Talk Composites - The Forum for Advanced Composites

Pinholes :)

http://www.talkcomposites.com/Topic23381.aspx

By CARBONTOYS - 5/24/2017 9:00:50 AM

Hey guys, i need a help Smile



last week i start to play with infusion, first i decided to make some tests on glass Smile i made 3 tests and still have some tiny pinholes in my "parts", in first look they looks nice and shiny, but under sun u can see small dots inside the laminate.

as i say, i did 3 tests, and after every one was better, but still not nice
in every infusion i made few diferent sheets cca 20x20cm (4x200g twill weave, 1x200g+1x420g, 2x200g+soric 2mm,...)

1.INFUSION: cloth, peelply, infusion mesh, spiral tube,... Infusion was very fast, next day tiny pinholes in whole parts

2.INFUSION: the same, just excluded spiral, and made resin break, and leave the resin to degas around 10mins...better result, but still loads of pinholes in 75percent of part

3.INFUSION: infusion mesh-only small pieces under silicone connectors, i clamped out vacuum line first and wait for 20seconds, then clamped a resin line, resin was degassed for 10-15mins... 2/3 of part nearly without pinholes(maybe 1 small bubble every 8cm, but 1/3 of part, under the resin feed line is still full of pinholes Crazy



in every infusion i made leak test, and bag was always tiny, without leaks

i am using all infusion stuff from EC, except vacuum pump...... I cant reach -30inHq on gauge, there is always -29 Ermm What do u think guys, can be this cause of my issues? 


THANK YOU 


By Warren (Staff) - 5/24/2017 10:28:48 AM

depends on the accuracy of the gauge.  Uncalibrated gauges can vary a bit as well as variance at altitude.  If you shut the valve on the pump and the tone does not change, then you are likely at full vacuum.