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fibernoob
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Group: Forum Members
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Hi all. I am having some trouble with the covering of a complex part. (Automotive gear lever surround) The CF Fabric is not responding well to the contours and hole in the center. Lifting with resin etc etc.... I have tried a quick method using vacuum bagging material and the pump ... It seems to be ok so far..but haven't seen much info on doing things this way. Just curious to know if anyone else has tried this. Im still testing the best way to adapt the fabric to the part ...but it seems like a possible shortcut to covering complex parts - Cover the part in CF Fabric
- Cover part with Resin
- Cover wet part with peel ply
- Set in bag and apply vacuum.
- After part has dried ... sand the marks from the peelply using thin sandpaper....
- Apply normal layers of resin as finishing coats.
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scottracing
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why are you using peel ply? you dont need to and also have you tried using spray tack to locate the dry fibre in position?
A couple of photos would be good too , but when you are trying to do a wet lay and vac bag you dont want to pull full vac as you will pull too much resin out.
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Interloper393
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The peel ply will leave a texture finish which iv found helps grip next coat, I still sand just to be sure  also means bag can be reused. I tack spray the cloth to the piece, wet the fabric , apply peel ply then vac bag. Iv started to use poly resin as it' much quicker wit the extra work with the vac bagging plus parts and cured in 2mins XD
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fibernoob
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Group: Forum Members
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+xThe peel ply will leave a texture finish which iv found helps grip next coat, I still sand just to be sure also means bag can be reused. I tack spray the cloth to the piece, wet the fabric , apply peel ply then vac bag. Iv started to use poly resin as it' much quicker wit the extra work with the vac bagging plus parts and cured in 2mins XD Yes, ... If more resin will be used I often sand it down with thin sand paper because if the texture is left , small dots can be seen from the layers above. If more carbon is to be used, i think the texture is great for the next layers to grip. I am still using epoxy and experimenting ...but it helps a lot with tight curves and nasty angles that the CF does not want to contour.
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fibernoob
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Group: Forum Members
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+xwhy are you using peel ply? you dont need to and also have you tried using spray tack to locate the dry fibre in position? A couple of photos would be good too , but when you are trying to do a wet lay and vac bag you dont want to pull full vac as you will pull too much resin out. I am using peel ply because if i use the vacuum bag directly it will stick to the resin ... Ive used spray tack but with the part im doing ... its loosens up the fabric especially on the plastic rib just arrounf the center hole. (location of the gear boot) The resin stays under the peel ply... the vac is mainly to tighten the fabric to the parts contours. This is the part i am trying to skin....  And this is the desired end result.
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Hanaldo
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That part shouldn't be difficult to do without vacuum, it sort of sounds like you aren't leaving the initial cost of resin long enough before applying the carbon/further coats of resin.
But, there's no harm in using vacuum either, so long as you don't pinch the fabric or get lots of bridging.
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MarkMK
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It might also help to attach a temporary flange to the inner edge of the part to give the fabric some additional surface to grip to. Making this flange follow the angle of the lip would likely make the fabric less likely to want to lift, especially if you're currently trying to fold it around the inner circle
I wouldn't be averse to the idea of using separate pieces of fabric for the lower sides of the parts also. This will leave an overlap to deal with in your finishing, but would allow you to put some small cuts in the corners of your main piece of fabric which will help maintain the weave alignment on top and, perhaps, ensure there's less 'pull' on the fabric when trying to get the area around the centre hole to conform. If the fabric's cut and placed neatly, I'm sure that a great finish is possible
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fibernoob
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Group: Forum Members
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+xIt might also help to attach a temporary flange to the inner edge of the part to give the fabric some additional surface to grip to. Making this flange follow the angle of the lip would likely make the fabric less likely to want to lift, especially if you're currently trying to fold it around the inner circle I wouldn't be averse to the idea of using separate pieces of fabric for the lower sides of the parts also. This will leave an overlap to deal with in your finishing, but would allow you to put some small cuts in the corners of your main piece of fabric which will help maintain the weave alignment on top and, perhaps, ensure there's less 'pull' on the fabric when trying to get the area around the centre hole to conform. If the fabric's cut and placed neatly, I'm sure that a great finish is possible Thanks Mark. Sometimes its just those small things that can mess everything up. I have considered using some fabric in the inner hole as you have mentioned. Thanks for the feedback.
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fibernoob
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+xThat part shouldn't be difficult to do without vacuum, it sort of sounds like you aren't leaving the initial cost of resin long enough before applying the carbon/further coats of resin. But, there's no harm in using vacuum either, so long as you don't pinch the fabric or get lots of bridging. Yes, bridging is the issue im trying to get around when using the vac. I will try again letting the resin come to a perfect tach stage to apply the fabric.... Thanks for the help
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fibernoob
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Here is a pic of the part Note the inner part still shows the peelply texture since it was not sanded. The outer part has already been wetsanded and ready for extra coats of resin. 
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