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MMCtuner
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Hi, after many years as a member, I think this is my first post, so I hope to be useful.
Anyways, as suggested before, you should leave a mesh free section before the vacuum line, that would help pass air through the laminate faster than the resin and degass your laminate before the catchpot starts to fill. Easier/costier option, use MTI hose.
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Raf4C
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Group: Forum Members
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+xLooks leak free. What temperature are you working and curing at? How was the sheet like when demoulded? Dear Warren, Thank you for your reply. I am working at room temperature (20-25 °C). I am curing at room temperature (even if the idea is to do a post cure in the oven according to the datasheet when I'll fix these issues). I am interested in mechanical properties and for this reason I am using a peel ply on both the surfaces in order to have the same surfaces. For this reason, I cannot see if I have some bubbles in the plate. However, the surface does not look uniform. As you were able to see from the previous figure, after the infusion I have no air bubbles, they came out later. I noted also some air bubbles in the inlet and outlet tubes (only on the composite plate side), I attach some pictures. I am producing a plate (30x30 cm) with glass fibres, and the pump that I am using is the DVP EC.20 (the industrial one sold by EasyComposite). Can this pump be too strong for my purpose?  
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Warren (Staff)
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Looks leak free. What temperature are you working and curing at?
How was the sheet like when demoulded?
Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant
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Raf4C
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Group: Forum Members
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Dear guys, Thank you for your help. Yesterday, I repeated the infusion by using your precious comments. I can say that the biggest problem was mainly due to the fact that I closed the outlet clamp in late (in the case of my first infusion). As you can see by the pictures I am uploading, at the end of the infusion, I have no air bubbles. Unfortunately the day after I found some thin air bubbles on the top surface of my laminate. In your opinion, can this problem be due to the degassing phase? I kept the resin (IN2 with slow hardener) under vacuum for 15 minutes. there were just few bubbles that were coming out at that point. I hope you can help me again.   
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oekmont
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Yes, that's far too much air to be caused by degassing, at least if you degassed the mixed system. There has to be a leak somewhere.
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Matthieu Libeert
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You might not believe me but to me, by seeing your pictures after infusion I'm pretty sure you have a leak somewhere. those "cracks" you are seeing in your infusion mesh is 99% of the time the sign you have a small leak somewhere. Another possibility is you dont have enough resin in your laminate during the infusion and close the lines, the resin in the laminate will look for an "average of saturation" through the entire laminate using the resin in the infusionmesh as a last resort, causing those marks you see. If you say you are sure you dont have leaks, did you do an overnight droptest to be sure?
Matthieu Libeert
Founder MAT2 Composites X Sports
website: www.mat2composites.com  
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JasonFL
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I’d consider a resin brake next time. From the resin line to the back edge use flow media, then from the back edge of the laminate to the vacuum line have a solid 3 fo 4 inch peel ply only layer. This will slow the resin down, allow residual gas to come to the surface and escape, and prevent resin from making it to your vacuum line before all your fibers are infused.
Jason
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Legoman
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+x+x"3) I close the pipe outlet (catch pot side) after few minutes." It should be few seconds! If the mixed resin is degassed properly and the vacuum is perfect and drop tested no way there are so many bubbles in your bag... Thank you, I'll try to lock it after few seconds. Why does it make bubbles if I leave it for some minutes? It doesnt make air bubbles just the pump simply sucks out too much resin from your lamiate and some spots will be resin poor. I think... If you close both of the sides and air bubbles still coming then your bag is leaking or the resin degassing is not 100%.
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Raf4C
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Group: Forum Members
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+x"3) I close the pipe outlet (catch pot side) after few minutes." It should be few seconds! If the mixed resin is degassed properly and the vacuum is perfect and drop tested no way there are so many bubbles in your bag... Thank you, I'll try to lock it after few seconds. Why does it make bubbles if I leave it for some minutes?
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Raf4C
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Group: Forum Members
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