Hoping for some help here.  My bagging is basically 50/50 ie one success to one fail. I'm making the bags using both the standard EC bag and the stretchy stuff depending on the part. I try to take a lot of care in making the bag and I feel I'm fairly precise with it but when do the vac drop test the needle will often pop up when I release the clamp.  Try as I can in terms of checking the tape and the bag, it's usually the case in a failure that all the pressing and checking will not find a leak, but there is one there of course.  Is there a device which can find a leak? I have tried everything including smoke to try to find a leak to no avail.

Hello

I had the very same problem when I first started infusions. I posted the fix some where on this site.

But in a nut shell this is where my leaks came from. The infusion mesh. It occurred to me that the cut edges of the the infusion mesh are sharp and they would puncture the bag every time. Not so much that you couldn't infuse, as long as you didn't shut the vacuum pump off. I was so frustrated that I thought that it was impossible to get a leak proof bag.The punctures were so slight that you couldn't track them down with a leak detector.

What I do now is cut strips of peel ply and lay it over every last infusion mesh cut edge under the bag as well as the spiral tubing. especially the ends of the tubes.

From the first time I tried this I have now had at least 14 perfectly sealed bags in a row and don't expect anymore. I once drew a full vacuum on a mold (and didn't infuse it) and it held a full vac for weeks and counting.

Hope this helps.

Fred

Aha! Cheers Fred will look again at the current part I have bagged

Hi Mike,

If you're infusing you shouldn't be using the Elasti-Film, it doesn't work well with infusions because the stretchyness of the film means that it fills the contours of the infusion mesh, slowing down the infusion significantly. It does seem that quite a few customers who have used the elastifilm with the infusion mesh have had problems with the mesh puncturing the film in the way that Fred has mentioned (i.e. on cut edges). This wasn't something that we were aware of because we already knew that the Elasti-film isn't good for infusion (it also sticks to epoxy resin which makes removing the mesh from the peel-ply more difficult). As Fred says, there's post where this has been discussed in a little more detail which also promted us to add this information to the ElastiFilm product page.

All the best, Matt

Matt Statham
Easy Composites / Carbon Mods - Technical Sales

Every time I've used the elastifilm it has burst on the silicone connectors  through the two unused slots meaning I have to keep chasing a leak with gum tape which slowly gets sucked inside aswell so chucked it in the bin.

Ok thanks Matt. I have a bagged part at the moment with elastifilm and I can't find the leak.  Very frustrating so I'll have to remove the bag and the gum tape and use a normal bag with more pleats.

I had the same problem on the silicone connectors with elastifilm. The film is soo stretchy that it can get sucked in the port holes and then burst.

A piece of peel ply over the connector stopped that happening.

Also, make sure that your catchpot is indeed leak proof. I performed a drop test over 20 mins and nothing changed on my bag, so I infused. Then I clamped off the lines. Yet I left the catchpot in a vacuum with the pump.

In the morning I came to check, infusion was very good, catchpot had lost about an 1/8th of vacuum.

And the mesh has never punctured my regular bagging film. That is some tough stuff, not that easy to puncture, you feel how strong it is when cutting the holes for inlet/outlet. Shouldnt be a problem.

cheers

Hi

I got punctures from the green mesh everytime. I tried 3 different kinds of bagging material same problem. I did notice if I pulled full vac and then released the vacuum to shift materials that when I pulled full vac again the leaks were even worse. Your lucky to have gotten away with it.

Fred  

To be fair Fred I don't think you're using our infusion mesh (our infusion mesh has been clear in colour for at least 9 months) and so we need to be careful in this area of the forum that if experiences of products don't relate to our products that we make that clear. Most people would assume you're referring to our mesh and film and although you're a valued customer I can't see that you've ever purchased either.

In my experience our standard bagging film will not be punctured by our standard infusion mesh in normal use. I never say never but we've done a lot of infusions ourselves with this combination.

Kind regards, Matt

Matt Statham
Easy Composites / Carbon Mods - Technical Sales