Cracked carbon fiber hull

[MG1234]

Well shoot ,bumped a cement wall a little hard with my Zonda and it cracked across the top of the sponson ,it is an off set crack,can I clean it up and use JB weld ? Or do I need to order that west product resin for carbon fiber repair? Same approach as fiberglass repair? Other than that what a great day at the lake ,smooth water and fast boats ,

[SD Eracer]

Do you have a pick of the crack?

You really should reinforce it from the back side, normally a sheet or two of carbon fiber cloth and resin is an easy yet effective fix, but considering its location, it maybe difficult to reach.

On new boat builds, I normally would fill the tip with epoxy resin, it makes it almost bullet proof and adds a nice amount of weight to the front of the hull. Then brush a light amount of thin epoxy or resin on the exterior crack itself. Then I hide the crack with a nice decal or something like that.

[MG1234]

I did the resin fill on my genesis and it did make it stronger but now I can't get the nose up,on my Zonda the crack runs across the top of the sponson straight in line with the front of the hull then down the inside of the sponson ,it also opened the seam across the front ,I cleaned it out with a dremmel and put black epoxy in the crack ,can't get to the inside,I have a body shop guy that says he can fix it I just need to buy the repair kit on eBay ,2 more weeks and it will be desert season anyway ,

[SD Eracer]

I did the resin fill on my genesis and it did make it stronger but now I can't get the nose up,on my Zonda the crack runs across the top of the sponson straight in line with the front of the hull then down the inside of the sponson ,it also opened the seam across the front ,I cleaned it out with a dremmel and put black epoxy in the crack ,can't get to the inside,I have a body shop guy that says he can fix it I just need to buy the repair kit on eBay ,2 more weeks and it will be desert season anyway ,

How much resin did you put into the nose of your Genesis? I have two Genesis boats with epoxy filled sponson tips, filled with expanding foam which makes them even heavier in the front, but I still have to use an airdam to keep them from flipping over.

That's cool about the body shop guy, what kind of repair kit did he want you to purchase?

[MG1234]

There is a Carbon fiber repair kit ,like a 2'x2' mesh and resin,to do small repairs ,on my genesis it has a 4092 1750 kv ,I milled the strut to get a little higher,have a M447 and x648,I have the batteries back to the water out let,and it still runs wet ,it used to blow over and I had a wind damm on it ,but after multiple sponson repairs it won't get up on its tail ,I'm going to try a little weight in the back tomorrow ,

[SD Eracer]

Wow, our setups are pretty close. I run a Leopard 4092 1730kv with a M445 & M447. On that hull, after getting a few stress cracks after some 60 mph flips, I reinforced it with a couple of layers of fiberglass cloth and resin. Quick and dirty like, just laid and resined around the motor mounts and trays, didn't remove anything. Been bullet proof ever since, including some crazy 70 mph flying barrel rolls. My newest hull has been reinforced with 12K carbon fiber sheet, should handle 90 mph flips.

I guess its just too much weight in the front of your boat. I've seen someone put a spoiler wing the back of their SAW cat to help with the front, maybe an idea instead of adding ballast to the rear.

[MG1234]

At our local lake there is a cement curb that holds the shore in place,that thing is my enemy,some hits were my fault ,others were just bad luck ,but all my damage to both boats is that curb ,the water is about 2' deep and you need to stand in the water to see because of tall vegetation ,I can get a hull already re enforced for 89$ ,might buy one this winter and swap stuff over unless I find a better hull ,just bought a used HOR racing 41" cat ,put twin 1800 kv ,came with shafts and huge props ,it has been so re enforced it's heavy ,gonna run it for the first time tomorrow ,6s each motor,

[dmitry100]

You're probably better off with either fiberglass or CF mesh along with some epoxy balloons + epoxy and filling up that sponson... check my thread about it if you want

[MG1234]

How do I check your thread ?

[z400]

How do I check your thread ?

You click this link and read through the provided information.
https://forums.offshoreelectrics.com/...-it&highlight=



Do you wreck all of your boats?

[MG1234]

Yes ,just started this summer on boats ,Spartan ,then genesis ,then Zonda ,now HOR racing twin,buy hey my kids are grown and I can buy a fast RC boat for what it cost to go skiing one day ,

[dmitry100]

https://forums.offshoreelectrics.com/...-it&highlight=

[MG1234]

I read that but I still don't understand epoxy balloons ,what or how they work ,thanks

[dmitry100]

It's just used as a filler to keep the weight down ... Scroll down to "Micro balloons" http://kintecracing.com/Building_Supplies.html and I'm sure you can find similar stuff on places like amazon with free shipping etc.

Is your damage similar to mine ?

[MG1234]

So micro balloons are not balloons at all it's just an adative,I had some idea that they were balloons you insert in hard to reach places ,like the tips of a sponson ,that would help shape the repair ,then once the glass is done you remove them ,so energy of my ignorance ,if I fill the sponsons all the way to the crack which is at the front of the boat ,what's the lightest stuff to use ? I've read so many ideas ,there's that expandable stuff ,or the micro balloon adaptive ,help please

[RandyatBBY]

You can use milled fiberglass and MB to do a repair too.

[MG1234]

I think I want to fill the tips for strength ,what would you recommend ?

[RandyatBBY]

I would cut a piece to the close shape in pink or blue foam to fit in side the hull and pre-wrap in fiberglass cloth before final installation. Taper and sand the out side and cover in cloth and use a good quality masking tape to hold in place and let harden. Use a the FG milled and cab-o-seal mixed as a paste to fill and help hold together before taping.

[rickwess]

Using the micro ballons as an additive to repair a crack is not the best idea. Micro ballons is used to make epoxy easier to sand and actually weakens the epoxy. A better application for epoxy/ballons would be to repair surface impefections on the outside of the hull so it can be sanded smooth. It is porous, so it will need to be sealed with something.

As mentioned already, there are better additives for strength........milled fiberglass, milled carbon fiber, silica, graphite. For example, I use silica mixed with epoxy (G-Flex) to eliminate sag while the epoxy cures.

[MG1234]

But it's just cracked on 2 sides and its to far in to reach the inside ,is there a light weight filler I can pour in each tip to that area to help hold it ? Then do carbon work on the outside?

[MG1234]

Thanks I'll look for milled fiberglass,in construction we acually mix something like that in cement for strength ,

[MG1234]

Found the milled glass on OSE what is MB? I assume it's the epoxy I need ,thanks

[shua]

MB is short for Micro Balloons.