By JoseLuis - 10/2/2019 7:26:09 AM
Hello, I'm Luis, new member,
I'd like to ask the experts, I'm confusing a bit, the last night I bagged off a part, small part, the temp inside the workshop was 20º ish, and I leave the vacuum more than 1 hour to see if there was a leaking, I fitted a vacuum leak detector from easycomposites, and doesn't show any changes over an hour, the gauge indicator was 2 marks closed to the full vacuum, then I went to sleep, this morning my surprise is, the gauge is far away from the full vacuum, I switched on the pump, there is no sight of leak and the room temp is about 8º, so could the temp are affecting the gauge? if that is correct how I have to deal with it? Thank you.
|
By JoseLuis - 10/3/2019 6:33:26 AM
+xfirst of all those gauges measure relative pressure and not absolute pressure. so depending on your altitude you are already off. Then those cheap gauges are never accurate. If you connect a couple of them in parallel they all show a slightly different value. For a drop test i usually clamp everything off, let it sit for a while, then when i come back i pull a vacuum in the vacuum gauge with the connection between the gauge and the part closed still. this is now the full vacuum the pump can deliver. then i close the clamp between the gauge and the pump, and then i open the clamp between the gauge and the part. if the needle moves it wasn't airtight. Thanks Lester, I discovered, that the low temp affecting to the gauge, I have to switch on my Halogen heater, getting 20º and I can start, definitely low temp, bad friend |
|