Carbon SJ Mould and Ski Build

[cbr600rr]

Figured I would throw this up for anyone who is interested,
Last spring I bought this superjet with the sole intention of gutting it to build some moulds. It turned out to be quite a job, but has also been a lot of fun. As of right now I am about half done, I will start to post what I have done so far…

 

[cbr600rr]

The first thing I did after I got it home was rip the engine out and powerwash all the nasty crap out of the ski. Apparently the previous owner didn’t do jack for keeping it clean.

 

[cbr600rr]

After I had the ski looking nice, I started the teadious process of splitting the hull.
Now, I did some research and figured from what I read that it would take around 5 hours. Now I am not sure exactly what the hell they are talking about, maybe this glue was a bit ‘aged’ but I spent all of 25 hours on this thing. I used everything from heat guns, to screw drivers, wedges, jacks and heating elements. This was by far the worst step in my opinion.

 

[cbr600rr]

Once the hull was split I was faced with pounds of water logged nasty foam.
I tore out literally 15+lbs of soaked foam.



I then had to remove the bulk head, this wasn’t exactly an easy task either. Once again I am not sure if the glue was just aged for too long, or what. A heat gun didn’t exactly melt the glue, it made it slightly brittle but that’s about it. I ended up standing in the hull and using an electric ceiling hoist to apply an upwards pressure to the bulkhead. This in addition to the heat gun and screwdrivers did the job.

<o> </o>
Once the hull was split, I was able to make slight modifications the hood and hull and then prep, and prime them.

 

[cbr600rr]

I also found out that the previous owner attempted to do a small reinforcement job on the underside of the side rail. The quality of his work was complete $%#@. So I spent a couple hours ripping out his reinforcement, using the dremel to carve out some cracks, apply epoxy and reinforcement in the correct fashion.

The bottom hull was also in terrible shape, I spent at least a couple days redoing the bottom of the hull.


Attached pics are the initial state of the bottom hull

 

[cbr600rr]

After spending some time repairing the hull, I had to patch up all the holes for bolts, gas switches, chokes/primers, exhaust, oneway, pisser, etc...
You need to make sure you patch these orifices because in the process of making the mould, resin would seep in these holes and you would never pop the plug out of the mould.

At this point, the hull was basically ready for making some moulds...

 

[cbr600rr]

I figured I would experiment first with the smallest and thus if something went wrong, the least expensive part.

So I decided to make a mould of the nose cone.
Attached flanging to the part, applied release agent, gelcoated, fiberglassed, popped part from mould. Once mould was done, I applied expoxy and carbon and vacuumed bagged.

Result,..ridiculously light and durable nose cone!

 

[cbr600rr]

After the success of the first part, I decided to attempt the hood next.

You will notice in the first picture, the hood is actually primed and not painted yet. This was my first mistake. Even though I applied the release agent the the hood, after gelcoating and making the mould I was not able to release the part from the mould! The primer was too porous and cause some problems, along with maybe not using enough release agent. At that point I wasn't very happy, I had even installed ports in the mould for injecting air or water to release the part but they weren't working.

I eventually had to cut the mould off the part, reprime and this time "paint" the hood, and start the process over. The second and rest of the pictures are of the "second" attempt.

The second one popped much easier, and I had a nice shiny mould. (edges of mould still needed to be trimmed in pictures)

 

[cbr600rr]

:::Second lesson learned:::

Always make sure you have "all" necessary supplies before you begin to vacuum bag a part lol.

I must have only initially bought a little bit of vacuum bag supplies because I didn't want to waste money if I decided to not finish this project.

The result was that I didn't have enough vacuum bag for the hood.
Of course I didn't find this out until after I applied all my composite layers, and epoxy. I was now reaching the end of the pot life for the epoxy and couldn't apply vacuum. So I did some quick thinking, and threw the original hood in the mould and used it as a 'press' haha.

It ended up working altight, although slight bridging occurred, but this was obviously expected. The hood weighs in at 6 lbs!!! (with no liner yet)

Note: if anyone is interested in this hood, PM me, I am looking to get rid of it.

 

[ADDict]

Very impressive!

 

[cbr600rr]

The next step, and the one I was looking forward to was the bottom hull! I spent a lot of time researching composites and contacted two of the only software developers in the world that focused on epoxy mould flow analysis and composite engineering. I was able to obtain demo software for resin injection simulations. Unfortunately I later decided not to use resin infusion due to the large investment going into the top and bottom decks, and didn't want to risk a layup that didn't fully wet out and be out upwards of a grand. I went with a wet layup that is vacuum bagged which many of the major manufactures use.

**the software would have been sweet, because It could be used to predict optimal vacuum and resin port locations,..oh well maybe next time around!

Regardless, I learned a lot about composites and did some test panels of carbon composites to see which was the optimal choice.

below are some half-a$$ed meshes I used in the software. The had element and nodal limits, so I couldn't get to fancy.

 

[MADMAT]

uumm....wow!

 

[cbr600rr]

Alright on the bottom hull,...

I used an orange gelcoat this time, no specific reason other than I found a cheaper supplier and as a bonus I think It is easier to tell when your fabric wets out!

Same process as before for mould,..
used the best composite I determined from previous tests.
and vacuum bagged!

The one thing I learned from this is that is would have been nice to have another person there to help. epoxy had a 1 hr pot life and this thing took more than that. It still turned out great, but next time I will need another person, or maybe split the vacuum session up in 2 parts!

 

[cbr600rr]

money shot haha, no but seriously I actually fought with this one in the mould for some time, the sound of it finally 'popping' from the mould was such a relief! lol

Lesson:: never enough mould release! wax mould at least 5-6 times prior to layup!

 

[keith t]

youve got some seriously good skills there mate

 

[cbr600rr]

youve got some seriously good skills there mate

thanks!

Very impressive!

thanks man, yeah I originally figured I could do this in like 4 months lol. However with finishing up my last semester and other stuff going on, and then winter! :aargh4: the process has taken a bit longer.

 

[cbr600rr]

Then I started up class in the fall again, and wasn't able to work as much on the project as I liked. Around christmas time, I really didn't feel like starting up the project again and was getting frustrated with 2-3 skis lying around the garage all in pieces. I decided to get 2 of my other skis back together and ready to sell.

The superjet that I used for this project, I finally got back together in one piece, and used 3M 5200 to glue them back in one solid piece! I then painted and primed it and threw the engine back in. Now I can get rid of this ski and make some garage space for the carbon one.

back to the carbon project....

 

[Big Kahuna]

Why make molds of the stock hood instead of re-shaping it to a lowered profile hood?

 

[cbr600rr]

Next I had to mock up a bulk head for the carbon ski,...I used 1.5 or 2" polystyrene (cant remember) for the bulkhead. I traced the original on onto the polystyrene and used a hot wire (rigged up to the elements on a hot glue gun lol) to slice out athe shape of the bulkhead.


Then mould building,....carbon layup....etc...

I was amazed with the result,...the thing fit like a glove! It looks pretty dull in the picture, but that was pretty much right out of the mould and I think I wet sanded it a bit. After some clear, it will look great!

 

[cbr600rr]

Why make molds of the stock hood instead of re-shaping it to a lowered profile hood?

Yeah that's a good question, well I wasn't sure how far I was going to take this project, after I had the nose cone done I was under the impression that a lowered hood would not match the nose cone. So I just went with the original height. I removed some features from the original hood, and obviously blocked out the extinguisher box.

Also I've never really used a smaller hood, so perhaps I have not 'experienced' why they are so great lol... anyways, at 6lbs, whats the difference really?

If I make some new moulds, I would definitely consider it though!