looking for really radical solution against infusion air leaks

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looking for really radical solution against infusion air leaks

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ARSOUILLERB26	ARSOUILLERB26 posted 13 Years Ago HOT Topic Details
Group: Forum Members Posts: 16, Visits: 122	Hi I try desperately to find a solution to my micro air leaks in infusion process. According to the tutorial on the process of infusion, I seal my vacuum mold then do a vacuum test. Here, I have almost all the time, really tiny air leaks (invisible after 15 min like suggested but the leak make the pressure down if I wait overnight : 0.1/0.3bar) I specify I have an Accutraz VPE ultrasonic detector which cannot find the leak origin (I suppose to tiny for the detector sensibility) The leak searching of that really tiny leaks make me lose a huge time because I m obliged to wait a really long time to discover they is a leak, to try to find it, to wait again etc.... that s why I wonder if it can exist any solution to save time. I'd thought about that solutions (if you have an other one, don't hesitate ^^) - Make something like a kind of big catch pot under vaccum inside which I could put the mould and start the infusion process. If there is an leak, it cannot find air outside the vaccum bag (the hardest solution to put in place) - Put the first vaccum film under an other vaccum film (elastifilm) to put 2 layers and invoid possibles leak caused by the flanges of the interior vaccum film. - Run the vaccum pomp 5 seconds each hour or two to put again the perfect vaccum. How do professionals to achieve very large supercifies for a ship's hull for example, when they have micro air leaks? I just hope not to be looking for the quick fix that does not exist, the holy grail of the composite. Thank you very much for your future answers and long life to talkcomposites Geoffrey
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Warren	Warren posted 13 Years Ago HOT Post Details
Group: Administrators Posts: 214, Visits: 782	Try envelope bagging to eliminate any chance of the mould leaking. Ensure anywhere you play with bagging film is both clean and has blunted edges to reduce the chance of tiny holes. You could make up a "blanket" by putting some breather fabric between two layers of normal bagging film, selotaped at the edges. You then have a softish and clean blanket to lay over your work table for bagging. Try measuring the pressure drop over 8 hours. It takes roughly 8-11 hours for the resin to gel in the mould using a slow hardener. Fast hardener takes 2-3 hours to gel. If its a smallish part then use fast hardener and leak test it over say 3-4 hours and if the drop is negligible then you should be fine to infuse.
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