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Castle Works Motorsports
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Group: Forum Members
Posts: 4,
Visits: 11
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Hi,
I am new to carbon fiber parts, but want to give it a try and start with some small parts.
I am comfortable creating 3D parts in CAD, I have CNC mills and able to create molds.
I would like to try some prepreg parts but unsure about what to use when it comes to an oven. Can you simple use a conventional kitchen oven (assuming vacuum could be plumbed into it). What problems would I encounter?
If a conventional oven cannot be used, what do most use starting out? I would prefer not to invest in the cost of an oven specifically designed for curing CF parts until I know this is sometime I would like to do more of.
Thanks,
Kevin
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Hanaldo
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Group: Forum Members
Posts: 2.5K,
Visits: 28K
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+x+x+xA few members on here have made their own ovens so it is doable DIY. There are a few threads on members own oven projects. However we always tend to advise you take the safety side of it very seriously. If you get it wrong you could burn your shed down! Hence why we are always a bit hesitant in suggesting making your own unless you have the correct electrical knowledge and general knowledge on making an oven safely. Warren, thanks, yep, I completely agree. Kevin Agreed, safety is always important when dealing with electricity. If you are not confident there are plenty of electricians that will do the work for you. If you are concerned about using heating elements you can use light bulbs as the heat source. They will be surrounded by heat resistant materials and the max temperature will be around 120 deg C for basic curing (you can cure most prepregs below 100 deg) or 160 deg C if post curing, all of which are not even hot enough to ignite paper. So the chances of setting your garage alight, as long as you don't have an electrical issue (but that is the same for any appliance/lighting/heating circuit) are virtually nil. However, I accept that EC staff members have to be very careful with what they recommend. And, likewise, these comments are my own personal opinions based on a fair few years of experience in building curing ovens. You will have to make your own judgement on your skills and capabilities when it comes to building anything involving electricity. The biggest danger, aside from a wiring issue, is the heating element. Sure 120° is quite low temperature and not going to ignite anything, but it's the element - these are just on and off full power and get extremely hot. Especially if you are ramping straight up to 120, thats going to be a solid 20-30 minutes in a mid sized oven where a 2kw element is at full power and very very hot. So everything right next to the element is what you have to be worried about, you don't want anything there that could be flammable, and you have to make sure that nothing can shift or fall on the element. Anyway, I think it is quite a low risk sort of project, you just have to think about it a bit. It's really dead easy to do.
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Steve Broad
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Group: Forum Members
Posts: 408,
Visits: 4.1K
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+x+x+x+xA few members on here have made their own ovens so it is doable DIY. There are a few threads on members own oven projects. However we always tend to advise you take the safety side of it very seriously. If you get it wrong you could burn your shed down! Hence why we are always a bit hesitant in suggesting making your own unless you have the correct electrical knowledge and general knowledge on making an oven safely. Warren, thanks, yep, I completely agree. Kevin Agreed, safety is always important when dealing with electricity. If you are not confident there are plenty of electricians that will do the work for you. If you are concerned about using heating elements you can use light bulbs as the heat source. They will be surrounded by heat resistant materials and the max temperature will be around 120 deg C for basic curing (you can cure most prepregs below 100 deg) or 160 deg C if post curing, all of which are not even hot enough to ignite paper. So the chances of setting your garage alight, as long as you don't have an electrical issue (but that is the same for any appliance/lighting/heating circuit) are virtually nil. However, I accept that EC staff members have to be very careful with what they recommend. And, likewise, these comments are my own personal opinions based on a fair few years of experience in building curing ovens. You will have to make your own judgement on your skills and capabilities when it comes to building anything involving electricity. The biggest danger, aside from a wiring issue, is the heating element. Sure 120° is quite low temperature and not going to ignite anything, but it's the element - these are just on and off full power and get extremely hot. Especially if you are ramping straight up to 120, thats going to be a solid 20-30 minutes in a mid sized oven where a 2kw element is at full power and very very hot. So everything right next to the element is what you have to be worried about, you don't want anything there that could be flammable, and you have to make sure that nothing can shift or fall on the element. Anyway, I think it is quite a low risk sort of project, you just have to think about it a bit. It's really dead easy to do. That's why I suggested light bulbs. However it is interesting what you say about the element being on full power. I use the PID to raise the temperature from ambient (15-20 deg C) to an initial 80 over 30 minutes , hold for 30 minutes then continue to 120 over 20 minutes and hold for an hour. The controller is constantly turning the element on and off and it never gets red hot and therefore doesn't emit any light, so I am going to have to install a low wattage lamp so I can monitor what is going on :-)
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Hanaldo
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Group: Forum Members
Posts: 2.5K,
Visits: 28K
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+x+x+x+x+xA few members on here have made their own ovens so it is doable DIY. There are a few threads on members own oven projects. However we always tend to advise you take the safety side of it very seriously. If you get it wrong you could burn your shed down! Hence why we are always a bit hesitant in suggesting making your own unless you have the correct electrical knowledge and general knowledge on making an oven safely. Warren, thanks, yep, I completely agree. Kevin Agreed, safety is always important when dealing with electricity. If you are not confident there are plenty of electricians that will do the work for you. If you are concerned about using heating elements you can use light bulbs as the heat source. They will be surrounded by heat resistant materials and the max temperature will be around 120 deg C for basic curing (you can cure most prepregs below 100 deg) or 160 deg C if post curing, all of which are not even hot enough to ignite paper. So the chances of setting your garage alight, as long as you don't have an electrical issue (but that is the same for any appliance/lighting/heating circuit) are virtually nil. However, I accept that EC staff members have to be very careful with what they recommend. And, likewise, these comments are my own personal opinions based on a fair few years of experience in building curing ovens. You will have to make your own judgement on your skills and capabilities when it comes to building anything involving electricity. The biggest danger, aside from a wiring issue, is the heating element. Sure 120° is quite low temperature and not going to ignite anything, but it's the element - these are just on and off full power and get extremely hot. Especially if you are ramping straight up to 120, thats going to be a solid 20-30 minutes in a mid sized oven where a 2kw element is at full power and very very hot. So everything right next to the element is what you have to be worried about, you don't want anything there that could be flammable, and you have to make sure that nothing can shift or fall on the element. Anyway, I think it is quite a low risk sort of project, you just have to think about it a bit. It's really dead easy to do. That's why I suggested light bulbs. However it is interesting what you say about the element being on full power. I use the PID to raise the temperature from ambient (15-20 deg C) to an initial 80 over 30 minutes , hold for 30 minutes then continue to 120 over 20 minutes and hold for an hour. The controller is constantly turning the element on and off and it never gets red hot and therefore doesn't emit any light, so I am going to have to install a low wattage lamp so I can monitor what is going on :-) If the PID is ramping the heat up, then it shouldn't be switching the element off. It will constantly switch as it approaches target temp and maintains target temp, but if your thermocouple is reading 80 degrees and your target temp is 120 degrees, then it should just switch the element on until it gets to about 110-115 or so. And it should only take @ 20 seconds for the element to get red hot.
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Steve Broad
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Group: Forum Members
Posts: 408,
Visits: 4.1K
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+x+x+x+x+x+xA few members on here have made their own ovens so it is doable DIY. There are a few threads on members own oven projects. However we always tend to advise you take the safety side of it very seriously. If you get it wrong you could burn your shed down! Hence why we are always a bit hesitant in suggesting making your own unless you have the correct electrical knowledge and general knowledge on making an oven safely. Warren, thanks, yep, I completely agree. Kevin Agreed, safety is always important when dealing with electricity. If you are not confident there are plenty of electricians that will do the work for you. If you are concerned about using heating elements you can use light bulbs as the heat source. They will be surrounded by heat resistant materials and the max temperature will be around 120 deg C for basic curing (you can cure most prepregs below 100 deg) or 160 deg C if post curing, all of which are not even hot enough to ignite paper. So the chances of setting your garage alight, as long as you don't have an electrical issue (but that is the same for any appliance/lighting/heating circuit) are virtually nil. However, I accept that EC staff members have to be very careful with what they recommend. And, likewise, these comments are my own personal opinions based on a fair few years of experience in building curing ovens. You will have to make your own judgement on your skills and capabilities when it comes to building anything involving electricity. The biggest danger, aside from a wiring issue, is the heating element. Sure 120° is quite low temperature and not going to ignite anything, but it's the element - these are just on and off full power and get extremely hot. Especially if you are ramping straight up to 120, thats going to be a solid 20-30 minutes in a mid sized oven where a 2kw element is at full power and very very hot. So everything right next to the element is what you have to be worried about, you don't want anything there that could be flammable, and you have to make sure that nothing can shift or fall on the element. Anyway, I think it is quite a low risk sort of project, you just have to think about it a bit. It's really dead easy to do. That's why I suggested light bulbs. However it is interesting what you say about the element being on full power. I use the PID to raise the temperature from ambient (15-20 deg C) to an initial 80 over 30 minutes , hold for 30 minutes then continue to 120 over 20 minutes and hold for an hour. The controller is constantly turning the element on and off and it never gets red hot and therefore doesn't emit any light, so I am going to have to install a low wattage lamp so I can monitor what is going on :-) If the PID is ramping the heat up, then it shouldn't be switching the element off. It will constantly switch as it approaches target temp and maintains target temp, but if your thermocouple is reading 80 degrees and your target temp is 120 degrees, then it should just switch the element on until it gets to about 110-115 or so. And it should only take @ 20 seconds for the element to get red hot. Ah, no, it is cleverer than that :-) You set the desired temp and the time you want it to take to get there. So, working on 3 degC/min ramp (recommended max temp ramp for the prepreg I use), 20degC ambient and 80degC initial target, I would set the time at 20 minutes. This PID then calculates how often to switch the element on and off to maintain this temp ramp rate (using the thermocouple data to monitor and moderate). The PID has a light that indicates when the element is on and it is off and on like a slow car indicator :-) And this is in an oven 1.7m x 1.7m x 0.8m. The element gets very hot but not hot enough to glow.
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