Talk Composites - The Forum for Advanced Composites

looking for really radical solution against infusion air leaks

http://www.talkcomposites.com/Topic1943.aspx

By ARSOUILLERB26 - 6/16/2012 2:20:17 PM

Hi

I try desperately to find a solution to my micro air leaks in infusion process. w00t

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) Angry

I specify I have an Accutraz VPE ultrasonic detector which cannot find the leak origin (I suppose to tiny for the detector sensibility)Crazy

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? Rolleyes



I just hope not to be looking for the quick fix that does not exist, the holy grail of the composite. Laugh



Thank you very much for your future answers and long life to talkcomposites Wink

Geoffrey
By fgayford - 11/7/2012 2:25:07 AM

ARSOUILLERB26 (16/06/2012)
Hi

I try desperately to find a solution to my micro air leaks in infusion process. w00t

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) Angry

I specify I have an Accutraz VPE ultrasonic detector which cannot find the leak origin (I suppose to tiny for the detector sensibility)Crazy

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? Rolleyes



I just hope not to be looking for the quick fix that does not exist, the holy grail of the composite. Laugh



Thank you very much for your future answers and long life to talkcomposites Wink

Geoffrey
Hi Geoffrey

If you look at the topic before this called "How to get a perfectly sealed Bag" I explain how I had your problem and have since had 10 perfectly sealed bags in a row. Its a no brainer now that I know what is causing the leaks.

Fred