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AlpineCoupe
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Group: Forum Members
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Happy to report that the new mold worked! Thanks to all for the suggestions! Used FMS, Loctite 700, and then about 9 coats of partall wax and the part slid off of the mold while I was removing the peel ply! Bagged:  Out of the mold pre-trim:  And finally trimmed with the first one I made:  I'm pretty sure the one on the left (first one I made on the old mold) is way too resin rich. The one I de-molded yesterday seems to have a much better resin/ fiber ratio. I'm no expert though, maybe someone can look at the pictures and see if that seems right? Again thanks for all the help!
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AlpineCoupe
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Group: Forum Members
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+x+xLooks great and no doubt you'll have learned a lot from the experience that'll stand you in good stead when making more As mentioned previously, if you're building-up a mould from scratch, rather than looking to create one from your existing part in the usual way, it'd likely be best to give it a fibre-glass skin on top of any foam base. This should, hopefully, help everything hold together better when de-moulding. That said, de-moulding from a new mould can require some force, so weaknesses such as a relatively 'soft' surface coat or layers of filler underneath can be prone to breakage, even if quite thinly coated on a firm grp base . If you're looking to make a few more, then it might be worth creating a traditional gel coat/grp or epoxy mould, which should prove a lot more reliable. Yeah, I should have done the fiberglass as mentioned earlier in the thread. No doubt that will be part of the plan on the next one. I think I hesitated to make the mold in a traditional way (gel coat, fiberglass) because I wasnt sure how it would work to have just a hollow mold. As I type this I'm realizing there is no reason why it wouldnt work. Maybe that will be my next try! Just bumping this back up because I made another mold of the part, this time using the more traditional gel coat and fiber glass approach. Hope to get some carbon fiber laid up on it this week. 
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AlpineCoupe
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Group: Forum Members
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+xLooks great and no doubt you'll have learned a lot from the experience that'll stand you in good stead when making more As mentioned previously, if you're building-up a mould from scratch, rather than looking to create one from your existing part in the usual way, it'd likely be best to give it a fibre-glass skin on top of any foam base. This should, hopefully, help everything hold together better when de-moulding. That said, de-moulding from a new mould can require some force, so weaknesses such as a relatively 'soft' surface coat or layers of filler underneath can be prone to breakage, even if quite thinly coated on a firm grp base . If you're looking to make a few more, then it might be worth creating a traditional gel coat/grp or epoxy mould, which should prove a lot more reliable. Yeah, I should have done the fiberglass as mentioned earlier in the thread. No doubt that will be part of the plan on the next one. I think I hesitated to make the mold in a traditional way (gel coat, fiberglass) because I wasnt sure how it would work to have just a hollow mold. As I type this I'm realizing there is no reason why it wouldnt work. Maybe that will be my next try!
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MarkMK
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Looks great and no doubt you'll have learned a lot from the experience that'll stand you in good stead when making more
As mentioned previously, if you're building-up a mould from scratch, rather than looking to create one from your existing part in the usual way, it'd likely be best to give it a fibre-glass skin on top of any foam base. This should, hopefully, help everything hold together better when de-moulding.
That said, de-moulding from a new mould can require some force, so weaknesses such as a relatively 'soft' surface coat or layers of filler underneath can be prone to breakage, even if quite thinly coated on a firm grp base
. If you're looking to make a few more, then it might be worth creating a traditional gel coat/grp or epoxy mould, which should prove a lot more reliable.
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AlpineCoupe
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Well got the part made... and ran into a problem when de-molding it. Turns out the mechanical lock was too much for the connection between the foam and the board I adhered it to. So a one and done mold. On a positive note though, the part looked good when I got all of the foam out of the center! On to attempt number 2 at making a mold! Bagged:  Attempted de-molding, and mold failure:  Foam removed, still needs to be trimmed: 
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AlpineCoupe
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+xThat approach to laying down the fabric sections looks okay. You could likely do away with a separate surface piece at the horizontal base and just make the side section pieces a touch longer so that they extend down onto the base. Some diagonal cuts made at the overlapped corners should make everything look quite neat when finished Thanks! That's a good suggestion!
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MarkMK
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Group: Forum Members
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That approach to laying down the fabric sections looks okay. You could likely do away with a separate surface piece at the horizontal base and just make the side section pieces a touch longer so that they extend down onto the base. Some diagonal cuts made at the overlapped corners should make everything look quite neat when finished
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AlpineCoupe
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I think I'll use PVA on the first one I make just to ensure everything comes apart. As far as how to lay the carbon fabric I was thinking about using 5 different pieces with slight overlap to cover the piece, like in the picture below. Does anyone see any issues with doing it this way? 
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Lester Populaire
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+xJust wanted to say that I moved forward with primer and clear coat on this mold. Going to do some finish sanding and then seal the mold in some way. Thinking I might go with partall wax and PVA just took be sure I don't get any lock up. Can anyone confirm this to be a reasonable idea? If not, no offense taken I'd rather do it the right way! I usually just use a paste wax (formula five) for the plug and as i had good luck with partall in the past I'm sure this would work. However, as it is a brake duct and you probably don't have big requirements in the surface quality you could use some PVA on top of that. Belt and suspenders type approach. I hate PVA and think it is too fiddly tho
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AlpineCoupe
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Group: Forum Members
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Just wanted to say that I moved forward with primer and clear coat on this mold. Going to do some finish sanding and then seal the mold in some way. Thinking I might go with partall wax and PVA just took be sure I don't get any lock up. Can anyone confirm this to be a reasonable idea? If not, no offense taken I'd rather do it the right way! 
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