first infusion

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#1

First infusion this week, would like any advice. Here is how i plan to do setup.

I have a small mold as im not jumping in feet first with anything to large (i will add pics) it is a spark plug cover, so nothing structural, all molds will be waxed as normal.

Layup:

4 layers Carbon Fibre 200g 2x2 Twill
Peel ply, full length of the carbon?
Flow media, also full length or carbon material and peel ply?
Bag.

I Will be using spiral wrap. and i am using a vacuum venturi genorator to pull vacum.

I am not going to gel coat the mold first. and i will be using a specified infusion epoxy.

I will geep this thread going and update with pics so any help along the way would be great. I will be adding a pressure pot to the setup but not until i get hold of the basics :slight_smile:

#2

For infusion I would say you need an actual vacuum pump to remove as much as possible. I doubt a venturi vacuum can will provide a sufficient vacuum

#3

I can pull 4bar with this venturi?

#4

I don’t know how constant will be the vacuum using a ventury. Why don’t u use woven fiberglass for testing first?
Peel ply and flow media to whole surface.

#5

Put first all the photos and we will tell you. In infusion system I can help you very well. All my parts are through infusion system. :wink:

#6

1: test a small piece to make sure the vacuum source you are using can handle pulling infusion. It should, but test first!
2: 4bar is pressure, not vacuum. The vacuum you see has an “apparent” vacuum of 14.9psi. But anyway, your question: Some can, but VERY slowly. When you first turn it on, it will suck air out, but the less air it has to suck out, the slower it takes to get down to full vacuum (normally " of Hg)
3: peelply over the full part is ok. Place the spiral UNDER the peelply to make sure the cuts in the spiral don’t cut the vacuum bag!
4: flow media should stop (depending on many factors) before the edge of part, NOT past the part edge!!! Try 1/2" for now, see how it works for your part size, thickness and vacuum flow.

#7

Thanks alot. i will get some pics up tomorrow and i will put a order in this week to get the stuff to me.

#8

Bit of an update i am looking for a vacuum pump instead of using my vacuum venturi how about this any one ??

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=200447864406&ssPageName=STRK:MEWAX:IT#ht_755wt_654

#9

i bought the 3 cfm pump from harbor freight.im not sure if that is an option if you are in the uk.i have had good luck with it.the total cost with the 2 year warranty was 170$

#10

question is 1.5 cfm do the job?

#11

It depends on how big the job is.

#12

Biggest I would be doing is a large bonnet.

#13

well, once the air is pumped out, I don’t think CFM means much…after all, if you won’t have .1cf of air in there, 1 or 5 cfm won’t mean much. Right? If you get really big, you can use a vacuum cleaner to suck most air out, then use the pump to get it down to 29"

#14

The efficiency of the pump is measured in the mircons that it can ultimately pull. You probably don’t need something that will pull down to 50, 200 should be heaps. I can’t remember what that translates to, but it’s something like the difference between pulling 29.5hg and 29.9hg. As far as the CFM goes, it just means it’ll evacuate the majority of a bigger bag quicker, and even a smallish pump will handle your bonnet ok.

#15

Malcolm thanks for your info.

#16

I hope that helps. Remember that it’ll all be dependent on the mould shape, layup, flow media type, etc etc etc, so you’ll always have to experiment somewhat. Don’t forget the basics though, a well sealed bag will always be a must.