pre-wet airframe when using sleeves? - Northern Colorado Rocketry

This topic has 7 replies, 6 voices, and was last updated 14 years, 6 months ago by bryans.

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April 3, 2011 at 3:02 am #41230
bryans
Heya gents… doing my first project using carbon fibre sleeve… the weave seems too dense to push epoxy through like I did with my (only) fibreglass project.

Does everybody pre-wet the airframe with epoxy before putting a sleeve (FG or CF) around it? It seems like I should to get a good bond, but also worried about the epoxy grabbing and causing me trouble when sliding the sock on.

This happens to be 4 inch, 15oz CF sock… pretty heavy, but i figure around paper tube i only need one layer to get pretty good strength for this J-K-L powered project.

Advice?

-Bryan
April 3, 2011 at 3:05 am #54087
Warren B. Musselman
Moderator
4″ 15oz sock? Woah…I’d seriously consider that M or N-fodder on an Estes paper tube even.

Realistically speaking, wetting out carbon is such a pain compared to glass. Very hard to see unless you have the light right… That said, it would be a helluva lot easier to put the sleeve on the tube before wetting it out. On the other hand… wetting it out first is the only way to be sure.

Hope I confused you as much as I am over sleeve….
April 3, 2011 at 3:14 am #54088
Chris LaPanse
Personally, I wouldn’t. It would make it very challenging to get the sleeve on after soaking the tube in resin. What I would do is use a fairly thin, slow-cure epoxy, and really work it into the weave. Spend some time with brushes, rollers, and possibly even just your hands (with gloves of course) and make sure that the epoxy is rubbed and brushed into the cloth as well as possible.
April 3, 2011 at 3:44 am #54089
greywolves
Hey Bryan,

I on the ones I’ve done with 2 layers, the second layer is a real challenge to get on straight. So, on my first layer i don’t wet it out, so you can pull it real tight, then tape down the ends to hold in place, kinda like those ole Chinese finger cuffs. I’ve been using 206 hardener, West Systems. Seems to allow sufficient time for work it in, I use a soft plastic scraper. Hope this helps.
April 3, 2011 at 5:07 am #54090
Adrian
Participant
Apparently there are lots of ways to skin this cat…

I wet mine out thoroughly, and then put it over the tube. I squish it end-wise to make the diameter a lot bigger and then stretch it out to place it as I go from one end to the other.
April 4, 2011 at 2:39 pm #54091
SCOTT EVANS
Apparently there are lots of ways to skin this cat…

I wet mine out thoroughly, and then put it over the tube. I squish it end-wise to make the diameter a lot bigger and then stretch it out to place it as I go from one end to the other.

Sounds Messy! Ive been known to let a few colerful metephors fly trying to play with pre-wetted stuff. 🙄

I never really had any trouble getting cf to wet out. 8)
April 4, 2011 at 4:47 pm #54092
Adrian
Participant
In almost all of my layups there comes a point where I say to myself “oh crap, this layup is doomed!”. Sometimes it’s true, but not usually.
April 4, 2011 at 8:46 pm #54093
bryans
Thanks guys for the feedback. I’ll use West System 105 with 206 (slow) hardener, and just work it in with squeegee thingy and brushes.

Warren, yes its overkill, reason being that if it goes well, this will fly solo twice, then become the first stage of a two-stager, so a little stiff and heavy overkill is better for my first time in that territory. Maybe should have been all fibreglass, but i wanted it to be inexpensive and already had lots of LOC tubes and couplers and plywood stock on hand. Even with the $70 of CF sock and tip to tip glass, its still going to be a fairly low cost project for when all is done compared to an all-glass setup.
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