Fighting a new issue with infused Carbon.

General Composites Discussions Composites Talk
#1

Hey there folks,

I’ve been manufacturing cosmetic carbon fiber components by way of VARTM for going on 5 years now and it’s been fairly consistent.

Over the last two or three months, I’m seeing something I’ve never experienced before.

If you notice, I’m getting what’s almost like a foaming or clouding in spots on the parts and I can’t figure out what’s causing it for the life of me.

I’m using the same chemicals (polyester resin, PVA release, etc…), same consumables, same process, same pump, same carbon, same EVERYTHING and for the last 4 pieces I’ve made, 3 have had this issue and are unusable as cosmetic components.

I’m pulling out my hair at this point, so if you’ve got advice or ideas, I’m all ears,since I’m about to infuse 4 more pieces, shortly.

Here are some pics.

As an aside, the breakage in the pics is a mold release issue and it just needs additional training and coaching of my new techs. (theyre trying to go to fast and not letting the PVA dry properly)

Thanks in advance for the advice!

:slight_smile:

And in this pic you can see how the parts are beautiful in the areas that aren’t clouded.

#2

Stop bridging your layup, first or any of the following layers, and this will just puzzlingly disappear…

#3

Is moisture a possibility? I don’t know about carbon but if you get fiberglass wet (even just damp) and use it, you can get a cloudy, milky result. This can happen even if the material gets wet and subsequently dries before you use it. I’ve been told it’s the binders that are the culprit.

By the way, I don’t see any pics.

#4

There’s no way this is bridging. It’s too far spread and mostly in the flat areas, not the radius like you would expect with bridging.

I think Roger might be more on the right track, it looks like moisture or a foaming issue to me. BigTop, you mentioned your techs are rushing the PVA… Is it possible they did this on all three pieces?

#5

Do you use an in mold coating? Had something similair with an IMC.
Do you degas your resin and do you mix it after or before degassing?

#6

Looks like a bad charge of Polyester resin. We had something similar with epoxy, in that case it has been the spray adhesive.

#7

Thanks for the help, guys.

In reading your feedback, the first place I looked was the PVA process.

It looks like it’s a combination of wet PVA mixing with pooling gelcoat when sprayed into the mold.

We slowed down and are making extra certain the PVA is dry and the last 4 pieces I’ve made have been solid.

#8

Im doing some learning, are you spraying clear gelcoat into your mold? Is it just clear or are you adding any additive?

Thanks

Parts look good

#9

Thanks man.

When the process is doing what it’s supposed to, the parts have been consistently excellent.

We spray clear resin (“gelcoat”) into the molds, lay up behind that, infuse, trim, scuff, clear coat, wet sand, then polish.

You can see a BUNCH of our work at www.instagram.com/g3carbon

:slight_smile:

#10

Product looks great BigTopGT. I am curious what you are using for a clear resin before layup. I have been using a 2K clear, but would like to try something a little thicker like a gel coat to see how it works.