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kmulloy - 6/19/2018 7:34:50 AM

Good morning,
I am using Axson Epolam 2017 General Purpose Epoxy Resin System - Lloyds Approved with 420 biaxial fiberglass.  I am using easy composites vacuum bagging materials, I am finding small leaks where the bagging tape is allowing air through the seal onto of the epoxy resin. When laying up the fibreglass I have used peel ply in hopes to remove the tacky film left behind.  I have also tried sanding. and of course washing down with acetone.  The leaks are minute and barely dectable with leak detector.  ANY suggestion on how to get a better seal? 

+x

 

Matt (Staff) - 6/19/2018 7:44:40 AM

+x

 

kmulloy - 6/19/2018 7:34:50 AM

Good morning,
I am using Axson Epolam 2017 General Purpose Epoxy Resin System - Lloyds Approved with 420 biaxial fiberglass.  I am using easy composites vacuum bagging materials, I am finding small leaks where the bagging tape is allowing air through the seal onto of the epoxy resin. When laying up the fibreglass I have used peel ply in hopes to remove the tacky film left behind.  I have also tried sanding. and of course washing down with acetone.  The leaks are minute and barely dectable with leak detector.  ANY suggestion on how to get a better seal? 

This is not uncommon at all for those less experienced with basic bagging technique and less familiar with using sealant tape. Almost certainly, all you need to do is spend more time going around the seal, pressing it very firmly and pressing and squeezing the bag to the tape (and the tape to the mould, if you're taping to the mould). It's not just a matter of pressing the tape/bag/flange to make a proper seal, you need to really press and push and pull all the way round. You then closely inspect the seal, visually looking for tiny giveaway 'lines' in the tape where there might be creases or stray fibres or folds that - although tiny - are enough to cause a small leak. It's quite common for these leaks to be undetectable using a ultrasonic leak detector.

On our training courses, one of the first things we show delegates is what it takes to make a perfectly sealed bag. Many people are surprised that it's not easier and more instant but it soon becomes second nature to expect to be spending several minutes making a perfect seal (and to get good at doing it).

+x

 

kmulloy - 6/19/2018 7:52:02 AM

+x

 

Matt (Staff) - 6/19/2018 7:44:40 AM

+x

 

kmulloy - 6/19/2018 7:34:50 AM

Good morning,
I am using Axson Epolam 2017 General Purpose Epoxy Resin System - Lloyds Approved with 420 biaxial fiberglass.  I am using easy composites vacuum bagging materials, I am finding small leaks where the bagging tape is allowing air through the seal onto of the epoxy resin. When laying up the fibreglass I have used peel ply in hopes to remove the tacky film left behind.  I have also tried sanding. and of course washing down with acetone.  The leaks are minute and barely dectable with leak detector.  ANY suggestion on how to get a better seal? 

This is not uncommon at all for those less experienced with basic bagging technique and less familiar with using sealant tape. Almost certainly, all you need to do is spend more time going around the seal, pressing it very firmly and pressing and squeezing the bag to the tape (and the tape to the mould, if you're taping to the mould). It's not just a matter of pressing the tape/bag/flange to make a proper seal, you need to really press and push and pull all the way round. You then closely inspect the seal, visually looking for tiny giveaway 'lines' in the tape where there might be creases or stray fibres or folds that - although tiny - are enough to cause a small leak. It's quite common for these leaks to be undetectable using a ultrasonic leak detector.

On our training courses, one of the first things we show delegates is what it takes to make a perfectly sealed bag. Many people are surprised that it's not easier and more instant but it soon becomes second nature to expect to be spending several minutes making a perfect seal (and to get good at doing it).

thanks Matt.
I am registered for the EasyComposites course in September. I am working on laying carbon fiber to build up the hull floor of a sailing yacht, so not a straight forward bagging on a flat surface.  I am laying another bag this afternoon and will follow your suggestions.  I'll let you know how I go. THANK you for your speedy reply.  Kittie