VIP pump cfm?

General Composites Discussions Composites Talk
#1

I have a Thomas 2660 vacuum pump, on free air movement it can suck a bag down quickly. However when i went to infuse a 4 layer 6K cf flat laminate it wouldn’t do it. I was using 500 cps resin. The flow traveled 10 inches then stopped, the resin was still fresh in the cup.

I used perforated release ply under the red flow netting. Did the perf release hinder the flow? It is perforated .030" every 1/4".

Previously, another pump, a little refrigerator vacuum pump had no problems infusing a flat panel, 4 layers cf that was twice the size/area. On that infusion i used peel ply, no perf release.

What is the minimum cfm of pump for infusing? I can pull 27hg all day long with both pumps.

#2

Don’t know the min. but with my Robinair 6 CFM I pull 30" HG every time but then again I’m not that high above sea level.

#3

CFM is not important, as long as the pump can cope with the flow, which is very soon already enough.

Also the perforated film should not hinder flow. Did the resin travel through the mesh? It should, even if you have non perforated film below it. If not, something else is going on. (obstruction, dying pump). Do you have a gauge on the pump to monitor actual pressure?

#4

I need to install a vacuum gauge when infusing.

where in line should i install the gauge? I run my vac line from bag to catch pot, from catch pot to pump.

also where should i install my gas ball shut off valve in there?

On my old set up i had the pump, then ball valve, then gauge, catch pot, then the lay up.

#5

the flow medium was flowing… just stopped after it moved 10" or so.

Also will length of tubing effect vacuum air flow?

from the cup to the laminate is 3ft length of tubing 1/4" I.D. polyethelene.

from the catch pot to the lay up i used 10ft length tubing 1/4" I.D. polyethelene.

if i recall i have almost always used 10ft of tubing between the pump and catch pot, and anywhere from 5ft to 10ft from catch pot to lay up.

#6

Try a larger I.D. tube. I’ve used 1/4", 5/16", 3/8" I.D. intake tubing and noticed a difference in the infusion speed when that was the only thing changed. Exhaust I have only used 1/2" I.D.

Why is there 3 feet between the cup of resin and laminate? I try to keep this as short as possible to reduce waste. Plus I think the longer the intake tube is the more it could add to the resistance?

#7

a leak can stop the infusion…sometimes the resin will drop back into the cup (sure sign)…
But again, CFM does not matter unless you are infusing a boat hull, when you are sucking in gallons of resin in one shot. But even then, CFM is only related to how quickly it evacuates the bag.

the only safe place for a vac gauge, is on the pump, and catch bucket. Ball valve between the pump and the bucket (normally: Bucket, ball valve, guage, vacuum fitting. Another gauge on another bucket port to use as leak checking. Guess you can go: bucket gauge valve gauge vacuum fitting.)

#8

Infusion speed is highly dependant on feed tube diameter. It is in the equation that determines infusion time.

#9

What about feed tube length?

#10

I would think so Rotor, on the resin side. Short and tiny can have the same friction as long and large. Also depends on the part size of course.

#11

So your saying they need a big pump for something like this boat hull? :smiley: :wink:

#12

This is RMK in Turkey. Infusing a 30-ish meter sailboat hull (Oyster). Supervised by my friends of www.polyworx.com.

Basicly, a 100 m3/h pump and a 65 m3/h (backup) pump were used.

Now working on an even larger project, which uses 4x 100 m3/h pumps, and 20 of those resin catch pots. Guess who supplied all this… :slight_smile:

#13

How long does something that big take to infuse herman?
I know the rest of the world runs on metric but we here in the states do things alittle azz back wards. Could you put this into English for me? 100 m3/h pump

#14

I would hate to leak check that

#15

i probably had a leak. just peeves me when taking all that time and materials then it goes bad.

#16

100 m3/h should be around 60 cfm, if I am correct. (does that make sense? Around 40-50 times the average small size DIY pump)

Infusion time usually is between 2 and 3 hours.

Leak checking: yes, that is a bunch of work. Although it does not add up that much to smaller projects, as the tape perimeter is smaller.

#17

And that ladies and gentlemen…is one FUDGE of an infusion…

:open_mouth:

#18

Feed length is not in the equation, but specifically height of the resin barrel can make a big difference, as gravity plays a factor.

#19

This definitely has to be a huge factor. From fluid energy equations the easiest way to get more energy is just to lift your source!

@Fastrr
I hate when layups go bad too, so much time and effort gone to waste!