i may have missed this but have you isolated the catch pot entirely? ie, pulled a vacuum then clamped off both lines and not just relied on the valve on the pump?

also just looking back at the pics have you fitted the valve on the pump and the barb conector with PTFE tape?

Don't feel bad. I have never been able to get a perfect leak proof infusion no matter what I tried.

I have used the best bag, best tape, best hose, best of everything.

I almost think the video demonstration of the car scoop is smoke and mirrors.

It looks so easy when they do it. The only explanation that could possibly make sense is that my mold leaks.

But how could a 1/4 inch thick mold leak?

I hope you can track it down because it appears pin holes will never be absent if you don't stop the vacuum flow.

Fred

The reason it looks easy when they do it, is because they have done it hundreds of times... as with everything else, it takes practise. My first and second bagging I couldnt get it to seal no matter what. The third bag I took extra care and through what I learned on the way, it held the drop test for 2 hours. So I reckoned it was pretty much perfectly sealed. After that, did not touch the bag. Infusion came out great.

cheers

Thats great. So what did you discover to be the source of your leaks in the first 2 bags?

Fred

I have made (for me) an important discovery!

 You all know the trouble I have been having trying to get a perfectly sealed bag. I have never got one no matter how careful I have been.

I have used 3 different types of bagging material.

I have used 3 different types of tacky tape.

Spotless dust free work space no go.

Well I tried something different and have had 4 perfectly sealed bags in a row.

Here is what I did differently.

I layed down my carbon layers- peel ply - and then the green flow media.

I then cut strips of vacuum bag and covered over every part of the flow media that was cut with the scissors.

I also cut a few small squares of breather material and put them over the cut ends of the spiral tubing, they are very sharp as well.

I also covered the spiral wrap with the protective strips. Now there is nothing to cut through the main vacuum bag. 

I then used regular vacuum bag material and yellow tacky tape to make the vacuum bag.

Bing! no vacuum leaks! I hardly needed to go over the tacky tape. It is amazing!

This is my take on what the problem was. Imagine you took a chain link fence to a giant set of shears and cut it. Can you imagine how sharp the edges would be. The green flow media would look the same under a magnifying glass.  As soon as you pull vacuum your going to get a puncture.

In the last infusion I used strips of peel ply laid over every cut edge of the flow media instead of the strips of vacuum bag. It worked the same and a perfectly sealed bag.

Try it and see. Just make sure you don't have even one cut of the flow media exposed to the vacuum bag.

Let me know how you make out.

Fred

thanks for sharing that information! 

Matthieu Libeert
Founder MAT2 Composites X Sports
website: www.mat2composites.com

Fred,

I feel like that is amazingly good advice. I have always had trouble with bags not sealing, and I had never thought about the sharp edges of the spiral tubing or mesh and will definitely be trying this next time I infuse. Thanks for the great info!

-Mike-

Your welcome

It really makes you nuts with all the time it takes to set up an infusion and then you have a leak so small you will never find it.

Just an update from the last time I posted . Following the advice I gave above I have now had 8 perfectly sealed bags in a row.

Even with the stretchelon vacuum bags. You will find that you hardly have to spend any time going over the tacky tape seal as well.

Fred

Im doing another roof i will try this

Thanks