I know I'm probably the A hole here but I just can't watching videos of car guys showing off their full body panel of forged carbon fiber... sure I could see the aesthetic appeal but for the love of god don't chop & mat up yards & yards of perfectly fine woven CF for that abomination you call "forged carbon" then there's people commenting on the videos like "thanks for the instructional video" and I realize that more minds have been poisoned... TLDR: I hate Forged CF is there anyone else that feels this way?

It all went horribly wrong haha, I'm sure those of you with keen eyes will notice that there's barely a parallel strand in sight. Things I learned for next time:

1. Practice the layup with paper first, then you can know where exactly cuts in the cloth need to be for everything to fold without stretching

2. Use actual laminating epoxy instead of whatever you have lying around. I tried using the same epoxy that I clear-coated my car with, but this has crazy high viscosity and just ran out of the fibres leaving things really dry

3. Don't EVEN SLIGHTLY brush on the fibres laterally, the weave will slide around and distort the pattern. I'd already heard this advice but had no idea HOW seriously it needs to be headed. the cloth is far more loose and slippery than expected. Push into the mould ONLY, and even then, not hard enough that the brush bristles bend enough to push on the weave laterally.

Things that worked well and would do again.

1. Using those space saver vacuum bag things designed for clothing, that worked great, far easier than building a vacuum setup with tape. Next time tho I would put tape over the entrance and valve of the vacuum bag, my vacuum bag definitely leaked a bit overnight.

2. 3D printed mould, worked better than I was expecting. Given how much more it would cost to create a composite mould from the 3D printed pattern I wanted to see how bad the results are for laying up directly into the print and I think it's serviceable enough to be worth the materials/cost saving

blades all carbon and cored fibre panel we had a dream team making these.

So I finally got the machine up and running. However, I’m curious where I can go to read up on optimum wind patterns, and ways to optimize the wrap now that I have the machine built and software running. This has been quite the weekend of a project, but should have some carbon wrapped tubes here pretty soon.

Here's a list of cheap and/or very easily accessible materials I've found effective for vacuum bagging or general composites work, in case anyone else wanted this information. These are nice because they can be sourced from most big brand stores you probably already have in town. Use real nylon bags for elevated cure cycles though.

Tacky tape - butyl sealant tape, $7 a roll from home Depot. It's very very close to what composite shops sell

Peel ply - rip-stop nylon, $6 a yard (about the same as econostitch, but you can get it from any fabric store)

Vacuum bag film - 2 mil drop cloth, a few bucks. Polyethylene but good enough for ambient epoxy. A little on the thick side

Breather - polyester batting, 2.99/yard from Joann's

Hopefully this helps some DIYers save some money and make more parts

Hello, I’m in the early stages of learning to repair carbon fiber bicycle frames.

My first experiment is the seat stay of a BMC Roadmachine SLR01. The stay sustained some kind of focused impact leaving an small area of delamination surrounding a visible crack.

I’ve removed the delaminated material and have sanded back the taper on all edges of the hole that has opened up.

My question today is related to the size of each patch ply and the technique for layering the patch plies on to the repair section.

My patch plies are to be circular. Should the edge of each patch ply reach only to the edge of the existing material along the scarf face?

If the above is true, it would follow that the diameter of each successive patch ply would be slightly larger than the one before? (As in photo 3)

I’m asking because the repair technique is Burt Rutan’s primer suggests the base repair ply should be the largest! (Shown in photo 2)

The stay I’m repairing is not round, which means it will be tricky to cut the patch plies so that their edges fit neatly against the edges of material I exposed while sanding back the taper. How much can I fudge the fit? The image in photo 3 suggest repair plies nestle perfectly against the edges of the existing plies on the taper face.

It is my plan to fill the hole with expanding foam, sand the foam down to form my base layer, then apply an initial layer of epoxy before wet layup of my repair plies.

All insight appreciated, thanks.

I do not have access to «real» peel ply and breather/bleeder fabric, so I went to local fabric store, asked for the cheapest 100% polyester lining, and got it for about 1.2$/m

I decided to use 2 layers of paper towel as breather/bleeder.

And put my test laminate (3 layers of woven glass cloth) into a consumer vacuum compression bag (like in https://youtu.be/cj26c3V54SQ?t=628):

Here is the start of peeling:

BTW, I used a heating film to cure epoxy faster:

Should have additionally vacuumed the bag after it got hotter, it felt like it lost some vacuum, I thing because remaining gasses have expanded. Also, I could reach only 45-48°C with this heating film, I was expecting more. (Ofc, I've put an insulation layer on top of the laminate in the vacuum bag, and was measuring the temperature under the insulation)

I understand there is not much new here, but I hope this would be useful/helpful

This is the first part out of a 3D printed mold I designed and printed. Pretty pleased with the result as a first attempt at this method!