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Shaneer22
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Group: Forum Members
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The best thing anyone can do is read about boat building and the techniques involved iam quite amazed at people that don't understand the basics regarding fillers general bonding etc. iam no engineer but to use carbon to its full potential weighing up all the variable's and calculations is way above my head,but there is something satisfying with the finished product,many years I attended a carbonology course to try to resolve problems I was having but at the end I learnt jack s***,the only way you learn is through your own mistakes getting yourself into a mess is part and parcell.
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andygtt
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Group: Forum Members
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Notwithstanding the name of the forum, this is for discussion with the odd chip in from EC... They have a separate forum for technical support. It's quite clear a lot of EC target market is the amateur rather than professional and to me it's one of their goals to remove the 'black art' claims that the carbon industry as a whole gives off. I'm all for additional advice, but I'm going to be pretty vocal about people dissing EC advice and support because as a client of theirs that had absolutely zero knowledge before speaking to them I have now produced quite exceptional and hugelly complicated/ challenging parts that I couldn't have dreamed of without their support. Now it's true I don't yet have the quality that a full professional may have, but also I don't have the facilities as I'm doing it in my garage and im making parts that are 2.5x2.5m that even the composite professionals refused to attempt (I did try)... Hence I sought out EC and they gave me the confidence to have a go myself. I know I'm not alone in believing their advice and service to their target market is second to none! We welcome your advice and expertise and I am especially looking forward to your advice in the resin infusion process as that's realistically the only way I can make the relativelly complex large parts I make :-)
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compositepro
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Group: Forum Members
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mawgan
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Group: Forum Members
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Hi Warren As I stated in my report, I am merely talking about pre-preg here that is why I posted this on the pre-preg board, I will write another one for resin infusion in due course. In my opinion, void free and pinhole free composites can be easily produced using a wet layup method (vacuum or no vacuum) its just about correct method. I completely agree that resin infusion is a great way to manufacture components but each method has there advantages and disadvantages. Possibly the best method for void free composites is the SP GURIT Sprint system. It is a dry reinforcement with the resin contained within the centre of the cloth and a very light tack glue film on one side. This is basically infusion but with the resin already weighed perfectly for the cloth being used - resin infusion often produces a higher resin to cloth ratio than pre-pregs/sprint. You typically find that the void content is between 0%-0.5% with sprint. Infusion also requires low viscosity resin systems which are often inadequate when compared to pre-preg resin systems but this really depends on what you are making, etc. But yes, infusion is a great way to go for easily making parts and is much safer/cleaner that wet layup but can have its problems when the mould/laminate gets a bit complicated etc. Many thanks for your input. Mawgan.
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wozza
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Group: Forum Members
Posts: 688,
Visits: 5.4K
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mawgan (17/08/2013)
Hi Warren Many thanks for your response. I appreciate the service that is currently offered although the forum is called "Advanced Composites Forum" so a certain level of professionalism is required no matter what the objective. Even if you are making the simplest component from your own garage there is a very basic level of understanding that is required and I believe that the correct way to do something should be applied no mater how insignificant that may seem. I see people all the time with what they refer to themselves as 'professional' who are completing composite projects with no knowledge of the basics, if you are doing anything you have to get it correct and I feel that shedding light on a few basics which people may know of but are not sure on how to apply this to there work will make all the difference in how there project will come out. I have seen a lot of posts here referring to "I get pinholes in my pre-preg", these are issue resulting from not one particular thing, but a combination of very small actions that can make a big difference in the end. I hope to hear from you again. Thanks. Hi, again I agree with many of you comments in principle. Having spent over 25 years around composites starting in the Aircraft Industry I have seen Pre-Preg introduced and developed over the years to its current level. You talk about "Advanced Composites" yet you fail to mention Resin Infusion which is actually a newer and in my opinion more advanced process than Pre-Preg. You have total control over the amount of Resin in the part (unlike Pre-Preg which is dictated by the manufacturer) and for a fairly modest budget (compared to an autoclave) you can produce high quality pinhole free composite parts in a home workshop. Warren
Carbon Copies Ltd
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mawgan
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Group: Forum Members
Posts: 12,
Visits: 32
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Hi Warren Many thanks for your response. I appreciate the service that is currently offered although the forum is called "Advanced Composites Forum" so a certain level of professionalism is required no matter what the objective. Even if you are making the simplest component from your own garage there is a very basic level of understanding that is required and I believe that the correct way to do something should be applied no mater how insignificant that may seem. I see people all the time with what they refer to themselves as 'professional' who are completing composite projects with no knowledge of the basics, if you are doing anything you have to get it correct and I feel that shedding light on a few basics which people may know of but are not sure on how to apply this to there work will make all the difference in how there project will come out. I have seen a lot of posts here referring to "I get pinholes in my pre-preg", these are issue resulting from not one particular thing, but a combination of very small actions that can make a big difference in the end. I hope to hear from you again. Thanks.
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wozza
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Group: Forum Members
Posts: 688,
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mawgan (17/08/2013)
I am new here and have had a quick look through the forums and on the easy composites website/videos and I have yet to see any real advanced techniques shown (please correct me if I'm wrong and there is in fact advanced tutorials somewhere that state the techniques that I am referring to). I have personally had over 10 years experience working with all aspects of advanced composites and the family run company that I own has been in the business for over 30 years. We have worked mostly in marine but have covered all aspects along the way from F1 through to aerospace. I thought that I would list just a few things here and people can maybe carry this on and extend any knowledge/tips they may have learnt along the way. To start with, no matter what composite project you are working on, it is all in the preparation, it is the most important thing. I.e, cutting materials correctly and all consumables ready to go before you even think about getting started. Working cleanly is also very important and something you learn working professionally within the industry. I will post some of my top tips of preparation and working cleanly later on this thread. For now a couple of advanced pre-preg tips: Spike rollers - I have not seen these listed anywhere on this forum or the main site, if you do not know what I refer to, it is basically a roller with spikes sticking out. It is important to spike roller each layer of pre-preg that you put down in the stack as this creates small holes within the otherwise solid resin structure for any air pockets to escape during debulking. Debulking - As a general rule of thumb you should always debunk every 2 layers, along with the spike roller this gets rid of air pockets trapped in the stack and helps 'set' the pre-preg in place as you go. Breather tows - A breather toe is simple a short tow of fibreglass placed around the edge of the laminate (in the area to be trimmed), you should place one tow roughly every 250-500mm for large panels/mouldings and smaller distances apply for smaller jobs. This is more important with infusion and Sprint system pre-pregs as it enables the air to escape more easily between layers but also applies to pre-preg as well if you want to do a professional job. Pre-preg curing - I have had a quick look through the easy composites pre-preg offering and was surprised to find fairly basic information regarding the resin systems used and the cure process. Not anywhere mentioned is the recommended ramp rate for cure which is extremely important. As a general rule of thumb anywhere from 0.3C to 2C per minute is acceptable but this really depends on the application and should be specified by the manufacturer. Ramp rates allow the resin to flow correctly eliminating pin holes and voids and it allows the cured resins tg1 to stay ahead of the 'cure'. Dwell times - A dwell is a temperature hold for a set period of time in order for the stack and mould to catch up with the rest of the cure, this all depends on the oven and should be analysed using oven test before curing any pre-preg. Once you have learnt your oven you can apply this to all future cures and can set an appropriate dwell time. That concludes just a few things that I have noticed were never mentioned thus far. I am working on a very detailed pre-preg guide which will include many tips and goes into extreme detail in order to achieve results seen in the most advanced racing yachts/f1/aerospace applications. Please let me know if you are interested in this. Please feel free to add any other advanced suggestions on working with pre-pregs and I will post more up when I have time. Thanks and I hope this helps anyone interested. Welcome to the site. I think like me, some will value the advice you have given although the majority of people on this forum are making composites in their home workshops and EC provide an excellent service and product range for that market. Just my opinion  Regards Warren
Carbon Copies Ltd
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mawgan
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Group: Forum Members
Posts: 12,
Visits: 32
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I am new here and have had a quick look through the forums and on the easy composites website/videos and I have yet to see any real advanced techniques shown (please correct me if I'm wrong and there is in fact advanced tutorials somewhere that state the techniques that I am referring to). I have personally had over 10 years experience working with all aspects of advanced composites and the family run company that I own has been in the business for over 30 years. We have worked mostly in marine but have covered all aspects along the way from F1 through to aerospace. I thought that I would list just a few things here and people can maybe carry this on and extend any knowledge/tips they may have learnt along the way. To start with, no matter what composite project you are working on, it is all in the preparation, it is the most important thing. I.e, cutting materials correctly and all consumables ready to go before you even think about getting started. Working cleanly is also very important and something you learn working professionally within the industry. I will post some of my top tips of preparation and working cleanly later on this thread. For now a couple of advanced pre-preg tips: Spike rollers - I have not seen these listed anywhere on this forum or the main site, if you do not know what I refer to, it is basically a roller with spikes sticking out. It is important to spike roller each layer of pre-preg that you put down in the stack as this creates small holes within the otherwise solid resin structure for any air pockets to escape during debulking. Debulking - As a general rule of thumb you should always debunk every 2 layers, along with the spike roller this gets rid of air pockets trapped in the stack and helps 'set' the pre-preg in place as you go. Breather tows - A breather toe is simple a short tow of fibreglass placed around the edge of the laminate (in the area to be trimmed), you should place one tow roughly every 250-500mm for large panels/mouldings and smaller distances apply for smaller jobs. This is more important with infusion and Sprint system pre-pregs as it enables the air to escape more easily between layers but also applies to pre-preg as well if you want to do a professional job. Pre-preg curing - I have had a quick look through the easy composites pre-preg offering and was surprised to find fairly basic information regarding the resin systems used and the cure process. Not anywhere mentioned is the recommended ramp rate for cure which is extremely important. As a general rule of thumb anywhere from 0.3C to 2C per minute is acceptable but this really depends on the application and should be specified by the manufacturer. Ramp rates allow the resin to flow correctly eliminating pin holes and voids and it allows the cured resins tg1 to stay ahead of the 'cure'. Dwell times - A dwell is a temperature hold for a set period of time in order for the stack and mould to catch up with the rest of the cure, this all depends on the oven and should be analysed using oven test before curing any pre-preg. Once you have learnt your oven you can apply this to all future cures and can set an appropriate dwell time. That concludes just a few things that I have noticed were never mentioned thus far. I am working on a very detailed pre-preg guide which will include many tips and goes into extreme detail in order to achieve results seen in the most advanced racing yachts/f1/aerospace applications. Please let me know if you are interested in this. Please feel free to add any other advanced suggestions on working with pre-pregs and I will post more up when I have time. Thanks and I hope this helps anyone interested.
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