Vacuum bag heat sealing, anyone tried it?

Hi,

I use bags rather than the more conventional method of placing 1 layer over the part. I wondered if anyone has tried to bag a complete part by heat sealing the bag shut? Not sure if this works but I’m looking to experiment with different methods if possible.

I also see these C Channel closers but can’t seem to find any sources in the UK?

I tried to source C channels in the UK as well, but to no avail either.

Heat seaming is possible, but it can be cumbersome. I noticed nylon bags sometimes boil when seamed, probably locked in water that is getting out. This might cause some porosity.

I have heat sealed bag for storing material in, never tried it for vacuum.

The C channel closer are nice though… I should get some myself. Great for a tube bag, then sealed with the C channel. Not sure how great a seal, I’ve only done some overlay/veneer work with that method.

We have made our own with two sections of PVC pipe that fit inside one another. Cut the larger diameter tube lengthwise, just over half the width…then sand the crap out of the edges. They work great when we have to use tube-bagging, though I prefer not to (pain to slide large layups in). As long as you are careful to prevent wrinkles in the clip, they seal perfect.

Hi,

Can you confirm what sizes you use please as I will see if I can source similar sizes in the uk. Is the tube PVC too please?

Search for Quick Lock Seals. ACP sells them I think. I haven’t used tacky tape to seal envelope bags since I found these years ago. They will also custom cut to length for you if need be.

I use a heat sealer on large bags that I need to piece together. It didn’t work well with actual bagging material for infusion, but it works great on 8 mil poly material from the hardware store.

I talked to an aerospace engineer/entrepreneur out in California and he swears by heat sealing bags. Here is his website. http://finishlinecomposites.com/

We use 3/4" PVC as the solid core and 1" PVC as the cut clip. PVC sizes are IDs. Those ACP clips look like a great deal though. If I had come across that years ago, I would have bought - not built.

They really are awesome. I’m using 8mil poly bags now with most of my molds. The only bagging tape I’m using is for resin inlet and vacuum connection. So much cheaper and have yet to have a failure due to the seals. The only downside is having to clean the backside of the mold between layups.

These sounded interesting so I ordered up a few and I’m quite impressed. Reasonably priced, they work great and reusable which saves us on bagging tape. Thanks for the suggestion!