Hi,posted this on the general composites...thought it might suit better here.

Hi
Id like to know what are the main differences between using a venturi vacuum system and a pump sistem.
Purchasing a venturi one seems cheaper(already have a good compresor),but Id like to know what is the downside if there is,and its limits.
We are focusing on small bycicle parts,no infusion.
Thanks in advance.

A Venturi will not produce the required vacuum, and is impractical to use for the hours needed

and they can be quite noisy

A vacuum pump will produce better vacuum and for longer.  A venturi doesn't pull deep vacuum  like only 25 inches of HG (i am american .8ish bar I know we use a horrible system)  They also cannot be used for long duration of time like pulling vacuum overnight. IMHO Pay a little more and get a dedicated vacuum pump.   

Thanks for the replies
OK,I understand that the ideal is a vacuum pump.Actualy,its what Im using now.I have an ole vacuum pump,that works.But I use it in my studio for degassing mostly silicone and some resins.Its a must for my daily job,and degassing only requires some minutes work for the pump in my case,and I dont like having it on for long periods.
So,the next purchase will be a dedicated pump for Cbf,as recomended above.Also,now we are playing around with small parts,but who knows what will come after.For what I read the venturi might be a bit on the short side I guess.
Thanks for claifying.