small bubbles/pulling too much vacuum?

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small bubbles/pulling too much vacuum?

Author	Message
spearonic t	spearonic t posted 6 Years Ago HOT Topic Details
Group: Forum Members Posts: 1, Visits: 53	Hi there, merry xmas everyone! Lately my last 2 infusions have gone wrong,i have noticed that when my part is 95% finished i shut the resin line off and leave the vac line going to get rid of the excess trapped air.the whole infusion looks nice and clear but once the vac is on to long i notice the top section of my mold (near the resin inlet) it starts to go cloudy and i can see small bubbles forming everywhere coming up through my fibreglass,this section is thicker in reinforcement. Am i leaving vacuum too long? it almost seems like the resin is boiling. I have degassed resin prior to infusion and i have 100% no leaks . any help would be much appreciated,cheers
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Lester Populaire	L Lester Populaire posted 6 Years Ago HOT Post Details
L Group: Forum Members Posts: 311, Visits: 13K	+x spearonic t - 12/30/2018 12:00:55 AM Hi there, merry xmas everyone! Lately my last 2 infusions have gone wrong,i have noticed that when my part is 95% finished i shut the resin line off and leave the vac line going to get rid of the excess trapped air.the whole infusion looks nice and clear but once the vac is on to long i notice the top section of my mold (near the resin inlet) it starts to go cloudy and i can see small bubbles forming everywhere coming up through my fibreglass,this section is thicker in reinforcement. Am i leaving vacuum too long? it almost seems like the resin is boiling. I have degassed resin prior to infusion and i have 100% no leaks . any help would be much appreciated,cheers No resin outgassing would be on the other end at the flow front, where the pressure is lower. In an infusion you have a pressure gradient, with a full vacuum at the flow front and nearly ambient pressure at the feed line. My guess is that you have trapped air near the feed line and when you clamp off the resin, then the overall pressure drops and the super tiny bubbles grow because the pessure around them is lower. when you open the feed line, make sure to open it quickly and close once the resin advanced to the clamp. Wait a minute for all the air that was in the tube to escape before opening the line again. Other than that i think you just need to wait a little longer before clamping off the feed line. Cheers, Lester!
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