Carbon Fiber Repair

"roflcopter" (roflroflroflcopter) 01/27/2016 at 20:55 • Filed to: None

5

17

So I ended up with a 66" APR GT-250 wing for free because it had been used to catch tires after going into the wall at nearly 100mph, it was destined for the trash so my friend let me have it. I'm fixing it up to be completely functional and look like new again, I don't think he thought I could do it. I'm not done yet, but who would be interested in a write up after I have it all sorted out and shining?

Daily Drives a Dragon - One Last Lap > roflcopter 01/27/2016 at 21:00

4

I would be very interested in a write up

slipperysallylikespenguins > roflcopter 01/27/2016 at 21:01

2

I would like to read more as I have been looking into dabbling with CF parts for my motorycle. More insight is always welcome.

MM54 > roflcopter 01/27/2016 at 21:04

2

Having done (what I’ve recently found out is) wayyyy more work with carbon fiber than most people, I see what you’re doing and approve. Looking forward to the finished product and before/after!

XJDano > roflcopter 01/27/2016 at 21:06

1

Yeah I’ll read that.

Does your sailing experience help with this?

Iheartmy365kHonda - Car enthusiasts do like FWD > roflcopter 01/27/2016 at 22:16

2

I want to learn how to repair CF!!! DO A WRITE UP, PLEASE!!

roflcopter > Iheartmy365kHonda - Car enthusiasts do like FWD 01/27/2016 at 23:11

2

I shall do one since there seems to be plenty of demand!

roflcopter > XJDano 01/27/2016 at 23:12

0

It does! I’ve done a decent bit of fiberglass work, but only messed with carbon a few times beyond minor repairs. It is nice to have limitless epoxy and a full variety of fillers at your job though.

roflcopter > MM54 01/27/2016 at 23:15

1

What all have you had to do? I’d be interested to hear your projects. Also, any pointers you have are more than welcome, I’m usually doing fiberglass repair where it will be faired and painted, not carbon where the whole layup will be visible.

The overall plan has been made some spacer blocks to put behind the seams and tab it all back together, then skim coat it with fairing compound to work the shape back to original, then wrap another layer of 3x3 6k tow twill carbon around the entire thing(seam being at the back edge where I can cut it flush easily, then wetsand and clearcoat.

BaconSandwich is tasty. > roflcopter 01/27/2016 at 23:31

1

Please do a write up. I've been wanting to learn to work with carbon fiber.

uofime-2 > roflcopter 01/28/2016 at 10:08

0

My only comment is that I doubt one layer will be enough, even with 6k it’ll still not be very stiff.

roflcopter > uofime-2 01/28/2016 at 10:28

0

The structure of the wing is fine, that’s what I’ve been working on this far, the last layer will just be to cover up all the ugly parts I’ve made getting the structure sorted out.

uofime-2 > roflcopter 01/28/2016 at 10:34

0

so its just cosmetic really?

The biggest issue you’ll have wrapping wings is keeping the plys taunt, especially when you vacuum bag them, as it shrinks around the wing it has a really bad tendency to to cause wrinkles, especially at the leading edge, and if you want to show pretty CF there is not way to fix it.

roflcopter > uofime-2 01/28/2016 at 11:07

0

Yeah, the last later will just be cosmetic. Worst case I guess I’ll just paint it if I can’t get the weave to look good.

My plan was to wet lay it so that it would be easier to get it all lined up and all. I don't have any vacuum bag equipment for this project.

MM54 > roflcopter 01/28/2016 at 17:47

0

Sounds like a good plan! 6k might be a little heavy to get a crisp edge on the front, but with your clamping setup it should be fine. As a handy tip, most carbon fiber epoxy won’t stick to packing tape (very well, at least) so it’s a handy release agent for clamps, etc.

When I was in college I was on/ran the SAE Supermileage Team (Formula SAE’s efficient little cousin) - over the course of 4 years we built 3 cars, each a carbon fiber monocoque. A lot of pieces for the vehicles were also hand made in carbon by the team. All sorts of different tow weights, weave patterns, etc. We even experimented with carbon/kevlar but you can’t sand it, which we often had to do to get the surface finished super-smooth.

I’m the one running around in a grey flannel with long hair.

It’s funny, to a lot of people carbon fiber is this amazing high-tech super-material; to me it’s just the black stuff that comes in rolls and gives you ungodly splinters.

MM54 > roflcopter 01/28/2016 at 17:50

1

For a male mold (which you’re working with the equivalent of) you don’t want to bag it unless you’re going to the asthetic of a raisin

Iheartmy365kHonda - Car enthusiasts do like FWD > roflcopter 01/29/2016 at 00:57

1

You rock harder than a metal concert, bro.

roflcopter > MM54 01/29/2016 at 08:47

1

Haha yeah, I’ve done a decent bit of work with fiberglass due to a background of working with sailboats, I see carbon as just another mat material to use.

I wasn’t planning on using the clamps for when I actually lay the carbon over it, I was just going to coat the part and let it tack then lay the carbon and wet it out so it will stick the contour and I can roll it out well. More like if you were going to skin a part for looks(essentially what I’m doing).

I'm excited to see how it all comes out, maybe a lighter tow would be a good idea, the only reason I was thinking 6k was because that's what APR used on it to begin with.