vacum bag problem..

hi guys,

today a try my first sandwich glass + hyrex + glass composite fabrications.
But i have one problem with vacuum bag in the corner.

see image attach.

can you help me?

hi,

you have to wrinkle the vacuum bag a little bit, otherwise there isn't enough material to "fill" the corner. maybe a more elastic foil could help.
after applying vacuum you could try to push the foil carefully into the corner (use a rubber)!
for smaller parts we use clingfilm that is very elastic!

thanks

Hi,

I agree to Martin. Your bag must be large enough to wrinkle. I always push the vacuum bag in the corners WHILE the vacuum is generating.

In addition to the wrinkles mentioned by Martin you can place some extra fleece fillets into the corners before it goes into the bag.
Just use narrow strips of the vacuum fleece you are already using.

To get the wrinkles, don't apply full vacuum from the start, but rather extract most of the air out of the bag without much of a vacuum.
Then gently push and pull the bag, until all corners seem to have enough vacuum film for an easy fit.
Then pull full vacuum.
You can redo that until all looks good enough to you.

Edit: I just see my comment being kind of redundant, as Action-Heinz has brought essentially the same advice, already.

Kurbel

Hi,
in such sharp corners no film will make it to the egde.
You have to fill the corners
with epoxy + thixo / bubbels / other filling stuff like cutted fabric
or
cut the fabric in the corner and press it with a fitting made of silicon for example in the corner





Hans

kurbel schrieb:

In addition to the wrinkles mentioned by Martin you can place some extra fleece fillets into the corners before it goes into the bag.
Just use narrow strips of the vacuum fleece you are already using.

Zum Vergrößern anklicken....

My recommendation is quite contrary to the latter: leave the space between the mould flange and the edge of the part free of breather fleece (5-10 mm wide strip). Otherwise the pressure will be reduced significantly, which then will lead to a porous surface and even trapped air (pockets)

Guess why i know

Hm, it did work for me, though.

Ymmv.

Kurbel