Fiberglass goof. Is it repairable?

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Yesterday, I glassed my first airframe section in 14 years, and I didn't do as well as I had hoped.

I used a 4" light sock from Soller Composites on a section of 4" PML airframe, applied epoxy, then applied a teflon release followed by a breather layer, then placed the entire section into a foodsaver bag and vacuumed it down.
IMG_5234.jpg

At the time, I thought I had maybe used a little too much epoxy, but after I removed it from the bag and peeled off the teflon and breather this morning, there are areas where it looks like the epoxy was insufficient. I also noticed that there are a several areas where I had bubbles, and it looks like I had a few wrinkles in the teflon. I had the sock completely smoothed out prior to applying the release, and the again prior to wrapping the breather on it. The following photos show after I sanded it down.
IMG_5242.jpg IMG_5243.jpg IMG_5244.jpg IMG_5245.jpg IMG_5246.jpg IMG_5247.jpg

So, my question is, is it salvageable? I was an idiot and used the slotted section first, and so it will not be as cheap to replace. I am tempted to sand it more, then apply a second layer of the sock over it and carry one, but I am not too sure. My other choice is to go with option B and purchase some FG tubing from Madcow or similar and call it good.
 

amarillo_rocket

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What kind of performace are you expecting for the rocket ie.. Mach 1 or greater?
 
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It's a 4" airframe with a 54mm MMT. The fastest sim was with a K1275 at just under mach.
 

BDB

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I think it's fine. I'm not an expert, but I have had a layup look like that (though I didn't use a sock). In my case the tube was still stronger, so I was satisfied. But you are in for a lot of sanding and filling.
 
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amarillo_rocket

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I agree you should be OK to use it. If you have voids that are deep a light coat of epoxy spread with a putty knife should fix them then sand smooth.
 

Woody's Workshop

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Coat it with 30 minute epoxy and rotate so it levels out evenly until it sets up.
Sand it smooth and you'll be good as gold in your pocket.
What's a little more weight, more or less?
For a really ruff air frame.
Just for fun facts, I coat all my LP air frame inside and out with TiteBond and sand the outside smooth with 220 for primer.
Makes for a sturdy air frame, and I really ain't tryin to reach the moon or some other goal.
 

Steve Shannon

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I wouldn't use 30 minute epoxy. I would brush on something like Aeropoxy laminating epoxy with very little viscosity and see if it wicks in and fills those starved looking areas.


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REK

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It appears to me that you had a vacumn leak somewhere. I did no tube, but on a flat panel that I was doing to show high school students, there was an unfortunate leak somewhere that we could not identify and it resulted in massive air filled areas and dry spots.

I would ditch the vacumn and just use peel ply or a heat shrink tubing.


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Thanks for the advice, guys. I think I will start over and order another tube. I'm thinking one of two things happened. 1, either I didn't pull enough of a vacuum on the tube prior to sealing the end, or I unknowingly caused a few wrinkles when I applied the breather cloth and placed it in the bag. I might try again on another section of tubing, since I already have to order another slotted section. If I fail again, I'll just go with not bagging it.
 

REK

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Thanks for the advice, guys. I think I will start over and order another tube. I'm thinking one of two things happened. 1, either I didn't pull enough of a vacuum on the tube prior to sealing the end, or I unknowingly caused a few wrinkles when I applied the breather cloth and placed it in the bag. I might try again on another section of tubing, since I already have to order another slotted section. If I fail again, I'll just go with not bagging it.
Im sure you didnt pull down enough vacumm. Hopefully it works for you.


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watheyak

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I have always had wrinkles when I tried to vacuum bag a tube, no matter what I tried. I second the use of heat shrink tape. Soller also had heat shrink tube that have used a couple times and it works great. Easier than the tape if you don't need super high compression.
 

dhbarr

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Seems like first heatshrink tube then vacuum could be workable, anyone try it?
 

watheyak

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Seems like first heatshrink tube then vacuum could be workable, anyone try it?
In another thread recently someone tried heatshrink tape then vacuum and it seemed to work pretty well. The heathrink tube and vacuum would probably also work well with no wrinkles. Hmmm....
 
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