Talk Composites - The Forum for Advanced Composites

Vaccum problem

http://www.talkcomposites.com/Topic2544.aspx

By pedcrist - 8/6/2012 4:43:15 PM

Hello,

I´m with difficulty to make total vaccum.

I´ve tried 3 times, with 3 diferent moulds, and never achieved total vaccum, there´s always a leak.

I´ve checked the gum tape several times, and nothing.

So i´ve tried with a Trough Bag connector at the vaccum line, and  the feed line without connector, only the pvc hose with gum tape.

The result was the same, so i decided to make some tests.

First test:

With the Trough bag connector closed, i´ve switched on the pump, and when the gauge indicator got to the end, i´ve closed the pump valve, and then switched off. The gauge indicator moved, so there is a leak somewhere between the Trough bag connector and the pump.

There´s a few fotos taken with 2 minutes between them:

http://i675.photobucket.com/albums/vv112/pedcrist/P8060081.jpg

http://i675.photobucket.com/albums/vv112/pedcrist/P8060083.jpg

http://i675.photobucket.com/albums/vv112/pedcrist/P8060085.jpg

http://i675.photobucket.com/albums/vv112/pedcrist/P8060086.jpg

http://i675.photobucket.com/albums/vv112/pedcrist/P8060088.jpg

http://i675.photobucket.com/albums/vv112/pedcrist/P8060089.jpg

http://i675.photobucket.com/albums/vv112/pedcrist/P8060091.jpg

Second test:

With the Trough bag connector closed, i´ve switched on the pump, and when the gauge indicator got to the end, i´ve clamped the vac hose between the Trough bag connector and the catch pot, closed the pump valve, and then switched off. The gauge indicator moved not so fast as the first test, but moved, so there still´s  a leak.

There´s a few fotos taken with 2 minutes between them:

http://i675.photobucket.com/albums/vv112/pedcrist/P8060092.jpg

http://i675.photobucket.com/albums/vv112/pedcrist/P8060093.jpg

http://i675.photobucket.com/albums/vv112/pedcrist/P8060094.jpg

http://i675.photobucket.com/albums/vv112/pedcrist/P8060095.jpg

http://i675.photobucket.com/albums/vv112/pedcrist/P8060096.jpg

http://i675.photobucket.com/albums/vv112/pedcrist/P8060097.jpg

I don´t know what´s happening, if someone know, please give me a help.

Another issue: When i connect the vac hose to the silicone connector, i´ve got to cut it to be more thin, otherwise the tube won´t fit in the hole with the bag thickness.

Thanks,

Pedro
By Daz - 10/27/2012 9:36:32 PM

Im doing another roof i will try this

Thanks