Damage to H18 Hulls - is this a problem?

I recently bought an H18 and have been slowly fixing items. We noticed a slight amount of water in the starboard hull and I investigated. What I found is a couple of soft spots under the lip of the deck, just below the aft cross bar attachment. What's the best way to fix and prevent from recurring?
On another thread, I noticed a guy bought two brand new hulls, and he added a brace under the rear cross bar similar to the one used under the forward cross bar. He also added a 4" inspection port aft of the aft cross bar so he could work in that area. I'm wondering now if there is a known issue with stress at that point which he was trying to address.
I've added a couple of photos of the damage on the starboard side. The port side shows similar damage in the same area, though to a lessor extent.

Image address is not valid or may be private?

Be sure to go to the image and right click to get the image url. Should end in something like .jpg

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

I am having trouble getting the files attached. But, the photo's are available at:
photos.cooksplace.us
Select the Hobie gallery to see them.
I'll keep working to figure out why adding the url doesn't work.

Those look like very typical "check" marks in the gelcoat. There is a lot of flexing that goes on in that area of the hull as it is a very high-load point. The gelcoat doesn't like to flex, so it cracks even though the fiberglass below the surface is usually fine.

You stated in your original post that the area is soft. Maybe you can provide more details. That area of the hull is not cored, it is solid laminate, so softness/delamination would be pretty unlikely.

I would start by doing a pressure test with soapy water and compressed air to see if the hull truly is cracked/separated in that area. I suspect it is not, but the soap test will tell you for sure. If it is cracked, then you will want to add an access port in the hull to add some reinforcement inside (it is a tight space to work). You could also add the crossbar reinforcement brackets (same brackets used for front crossbar & shroud anchors) to the rear crossbar anchor points. Keep in mind that they really aren't designed for this though and so the fit is very tight. You may have to squeeze the "U" portion of the bracket closed a little to get it installed and you also may need to route out the lip slightly when mounting the inboard reinforcements to allow access to get a screw driver on the screws.

sm

Ok, that's what I was hoping to hear. This looks like the lip was being flexed, rather than stress from the cross bar attachment. There is also no sign of cracking on top of the deck.



The edge of the gelcoat bordering the dark area gives when I press on it. But, it's solid farther (say 1mm) from the dark area.



I wondered if the crossbar anchors would fit correctly there.
I tried the pressure test with soapy water, but couldn't find anything. I was very conservative with applying pressure though, as the max pressures I've found online range from .25 - 4 psi. I could probably hold .25 psi without even puffing my cheeks . Actually, I used the exhaust of a shop vac, directed at the drain hole from a foot away, but left the inspection port open, with the cover only partially blocking the opening so that it fluttered a bit from the escaping air. Anyone know a better way to control the pressure? I'd rather have to bail out water than blow a hull.

By the “dark area” do you mean the small spot where the gelcoat is missing? The gelcoat is flaking off in this area, so yea the edges are going to give, but that is not a soft spot. The fiberglass underneath is probably rock solid. This entire area of the hull (the depression where the anchor plates fit in) is solid fiberglass – no core, so delamination is highly unlikely. Unless you’re able to press on the hull with all/most of your weight and get significant flexing, it is not a soft spot.

Pressurizing the hulls isn’t going to work if you have the deck plates removed… The technique I typically use is to just put a piece of rubber hose in the drain plug hole. Wrap some tape around the hose to get a tight fit. Then blow five or ten lung fulls of air into the hull, clamp the hose and spray down the hull. I’ve never had a problem doing it this way.

To reiterate, looking at your pictures, this looks very normal. Unless you see fractured glass fibers, it’s just gelcoat checking and is not an issue.

sm

I assume this boat is a 1984 to 87 ish? This is a MAJOR concern. You risk failing the bow(s) if not properly reinforced. Boats in that vintage... especially when using wings were known to break bows or crack at the rear beams. We added a reinforcement plate (similar to the shroud anchor) at the forward beam and then went in and did post glue internal patches in the late 80s to finally correct it.



This comment is the way to handle it. It should be reinforced within the hull at the forward crossbar and if possible do as this guy did at the rear. There are several threads about the reinforcement patch required.

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

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

No this is a 1992. Should I still be concerned?

I took a shot of the inside of the hull, as far back as I could reach past the dagger board well. I can't tell anything from this, but thought it was worth a shot.

Are all hobie innards like that?? Looks like the laziest, sloppiest, stoner on LSD thats high on epoxy fumes fiberglass job i've ever seen! No wonder a +/- 50 lbs weight difference on boats year to year.
No quality control at all? If my hulls interior look like that i'm scraping my 3 hobie cats and buying something else this spring! YIKES!

_________________
Tim Grover

Memphis, TN fleet 134
Hobie 20! G-Cat5.0 and 2 Hobie 14's
Photobucket now wants $100 to post pics on forums......... pass.

While I agree that sniffing glue doesn't automatically help manufacturing a quality product, I can asure you that neither my hulls, nor the ones in the thread-starter's pictures look like that.

_________________
information is not knowledge
Hobie 18 Formula, Hobie DuraGlide 10'10

On a 1992 boat, it is unlikely there is any need for concern. I could tell your boat was a 1990's era boat by the section of the large "Hobie Cat" decal that showed up in your first picture. Dead give away. That's why I said that what you're seeing are most likely typical gelcoat fractures up under the hull anchor area. If it were a mid-1980's boat, it would be a totally different story. As long as the glass is in tact, minor gelcoat fractures like what you're seeing are a non-issue. If you're going to lose sleep over it, then go ahead and install the updated crossbar anchors in the rear, but I can tell you from experience, it is a little bit of a PITA. The fit of the anchors on the inboard side is very tight.

sm

The picture is the inside of the hull shown at the start of the thread. I don't understand the flaking noticeable on the underside of the deck, or why there is a large area of unsaturated fiberglass cloth.

Oh, I get your point. Any such mods carry a risk of making things worse also. I could easily screw it up, even though I have some experience with fiber-glass. There just isn't much room to work when you have to do everything through a 4+" access port that you have to cut out and can't see what you're doing.
I did read up on the hull issue in the mid-80's, which is why I paid a bit more to get one from the 90's.

It doesn't look like unsaturated cloth to me, just the opposite. It looks like there are areas with a lot of excess resin and the excess resin is what has flaked off.

Hobie has had quality issues over the years, but in general, the early/mid 1990's Hobie 18 hulls were built like tanks (heavy but strong).

sm