Bubbles visible in flow media

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Bubbles visible in flow media

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quinn	q quinn posted 7 Years Ago HOT Topic Details
q Group: Forum Members Posts: 155, Visits: 992	Here's a panel I infused 30 hours ago. As you can see in the pics, I have some bubbles in the flow media. Before infusing, I pulled full vacuum and left it for 20 minutes, no vacuum loss. Fully degassed my resin in vacuum before infusion. During the infusion I could see some very tiny bubbles flowing with the resin. Finished the infusion, next morning I could see all these bubbles. Looking through the glass on the finished side, it looks flawless. No voids or bubbles. Probably going to debag it in a couple hours and see how the panel looks. Hopefully bubbles are only in the flow media. So what went wrong? Is it likely I developed a leak somewhere during the infusion? Or I didn't have full vacuum in the first place? My gauge only pulls to 26 but i can boil water with vacuum so it's at least hitting over 29. If I was only getting 29.5 inches or so, would that be bad enough to end up with air like this? Or more likely that it just started leaking at some point? After 30 hours, the bag is still pulled down very tight. I'm also still using regular laminating resin, 600cps, not actual infusion resin.
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quinn	q quinn posted 7 Years Ago HOT Post Details
q Group: Forum Members Posts: 155, Visits: 992	+x oekmont - 9/1/2018 3:26:50 PM You can get a perfect resin ratio with infusion. This usually means, that you have to close the feed line before the resin front reaches the vacuum line. Ideally to the right time, that the excess resin barely can impregnate the rest of the part. Alternatively you can close the feed line, and let the vacuum line open, until no more resin enters the catch pot. Both will increase the chances of getting not a perfectly good finish. And the carbon optics are less "deep". If you decrease your resin ratio, you will get a less stiff plate, as the thickness (wich is the major factor for stiffness) decreases. To get the same thickness, you would have to compensate with additional cloth. This will lead to increased weight for the same thickness, but slightly better rigidity. Basically what I said before, but from a different perspective. Ah ok. This panel I just did, the resin was setting up right as it finished. Took about 40 minutes, probably because I'm still not using infusion resin, which i will next time. I did close the feed line a little while before vac line, but as I said the resin was already thickening so I'm sure it didn't pull much out. I think I'll get a bit better results next time with proper resin and also experimenting with other fabrics. grade A finish is not important for these parts so I will let it suck out a fair amount of resin at the end next time. Also I'm thinking when I try using some inner layers of non woven biaxial, it should not only improve stiffness a bit from the non kinked weave, but also I would assume it has the potential for lower resin content. Non woven fabric should have less voids for resin to fill, right?
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