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Carbon fiber roof - making the mold
Carbon fiber roof - making the mold
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Carbon fiber roof - making the mold
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BlackNDecker
BlackNDecker
posted 10 Years Ago
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Greetings all,
I bought a brand new OEM steel roof and plan to make a mold and eventually a carbon fiber roof.
A little background...My car is a 2007 Honda Civic Si and comes with a heavy sun roof assembly (this comes standard from the factory). I contemplated simply swapping roofs for the OEM "non-sunroof" steel roof. That would save me around 20 lbs...but instead of going that direction I've decided to make a carbon fiber roof and hopefully save 30+ lbs.
Some pictures of my progress...
Made some progress on the roof project.
Transferred it out to the garage:
The antenna hole will be covered:
And the tabs for the weather seal have to be cut off:
Luckily I have a Dremel for these types of projects:
Made some flanges:
Antenna hole covered (with a fresh coat of wax):
Flanged, waxed, and ready to go...
Unfortunately, it's going to be too humid all weekend to lay the gel coat...so I'll probably have to wait until Monday or Tuesday. fml
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Hanaldo
Hanaldo
posted 10 Years Ago
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A lot of effort to go through for little reason. Firstly, the first layer behind the gelcoat is the critical one that you don't want voids behind. The gelcoat is what needs the support, after that first layer any voids in the mould aren't too critical. Obviously this is within reason, you don't want large areas of bridging or large/lots of voids. But regular laminating techniques, so good stippling with the brush and then going over the entire mould with a roller, will ensure that those voids don't occur.
Secondly, you haven't got any angles there that 450g csm couldn't easily conform to. In fact, I don't see anything there that even a 850g couldn't cope with, with a bit of rolling.
Smoothing that transition out isn't worth the time and effort you out into it. Just go on with the csm.
If I might make a suggestion, that panel is quite large and flat. So I think you will find that the usual mould layup of 4-5 layers of 450g csm will still be a bit flexible. Couple options you have, one is just to live with the flex and hope it doesn't flex under vacuum and result in a distorted panel. Another option is to put a few extra layers of 450 on. But what I would do, to save resin/expense/weight, is do 2 layers of 450g csm and then 2 layers of 850g woven rovings, followed by another layer of 450 csm. Let that cure, then if it still isn't rigid enough, laminate some stiffeners onto the back (12mm mdf is my choice, can also use cardboard tube cut in half, coremat, etc) in the direction of the flex.
Not sure if EC have 850g woven fibreglass, they might not. In that case just go with 5-6 layers 450 and then the stiffeners on the back if they are needed.
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Carbon fiber roof - making the mold
BlackNDecker
-
10 Years Ago
I decided to go ahead and lay down some gel coat this afternoon. It is really hard to get everything...
BlackNDecker
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10 Years Ago
Really narrow flanges, will you be infusing?
Hanaldo
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10 Years Ago
Yes and yes. The flanges are pretty narrow...about 2.5". I'm a little nervous about brushing on...
BlackNDecker
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10 Years Ago
Yeh it's a harrowing time haha. What temperature is it where you are working and what did you...
Hanaldo
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10 Years Ago
I catalyzed at exactly 1.5%... Tomorrow looks like this:...
BlackNDecker
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10 Years Ago
Hmmm, could be an issue. I would be using 2% catalyst at 25 degrees and INCREASING that level for...
Hanaldo
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10 Years Ago
Thanks for the back and forth. Sometimes it's just nice to talk through the stress of mold making....
BlackNDecker
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10 Years Ago
Yeh so have I! Don't think you can play the game without having a few losses... For what it's...
Hanaldo
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10 Years Ago
That is a really good tip...but in addition to varying temperature, we have widely varying humidity...
BlackNDecker
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10 Years Ago
This was my stopping point when I ran out of resin:...
BlackNDecker
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10 Years Ago
How many "layers" of wax did you used? I follow your project with interest :)
Jacopo Carbonio
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10 Years Ago
I laid down about 4-5 coats of heavy wax. I think this will be enough since this is a brand new,...
BlackNDecker
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10 Years Ago
Is that bridging all along the back edge or did you use a filler of some sort?
Hanaldo
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10 Years Ago
I used a slurry of chopped glass fibers mixed with resin and worked it into the corners all the way...
BlackNDecker
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10 Years Ago
Sanded the whole mold down and filled some voids with Duraglas......
BlackNDecker
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10 Years Ago
Looking good.
Hanaldo
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10 Years Ago
Thanks. I think I'm going to smooth out the transition all around the perimeter with long-strand...
BlackNDecker
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10 Years Ago
A lot of effort to go through for little reason. Firstly, the first layer behind the gelcoat is the...
Hanaldo
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10 Years Ago
Thanks for all the help. I took your advice and applied two more layers of heavy CSM then heavy...
BlackNDecker
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10 Years Ago
Canvas? Interesting. Haven't heard of that being used in composites before?
Hanaldo
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10 Years Ago
It's a heavy cloth that saturates with resin...any reason why it wouldn't work? BTW, this forum...
BlackNDecker
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10 Years Ago
Well what's the modulus of canvas? Denim is a cotton fabric and will absorb a lot of resin but it...
Hanaldo
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10 Years Ago
Depending on the type of "canvas" it may work just fine .. It will add some strength, but not nearly...
Dravis
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10 Years Ago
Finally done with the mold. I have about 6 layers of chop strand mat and 1-2 layers of heavy weight...
BlackNDecker
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10 Years Ago
I think it might be useful to put reinforcements also horizontal and diagonal to prevent flex as you...
Jacopo Carbonio
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10 Years Ago
i cant wait to see more. This is a project ive often thought of doing
kidpaint
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10 Years Ago
The mold is done and the OEM roof pulled cleanly with surprisingly no drama....
BlackNDecker
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10 Years Ago
That looks excellent, congrats and well done. Is the mold a little flexy for your liking now that...
redeye
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10 Years Ago
Yes, it's a little flexy from corner to corner, but not so much that it will be an issue. I think...
BlackNDecker
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10 Years Ago
That will repair no problem. Once the repair is filled, its just a case of flatting back then...
Warren (Staff)
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10 Years Ago
Repair it mate, like Warren says its cut out, fill,sand then polish. You will regret it as the...
VVS
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10 Years Ago
Thanks gents...looks like I will be spending some time on minor repairs. I will use the chisel,...
BlackNDecker
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10 Years Ago
If you take a look at the last picture I posted on my bike build you will see a mould done using the...
VVS
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10 Years Ago
[quote][b]VVS (13/06/2015)[/b][hr]If you take a look at the last picture I posted on my bike build...
BlackNDecker
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10 Years Ago
Definitely worth repairing, especially given it is a large flat surface. Will only take 20 minutes...
Hanaldo
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10 Years Ago
These are very small, shallow surface imperfections in confined areas... Should I: a) sand and...
BlackNDecker
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10 Years Ago
Nah use a scalpel to pick away any loose bits and just scratch up the imperfections. Then use a pop...
Hanaldo
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10 Years Ago
[quote][b]Hanaldo (13/06/2015)[/b][hr]Nah use a scalpel to pick away any loose bits and just scratch...
BlackNDecker
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10 Years Ago
Yeh it'll be fine. Scratch it up well, it's just easier than trying to sand inside the alligatoring....
Hanaldo
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10 Years Ago
Looking good ! Repairing those little alligators will be easy, just grind out an neat shape and...
davro
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10 Years Ago
Thanks so much! I was really hesitant to chisel out and/or try to sand all these superficial...
BlackNDecker
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10 Years Ago
Decided to put some work in on the mold. I pulled it out to the back yard for trimming:...
BlackNDecker
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10 Years Ago
I would give that voided area a real good prodding with a rigid tool to see if it caves in. If still...
Warren (Staff)
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10 Years Ago
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