Hi All,

I've been infusing for a few years now and recently I've purchased a Greisinger GDH absolute gauge. My question is, when everyone says they get a perfect leak proof bag - is it really? Is there an acceptable tolerance for a leak to still be considered perfect?

Obviously the volume/size of the part being infused is relevant so after multiple tests envelope bagging a 1m2 glass mould with about 1mm thick laminate + flow media. I've had leaks ranging from 1mbar/hour to 10mbar/hour.

I've been under the impression that a perfect seal means it should keep the same vacuum for days on end. Is this asking too much?

The parts I'm infusing are cosmetic carbon so avoiding any pin holes or bubbles is the goal.

Thank you.

hi guys, ive purchased a digital gauge (gersinger GDH 200) its very useful for finding leaks by watching the gauge while the pump is running. however as soon as i switch the pump off, the vacuum drops dramatically, but the bag is still extremely tight, this leads me to believe i am using the gauge wrong! 
i did a quick test, by connecting the gauge directly to the pump, and then block the line when it hits zero psi. but then the gauge reading kept creeping up by 0.1 psi every 2 minutes. 

am i doing something wrong, should i be setting the absolute (zero) before pumping vacuum?


thanks

I had the same issue with mine when I first purchased a GDH. You will find the issue being you require more volume for the gauge to read accurately without the 'creep'. If you do not have a catch pot/vacuum chamber to gain additional volume, try doing the same test with a lot longer vinyl hose - atleast 3+ meters.