Bubbles and voids

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Bubbles and voids

Author	Message
Gg_knives	Gg_knives posted 8 Years Ago HOT Topic Details
Group: Forum Members Posts: 9, Visits: 317	Hello there, I have produced several sheets of carbon using a press I have made out of two sheets of 10mm aluminium which I bolt together. My intention is to make thick slabs of carbon which I can then cut into small blocks and use them for making knife handles. The trouble I am having is small air bubbles and voids I use 12k 650g 2/2 twirl carbon 8 layers thick. I compress this stack down to 4mm using a shim on each side of my aluminium plate for a thickness guide. At first I was worried about applying too much pressure as a lot of epoxy is already forced out the sides of my press but maybe more presure might push the air out?? The questions I have are: Is there such thing as over compression will it make dry spots or weaker carbon? Will a simple case of using a bristled roller instead of a finned roller solve this? Would using thinner 6k 200g 2/2 result in no bubbles? I'm using standard el2 epoxy is there an epoxy that will give better results?
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Gg_knives	Gg_knives posted 8 Years Ago HOT Post Details
Group: Forum Members Posts: 9, Visits: 317	https://www.dropbox.com/s/a6elkl1n5dkkn17/Photo%2003-10-2016%2C%2014%2043%2028.png?dl=0 Hi im not sure the link to the picture worked on the original post sorry about that. anyonr have any advice for reducing voids and air bubbles?
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scottracing	scottracing posted 8 Years Ago HOT Post Details
Group: Forum Members Posts: 460, Visits: 5.2K	it definitely looks like the material isn't wetted out properly or there's some excess resin being pushed out. Are you wetting out each ply individually then laying them on top of each other? I would add a cork dam or use some other means of retaining the resin into the laminate when you are pressing, also what temperature are you curing at?
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Gg_knives	Gg_knives posted 8 Years Ago HOT Post Details
Group: Forum Members Posts: 9, Visits: 317	Hi thanks for the reply, yes I put resin on each layer and spread with a paint brush. Then place the next piece of carbon and use a finned roller to work the carbon and epoxy. Usually there's a fare bit of epoxy wetting through before I pour more resin for the next layer. With this being a knife handle the carbon is sanded through the layers witch brings out the smallest of voids.
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Warren (Staff)	Warren (Staff) posted 8 Years Ago HOT Post Details
Group: Administrators Posts: 2.5K, Visits: 7.9K	A better tool for getting the trapped air out is a Bristle Roller as they are much more effective than flat and finned rollers. After wetting out each layer of reinforcement with resin, use the roller with a medium pressure over the entire laminate, for the first layer in a cosmetic carbon fibre part we recommend that the entire area has had at least 5 strokes to eliminate the small entrapped air bubbles.After use rinse the roller in an acetone bucket and leave it submersed until the next use, ensure that the acetone is thoroughly shaken out before each use. If cleaned properly a roller can last many months of daily use. Warren Penalver Easy Composites / Carbon Mods - Technical Support Assistant Tags Bristle roller
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Gg_knives	Gg_knives posted 8 Years Ago HOT Post Details
Group: Forum Members Posts: 9, Visits: 317	Thanks warren I've ordered a bristled roller and will give it a go in the next few days. Hopefully will get some better results. Do you have any information on how much you can compress the stack of carbon and wheather i may be over compressing or under compressing? Edited 8 Years Ago by Gg_knives
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