Those are SO MUCH WORK!!! I hope the pulls go okay (I know I'm not alone in that).

Hardest part is trying to work out if the middle layers of biaxial fabric is going to work. The harness weave I'm using on the outer layers should be fine, but I'd like to get this inner layer going in the right direction (it's a +- 45º weave). Then there is the core material and the primer. What am I doing?

Good thing I race on Saturday so I can resist doing this for another day.

Sorry folks...I've been a bit busy. Time for an update post. After three weeks of hard work getting the molds prepped (see above video's) it was time to move on.

So a few patterns got made...



I sprayed a few coats of Duratec VE Primer (with a 2.3 mm fluid tip gun...this stuff is thick) in the mold once the surface was coated with mold release.



It dried nicely. Revealing a few small flaws that I decided I don't care about (just a few pin holes).



Then it was time to start loading the carbon fabric. I'll try to keep this part sensible - it's harder than it looks to do a fender. Lots of compound curves and flanges and stuff in the way. I'm also down to working in about 2 square metres in my garage.

The fabric is a 6K 369 gsm 5S Harness weave. It's got some good strength properties and drapes nicely, but was shifting a lot, so I'm glad I'm painting this stuff. Twill is far easier to work with.



This layer is laid with the "strength" going along the panel. Next up some 12K 150 gsm ±45° biaxial cloth. It's not woven - and the angles were placed off set to the first layer (so they're going across the panel at ±45°. Make sense?



Then another layer of the harness weave 90° to the first layer. It went in easier than the first.



I then added a urethane foam core (mycell) - 6 mm thick with 1/8" holes drilled on a 1.5" grid.



Another layer of the ±45° biaxial cloth over that...we're starting to have some bulk here.



And a final layer of the harness weave.



I'll be bagging this all up later tonight and then infuse it with epoxy later this week. Total weight of the finished part is 1.7 kg of carbon = total around 2.8 kg when done.

Last night (after a failed bagging attempt the day before) I got the fender infused. The bag pulled a vacuum without much trouble and in one hour it was finished. I'll demold it tonight - so stay tuned. Video will follow - I'm providing complete details there if you're crazy enough to give it a whirl.

First up - the infusion resin channel (the dark thing in the middle) worked great. Better than expected. I'm glad the guys on the DIY Carbon Facebook page convinced me to shorten it up a little.

This is about 10 minutes into the infusion.




The hard part is getting around all the curves in this fender. Here you can see the core material - should be overkill strong.



As the flow came around the headlight bucket, progress slowed - it has to draw through and increasingly saturated stack of materials, so takes more time. A few lines help me see that it's still working...and I was fidgeting.



Clamp that sucker off - it's all over now. It was suggested that I use release fabric as a resin "stop" - so areas up by the headlight for example. There is no carbon under these areas and the resin doesn't like flowing through the release cloth. So it stalls the flow while the resin finds a new path of least resistance. Same along the part edge mount flange. You can see the wet line and it doesn't get to the vac line. I may add a little fabric over the suction line in the next fender to keep my catch pot from doing silly things.

Haha, you must have been freaking the frig out waiting for that front corner to infuse, you sure sounded nervous over MMS. It would have sucked to have it not pull that last few square inches. Good call on the resin stop too!

I can't wait to see this fender in person. I'll try to get you the weight of a steel one this weekend.

Excellent. Ya, each of those lines is about 10 minutes. I was just staring at it and it didn't look like it was going to move...then you draw the line and find out it's just creeping along. It was around that point when I worked out what was actually going on physically and it then made more sense. I also had another small mess in the catch pot and had the ball valve get contaminated. I've got some work to do on the bag sealing so that I don't have to have the vac on it all the time. I will also be changing the cup once it's pretty much done so that I don't get a foamy mess.

Anyone want to see the result?



I had a hard time getting it out of the mold, but it did come out. I'll just let the pictures do the talking.

I am so stoked for you, buddy!

GEEEEEEEEZ THAT'S BEAUTIFUL.

Thanks guys...someone remind me not to START with the hardest parts to make work! I had reasons - it was stupid.

Had some trouble with the second fender. I switched epoxy (first fender was with some old stuff that I had for years and never used, new epoxy infuses faster - lesson learned) and needed to get an ultrasonic tester. These fender molds were generally brutal - I should have redone the gel coat and the flanging was pretty complicated. Learning how to bag a large part on such a complex part was a mistake.

It did turn out - lucky I guess.



Details were nice and crisp.



Nice and straight...they are not perfect - but a coat of primer is all that is needed to correct the surface - the error is in the mold!



I also made my first headlight bucket reinforcement ring. It's really nice. One more of these to make and a few other flanges that have to be added then they are done. Probably a few weeks away from them being done for real.



The harness weave is pretty cool looking stuff.



After these are done, then the hood and trunk need to be done.

Never ceases to amaze me the stuff that comes out of your garage. Unbelievable workmanship.

I know, right? Craig can do anything.

It's ridiculously light weight...but to get maximum strength and stiffness this stuff needs a post cure heat cycle. So, I figure I should reduce my floor space even further to about 1 m^2 of room to move with this magic.



It's just 1" X 2" spruce - so when the time comes to turn it into kindling, it's ready to go. Now, I'm going to need some insulation, so I added this bubble wrap foil nonsense to my shopping cart.

And we have a gigantic oven.



The idea is that is sits on the two folding tables and use my propane space heater as the heat source. I left an air gap at the material join on the top so things don't get out of control.

Loaded up with the fenders and associated parts.



This baked at 50° C for 8 ish hours and it all turned out great. I didn't dare take it to full strength at 85° C for 8 hours as it's only worth a few percent over what you get at the much safer "lower" temperature. The air gap was about right and on the lowest setting for the heater, it was nice and toasty in the garage for a change.

Next up - getting them all joined up.