(New Member) Vacuum Bagging Part Problem

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#1

Hi Guys - I’m new here but I’ve read most of all the post in the forums. I’ve been trying to make a light cover with little sucess. I’m trying to vacuum bag it and don’t know if it’s a problem with what I’m doing or the part. I’ve put up pictures of my mold and the problem area, and the parts I’ve made.

I’m having trouble with the ends. My first attempt was with some real cheap 6 oz fiberglass - 2 layers with West epoxy. I vacuum bagged it with a woven PE peel ply and it came out with almost no resin, though it did form to everything.

The second attempt was with 5 layers of a “boardy” 1.5 ounce fiberglass. This didn’t conform well but has a nice finish.

The final try was with 3k CF twill. The twill looks nice, but I didn’t get into the ends very well.


I don’t think I had any bridging in these areas when I bagged it. Do you think this is a difficult part or am I not good? Thanks for the help!

#2

that epoxy looks really yellow,

how thick is the epoxy?

#3

I think the lights make it look more yellow than it is. The first one is very dry - pinholes through both layers of glass all over. The second is very resin rich at the ends, but the center is pretty only a little resin rich. It was also done with West 205 hardener which is yellow colored. The last one is CF and is only resin rich on the ends. The thick end spots are maybe 1/16-1/8" thick.

#4

whre did you put the vacuum connector? if you put it in the middle then maybe it didnt pull enough at the ends.

what process are you doing this lay up?

#5

I’ve been wet laying them and then vacuum bagging. I’ve been using around 24 inHg and putting the part in an envelope bag. The vacuum port has been to the side off the mold.

#6

with a part that size it really wont matter where the vacuum port is providing that the breather cloth has a clear path without any breaks from the part to the vac port.

Looks like there is too much resin going on in there, especially between the first layer of cloth and the mould surface, that is stopping the cloth from going down to the mould surface.

Also then you need to make sure that there is no bridging in your vac bag, pull a partal vac and move the bag around making sure that it is pushed right into corners and doesnt have bridging, put pleets in the bag etc… life would be easier for you if your mould had larger flanges around the edges and if the mould was deeper so that the edge that gets trimmed wasnt the edge of your mould as it is.

#7

So the curves look ok to you, so it’s my technique? That is what I was figuring. It doesn’t seem to be bridging, but it must be. I’ll give it another go and see what I can do. I ordered some Stretchlon bagging film thinking that would eliminate any bridging. Maybe I should make a new mold with bigger flanges too.