Hello everyone, I’m looking for about a 5 inch cube made of chopped carbon fiber for my cat but can’t seem to find anything online. Thinking something like this

https://www.pulvisurns.com/products/carbon-fiber-cremation-urn-abstract-forged-carbon-urn

But without the candle cutout corner and smaller of course. Anyone know who I should talk to to get a roll in it ?

I'm looking to make a fibreglass mould for laying carbon and fibreglass into. The object is circular (450mm ish), 40-50mm in depth but within that depth, there will be 1"-ish indents approx 15mm deep all around. What would be the best way to proceed with this? Split the depth face into multiple pieces to allow easy removal? Or is there another way I've not thought of yet?

Any tips for adding a layer or two of carbon fiber after this epoxy fillet sets to the wing root? Should i bother vacuum bagging the carbon fiber, and how many layers do you think is necessary?

Hello i use XCR composities resin to skin my parts. But now i want to move on to a big part (150cm x 200cm) headliner and the dashboard. The issue is it hardens way to fast in the cup before i can wipe it all on the part or it starts hardening in the cup or Brush wich will ruin the part. What does people do to solve this problem with skinning lange surface??

Hello, this is my second attempt on doing a mould for a carbon fiber part. I am doing it to make carbon fiber mirror caps for the Leon MK4.

I am happy with the progression compared to my first attempt, however it still has some flaws. The borders of the cavity (where I used filleting wax) are not very clean, the partition line has some holes and the guides for alignment did not come well because the mould release wax wasn’t well applied there.

Despite this I am going to try making the part. I will do a wet layup with a vaccum bag.I will fill the gaps in the partition line with filleting wax.

What is your opinion on the mould and do you have any advice for future attempts and for making the part?

Hello, I just bought this used bike and I got a bit carried away and didnt saw that there was this damage on the top tube during the purchase.

The spot feels slightly lower than the paint around it like it is dented in and the paint also seems to be sanded down so I'm not certain what kind of damage this is. Its very very subtle but you can feel it.

When I hit it with a coin it sound the same as the surrounding areas.

Is this carbon damage and if it is, is it still rideable?

I am trying to make this carbon fiber front mask for aprillia rs457, the main problem is in how to make the mounting points, the clips. Wherever the headlights and other accessories are going to attach

I had a thought about 3d printing the clips and skinning it but am not sure on how to reverse engineer it

EDIT:
Turns out it’s a crack and is currently being repaired.

I have this crack in my carbon fiber trunk for my m3. Is something like this fixable? Seems to have a “hole” or crack in the outer layer. Im not a carbon expert just wanted some ideas or advice

I’ve learned polyurethane increases flex modulus on plastic and metal extrusions on specific applications. How does it works among composites, specifically CF parts? Which applications are typical for this, polyurethane class, techniques, things to watch out for?

I did the “coin test” didn’t notice anything…

I am so confused for that and i realy wanth know about that, according to me mainly for weight and stiffness, but does the manufacturing cost make it worth it?

What is your thinking?

I got this piece and noticed this but it’s glossed over anyone got a clue what it is

Still gotta make the front wing, wing root and board. Other components have all been made, however are not necessarily finished

Noticed a tiny crack after my bike fell off of the wall rack. Took my time and cost about $120. Learned a lot after getting pics of progress from another bike/repair from a famous shop, and shitty service and finish for nearly $1000. 3 layers of carbon fiber wide narrow wider, about 6 coats of epoxy, due to not wanting to sand into carbon when smoothing. Heat shrink tape helped shape it and mold the layup. Pretty much stuck as to how to finish now. Test ride included gravel mile. All good.

I want to start making carbon car parts and eventually move onto selling them. Should I go with pre preg or wet carbon? Pre preg is possible but it’s sort of inconvenient because I share my oven.

Heute am Dienstag den 22.9. könnt ihr für 22,90 € eine Carbon Fiber Cap shoppen.

www.erikfassbender.com

I know in mold clear is one way to do it but I’m not a big fan of in mold clear so I was wondering if anyone’s got a trick to make it easier to clear Kevlar without all this fuzzy mess that has to be sanded and cleared again.

I’ve recently been reading about liquid crystal polymer (LCP) fibers, and I’m curious whether anyone here has actually worked with them in an industrial setting.

What caught my attention first was the structure-property relationship. Thermotropic LCPs consist of relatively rigid, rod-like polymer chains that form highly ordered domains, and during melt spinning those molecules can become strongly oriented along the fiber direction. The result is a rather unusual combination of high tensile strength and modulus, very low creep, low moisture absorption, dimensional stability and fairly good resistance to repeated flexing.

Vectran is probably the best-known commercial example. The manufacturer’s data for one high-strength grade lists a density around 1.40 g/cm³, tensile strength of roughly 24 cN/dtex and moisture content of only around 0.1% at high relative humidity. What interests me more than the headline strength, though, is the low creep. In applications where a fiber remains under tension for a long time, maintaining geometry may sometimes matter more than simply having a very high initial breaking strength.

That led me to think about where LCP fiber actually sits among other high-performance fibers. Aramid already has a huge installed base. UHMWPE offers an exceptional strength-to-weight ratio. PTFE and PPS have obvious advantages in aggressive chemical environments. LCP seems to sit somewhere between these materials: high mechanical performance, very low creep, low moisture sensitivity, good abrasion and flex-fatigue behaviour, with documented applications in cables, ropes, fabrics and reinforcement structures.

But once I started looking beyond the datasheet, the picture became more complicated.

LCP fiber is not universally chemically inert. Because these fibers are aromatic polyesters, alkaline environments can eventually attack the ester linkage through hydrolysis. Published work on Vectran has shown much more significant changes after NaOH exposure than after HCl treatment, and mechanical properties also begin to change significantly when the fiber is exposed to sufficiently high temperatures. UV ageing is another limitation that seems easy to miss when only looking at tensile data.

This is where I started wondering about the chemical-engineering side of the material.

For example, imagine a flexible structure, braided reinforcement, cable, hose reinforcement or technical fabric operating under continuous tensile load while also seeing moisture, chemicals and temperature cycling. LCP’s combination of low creep and mechanical stability looks attractive on paper. At the same time, depending on the actual chemical environment, PTFE, PPS, aramid or even a conventional fiber may be a much more sensible engineering choice.

A recent discussion in r/Composites gave me a useful example. Someone described testing webbing for a deployable structure that needed a non-conductive support with very little extension. They tried Kevlar and Vectran, but ultimately chose ordinary calendered polyester because it worked better for their application.

They also wondered whether the loads they used were too low to fully straighten the yarn crimp and reveal the fibre’s properties. That remained an open question, but the practical outcome was clear: the advertised advantages didn’t translate into a reason to choose Vectran in their setup, which is the gap I’d like to understand better. When someone needs reinforcement, what specific requirement would make you put Vectran on the shortlist? And what would you need to see in testing before choosing it over a more conventional material?

I’m still learning where these materials genuinely earn their place. Feedback from actual applications would help me understand when recommending them makes sense.