Vacuum Gauge Precision (can't pull full vacuum)

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Vacuum Gauge Precision (can't pull full vacuum)

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H4RTM4N	H4RTM4N posted 12 Years Ago HOT Topic Details
Group: Forum Members Posts: 7, Visits: 203	Hi all, My name is Andreu and I'm new to this forum. I've just received my order from EC and I'm already trying to make my own carbon fibre parts using resin infusion. For the first trial I wasn't concerned about the final quality of the part (a simple plate) as I only wanted to be familiar with the process. However, I noticed I couldn't reach 'full' vacuum. Instead, the vacuum gauge was stuck at -29Hg (0.98+ bar). I closed all the leaks in the vacuum bag but I kept having that remaining pressure inside. In order to be sure of that, I connected the vacuum pump to the resin catch-pot only. The hose that usually comes from the resin catch-pot was clamped so the vacuum was only made inside the catch-pot. When I pulled vacuum from the pot, I obtained the same result. Taking into account that I live in Barcelona and my house is <100m above sea level, I wonder if my equipment is all right or not. In other words, I want to know if the the vacuum gauge is simply not representing the reality inside the bag because of its precision. I can imagine 2 possible answers to the question: - YES, the equipment is just fine. The precision of the vacuum gauge of the resin catch-pot is somewhat near to 2mbar and that is why I obtain these 0.98bar. - NO, there's something wrong. You should obtain -1bar (-30Hg), which in reality represents the advertised 99.995% vacuum. Could you please help my clarify this issue? Thank you a lot and good luck to everyone! Regards, Andreu Tags catch-pot full vacuum precision vacuum gauge Edited 12 Years Ago by H4RTM4N
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Warren (Staff)	Warren (Staff) posted 12 Years Ago HOT Post Details
Group: Administrators Posts: 2.5K, Visits: 8.5K	I think people are missing the point. Unless you are struggling to hear the tone change on the pump, then you dont really need a massively accurate gauge as the tone change will tell you when you have reached full vac and have no leaks. Warren Penalver Easy Composites / Carbon Mods - Technical Support Assistant
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morepower	morepower posted 12 Years Ago HOT Post Details
Group: Forum Members Posts: 242, Visits: 1.2K	Warren (Staff) (24/07/2013) I think people are missing the point. Unless you are struggling to hear the tone change on the pump, then you dont really need a massively accurate gauge as the tone change will tell you when you have reached full vac and have no leaks. It may tell you when you have a full vac under a draw but a tiny pin hole leak could take 10 or 20 minutes to drop 100Mb and if like me you are doing a pre-preg part and need to de-bulk overnight, could lose all the vacuum before you cook the part. Leaving the pump running all night is an option but it is adding wear and tear on the pump and as I am on my second Easy Composites pump I dont want to have that one die too... It already is noisier than my ebay pump so hearing for a full vacuum is not so easy anymore.....lol.. The only real way is a good fluid filled gauge and a drop test...
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Vacuum Gauge Precision (can't pull full vacuum)

H4RTM4N - 12 Years Ago

As I understand it, Your at full vacuum at 29.9 HG so 29 is great! You could suck a cat inside out...

fgayford - 12 Years Ago

Well but it's still far from the 99.995% vacuum advertised with the small vacuum pump (which means...

H4RTM4N - 12 Years Ago

[quote][b]H4RTM4N (19/07/2013)[/b][hr]Well but it's still far from the 99.995% vacuum advertised...

fgayford - 12 Years Ago

Fred, what brand of gauges do you recommend? And where do you purchase them? I have a feeling I am...

prairiecustomcomposites - 12 Years Ago

[quote][b]prairiecustomcomposites (24/07/2013)[/b][hr]Fred, what brand of gauges do you recommend?...

fgayford - 12 Years Ago

[quote][b]fgayford (19/07/2013)[/b][hr]As I understand it, Your at full vacuum at 29.9 HG so 29 is...

matthieutje65 - 12 Years Ago

[quote][b]matthieutje65 (19/07/2013)[/b][hr][quote][b]fgayford (19/07/2013)[/b][hr]As I understand...

fgayford - 12 Years Ago

They are not the most accurate guages on the market but they are very cheap and accurate enough for...

Warren (Staff) - 12 Years Ago

Thanks for the feedback people!

H4RTM4N - 12 Years Ago

I think people are missing the point. Unless you are struggling to hear the tone change on the pump,...

Warren (Staff) - 12 Years Ago

[quote][b]Warren (Staff) (24/07/2013)[/b][hr]I think people are missing the point. Unless you are...

morepower - 12 Years Ago

I've just finished bagging an airbox cover... I usually get perfect bagging, but this time, even...

alebassa - 12 Years Ago

An accurate guage will only tell you accurately what the leak has dropped to - which is irrelevant....

Warren (Staff) - 12 Years Ago

Although I have found there is a difference in total vacuum pulled between two different pumps. So...

morepower - 12 Years Ago

Thanks for the interesting feedback everyone. Warren made some valid points but I agree that there...

Matt (Staff) - 12 Years Ago

Sorry for adding my two cents in this old thread, but I had to reply. Maybe it will help others...

brainfart - 11 Years Ago

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