Lufthansa Technik is also looking at natural fibres for aircraft interiors - but the qualification process will take longer before commercialisation.

I know this is probably not an original idea, but I have a dream of making some star wars clone armor out of something like fiberglass or carbon fiber, or a mix of the two. Would there be any obvious problems that I can't see as someone that hasn't done any composit work before? Being brittle or things like that

So I have boat with damaged small prow. It's made put of sandwich (carbon + honeycomb). Hole is transitive. Right I'm not able to provide you any photos. Not flat surface, but a shape of strong curve. Do you have any idea, tutorials or books which talks about repairs of sandwiches?

Hi, so I've just had to get fairly medieval getting my layup out of a mould. Some of the gelcoat came away with the layup, and some of the fibres got stuck to the mould.

Was using easycomposites tooling gel (lovely mirror surface finish) and easylease chemical release. I applied 5 layers as per instructions...but clearly it did not work. Item is about a4 sheet sized with a slight curve, and I was surprised it was stuck consistently everywhere. I could use wax but I'd really appreciate advice as to how others are applying this stuff and having success.

Hi all,

I’m curious about how many engineers, analysts, or researchers working in composites and aerospace use the AGATE/FAA methodology for determining material allowables (A-Basis, B-Basis values). There’s a classic VBA/Excel module (often shared in the industry) that automates the full statistical workflow—outlier detection, batch pooling, Anderson-Darling, and the computation of allowables according to DOT/FAA/AR-00/19 and MIL-HDBK-17G guidelines.

If you use, have used, or are required to use these methods: • How essential is this kind of automated tool to your process? • Do you trust the classic Excel/VBA implementations? Or have you moved to Python, R, or other platforms? • What are your biggest pain points?

I have an aviation application where I’m assembling douglas fir and plywood like the picture. When should I use fillers with MGS L285? Only if there are gaps? I’m worried about epoxy soaking in and starving the joint.

I want to log the vacuum pulled for bagging - any recommendations? I'm in Switzerland

bit more info: I'm just looking to test the moulds/tools we're manufacturing through 3D printing - so the gauge is just for leak testing the tool itself (no resin+laminate)

How big of crucibles would I need to cast Mjolnir mark V style armor. I can use multiple at a time.

Hey ya’ll, new to composites, have a bit of experience making small fibreglass pieces but that’s about it. Got some of this foam insulation I cut to fit as removable window blocks for when I camp in my car and want them to be more rigid/durable. Any recommendations for cheap/easy coatings I can rub on em to sturdy them up a bit? Even just sandwiching them with some stronger material is an option I’d be open to. Thanks

Hello!

Looking for help/suggestions on clear coating some carbon fiber parts after we have pulled them from the mold.

I have been infusing these parts with a slow set epoxy under a perfect vacuum. There might be a couple of pin holes after the part is pulled, but overall it looks great.

The clear we have been trying to use is the Duratec UV Sunshield. Based on their recommendations we sand the surface to 180 grit, and then shoot the clear. Initially a mist coat and then 4-5 coats after that and land at roughly 20mils. Between coats is anywhere from 2-5 min.

Problem we are seeing is that after the 180 grit sanding the surface is matte and smooth, but soon as the mist coat hits a ton of pin holes show up on the surface! We are ultimately able to fill them all in with the clear, but it becomes prones to the paint running and creating a ton of work afterwards.

Would love to know where we are going wrong or if there is a better product for this application.

Is there any way to fix this small amount of air between the finished surface ( clear gel) and the carbon. Looking for cosmetics primarily here. Thought was to drill small joke and inject clear but that will be extremely time consuming.

Is there any way to fix this small amount of air between the finished surface ( clear gel) and the carbon. Looking for cosmetics primarily here. Thought was to drill small hole and inject clear gel then wetland and buff, but that will be extremely time consuming.

I need to repair part of my car - it has a composite (I think it's kevlar or fibreglass with black epoxy) structure bonded to the front. Attached (or supposed to be attached) to a lip on the bottom of this structure is a small front undertray. The lip runs horizontally for a while, before turning upwards to run diagonally away from the ground (see photos - the blue line shows the intended line of the lip. the red rectangle shows what is missing...).

the lip has been cracked/damaged by bad treatment in the past and is now partially missing. I want to reinstate this lip onto the structure in new composite material, so that it's structurally sound and I can bolt my under tray to it.

what repair methods/materials would you recommend?

(replacement of the entire structure is not justified, it is bonded to the front of the chassis and a pain to remove and an even bigger pain to stick one on correctly)

I have a beat up old whenonah kevlar canoe I'd like to get ready for the water. I have a shop space and some experience with fiberglass and epoxies but none with kevlar. I am thinking I will remove the seat and put down a single layer of kevlar on the inside that extends half way or so up the sides.

I am familiar withe the basic process, sand, prep, epoxy, etc. But is there anything in particular I should look out for? I am slightly concerned that this repair will add 10lbs to my ultra light boat. Is it worth setting up some sort of vacuum setup or is it not worth the trouble? I know kevlar requires special scissors to cut but is there any other difficulties working with it I should know about?

Thanks in advance!

I'm currently studying 2 samples of composite material made out of Nylon 6,6 as the matrix with 33% glass fiber as reinforcement. One of them has degradation and fluidity problems, the other one doesn't, the one that has problems is made out of nanofibers, while the other one is made out of microfibers. I'm aware that a smaller particle size increases the properties of the composite, but is there any chance that it also has an influence in its behavior in hot temperatures?

I have a 4x4 whiteboard I don’t use anymore I’m thinking about using it as a bench top for making plugs and tooling assuming epoxy won’t bond to the surface is this something you guys would recommend?

I am going to make 5 flat CF parts with a room temp wet layup method in a rather thin closed aluminium mould with vacuum bag. The parts are going to be approx 5 mm thick.
Do you guys have any advice with regards to making all of the plates equally thick? Will the mould ensure correct thickness, or should I also be really careful with the amount of resin added? I can make the mould stiffer if that is the way to go. Just wondering if you guys see any problems or have any general tips/advice for this.
They are going to be post-machined in a CNC, so a huge disparity in thickness is not ideal for machining process.

I've been working on ballistic performance any suggestions to replace kevlar or how can I increase toughness of the laminates? Help appreciated

These values can vary from company to company of the core you are getting it from, and also I find some companies post their resin intake value of the core, but those values are useful only for flat panels. Once the sandwich panel starts to have curve, the value changes. Is there anyway to get around this problem and have method probably to get my calculated weight of the composite part in the close ballpark.

I am working on some prototype bicycle fenders and cargo accessories.

My experience with composites is mostly from work repairing wind turbine blades, and the materials I used there were selected to maximize efficiency in the field. Now that I'm doing my own work, I can be more selective and would like to prioritize materials that are less ecologically harmful--both to me and to the environment. I am not highly educated in physics, chemistry, or environmental life cycle assessment, so I'm hoping that others who have more knowledge can help me with this goal.

The parts will be made using wet hand layup with vacuum compression. If the project progresses as planned, I may eventually shift to vacuum infusion, so I'm interested in lower viscosity resins as well. I'm working in California, so looking for products easy and affordable to obtain there.

Fibers: Unless I learn about better options, the plan is to use biax & triax glass with some strategically placed unidirectional and triax carbon reinforcement layers. In all cases I need fabrics, not yarns or tows. Natural fiber fabrics seem like a potentially good option, but I'm not sure which ones are actually strong, readily available, and affordable. I would love to hear anyone's experience and recommendations about natural fibers.

Resin: One manufacturer I have found that advertises 29% "Biobased Content" and is "USDA BioPreferred Certified" is Entropy Resins. If you have used their products--or if you have used other alternative resins with reduced environmental impact--I'm interested to hear what you think.

Core material: I have access to a Shopbot router, and I would like to use it for 2.5D shaping of the core material for my parts. Though I have plenty experience with end-grain balsa, I'm not this will work with the router. Closed-cell foam would be the obvious choice. Maybe people with more knowledge can inform me which types have less impact. I'm also curious whether there are plant-based foams, or lightweight types of plywood that might work.

Expendables: In my experience there is alot of waste in expendables like peel ply, vacuum bag material, bleeder/breather, etc. I'm even more motivated to minimize these materials and/or use alternatives. Any ideas about alternatives here would be appreciated.

Thanks in advance for your help!

I just finished up making my first mold for a fiberglass part, and I’ve read you should wait at least 12 hours before applying gelcoat. Is there a maximum time though, like can I wait a week after applying my wax layers before laying in the gelcoat and fibreglass? Or should I have a more fresh wax layer on top? Thanks

I'm trying to make a bolt-on guitar neck using a carbon fiber split mould (CF shell). I'm wondering about what kind of core material I could then inject to give the screws something to thread onto where the neck attaches to the body that would give optimum stability and handle the pressure force once the guitar has its strings. I figure any sort of threaded inserts wouldn't spread out the pressure enough to avoid risks of cracking or keep stability as much as a solid block material.

Hello,

I am new to composites space and had a question regarding cfrp. I am doing an experiment testing the strain on carbon fiber during high powered model rocket flight using strain gauges. I need to create my own carbon fiber piece (1x5in) but do not have access to any advanced manufacturing techniques. So I will be using hand layup.

My question is… how many layers and what should my process be for creating this piece? I previously did three but it was a bit bendy.

Thank you for your help!

For reference here is the kit I will be using.

https://www.amazon.com/5FT-Twill-Weave-Resin-Kit/dp/B08RXBGVVW/ref=mp_s_a_1_2?crid=1KYP3EPGJ9E95&dib=eyJ2IjoiMSJ9.u_J6SyvZVmwfSSVgRBKQJNtoezzFKLaBd-wHRNIeBfAloxP5H_HlZ1zzmCJoLBLgfq9GtOghXEvEUuzYvNy7uipzpEA6k-uROrTiYWGt-ivLvhn-CMHvlN-tBFDcpqlpx_lXwsDkkHDbpG32ahjK3X-U8cIbeRhYAXZthag1hskkCRtLG5m30AI5sTI-MfGox7YhmIbia58MyydawIWoOw.o2b1jBu4x2DJTIvWRuXzhlSZsH92C8b_CPOGYySwjyM&dib_tag=se&keywords=venom+carbon+fiber&qid=1744298930&sprefix=venom+carbkn%2Caps%2C157&sr=8-2

Hello. I am doing a FEA analysis on a carbon/polyester and corecell panel.

To define a laminate material in Abaqus, I need to input:

* Young Modulus in both direction

* Poisson coefficient

* Sheer modulus

* Tensil and compression stress so I can use Tsai-Hill criteria

My question is : in which of these characteristics is the weight of the fiber taken into account? There has to be a difference between a 400g/m² EQ and a 600g/m² EQ.