First vac infusion w/VE - accidentally under catalyzed

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#1

I just did my first vac infusion w/VE last Saturday. Four layers of 9oz bi-directional glass cut on a 45 degree bias 42" x 22". Infusion went very well but 8hrs later the resin that entered the vac tubing still hadn’t cured - it was then that I realized I had accidentally under catalyzed the resin. My digital scale goes blank whenever I exceed 120 grams so I measured 4 x 100 gram batches, then poured 2 of the 100 gram batches into the same cup and catalyzed… I repeated this proceedure for the next 200 grams… midway through the infusion I realized I needed just a bit more resin so I mixed up another 100 grams and catalyzed. I intended to catalyze @ 1% but mistakenly added only enough catalyst for 100 grams for the first two 200 gram batches… the last batch of 100 grams was catalyzed at 1%. After mixing, all were poured into the feed cup (not stirred after combining) and then degassed for 5 min or so.

The ambient temp was around 60 degrees so I covered the laminates with a blanket and heated the bottom of the glass table I was using in the hopes of salvaging my work. Today I removed the consumables and the laminate appears to have cured for the most part (slight tackiness on the vac tube side). I warmed the entire laminater with a heat gun and then set the glass table top with the laminate still on it out in the sun thinking the heat would help cure it.

Question: Do you guys think the VE resin catalyzed at 1/2 percent will fully cure eventually? I plan on using the laminate to make several 6" x 8" rectangular flanges that will then be bonded to the inside skin of a wing tank where I had to cut several access holes in the tank for maintenance (the flanges will provide a ledge to bond the rectangular pieces previously cut from the wing back into place.

The sheet is going to be used inside the wing tank and will be exposed to AV gas so I need to be sure of its integrity.

#2

Heat it up real good, and for a longer time (heat gun is useless, use an oven) and it will probably cure sufficiently. If you do not have an oven, but you have enough sun, then cover it with some black plastic, and put it in the sun for a day or 2.

#3

I think you will be fine. Depending on what gel time you THOUGHT you mixed for, if you only did half, you should have double the gel time. It will cure, but just take long. Heat if possible to speed it up.

#4

Thanks guys! Do you think a heat lamp would do the job? If so I will pick up a heat lamp and place it over the part for 6-8 hrs or so…

#5

Flood lights work as good as anything else, plus they are relatively cheap at local hardware stores. Grab a set of those, the kind on a stand and point the light directly at the tacky part of your laminate, about 3 to 4 inches away, in a few hours it’ll be cured.

#6

Depends what heat lamp??

#7

I’ve had VER laminates take up to 48 hrs to cure when temp was near 60f. Set it out in the sun for a full afternoon, night bring it back inside. Don’t demold it until it is fully cured.

I completely agree, heat guns are useless for heating a laminate or mold. Been there, done that, failed. Heat lamps suck too but better than nothing. An oven is best. If your mold is polyester frp you can “bake” it at 110F for a couple hours with no issues.