Peças em Fibra de carbono

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Peças em Fibra de carbono

Mensagem  carlosfilipe94 em Dom 06 Mar 2011, 19:48

Boas...

Encontrei este topico no SMJ e achei interessante e ate possivelmente um assunto para testar e dar opinioes como fazer! Very Happy

=jaywood;970436]here ya go! hope it makes sense...

the resin i am using is silmar 249...and yes it is a polyester
http://www.shopmaninc.com/polyesters.html

you can also find carbon fiber from that website...i used an 11 ounce twill weave...
http://www.shopmaninc.com/carbonpage.html

in order to make the mold, you have to have your old piece..mine being this...



you can also make your own part with foam used for sculpting...not sure what it's called...but then you would cover it in bondo, sand it and smooth it out, then there's your own part...that you shaped..to your liking

for my mold, I made a stand for my heat guard and glued that to a bigger piece of wood....you always want your part to be stable and not move when you're applying resin.....

once you have that...cover your part in wax...I used carnauba car wax...do 3-4 layers of wax...be generous

allow that to dry....10 minutes or so...then cover your part in resin

once your first layer of resin gets tacky, apply another layer of resin.

when your second layer of resin is tacky..... I usually do 3 layers resin.....put one more layer of resin on. you only need to do 2 layers, but with 3..your mold will be less stressfull to sand because you won't have to worry about sanding into the fiberglass:)

now that your third, maybe second if you only did 2 layers, layer is tacky..you can use fiberglass mat, or fiberglass weave..whichever you prefer...i used mat...and cover your piece with it. be sure to get all the areas of the part. it's fine if you have extra fiberglass draping down the side...if you want your part stronger, repeat this process with another layer of fiberglass...I'm always worried about strength so I did 2 layups of fiberglass...

sorry I don't have pictures of laying up the fiberglass...but here's my mold....









as you can see...the mold is much different then the original part. I used a dremel and sandpaper to get rid of those bumps where the bolts go through....

I did this because trying to apply carbon fiber around those curves would be really tricky...and since I'm not using a vaccuum bag..impossible without getting big defects in your new carbon piece:headscrat

after I reshaped it..I sanded everything with 400 wet...600 wet...and then 1500 wet. you want the mold to be as smooth as possible. a few reasons...your final part will require less sanding.. and itll pop out shinier and easier from the mold

I then cut 2 strips of wood and glued them to the bottom of the mold....this gives it a sturdy base and you can glue it easier to the work table or your piece of wood youre working on





now for the carbon layup...


first...wax your mold. I used carnauba car wax, then a pva release agent on top of the wax
once again, sorry I don't have pictures of these steps, but I think it's pretty to understand:thumbup:


once your wax, or pva dries...brush a layer of resin on the mold...don't use too much. you don't want it to puddle in the center...any puddling will make a defect in your part..if any resin starts building up in the center, try moving it around from where it's puddling


allow that to get tacky...then brush another layer of resin over that...again, be as even as possible and avoid puddling


I usually do 3 layers of resin, so repeat that step above once your second layer is tacky.


once the third layer dries to a tackiness, lay your carbon fiber down....start in the center and work your way out...this is a lot easier with two people


then use your resin roller and roll ALL the bubbles out...also make sure the carbon is sticking to the resin around all your weird curves and corners...this is the side that you're going to see when it's on your bike so you want it as perfect as possible..then brush some more resin on the carbon...


once again let it get tacky...then do another layer of carbon...you could use fiberglass but if your weave got messed up when you were putting on the first layer of carbon...the fiberglass will show through and not look so good...so I always use carbon as the first and second layers to get the best finish... then repeat this process


i always use at least 4 layers of carbon/fiberglass to get a good strong part


when it pops out it should look like this..




there are air bubbles...
sand them with 320...then brush a layer of resin over them to fill them in and then sand again with 320 to get excess resin off


whenever you sand be sure to wear a mask or respirator or a dan and a vaccuum or something to stop the crystals from getting in your lungs! you do NOT want to breathe this stuff...

I used a dremel to get the shape I wanted and then this homemade tool to finish the edges and get them straight....its a block of plywood with sandpaper wrapped around it:thumbup:

once you have your desired shape you are going to want to sand it all with 400 wet, 800 wet, and 1500 wet. then take it to a buffer...put some rouge on it...buff it...take the rouge off of the wheel..rub your carbon piece with a liquid buffing compund...and buff off the compound

i used on of these...



it should look like this when its polished:D



i did drill holes as you can see...




youre going to want to start out with a small drill bit and work your way up to the bigger sizes...tape where youre drilling so it doesnt fray:)



if you have any questions feel free to ask...ill do my best to answer:thumbup:

carlosfilipe94

Data de inscrição : 13/04/2010
Idade : 22
Localização : Barcelos

http://www.facebook.com/home.php#!/profile.php?id=10000144934360

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Re: Peças em Fibra de carbono

Mensagem  Hugu em Dom 06 Mar 2011, 19:53

É praticamente o mesmo k trabalhar com fibra de vidro, tá fixe! thumbup

Hugu

Data de inscrição : 24/10/2010

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