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Resin Vacuum infusion Pinholes / Dry spots
Resin Vacuum infusion Pinholes / Dry spots
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Resin Vacuum infusion Pinholes / Dry spots
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Dromilious
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Dromilious
posted 7 Years Ago
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Hello my friends . I am happy to be a member of this forum for advanced composites .
In my spare time i make freedive blades from carbon fiber. After using many methods like closing first the vacuum line then after 30 seconds the feed line or the opposite first closing the feed line then the vacuum line to regain the lost vacuum , still i have pinholes / dry spots . In the link below you can see all the process in fast forward .You have to download it to see and the 30 minutes.
https://www.dropbox.com/s/xnmqseutrkk65lg/My%20Movie4.mp4?dl=0
The result of this process also had pinholes . I think that my fault here was that i closed the feed line quite early before the resin reached the vacuum hose so it sucked the resin and made it poor.
Yesterday i made a new attempt with the same process with the difference that i didn't use the adhesive spray and also i waited the resin to reach the vacuum hose and then i closed the vacuum line, counted to 30 seconds and then i closed the feed line.Unluckily the same results. I will take a photo tomorrow to see what i mean.
Today i made one more try witht hte diference that i waited 1 minute before i close the feed line to make it a bit resin richer ! Tomorrow i will see the results.
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Resin Vacuum infusion Pinholes / Dry spots
Dromilious
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7 Years Ago
Hi and welcome to the forum. First point is you are using a lot of unidirectional fibres. UD can be a right pain to infuse because there is a lack of gaps between the fibres for the resin to soak.....
Warren (Staff)
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7 Years Ago
It is hard to see and hear, but I think you might have a leak in your vacuum system. I think I hear the noise, which oil bath rotary vane pumps produce, if the system isn't sealed perfectly....
oekmont
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7 Years Ago
My friend you are so right ! I noticed what you told me for the glass jar and i am looking to make a degass chamber .Take a look at a can from baby milk what happened ! It exploded like a bomb ! Now ...
Dromilious
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7 Years Ago
I attach some photos from 3 different blades.
Dromilious
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7 Years Ago
To be more specific , The first layer you see at the video is 285T4 carbon fiber 1st layer The second layer is 100 U 2 layer The third and forth layers are 200 gr U 3-4 layers And the fifth...
Dromilious
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7 Years Ago
To be fair, that's not as bad as I was expecting considering the amount of UD in the stack. Try slowing the infusion down by partially clamping the resin feed line and also make it a little resin...
Warren (Staff)
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7 Years Ago
I have tried all these methods. I have left the feed line more than 1 minute to make it richer, i have done the opposite after closing the feed line ( i had the vacuum line with a mesh break with pee...
Dromilious
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7 Years Ago
Ideally you want a proper built vessel or at least something that has been tested to take the required pressures and levels of vacuum without failure. You can make a throw away catch pot/bag by...
Warren (Staff)
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7 Years Ago
Finally after making some tests i have no dry spots on my parts .I think the problem was the unidirectional fabric .Also i have to mention that i use the MTI hose. I dont do degassing . But sometimes...
Dromilious
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7 Years Ago
Its hard to tell from your photos exactly what it is. Almost looks like marks on the surface. Is it actual pinholes or bubbles trapped below the surface?
Warren (Staff)
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7 Years Ago
RE: Resin Vacuum infusion Pinholes / Dry spots
Dromilious
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7 Years Ago
Are you using a spray adhesive?
Hanaldo
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7 Years Ago
Try using acetone or soft polish compound to eliminate these marks. note: take care with the soft polish compound, you can reduce the resin and touch the carbon..
Geteda
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7 Years Ago
Hello my friends. Today i had the same issue . Like air bubbles trapped in but i am not sure. If you check the photos clearly you can see that they are not on the srface but a bit deeper . Like a...
Dromilious
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7 Years Ago
You have tried to make a piece without adhesive spray? How long you allow the mold to dry before starting the infusion? Your mold has a perfect gloss finish?
Geteda
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7 Years Ago
I don't use adhesive spray. i changed the wax with an other brand and i have not any more these marks
Dromilious
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7 Years Ago
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