Hello Guys!

Have been off the scene for a while, but I feel a project coming up very shortly. Have been flying a lot of model aircraft lately and have a beauty of a waterplane. The thing is it came with some very very light glass fiber floats, I assume about two layers max. of some light cloth. Some harder landings cause them to crack in sum places and flex causing paint to chip off. I would like to produce them in Carbon Fiber, (2 layers light cloth 90 or 130 g per sqm) in infusion, possibly with inmould coating/gel coat.

My initial questions to everybody out there now are, what would be the best way to go about making these moulds, ideally I would make a two part (seperate, not split) vertically down the center line, so the parts could be subsequently joined.

The pictures show the potential plug I will be using.



 




I would make two moulds (halves) for one float, because they are symetric, apart from the tabs, which can be subsequently installed in a mirrored fashion.

I would be willing to cut a float lengthways if needed. Was planning to try the unimould system.

All ideas are welcome! Lets hear them!

Cheers

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Seems like a straight forward split mould, and it sounds like you've got it thought out, so go for it? No need to cut anything, just use coreflute or polypropylene sheet to produce a barrier down the centreline. 

That looks like a Macchi M72 ?? ....

As above ... That can be done as a straight split mould, down the centreline  ...  Do a couple of layers of a light weight Carbon cloth --  Lay up/infuse two halves ,, fill with some sort of foam .. or glue in cross walls.

"Sapere Aude"... Dare to KNOW!

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Thanks guys for the replies! much appreciated as always. Yes Dravis you are spot on! that is a Macchi MC72 and she flies like a dream I tell you.

I think I will try a straight down the center split mould. The reason I was thinking to cut one down the center was because the material is so thin and deforms very easily. I was planning to reinforce and then take a mould.

Is it possible to apply the uni mould system carefully? (ie without denting the surface thus risk getting an inaccurate mould?) I've only used the mould putty so far, and for that a very rigid surface is needed underneath.

Furthermore, what are suggestions regarding the seamless joining of the two halves?

Cheers!

Do you need to save/keep the originals? Then you may be in a bit of a spot ...     I would drill a few holes in one, and then fill it with expanding foam, the kind you buy in a "spray-can" for building work.

Make sure to make enough holes to make sure the foam does not build up pressure inside... Then fill it with foam very quickly, and just let the excess foam pour out of the holes .. remember to wax the outside thoroughly or tape it up, so you can remove the excess foam .. it sticks like crazy to almost everything.. including skin and clothes ...

Once this foam has cured, the float will be much more rigid, and you should be able to use the Unimould system on it without any problems of deforming it.

Once done, test the new weight of the float.... it might still be usable.. i.e. not very much heavier than before, but stronger ...

Remember ... this is just an idea of how to reinforce the float in a simple and easy way, I make NO guarantees that it will work, since I do not know the strength of the float walls...

About the Macchi MC72 .. A guy here in DK has one built in a very large scale .. I think its close to 3 meters long, with custom made gearbox and double props, just like the real plane... It has a V12 four-stroke "Scale model "engine, that some old guy in the UK built many years ago ... I made some new parts for the engine a few years back, Titanium parts that is ...
The sound it makes just makes your hair stand up ....  Imagine what the original 24 cylinder 3000Bhp engine must have sounded like ...

The same guy also has a smaller model of the Bugatti 100P ...    If I was a billionaire, I would have someone build me a real one of those .... Pure beauty on wings ..

"Sapere Aude"... Dare to KNOW!

The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind...

103% of all people do not understand statistics...

Do not adjust our mind, theres a fault in reality :-)

I don't see why the unimould system should be so hard to apply as to be unable to apply it to the floats as they are? They are strong enough to fly and land, and I am certain this would involve a lot more forces than simply laying up a mould. I mean I've used filleting wax to produce general shapes and take moulds from that without any distortion, so I am sure these floats would be strong enough? 

@Hanaldo ... I'm sure you're right ... If the floats will stand up to then plane landing and taking off, they should not deform when laying up the unimould system, however I am a bit worried about the need to use rollers e.t.c when laying up the Chopped strand mat, and getting a good, void free secondary reinforcement on the mould. I know that I tend to have to put a bit of pressure on that roller ...

"Sapere Aude"... Dare to KNOW!

The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind...

103% of all people do not understand statistics...

Do not adjust our mind, theres a fault in reality :-)

True, but in my experience the tooling gelcoat itself will give a degree of stiffness. Certainly strong enough to apply the first layer of reinforcement to, and then after that you can lean on it a bit harder. You really shouldn't have to push on the roller that hard for one layer of glass, if you do then it's better to work the air bubbles out a bit with the brush first, then roll it.