I picked up a 5.0 G-cat last summer for a song and am just now getting around to bringing it to life. There is a bad soft spot just aft of the center beam on the port hull so I pulled the whole think apart. (If I'm gonna restore it I'm gonna do the whole thing) I found these cracks on the starboard hull at the center beam. Do I just sand and fill or are there bigger problems here I need to address?

Considering these mod's and upgrades, I am looking for a leisure vessel and a mobile swim platform more than I am looking for a race boat. I am located in north texas, so just lake sailing for me.
1) deck plates for storage and maintenance. How big is too big? styles and recommendations?
2) Running lights so that if we go out late and want to watch the sunset we can
2b) If I do the first two I am going to put a fair amount of power onboard so I can have a trolling motor to get us back to dock at night. How far fore or aft should the batteries go, I am assuming I need to split my banks between hulls, or am I overthinking for the small amount of weight they will be.





Edited by dreaminbohemian on Jul 22, 2019 - 11:44 PM.

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I found these cracks on the starboard hull at the center beam. Do I just sand and fill or are there bigger problems here I need to address?

IMHO: These are in a bad location (lots of compression and stress) and should be reenforced - so sand and fill is not enough
you should grind out these cracks, use epoxy with a structural filler (mill fiber, or similar) and use glass cloth for additional strength

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1) deck plates for storage and maintenance. How big is too big? styles and recommendations?

I assume you mean hatches - 5.0 g-cats typically use 4"

dreaminbohemian

2b) If I do the first two I am going to put a fair amount of power onboard so I can have a trolling motor to get us back to dock at night. How far fore or aft should the batteries go, I am assuming I need to split my banks between hulls, or am I overthinking for the small amount of weight they will be.

the deep cell batteries you will need for a trolling motor and running lights is gonna be substantial enough for you to work out the optimal location

batteries (weight) should be as close to the CE (center of effort) as possible this is typically a foot or 2 from the mast (aft) but with the front tramp on a g-cat / if you have ANY weight up there it will change your CE location

I used to sail with a h21 that had all sorts of powered items (lights above and below the waterline, speakers in the mast spreaders, blender etc) - he had 2 deep cycle marine batteries epoxied into his hulls via large hatches (epoxied so they couldn't shoot through a hull in a capsize/ these things must be very secure - they could kill you in multiple ways).
I am not sure what to recommend to you but keep in mind that these batteries are heavy and expensive and adding any type of motor may change your boat requirements (actual running lights per coast gaurd requirements)

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2) Running lights so that if we go out late and want to watch the sunset we can

We just took a handheld flashlight and taped it to the mast to illuminate the main. Hard to miss.
Seriously though, that doesn't meet guidelines. Don't do that. Officially.



Edited by badfish on Jul 23, 2019 - 10:34 AM.

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Joshua

Texas Gulf Coast
'82 Prindle 16 (Badfish)
'02 Hobie Wave (Unnamed Project)
‘87 Hobie 18 (Sold)
‘89 Hobie 17 (ill-advised project boat, Sold)
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badfish

We just took a handheld flashlight and taped it to the mast to illuminate the main. Hard to miss.
Seriously though, that doesn't meet guidelines. Don't do that. Officially.

I like to wear a headlamp, turned upside down - sitting on the brim of a baseball style hat
the light shines up at the sail, the brim keeps the light 100% out of your eyes

I had some major delaminaton on my 5.7. The bottom skin sepearted significantly from the core, and also cracked so when I tried to do injection method the epoxy just seeped through. I had both decks redone at about the cost of a used boat.

I have portable red/green bow lights and stern light that clamp on and a led lantern I can hoist up my spin halyard, I’m not a spin boat anyway. Battery life is amazing I prefer this to a house battery system but if your using a trolling motor I guess that makes since

I’m not a big fan of cutting into good deck to add a hatch but if the need is there make sure you seal the core well or you will see more soft spots.

It’s common on Gcats to add longer anchor bars to distribute the loads better along the deck lip. I have 12 inch anchors on my shrouds. If you are worried about the added stress on your cross bars you could add maybe 8inch bars or pipe. I chose 12 inch because the bar stock I bought was 24 inches and just cut it in half.

Good luck, they are great boats and worth restoring.



Edited by jalex on Jul 23, 2019 - 08:50 PM.

I agree with jalex about longer back up bars especially the one for the shrouds. If the back up bars aren't too large in diameter you might consider turning the hulls over and glassing the area under the lip to add some strength to the loaded area where the back up bars are.

As far as the cracks in the pics it's hard for me to comment without actually seeing them. My current G-Cat looked just like that when I got it apart but the cracks were just in the gel coat. One thing I might add is when you reassemble it, bed those "saddles" with silicone. I have taken apart G-cats were this wasn't done and it's not a pretty sight.

The load on the center cross tube saddles is actually pushing down into the saddles at least when you're sailing in a good wind. The shroud is pulling the hull up against the cross tube and the mast is pushing down on it. One thing a lot of G-Cat sailors have done is to replace the aluminum back up bars that are in the cross tubes and replace them with a long bolt that goes all the way thru. This will necessitate adding compression tubes made from aluminum pipe or even schedule 40 PVC. Grind the ends to approximate the curve of the cross tubes and make them as long as possible to fit real snug. The pressure on the saddles will be more spread out this way.


I had a 2hp outboard on a 5.7 many years ago. The motor was mounted on a "cheeta" bracket. This was back in the day when you could still get a lightweight 2 stroke motor. Even then, with that weight hanging off the back, it seemed like I could never get my weight far enough forward when sailing alone. I saw a Hobie 21 once where the trolling motor was on the main cross tube but I can't imagine dealing with those heavy batteries.


I've done some night sailing and all I've done is shine a flashlight on the sail if another boat was in the vicinity.


I've fixed soft spots in the deck by adding an opening port, turning the hull upside down and glassing from the inside. When I got done, an elephant could stand there! I believe decks get soft by boats sitting around for years with water in the hulls. I've never dealt with delamination issues with G-Cats. I hear its common though. Lucky I guess.

One more thing. If you cannot resolve your structural issues to your satisfaction, I saw once where the cross tubes were glassed to the hulls. This would be an act of desperation keeping in mind you would never get the boat apart again.

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Bill Townsend
G-Cat 5.0
Sarasota
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