I really f'd up today! Totally cracked my rear stern

[mrd72]

Finally I have everything running great, been a rough couple of trail and error's these past weeks but i learned and overcame with some help from fellow members, I actually enjoyed working and fixing things. Well today, I took it on on my lake that I been running it for the last 5-6 times. Well everything was great until I heard my low voltage alarm going off and pulled in to take it out of the water after about 5 minutes. I realized a *!***!***!***!** ton of water was coming out of it when I had it tilted down toward the props. I put it up on my stand and realize the whole back of the boat split. It looks like my rudder might of hit something in the water at high speed, but isnt that what a shear pin is for on the rudder?? Im really besides myself. Its a Genesis 56" twin set up. Hopefully I can repair some how. Im really bummed out about this, I really dont want to give up on this hobby yet, but it seems like its like a real boat, everytime you go out theres something else that goes wrong. Im going to attach my youtube video of the damage. Hopefully my electronics will be ok, I drained everything pretty quick and used a compressor to blow everything out. Seems like all the electronics are still working though, except the 12" crack along the transom, or is it called the stern? Video link>> https://www.youtube.com/watch?v=Mqr_EKFLS_k

[Panther6834]

Expensive "ouch".


~ More peace, love, and kindness would make the world a much better place

[30nitro]

Sorry to see that.... it certainly appears to me that the rudder hit something.. ?? The way the transom has cracked / split.... I have seen this sort of damage before..... I do believe it's fixable though...won't be easy but.....carbon fiber / epoxy...should work... Don't give up..!!

[1coopgt]

Wow you split that right at the seam where they join the top and bottom of the hull together. I've never had that rudder on one of my Cats so I don't know about the brass screw and how much force it takes to snap it. Was there any damage to the Rudder blade? With as much damage as there is to the stern of the boat I would expect rudder damage to. You might be able to fix that if you're handy and willing to work with fiberglass.

[larryrose11]

looks quite fixable to me.
You will have to remove all the rear end hardware, and put CF plate and fiber in the inside to get it back to operational. I would also use a nylon shear pin.

[mrd72]

Wow you split that right at the seam where they join the top and bottom of the hull together. I've never had that rudder on one of my Cats so I don't know about the brass screw and how much force it takes to snap it. Was there any damage to the Rudder blade? With as much damage as there is to the stern of the boat I would expect rudder damage to. You might be able to fix that if you're handy and willing to work with fiberglass.

no damage at all to the rudder. really supprised the brass screw didnt shear. Its kinda hard to reach that area from the inside, its set back pretty deep to reach. not what I wanted to happen with a new boat

[Panther6834]

no damage at all to the rudder. really supprised the brass screw didnt shear. Its kinda hard to reach that area from the inside, its set back pretty deep to reach. not what I wanted to happen with a new boat

When I got my first FE boat (ProBoat SonicWake), I initially wondered why the top screw holding the rudder to the bracket was steel, and the lower screw was plastic. After a few weeks, I discovered why. In reading what you just said, now I understand it even more. While brass is considered a "soft" metal, it's still nowhere near as soft as plastic.


~ More peace, love, and kindness would make the world a much better place

[fweasel]

The large TFL center mount rudder is a pretty nice piece of hardware for the money, but the shear bolt is crap. The head on the first one I worked on stripped out trying to remove it and I had to drill it out. Haven't had the opportunity to find a suitable replacement. The top stainless pivot bolt was also over tightened and limited the mount of movement the rudder had even if the shear bolt broke. It needed some adjustment to free up the rudder swing.

As far as nylon shear bolts go, I do prefer them because they break clean and are cheap to replace, but some rudders are just too big and speed alone will shear the nylon bolts. Not sure nylon would last in that rudder. Fortunately, my lake doesn't have turtles or frogs and most of the fish are bottom feeders so I rarely have rudder strikes.

The repair should be pretty straight forward. If I were doing it, I would first remove all of the hardware, and then glue as much of the hull back together with thin CA to cobble together what's left of the exterior shell. Tape off the outside with painters tape and cover the transom from the inside with fiberglass or carbon fiber cloth. A single layer should get the hull water tight and regain some of the structural integrity. I would then cut three pieces of carbon plate to fit the main flat portions of the transom wall (2 sides, and the rudder mount standoff). Glue them in with generous amounts of slow cure epoxy so it oozes out the sides and almost creates a flush surface. Once that cures, you could go back and do another layer of cloth tying the deck, transom, and floor back together if necessary. After all of the structural work is done, redrill your mounting holes from the outside, and remount the hardware. You might need longer mounting screws depending on the thickness of material added.

[mrd72]

BC8616FB-ED02-4E85-BE9D-48F23E8B0074.jpg397B7601-C252-4FE0-AB06-2194912ED9DB.jpg0F1F702C-74D7-4E08-B64D-F8948BC17991.jpgOk, so this is really the first major repair that I am trying. I used a dremel and cleaned up the crack (l) the best I could. I laid a few layers of glass fiber cloth and resin from the inside, probably 3-4 layers. I let dry for a few hours then cleaned the outside and layered some BSI epoxy. Going to wait until tomorrow to clean up everything and sand and shape. I might reinforce the outside transom with some carbon fiber clothe and resin, not sure if that’s overkill. I also think I’m going to cut out a few squares of thin stainless sheet metal to use as a backer for my rudder to bolt thru. Maybe I’m doing things wrong, but I’m gonna give it my best try.

[ray schrauwen]

Test your rudders ability to 'kick up'.

[30nitro]

That's lookin good to me...don't over do it ! Definitely abide by the above post !!

[1coopgt]

You did a great job fixing the boat.

[mrd72]

You did a great job fixing the boat.

Thanks, Still not done, Im not sure if this is even the right section of the forum for me to explain my repair procedure. This is the really the first real RC boat I had. Alot of what im doing is just naturally trying to strengthen the transom so this possibly wont happen again, hopefully next time the shear pin on the rudder will do its job. Still debating whether to keep the brass screw or go with a nylon/plastic shera pin. Just dont know how much force in can instill on fast corning with the nylon/plastic shear pin. So as an upated, I placed a few layers of fiberglass and resin inside the back of transom, Im really supprised thats the only place where TFL didnt reinforce the boat with the crabon/kevlar on the rear of transom. Not sure if thats their mistake or not, but Not going to point fingers and ill jus try to the best of my ability to fix it and use it as a learning tool. So today I sanded down the outside epoxy as best as I could. I mad a template and going to cut a piece of carbon mesh and some resin to add more rigidly, Not sure after when im all done which way would be best to try and blend it all together without noticing the repair too much. Ill send some updates. Thanks for all the feedback. It gives me some reassurance. OH, PS.. If this is the wrong section to be posting this, can the admins move to the boat building section? I wasnt sure where it belonged, another thought, WIth me adding the weight of epoxy and resins, It should make a big difference in performance? I mean its a 56" boat and seems pretty heavy already. Well happy friday!

boat repair (2).jpgbaotrepair (2).jpg

[1coopgt]

Just my opinion. If you're gong to put a layer of carbonfiber on the stern. I would put it on the inside of the hull if you can.

[mrd72]

Ok, so I reinforced the inside with a few layers of fiberglass, filled the outside with some epoxy and a layer of carbon fiber mesh. I’m just about done sanding everything. What do most use to give a final skim coat on outside of boat over all the repairs so I can give a final sanding and try to blend everything together. I’m afraid if I just use a thin layer of epoxy it will eventually crack. Thanks In advance!