By fgayford - 5/18/2012 2:30:35 PM
Hi Guys
This is my first post. (I can see that this forum will be very useful to me)
I have watched your videos many many times. I am not new to infusion, but pin holes or voids are my problem.
I understand that the problem is resin starvation caused by too much being removed by leaving the vacuum pump running over night. I am very careful to get a good seal and I use only the best bagging film and tacky tape. But cannot get a perfectly sealed bag! . My catch pot will hold a vacuum indefinately as well as my degasser. But the bag always loses its vacuum.
What is the most common cause to look for?
Thanks
Fred
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By fgayford - 6/17/2012 2:32:23 PM
Help!!
Well I just did another attempt at getting a perfectly sealed bag. IT DID NOT SEAL AGAIN! There is absolutely no way I have a leak from the perimeter tacky tape seal. I did have a perfect seal at first, but as soon as I let the vacuum out to shift the bag and re-vacuumed I could no longer get a perfect seal. Big disappointment! I was starting to think a perfect seal was a myth that only worked in the UK.
So, I needed to make a flat panel so I tried for another perfect seal infusion.( I am using the green fine flow media.)
I suspected from earlier failures that the flow media is making microscopic holes in the bag wherever you have cut lines. When I let the vacuum off to shift the bag. (in the example above) the punctures got worse.With this in mind I placed a layer of vacuum bag over the flow media to protect the outer vacuum bag. I did get my first perfect vacuum.
I infused and sealed off the vacuum line, the feed line and left it over night. I expected the worst, but the vacuum held and I had a good part. This is the first time I have left a part cure without leaving the pump running all night, its a bit scarey.
To anyone who has an ultra sonic leak detector, please let me know how well it works. With my leaky bags there was no chance of finding the leak with my stethiscope over the whole bag surface.
Thanks
Fred
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