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jameslawson
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So I have laminated small car interior trims with carbon fiber in the past, however now I'm embarking on a much more ambitious challenge.. I want to wrap the middle of my car bonnet in the V style carbon fabric. I bought a spare second hand bonnet which is made from aluminium and is sort of flexible. My plan is to palm sand the paint off, prep the middle area, spread on some base coat, hand lay the fabric, vacuum bag it for a perfect flat result before then painstakingly applying the resin coats. Is there anything I should be reconsidering or not doing here with this plan? I have always used the XCR epoxies but I'm worried about the heat resistance.. it doesn't get super hot but the car runs a pretty warm inline 6. Will the XCR resin stand up to this or do I really need to go with the high temp epoxies which have that unfortunate yellow look to them? Here's a mockup I made in photoshop.. ideally I'll overlap the middle, then when its complete my bodyshop who's going to paint it will presumably use filler to blend between the epoxy and aluminium to create a seamless transition before painting the main and power dome section.  Many thanks - I really appreciate any advice that can be provided. In my mind this is just one huge panel that I need to hand lay, but I will only have around 2-3 weeks to complete this in due to garage space so I want to try and prepare for everything.
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Lester Populaire
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+xSo I have laminated small car interior trims with carbon fiber in the past, however now I'm embarking on a much more ambitious challenge.. I want to wrap the middle of my car bonnet in the V style carbon fabric. I bought a spare second hand bonnet which is made from aluminium and is sort of flexible. My plan is to palm sand the paint off, prep the middle area, spread on some base coat, hand lay the fabric, vacuum bag it for a perfect flat result before then painstakingly applying the resin coats. Is there anything I should be reconsidering or not doing here with this plan? I have always used the XCR epoxies but I'm worried about the heat resistance.. it doesn't get super hot but the car runs a pretty warm inline 6. Will the XCR resin stand up to this or do I really need to go with the high temp epoxies which have that unfortunate yellow look to them? Here's a mockup I made in photoshop.. ideally I'll overlap the middle, then when its complete my bodyshop who's going to paint it will presumably use filler to blend between the epoxy and aluminium to create a seamless transition before painting the main and power dome section. Many thanks - I really appreciate any advice that can be provided. In my mind this is just one huge panel that I need to hand lay, but I will only have around 2-3 weeks to complete this in due to garage space so I want to try and prepare for everything. +xSo I have laminated small car interior trims with carbon fiber in the past, however now I'm embarking on a much more ambitious challenge.. I want to wrap the middle of my car bonnet in the V style carbon fabric. I bought a spare second hand bonnet which is made from aluminium and is sort of flexible. My plan is to palm sand the paint off, prep the middle area, spread on some base coat, hand lay the fabric, vacuum bag it for a perfect flat result before then painstakingly applying the resin coats. Is there anything I should be reconsidering or not doing here with this plan? I have always used the XCR epoxies but I'm worried about the heat resistance.. it doesn't get super hot but the car runs a pretty warm inline 6. Will the XCR resin stand up to this or do I really need to go with the high temp epoxies which have that unfortunate yellow look to them? Here's a mockup I made in photoshop.. ideally I'll overlap the middle, then when its complete my bodyshop who's going to paint it will presumably use filler to blend between the epoxy and aluminium to create a seamless transition before painting the main and power dome section. Many thanks - I really appreciate any advice that can be provided. In my mind this is just one huge panel that I need to hand lay, but I will only have around 2-3 weeks to complete this in due to garage space so I want to try and prepare for everything. Quick disclaimer as I've never done anything like this. But personally i would use a resin with at least 100°C Tg, but the higher the better to reduce print through in the final result. A resin like a Huntsman 5052 would probably be a good choice with a Tg of 130°C and is pretty clear, and easy to hand laminate with. I am worried about the thermal behavior and I'm not sure to what degree the carbon would warp the bonnet while post curing (you need to post cure to get the Tg). Other might have experience with this. Other than that I would definitely add a very thin fiberglass layer between the carbon and aluminum to avoid galvanic corrosion. Hope that makes sense!
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jameslawson
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Group: Forum Members
Posts: 11,
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+x+xSo I have laminated small car interior trims with carbon fiber in the past, however now I'm embarking on a much more ambitious challenge.. I want to wrap the middle of my car bonnet in the V style carbon fabric. I bought a spare second hand bonnet which is made from aluminium and is sort of flexible. My plan is to palm sand the paint off, prep the middle area, spread on some base coat, hand lay the fabric, vacuum bag it for a perfect flat result before then painstakingly applying the resin coats. Is there anything I should be reconsidering or not doing here with this plan? I have always used the XCR epoxies but I'm worried about the heat resistance.. it doesn't get super hot but the car runs a pretty warm inline 6. Will the XCR resin stand up to this or do I really need to go with the high temp epoxies which have that unfortunate yellow look to them? Here's a mockup I made in photoshop.. ideally I'll overlap the middle, then when its complete my bodyshop who's going to paint it will presumably use filler to blend between the epoxy and aluminium to create a seamless transition before painting the main and power dome section. Many thanks - I really appreciate any advice that can be provided. In my mind this is just one huge panel that I need to hand lay, but I will only have around 2-3 weeks to complete this in due to garage space so I want to try and prepare for everything. +xSo I have laminated small car interior trims with carbon fiber in the past, however now I'm embarking on a much more ambitious challenge.. I want to wrap the middle of my car bonnet in the V style carbon fabric. I bought a spare second hand bonnet which is made from aluminium and is sort of flexible. My plan is to palm sand the paint off, prep the middle area, spread on some base coat, hand lay the fabric, vacuum bag it for a perfect flat result before then painstakingly applying the resin coats. Is there anything I should be reconsidering or not doing here with this plan? I have always used the XCR epoxies but I'm worried about the heat resistance.. it doesn't get super hot but the car runs a pretty warm inline 6. Will the XCR resin stand up to this or do I really need to go with the high temp epoxies which have that unfortunate yellow look to them? Here's a mockup I made in photoshop.. ideally I'll overlap the middle, then when its complete my bodyshop who's going to paint it will presumably use filler to blend between the epoxy and aluminium to create a seamless transition before painting the main and power dome section. Many thanks - I really appreciate any advice that can be provided. In my mind this is just one huge panel that I need to hand lay, but I will only have around 2-3 weeks to complete this in due to garage space so I want to try and prepare for everything. Quick disclaimer as I've never done anything like this. But personally i would use a resin with at least 100°C Tg, but the higher the better to reduce print through in the final result. A resin like a Huntsman 5052 would probably be a good choice with a Tg of 130°C and is pretty clear, and easy to hand laminate with. I am worried about the thermal behavior and I'm not sure to what degree the carbon would warp the bonnet while post curing (you need to post cure to get the Tg). Other might have experience with this. Other than that I would definitely add a very thin fiberglass layer between the carbon and aluminum to avoid galvanic corrosion. Hope that makes sense! Thank you. When you talk about Tg are you referring to the temperature point in which the epoxy begins to soften again? I might try and get a temperature reading on the outer side of the bonnet after some hard driving, then I'll know for sure what the base layer is going to be roughly. Interesting hear about the corrosion, this is my first attempt at bonding carbon fiber to aluminium so it hadn't crossed my mind. So intheory I should be: sanding the old paint off > epoxying some fiber glass onto the sanded areas > then hand laying the carbon fabric down ?
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Lester Populaire
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Group: Forum Members
Posts: 311,
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+x+x+xSo I have laminated small car interior trims with carbon fiber in the past, however now I'm embarking on a much more ambitious challenge.. I want to wrap the middle of my car bonnet in the V style carbon fabric. I bought a spare second hand bonnet which is made from aluminium and is sort of flexible. My plan is to palm sand the paint off, prep the middle area, spread on some base coat, hand lay the fabric, vacuum bag it for a perfect flat result before then painstakingly applying the resin coats. Is there anything I should be reconsidering or not doing here with this plan? I have always used the XCR epoxies but I'm worried about the heat resistance.. it doesn't get super hot but the car runs a pretty warm inline 6. Will the XCR resin stand up to this or do I really need to go with the high temp epoxies which have that unfortunate yellow look to them? Here's a mockup I made in photoshop.. ideally I'll overlap the middle, then when its complete my bodyshop who's going to paint it will presumably use filler to blend between the epoxy and aluminium to create a seamless transition before painting the main and power dome section. Many thanks - I really appreciate any advice that can be provided. In my mind this is just one huge panel that I need to hand lay, but I will only have around 2-3 weeks to complete this in due to garage space so I want to try and prepare for everything. +xSo I have laminated small car interior trims with carbon fiber in the past, however now I'm embarking on a much more ambitious challenge.. I want to wrap the middle of my car bonnet in the V style carbon fabric. I bought a spare second hand bonnet which is made from aluminium and is sort of flexible. My plan is to palm sand the paint off, prep the middle area, spread on some base coat, hand lay the fabric, vacuum bag it for a perfect flat result before then painstakingly applying the resin coats. Is there anything I should be reconsidering or not doing here with this plan? I have always used the XCR epoxies but I'm worried about the heat resistance.. it doesn't get super hot but the car runs a pretty warm inline 6. Will the XCR resin stand up to this or do I really need to go with the high temp epoxies which have that unfortunate yellow look to them? Here's a mockup I made in photoshop.. ideally I'll overlap the middle, then when its complete my bodyshop who's going to paint it will presumably use filler to blend between the epoxy and aluminium to create a seamless transition before painting the main and power dome section. Many thanks - I really appreciate any advice that can be provided. In my mind this is just one huge panel that I need to hand lay, but I will only have around 2-3 weeks to complete this in due to garage space so I want to try and prepare for everything. Quick disclaimer as I've never done anything like this. But personally i would use a resin with at least 100°C Tg, but the higher the better to reduce print through in the final result. A resin like a Huntsman 5052 would probably be a good choice with a Tg of 130°C and is pretty clear, and easy to hand laminate with. I am worried about the thermal behavior and I'm not sure to what degree the carbon would warp the bonnet while post curing (you need to post cure to get the Tg). Other might have experience with this. Other than that I would definitely add a very thin fiberglass layer between the carbon and aluminum to avoid galvanic corrosion. Hope that makes sense! Thank you. When you talk about Tg are you referring to the temperature point in which the epoxy begins to soften again? I might try and get a temperature reading on the outer side of the bonnet after some hard driving, then I'll know for sure what the base layer is going to be roughly. Interesting hear about the corrosion, this is my first attempt at bonding carbon fiber to aluminium so it hadn't crossed my mind. So intheory I should be: sanding the old paint off > epoxying some fiber glass onto the sanded areas > then hand laying the carbon fabric down ? Yes Tg is the glass transition temperature, which is the max operating temp. Realistically I'd shoot for at least 20°C higher than what it will see in use. Also note that the claimed Tg of a resin is only gonna be achieved after a post curing cycle, which means you'll need an oven the size of the bonnet. Glass and carbon can/should be laminated onto the bonnet in one go ideally for the best bond. Realistically the limiting factor is going to be the bond between aluminum and laminate anyway, so you could do it in separate steps. Just don't sand through the glass by accident. I personally would probably do it by vacuum infusion in one go, but this is just the workflow I'm most comfortable with. No reason it can't be done by hand layup. Did you ever consider to replace the whole skin/bonnet by a composite part? I never quite understood the point of skinning with carbon fiber. This comes with all the downsides of a composite part with potential fibre print, complexity, cost, uv-degradation, ... and with none of the benefits like weight savings...
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jameslawson
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Group: Forum Members
Posts: 11,
Visits: 160
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+x+x+x+xSo I have laminated small car interior trims with carbon fiber in the past, however now I'm embarking on a much more ambitious challenge.. I want to wrap the middle of my car bonnet in the V style carbon fabric. I bought a spare second hand bonnet which is made from aluminium and is sort of flexible. My plan is to palm sand the paint off, prep the middle area, spread on some base coat, hand lay the fabric, vacuum bag it for a perfect flat result before then painstakingly applying the resin coats. Is there anything I should be reconsidering or not doing here with this plan? I have always used the XCR epoxies but I'm worried about the heat resistance.. it doesn't get super hot but the car runs a pretty warm inline 6. Will the XCR resin stand up to this or do I really need to go with the high temp epoxies which have that unfortunate yellow look to them? Here's a mockup I made in photoshop.. ideally I'll overlap the middle, then when its complete my bodyshop who's going to paint it will presumably use filler to blend between the epoxy and aluminium to create a seamless transition before painting the main and power dome section. Many thanks - I really appreciate any advice that can be provided. In my mind this is just one huge panel that I need to hand lay, but I will only have around 2-3 weeks to complete this in due to garage space so I want to try and prepare for everything. +xSo I have laminated small car interior trims with carbon fiber in the past, however now I'm embarking on a much more ambitious challenge.. I want to wrap the middle of my car bonnet in the V style carbon fabric. I bought a spare second hand bonnet which is made from aluminium and is sort of flexible. My plan is to palm sand the paint off, prep the middle area, spread on some base coat, hand lay the fabric, vacuum bag it for a perfect flat result before then painstakingly applying the resin coats. Is there anything I should be reconsidering or not doing here with this plan? I have always used the XCR epoxies but I'm worried about the heat resistance.. it doesn't get super hot but the car runs a pretty warm inline 6. Will the XCR resin stand up to this or do I really need to go with the high temp epoxies which have that unfortunate yellow look to them? Here's a mockup I made in photoshop.. ideally I'll overlap the middle, then when its complete my bodyshop who's going to paint it will presumably use filler to blend between the epoxy and aluminium to create a seamless transition before painting the main and power dome section. Many thanks - I really appreciate any advice that can be provided. In my mind this is just one huge panel that I need to hand lay, but I will only have around 2-3 weeks to complete this in due to garage space so I want to try and prepare for everything. Quick disclaimer as I've never done anything like this. But personally i would use a resin with at least 100°C Tg, but the higher the better to reduce print through in the final result. A resin like a Huntsman 5052 would probably be a good choice with a Tg of 130°C and is pretty clear, and easy to hand laminate with. I am worried about the thermal behavior and I'm not sure to what degree the carbon would warp the bonnet while post curing (you need to post cure to get the Tg). Other might have experience with this. Other than that I would definitely add a very thin fiberglass layer between the carbon and aluminum to avoid galvanic corrosion. Hope that makes sense! Thank you. When you talk about Tg are you referring to the temperature point in which the epoxy begins to soften again? I might try and get a temperature reading on the outer side of the bonnet after some hard driving, then I'll know for sure what the base layer is going to be roughly. Interesting hear about the corrosion, this is my first attempt at bonding carbon fiber to aluminium so it hadn't crossed my mind. So intheory I should be: sanding the old paint off > epoxying some fiber glass onto the sanded areas > then hand laying the carbon fabric down ? Yes Tg is the glass transition temperature, which is the max operating temp. Realistically I'd shoot for at least 20°C higher than what it will see in use. Also note that the claimed Tg of a resin is only gonna be achieved after a post curing cycle, which means you'll need an oven the size of the bonnet. Glass and carbon can/should be laminated onto the bonnet in one go ideally for the best bond. Realistically the limiting factor is going to be the bond between aluminum and laminate anyway, so you could do it in separate steps. Just don't sand through the glass by accident. I personally would probably do it by vacuum infusion in one go, but this is just the workflow I'm most comfortable with. No reason it can't be done by hand layup. Did you ever consider to replace the whole skin/bonnet by a composite part? I never quite understood the point of skinning with carbon fiber. This comes with all the downsides of a composite part with potential fibre print, complexity, cost, uv-degradation, ... and with none of the benefits like weight savings... Gotcha, yeah makes sense to lay it at the same time. I used to have a fiber glass version of the bonnet which had then been laminated with carbon fabric on top. The problem believe it or not was weight, it was too light and caused the whole thing to buffer around, some customers also experienced the hinges not being secure enough and cracking under high speeds causing the bonnet to lift open. Unfortunately a solid carbon fiber version of the bonnet is around £8000-9000 and that's providing you can find a good fitting one. In the end I opted for the ally version to add a little more weight as it's purely just cosmetic, I'm not in the game for weight saving.. which I appreciate will make a lot of you want to call me an idiot haha.
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Warren (Staff)
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That's crazy money for a bonnet for a normal car!! definitely a lot of BMW "M" badge tax going on there!
You would want to do the post cure very slowly with gradual steps to help prevent it warping. Also always post cure before the final sand and polish as you often get some resin movement.
Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant
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jameslawson
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+xThat's crazy money for a bonnet for a normal car!! definitely a lot of BMW "M" badge tax going on there! You would want to do the post cure very slowly with gradual steps to help prevent it warping. Also always post cure before the final sand and polish as you often get some resin movement. Haha glad you know about the M tax too! Technically the official BMW composite bonnet is a GTS/CS product which can only be bought with a GTS/CS model vin, not that it's a valid excuse for them to charge that kind of money.. Okay great to know, I'm going to have a chat with my local bodyshop to see if they can let me use their oven. Is there any specific resin that I should be going with? I want to avoid the yellow tint that comes with high temp epoxy as much as possible, I'm going to be using the V-weave carbon fiber cloth so it's a super cosmetic show piece that really needs clarity to pop. Thanks for the advice and help.
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Warren (Staff)
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Group: Administrators
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The XCR Epoxy Coating resin is the go to resin for most skinning applications and with a post cure will go to 80C.
Warren PenalverEasy Composites / Carbon Mods - Technical Support Assistant
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Hanaldo
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I wouldn't bother with an oven cure on body panels. The panels will post-cure in their working environment, and with skinned parts you have plenty of resin on there to cut and polish into once that has taken place. Just skin the bonnet, fit it to the car, and use it for several months (preferably through summer). Once it has seen a good bit of sun and engine bay temps, you'll notice the fibre print through to the surface and you'll get a bit of rippling. It will happen quite quickly if the weather is warm. But once it has been exposed to those conditions a few times, you can then take it off the car again, flat the surface down with 800 grit, and then move through to 1200>1500>2000>2500>3000, and finally compound to bring it back to a full gloss.
After that, you shouldn't see the print through come back unless it is exposed to a temperature higher than its Tg again. On a 30 degree day, a carbon bonnet can easily see in excess of 80 degrees. So it may never stay completely flat. But in all honesty, in my experience it is that initial shrinkage that is the worst, and after that it doesn't print too badly even if the bonnet gets up to 90-100 degrees. It's not as bad a problem as you might think.
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