Outer Hull Damage

[Providence]

Providence is a 2000 Mainship Pilot 34 with a blue Awlgrip hull.

I just had my marina pull the boat out of winter storage so I could wash/wax and apply fresh bottom paint to the hull before putting it in the water for the season.

Before I even got a chance to start I noticed some cracks in the paint, so I investigated further. Lo and behold I found a giant spider crack on the side of my hull. It is located on the port side and slightly forward of amidships and halfway between the rubrail and waterline. After notifying the marina the owner of the yard called and asked to meet with me at the boat. He explained to me the manufacturing process for fiberglass boats he primarily sells. Without stating it, he led me to believe this could be a manufacturing flaw and suggested that my fenders caused flexing in the hull, from wave action and the dock. These cracks were not present in the fall and they are now present in the spring. The cracks also seem to be located at a place where an inside bulkhead meets the hull. A place that would be significantly stronger than surrounding areas of the hull.

Does anyone have a similar issue? I’m all ears.

Thanks.

 

[Comodave]

You can indeed get stress cracking where a bulkhead meets the hull if the bulkhead is glassed right up next to the hull. Preferably the bulkhead should have a small seperation between the bulkhead and the hull. It creates a hard spot if the bulkhead is right up to the hull.

 

[Bacchus]

Providence

Been there - Done that on my '08 MS 34HT

Comodave is right on the mark w/ cause.
MY 34HT has a bulkhead that stops 4-6" below the side decks and I strongly believe the hull flex above the top of the bulkhead concentrates the stress right at that point.

What I did w/ the help of one of my yard guys (not sure who was the lead / helper but he knows fiberglass work so appreciated having him)
It was a 2 man job in my case because access aft of the bulkhead is around aft of the gen and fwd access was around the main engine so it was almost essential to have someone on both sides.

I cleaned off the sound insulation best I could - sanded and wiped w/ acetone.

Then cut FG mat various sizes so the inside reinforcing was multi layered but tapered to distribute the flex stress over a wider area. I cut a notch roughly in the bottom center of each piece so they would partially slip over the top of the bulkhead. Mixed West System epoxy resin (best choice IMHO as epoxy is a better adhesive that polyester) and we then worked together to brush some on the area to be patched and each layer of mat smoothing as we went. I forget how many payers we ended up using but I'd guess 4-5.

We ended up mixing 2 batches as the first started to set as we worked.
Easier to mix a couple small batches than rush to do it w/ one larger one.

Note above req'd a fair amount of prep to remove hoses & other stuff that was in the way - not sure what access on yours is like.

Nest step was external repair / repaint.
I tried simply gouging out the gelcoat & filling & painting but it didn't hold and a crack reappeared during the season.

I ended up grinding out a wide tapered area and building it up w/ increasing size layers of mat & epoxy resin. Final filling / fairing was done w/ conventional FG reinforced body filler - fast set & easy sanding. My guy didn't see the need to use a true marine epoxy filler above the waterline.

Paint info can be found on my Bacchus website in the Links are
see MS Hull Paint info & Links
Color match was excellent and you can barely find the spot repair even when close up.

If you have questions or want to discuss any of this either post or PM me here or via email on my Bacchus site.
I will PM you my phone # if you want to talk live.

I did the external repair in several steps over several days including the priming & final sanding w/ wet/dry. I had a friend that does truck repair including body work help me w/ the top coat spraying as he had the equipment & skills.
I helped him prep his hull accent stripe and we did both jobs in 2 days.

I had reasonable luck spraying the primer w/ a PreVal sprayer available at any big box store. PreVal sprayer

 

[siestakey]

Bacchus great information he is lucky to have your past experience shared with him

 

[North Baltic sea]

Hi,


It seems to me that someone has come across the boat or it has been negligently calculated if they appeared during the winter when you checked the boat when it was up, whether it was possible for someone to come into the boat last boating season or you knocked on something. Those cracks must be closed as the water enters capillary cracking inside the Hull. I'm sorry for your loss ...


NBs