Resin Infusion of carbon fiber with balsa core

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Resin Infusion of carbon fiber with balsa core - any experience?

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John Hansen	J John Hansen posted 6 Years Ago HOT Topic Details
J Group: Forum Members Posts: 42, Visits: 232	Does anyone have hands on experience doing resin infusion of carbon fiber with a balsa end grain core. In my research on the methods, I find statements of vendors that indicate balsa end grain can be fabricated as a core between carbon fiber this way but at this time, actual evidence or instructions by someone experienced doing this still eludes me. Does anyone know anyone what has done it (successfully), or is it mere hyperbole by the vendors of the balsa core material? FYI, I have written to one notable vendor with no response. I have also done a patent search and with one notable exception there are no patents that shed light on the process of sealing the end grain. The referenced patent simply says "seal the end grain". But how to seal it and with what to seal it? And how much weight is added to the balsa when it is sealed? Is this all a secret? Looking for replies with experience.... no theories or conjecture, please. A Lifelong Learner Edited 6 Years Ago by John Hansen
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oekmont	oekmont posted 6 Years Ago HOT Post Details
Group: Forum Members Posts: 550, Visits: 27K	I think the main reasons why balsa isn't that popular are the heavier weight compared to foams, the inconsistency, the soaking propertys and the lack of easy forming methods. Most foams can be brought in shape with a heat gun. With balsa you will have to sand or cut it into shape, if the part is curved in two directions. Wich is the case for most parts you can think of. And the core has very little influence on the strength of the part. A balsa core sandwich will be just as strong as one with an airex core, but the foam core will be significantly lighter. And balsa isn't even that strong. The strength numbers are often taken from heavier pieces. The lighter types of balsa can easily be scratched with finger nails. Easier than airex. Wich is also immune to humidity, has better fire resistance and has isotropic characteristics btw. You can definitely make nice things with balsa, but in my opinion it is a problematic core material compared to foam, and doesn't have the same performance potential. I only use it for plain, thick sheets or simple beams if price is the main concern. And I work quite a lot with core materials.
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Matthieu Libeert	Matthieu Libeert posted 6 Years Ago HOT Post Details
Group: Forum Members Posts: 955, Visits: 3.4K	+x oekmont - 3/7/2019 9:33:00 PM I think the main reasons why balsa isn't that popular are the heavier weight compared to foams, the inconsistency, the soaking propertys and the lack of easy forming methods. Most foams can be brought in shape with a heat gun. With balsa you will have to sand or cut it into shape, if the part is curved in two directions. Wich is the case for most parts you can think of. And the core has very little influence on the strength of the part. A balsa core sandwich will be just as strong as one with an airex core, but the foam core will be significantly lighter. And balsa isn't even that strong. The strength numbers are often taken from heavier pieces. The lighter types of balsa can easily be scratched with finger nails. Easier than airex. Wich is also immune to humidity, has better fire resistance and has isotropic characteristics btw. You can definitely make nice things with balsa, but in my opinion it is a problematic core material compared to foam, and doesn't have the same performance potential. I only use it for plain, thick sheets or simple beams if price is the main concern. And I work quite a lot with core materials. I'm following Eokmont on this Matthieu Libeert Founder MAT2 Composites X Sports website: www.mat2composites.com
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John Hansen	J John Hansen posted 6 Years Ago HOT Post Details
J Group: Forum Members Posts: 42, Visits: 232	+x oekmont - 3/7/2019 9:33:00 PM I think the main reasons why balsa isn't that popular are the heavier weight compared to foams, the inconsistency, the soaking propertys and the lack of easy forming methods. Most foams can be brought in shape with a heat gun. With balsa you will have to sand or cut it into shape, if the part is curved in two directions. Wich is the case for most parts you can think of. And the core has very little influence on the strength of the part. A balsa core sandwich will be just as strong as one with an airex core, but the foam core will be significantly lighter. And balsa isn't even that strong. The strength numbers are often taken from heavier pieces. The lighter types of balsa can easily be scratched with finger nails. Easier than airex. Wich is also immune to humidity, has better fire resistance and has isotropic characteristics btw. You can definitely make nice things with balsa, but in my opinion it is a problematic core material compared to foam, and doesn't have the same performance potential. I only use it for plain, thick sheets or simple beams if price is the main concern. And I work quite a lot with core materials. Oekmont, Let's talk about soaking properties. I simply cannot find data that tells me how much it soaks up and how to seal it to prevent the soaking. I have read descriptions of how to deal with it by sealing the end grain, but I am looking for some test data that will guide me in my efforts to seal it. One vendor told me what product to use for sealing it, but they have no data on how much weight is added by the sealing process. My needs do no require forming. nearly every part will be about 6mm thick and flat. Some parts will have a bullnose edge which is easy to produce with a router. If I have to test the strength and compare it to a foam core, I will do it, but I would enjoy knowing how to make the parts with the end grain balsa. End grain balsa is sold for this purpose and is advertised as being suitable for resin infusion. So why am I having so much trouble finding data or tutorials on how to do it. I cannot find any data that compared balsa core with a given thickness to foam core with the same thickness and carbon fiber skins in order to compare apples to apples. I would love to see the data that you refer to when you say that the core has very little impact on the strength. I have looked for it. And if the foam core does exhibit the strength that I need then I will use it, but I would enjoy seeing the data. Balsa is being use so there must be some merit to it. My understanding is the strength of balsa end grain is greater than the foam core. I guess I will have to do the testing myself, but I will still look for data. A Lifelong Learner Edited 6 Years Ago by John Hansen
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