Carbon Fiber Starter Kit: what did I do wrong?

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Carbon Fiber Starter Kit: what did I do wrong?

Carbon Fiber Starter Kit: what did I do wrong?

Author	Message
benji	benji posted 8 Years Ago HOT Topic Details
Group: Forum Members Posts: 7, Visits: 48	Hi, I tried to create an heavy duty hinge with the carbon starter kit but I came across the same mistake every time apparently. I "paint" a glass surface with the PVA release agent and let it dry for 20 minutes then I applied a layer of epoxy resin mixed with the epoxy hardener ( ratio 2/3 epoxy and 1/3 hardener) and let it dry for 2 hours. I weight the number of CF sheet I will use and the following relationship to decide which amount of resin I should: Epoxy Hardener weight = CF weight Epoxy Resin weight = 2 * CF weight I lay each layer of carbon one after another "paint" the resin on it and remove the excess resin from time. Leave it alone for the night. First: no way I can separate the CF from the glass surface. Should I leave the resin solidify for precisely 8 hours or "at least" 8 hours that may explain why the two are "glued" permanently together. Second: once I had a strange reaction in the pot where I mixed the epoxy & the hardener. It started to get really hot with fumes and it solidified almost instantly. What did happen? how can avoid that? I'm aware that for an hinge resin infusion is more likely the best course of action but my lack of success with this technique and the entry cost prevent me to use it. Thanks in advance. Benji Tags basic CF.
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ChrisR	ChrisR posted 8 Years Ago HOT Post Details
Group: Forum Members Posts: 363, Visits: 3K	Why on earth would you want to cool the pot down in a pot of ice water?? All that's doing is increasing the viscosity, changing the chemical reaction, making it harder to work into the fabric and potentially introducing water into the laminate - it's just a recipe for disaster imo. with such a short pot life (12-17mins @ 25deg according to the TDS) just normal room temperature (17degC) will slow the reaction a bit and increase the pot life. As already mentioned, the heat/fumes and speedy gel are from an uncontrolled exothermic reaction, if you fill the pot with resin then yes that will happen very quickly. If you increase the surface area of the resin in relation to the volume i.e. use a bigger pot or mix less resin, this will reduce the likelihood of this happening. With short life resins (on the few times I have HAD to use them) the clock starts as soon as you pour the hardener in, not once you've finished mixing, so if you spend 3mins mixing on a 10 min potlife, you've realistically only got around 6-7 mins left of working time. Best tip I was given on this was to have a bucket of water near your workstation so if the pot does start getting too hot/catch fire you can just submerge it and the water will absorb the heat making the area safe from fire and fumes. I always work with a slower hardener to give the longer pot life then heat the laminate up to cure it quicker and get better properties from the final laminate. Also, glass & wax, you need A LOT of coats to make it work, I successfully completed about 50 pulls of a sheet of glass before I messed up with the waxing and broke the glass so it can be done, you just need to treat it as a fresh mould every time and be very careful handling. The thicker the glass the better. (and don't use toughened glass!!)
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