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AndrewL92
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Group: Forum Members
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+xNo reason why you can't use it, some of those flange shapes are going to make things challenging for you but it's certainly usable. You either need to seal the flanges with something before bolting them together, or you will need to envelope bag the entire thing. Envelope bagging I find quite unreliable for infusion due to the propensity for leaks, especially on larger complex moulds like this, so I try to avoid it. for sealing the flanges, the easiest and most reliable way I've found is to use an RTV silicone gasket maker (do NOT use an adhesive caulking silicone, these will bond your flanges together regardless of release agent). The downside is this is a bit difficult to clean up after the infusion, so it becomes a bit of a pain to reuse the moulds. Another way I do it is to run a 'bead' of gelcoat all around the flanges, and then bolt the flanges together before the gelcoat cures. This is significantly easier to clean up, but doesn't seal as reliably as the silicone gasket. Using either method, don't forget to seal up your bolt holes as well. Thanks for the reply. I understand what you said. The only doubt I have is how to arrange the taky tape all around the perimeter, without any leakage, especially where the vertical and horizontal flanges join or in other parts where there are fairly tight curves. Maybe it's my inexperience that makes me see the problem! Another way I had thought of to proceed with the infusion was to slightly cut out the upper flanges to create a bead of a couple of cm along the entire perimeter to apply the taky tape. This way I would only have to finish the top flanges and would only need to seal the bolt holes. What do you think about it? I hope I explained myself.
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Hanaldo
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Group: Forum Members
Posts: 2.5K,
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+x+xNo reason why you can't use it, some of those flange shapes are going to make things challenging for you but it's certainly usable. You either need to seal the flanges with something before bolting them together, or you will need to envelope bag the entire thing. Envelope bagging I find quite unreliable for infusion due to the propensity for leaks, especially on larger complex moulds like this, so I try to avoid it. for sealing the flanges, the easiest and most reliable way I've found is to use an RTV silicone gasket maker (do NOT use an adhesive caulking silicone, these will bond your flanges together regardless of release agent). The downside is this is a bit difficult to clean up after the infusion, so it becomes a bit of a pain to reuse the moulds. Another way I do it is to run a 'bead' of gelcoat all around the flanges, and then bolt the flanges together before the gelcoat cures. This is significantly easier to clean up, but doesn't seal as reliably as the silicone gasket. Using either method, don't forget to seal up your bolt holes as well. Thanks for the reply. I understand what you said. The only doubt I have is how to arrange the taky tape all around the perimeter, without any leakage, especially where the vertical and horizontal flanges join or in other parts where there are fairly tight curves. Maybe it's my inexperience that makes me see the problem! Another way I had thought of to proceed with the infusion was to slightly cut out the upper flanges to create a bead of a couple of cm along the entire perimeter to apply the taky tape. This way I would only have to finish the top flanges and would only need to seal the bolt holes. What do you think about it? I hope I explained myself. Yes that's definitely the tricky bit now, I can foresee you struggling with leaks. I'm not sure i follow what you mean about cutting the flanges. I certainly wouldn't make them any shorter if that's what you are thinking??
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AndrewL92
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Group: Forum Members
Posts: 6,
Visits: 103
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I'm probably saying nonsense but yes, the idea was to include the top flanges in the bag. I made an image to make you see well. The black lines are where I would like to cut, and the red one where I would place the taky tape.  Nonsense?
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Hanaldo
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Group: Forum Members
Posts: 2.5K,
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Oh I see, no dont do that. Resin will go everywhere and make a big mess, and you will likely still struggle to get a seal due the bolt holes.
Just run your sealant tape around the perimeter of the flange as it is and try to get it to seal like that. Good chance it won't, so then I would double bag and place the entire mould inside an envelope bag. The first bag will prevent resin from going where you dont want it, while the second will provide the seal. Just watch out for puncturing the second bag on the mould or your bolts.
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AndrewL92
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Group: Forum Members
Posts: 6,
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+xOh I see, no dont do that. Resin will go everywhere and make a big mess, and you will likely still struggle to get a seal due the bolt holes. Just run your sealant tape around the perimeter of the flange as it is and try to get it to seal like that. Good chance it won't, so then I would double bag and place the entire mould inside an envelope bag. The first bag will prevent resin from going where you dont want it, while the second will provide the seal. Just watch out for puncturing the second bag on the mould or your bolts. Perfect, then proceed as you advised me. In this regard, I had some questions: 1. if I use gelcoat, to make a bead between the flanges, as you advised, how long do I have to wait to close the flanges together? As soon as I apply the gelcoat? And to proceed with the infusion? Can i use a gelcoat additive? 2. How do I seal the bolt holes? By applying the gelcot in the hole and then screwing? 3. What reinforcement do you recommend for these fenders? Would it make sense to use lantor soric? Thanks again for your availability
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Hanaldo
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Group: Forum Members
Posts: 2.5K,
Visits: 28K
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+x+xOh I see, no dont do that. Resin will go everywhere and make a big mess, and you will likely still struggle to get a seal due the bolt holes. Just run your sealant tape around the perimeter of the flange as it is and try to get it to seal like that. Good chance it won't, so then I would double bag and place the entire mould inside an envelope bag. The first bag will prevent resin from going where you dont want it, while the second will provide the seal. Just watch out for puncturing the second bag on the mould or your bolts. Perfect, then proceed as you advised me. In this regard, I had some questions: 1. if I use gelcoat, to make a bead between the flanges, as you advised, how long do I have to wait to close the flanges together? As soon as I apply the gelcoat? And to proceed with the infusion? Can i use a gelcoat additive? 2. How do I seal the bolt holes? By applying the gelcot in the hole and then screwing? 3. What reinforcement do you recommend for these fenders? Would it make sense to use lantor soric? Thanks again for your availability 1. Yes, bolt the flanges together as soon as you have applied the gelcoat. In all likelihood you will find the gelcoat will be starting to thicken up as you are ready to bolt the flanges on, which is perfect. As long as you get them bolted together before the gelcoat cures too hard to allow that then you're fine. 2. I generally just run a 'ring' of gelcoat around the hole and that will seal it up when you bolt the flanges together. Having a small rattlegun will make it quicker to remove the bolts when you are done as you will likely find gelcoat gets squeezed up into the threads, but even if you don't have a rattlegun its not hard, the gelcoat doesn't stick well to steel bolts. 3. Depends totally on your application. For a race car, I'd be doing a single layer of 200g and a single layer of ~400g, a bit extra in the mounting points, and thats it. For a street car, I probably still wouldn't use a core, but I would probably do 2 layers of 200g, 1 layer of a 400g Kevlar, and 1 layer of a 400g carbon.
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beliblisk
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Group: Forum Members
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Put mixed gelcoat in plastic food bag, squeeze it in one corner, twist bag around so you end up with all gelocoat trapped in one corner and then just nipp off tge corner (much like if you are baking cakes) and you will be able to apply nice lines quickly without any mess  For layup you can go as low as one 200g cf followed by 200 cf/kevlar hybrid as there is enough geometry on your side(extra 400g on the mounting points)..... for street car i normally go with 1mm in total for fenders.
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