I’m thinking of buying a second vacuum pump so i can have two lay seperate layups with offset times.
Ok this is just a guess… my 6cfm Robinair pump probably makes around 55 decibals of sound. How many decibals would a large refridgerator pump make?
(as a reference i think the average automobile engine makes around 75 decibals of sound.)
Also, is the 4cfm Robinair any quieter than the 6cfm version?
a large fridge pump makes 0 db… dead silent, it’s beautiful, you can even hear the slightest leaks just by runnin gyour ear close to the sealant tape around the edges to check for leaks! and hooing up to a large vac reservoir is great for that extra bit of oomph.
yup, fridge pumps are the way to go :rolleyes: i do all my work at night, so it’s very useful to have a quiet pump! be careful though of fridge pumps that dont have a separate cooling circuit. one that i had used to spit oil out all the time, and i didnt put it back in, until it died.
don’t buy another pump, (unless its a fride pump 
), just get a manifold and shut off valves so you can do multiple parts very easily
Yeah… a manifold with shut off valves for each port. Good idea. And buying a fridge pump… what type/model should i look to buy?
“seperate cooling unit” 
Do you change the oil on the fridge pumps or are they sealed?
When you say Large fridge pump… are we talking about a home size refridgerator or an industrial refridgerator?
large = ice cream or supermarket frozen products deep freeze
as far as i know, a normal home fridge pump can hold vacuum to infuse 3-4 sq. meters area… like 2 hoods !! every pump can achieve full vacuum, however flow is another thing. If your pump has higher flowrate, it can hold good vacuum even if you have a small hole somewhere.
by separate cooling i mean circuit. these pumps have usually 1 or 2 intakes, (suck) and one that blows.(yes if it has 2 intakes you can use them for multiple molds…if you dont use them both, you gotta clamp off the one that is not used) if the lubrication oil which is used for cooling too, is not on a separate circuit that the air, the blowing pipe may spit out oil (or smoke if the pump heats up) …this oil you should collect in a cup and put it in one of the sucking pipes, to suck it back in. That simple 
I found this one on ebay, these refrig pumps have overload relay and a capacitor. Do I need to wire all these components into the circuitry? If so how is that done?
If anyone wants to bid on this one I dont mind, i’m going to buy a pump locally.
yeah thats the kind i use…
If I’m only using one circuit can the second circuit be used to circulate the pump oil?
gezz, wish I saw this thread 10 years ago when I was trying to make a N2 laser, and I used a fridge pump for the vacuum. Ended up seizing all the time, and I gave up! (Well, me blowing out ANOTHER capacitor really made me give up!)
So all I need to do is catch the oil, and suck it back in? Might do this later.
As for the noise, if you have room, just run tubes long enough to stick the pump somewhere out of the way.
Down the very bottom of this link - there is a DIY vac pump guide.
He uses a fridge compressor.
http://www.theturboforums.com/PBcarbonfiber.php
^^ I managed to get me a small fridge compressor like the one shown in the link, however when I plugged it in and put my finger over the “in” tube, it seems rather weak? It is just my compressor or are all fridge compressors like that?
I mean I leave my finger over the port for like half a minute but when I lift it off, it doesnt feel like there is any strong vacuum at all, is this the norm?
nope, mine sucks the finger (lol) at once, and it sucks a mold about 50cm x 25cm in about 5 seconds completely
^ Lol I can feel the suction just not very strong :S I think I might have to find another compressor lol, this one was out of an old fridge
I built a system over the weekend using a new Embreco compressor and it pulled 88.7 kPa.
Here are a couple photos of the pump I used ot make my first infused parts. The core material is Divinycell foam.
http://picasaweb.google.com/Joe.Knesek/Sport20VucuumInfusion/photo#5184419190914824930
I think I’m just going to make a cut off switch set up for my Robinair. Just waiting to make some cash so i can buy all the necessary parts to build it.