 each side of the cracks. So, for a core hull 12mm core, cut back 144mm each side. Use a oscillating tool. Remove the core by hand with a chisel slowly. It will take a day.

The delamination was caused by running the boat and hydraulics acting on the laminate and will need removal back to good laminate. I have no idea the extent of it, but you need to remove all loose laminate and make damn sure you get it all. Once you have removed all the delam and removed materials back away from the cracks; you can repair. That can be done in another reply; too much to do here. Vacuum is advised.

If the boat has a 12mm core; you can probably go back in and repair without tearing up the boat insides.

To be fair to all repair shops, if they have to get to the inside of the boat for the repair; the dynamic explodes.

But, if you have a core; you can repair with a thinner core and more glass or solid glass if the core is 6mm or less.

Also, see if you can find a video or tutorial on fixing a Boston Whaler hull and you will get some ideas about what must be done. In the simplest terms, you need to decore just beyond good laminate and you must not allow any of the existing or remaining laminate to ever delaminate. The repairs also need to be done in epoxy.

I am a boat builder, not a professional repair person. But I can tell you how I would attempt to do it. One thing that does bother me is that your hunch on blocking is probably correct and that likely means the bottom laminate could be a bit thin...but is a guess. You don't need the manufacturer because it must be repaired differently than built. You must use more glass.

Save your 2" cutout section and measure the thickness of the glass/gel or paint and fairing and submit a picture of it in cross section to the forum.

Also, determine the core thickness to nearest mm when doing the removal of the core. It might be 10-12mm core on my guess.

Edited: this hull does not appear to be cored, but coremat based on further information

 

The best (only) way to see the full extent of the damage without removing everything inside would be using thermography.....
These guys advertise in Pro Boat.....don’t know anything about them, technology has been around for while now
If they can’t help you due to travel restrictions they should be able to guide you to someone who can

 

Hard to say what the state of it is, for PVC core to delaminate is not that easy, usually the core fails before the bond to the laminate. Without knowing exactly what materials are involved, difficult to formulate a plan, but if the damage is the responsibility of another person, and there is action being taken to get them to compensate for it, do not touch it. Another thing that comes to mind, caution is always advised when grinding near fuel tanks, or where any spillage from a tank could be involved, a spark and you can blow yourself into next week.

 

If you do not have a core; then the repair really requires gutting the boat I'd say.

 

Unneeded.

If the boat is cored hull, then in order for the outside of the sandwich to crack; the foam failed. If the inside laminate cracked or did not crack does not matter because the repair will require probably going back to nearly solid glass or much more glass.

If the hull is not cored; the boat needs to be gutted.

The only reason I could see for the imaging would be to determine if fuel tanks (or some other systems) are compromised.

 

By the way, whoever told you it doesn't need full removal is friggin clueless Dave. Hydraulic erosion happens when water pressures push on voids between the laminate and the foam. That was the cause of the original delam almost certainly. ...when the blocking crushed the core and pushed some laminate away from core and then the boat was run unknowingly forcing water pressures against the open areas which would delam more aft than for'd

None of the delam can be saved. In fact, delam must be looked for superbly well! If it is missed in the repair it will come back. And even after the repair; the boat will need to be hauled and tap tested to verify the repair got it all.

Pascoe has a good article on hydraulics, but he is a little overboard on core hulls. In your case a core can make this repair easier.

Cored Hull Bottoms https://yachtsurvey.com/cored_hull_bottoms.htm

 

Another thing to point out is someone went to some lengths to hide the damage. The entire hull bottom needs to be tap tested by a surveyor to find any other place where the blocking may have damaged the laminate.

Or Mudsailor's method..