Choosing Composite Reinforcements for Impact Strength; Kevlar, Carbon, Innegra, Diolen

[@mhgscrubadub9917]

Damn this channel really just taught me more about material science in 15min than a semester-long ME class

[@Veldtian1]

That's weird isn't it?

[@Ataraxia_Atom]

This is an amazing channel. Thank you for the information. I've decided to start my own carbon fiber project thanks to you. Cheers

[@chaseweeks2708]

Right there with you. Once I finally get space to do it, fenders and hood will be my eventual goal.

[@Ataraxia_Atom]

@@chaseweeks2708 hell yeah good luck when you get there. "Santa" got me a one wheel so I'm going to make a fender. After watching this episode I'm learning toward that diolen cloth. It's actually really affordable.

[@easycompositestv]

Fabulous to hear folks, good luck with your ventures/projects!

[@amadeo4977]

I am so grateful for easy composites. About to place a close to a thousand dollar order after having spent the last two years watching the majority of their youtube catalog and experimenting with vacuum bagging wooden skateboard layups. I am excited to receive my carbon fiber cloth, infusion materials, and more at a cost that including VAT and shipping is less than my local suppliers in California while supporting the company that gave me the confidence to evolve my product prototyping skills to include composites.

[@easycompositestv]

Glad we are able to help at a decent cost even as far as the USA away from us.

[@TheMrBrianh]

Alex Hibbert has 40,700 subscribers. I am one of them. That being said thank you for supporting him. He seems like a solid chap.

[@easycompositestv]

Yes is is, he's also a keen composites enthusiast and a long standing customer so it was great to do something with him. He's producing a fascinating series on the restoration of 'Allan', the lifeboat, that he's been doing through lock-down (which I'm sure you're following on 'alex hibbert originals').

[@iantoguy2613]

This is like the very best Open University programs from the 1980’s. I love it!!😃

[@dantheman642]

I can't stop watching these very educational videos on composites. Help for beginners with well laid out formats and directs you to their products. KZbin PERFECTION!

[@kylanlarsen6752]

Well said!

[@easycompositestv]

Thank you, that’s great to hear.

[@tyapka]

The level of particularity is from another world on this channel.

[@Boscovius]

Paul is, hands down, THE BEST composites instructor EVA!

[@easycompositestv]

Thanks Thomas!

[@Trihannes]

One of the most informative if not the most informative channels on youtube! No long talking, straight into the testing and results. I really love this channel!

[@easycompositestv]

Appreciate the really kind feedback, it's comments like this why we keep uploading videos!

[@bobjoatmon1993]

What would be interesting is a sandwich of Kevlar core with Diolen outer to see if the advantages of both combine in a superior way.

[@robertweekley5926]

BOB - Yes! In my younger days, I had multiple Fabrics Bonded together, for just this idea! Then I had S-Glass, Kevlar, & Carbon Fibre, to work with, but only small samples, and no testing gear!

[@gtxviper]

Was about to type the exact thing.

[@ClaytonwFirth]

I was thinking the same thing. I’m sure a mix of 3 or 4 of the materials would be a good combo..

[@urano1988]

Yep, compositing the composites! I was thinking the same.

[@pierrelezan]

afaik it isn't very interesting to mix multiple composite because they don't flex/break the same way : because it almost doesn't flex the carbon will take all the load and break first then all the load will be on the others layers and again the stiffer remaining material break first One way it could be beneficial is on multiple features of the same piece where the stress is different

[@hoss2200]

Like I said before... You are doing a great job with all this information. I am an automotive technician and also a construction worker for many years. I see the need for this materials in both fields. You have just answered the question I had in my mind about resistance to impact of carbon fiber. Thanks

[@easycompositestv]

You're most welcome, glad you're finding this information helpful.

[@char6364]

Really enjoyed this breakdown! My father was a composites specialist for various manufacturers in 80s rallying/90s touring cars. His choice of material would entirely depend on its location within the car. A reinforced carbon-kevlar composite was preferred in rallying for the whole external bodywork to account for both weight-saving and durability. Incredibly expensive to build (and rebuild) in large quantities but manufacturers were sparing no expense back then! In touring cars all the composite work was interior since only materials used on the production models were permitted for external bodywork. Impact damage was less of a concern for door cards, instrument panels, flooring etc. so carbon fibre would be used exclusively.

[@easycompositestv]

That's some great insight you have there! Getting the correct material for each specific location can be tricky especially when there are so many options, it is very important to consider the exact requirements and parameters and what is the most important to prioritise for each particular component. Thanks for taking the time to comment.

[@themiddleman9376]

We need a video comparing different layering techniques, or combinations of different fibres.

[@CraigLandsberg-lk1ep]

This video showed me sooo much 😅 what I would like to have seen is a test of a carbon/Kevlar mix fabric, good work 😀 thanks, i learnt a lot

[@aerobyrdable]

Please, All the *this*! All the youtube of this right here. Solid qualitative results plus with reasonable methodology equals an approachable and informative video for us real world problem solvers. Keep it up! I'll be looking at you guys when it comes time to buy.

[@easycompositestv]

Thank you very much Ryan, your feedback is appreciate. We’re problem solvers too, less theory, more ‘what will make a different *today*’. Look forward to working with you.

[@IainMcClatchie]

This is really good engineering. Good job. Nice clean short explanation of why to choose various materials.

[@easycompositestv]

Glad you enjoyed Iain!

[@markandoyo2204]

This is more intriguing channel here to seen those existing materiale inventory that I've never been found wayback more than 20 years ago

[@jayfeaver8243]

I love the clarity and use of actual strength test in this video. Very nice method and explaination of your reasoning. J

[@easycompositestv]

Thank you Jay!

[@MrAuzzie82]

As someone who is VERY interested in the fast lightweight vehicles, I love this video and would love more that delve into predicting strength and selecting materials and techniques to meet those strength requirements.

[@easycompositestv]

Thanks Austin, we'll certainly do more on material selection in the future.

[@MrAuzzie82]

@@easycompositestv thank you! I will be looking forward to it!

[@LesAventuresDeTigRRe]

I love your vids. This kind of info is difficult to come by. Whether it is the materials properties explained, or the build techniques you so kindly give to the DIY world.

[@SalSpaceKhan]

I just discovered your videos and they're some of the best out there even if I don't fully understand all of it! Love it! Thank you!

[@easycompositestv]

Appreciate the kind feedback! We'll have more videos up soon :)

[@MattTucker]

Very interesting test comparisons. It would be great to see the failure chart done with strength to weight instead of just purely strength. It would really give you an idea of the true difference between the products because weight is very often a big consideration for any laminate. Love the videos though, keep up the good work!

[@easycompositestv]

Great suggestion!

[@dynomike11]

Really outstanding job explaining the application, what you are testing for, explaining results - very clear!

[@easycompositestv]

Thank you, appreciated.

[@tifjosi]

It's alive! Lovely channel!

[@delinlo]

Thank you for making all these videos, I learn so much from all of them and my composite projects have gotten so much better since I've started watching your videos!

[@easycompositestv]

Thanks Delinlo, that's great to hear.

[@Artresin]

you folks are amazing! inspiring high-end work as always.

[@easycompositestv]

Thank you guys, back at you!

[@foolwise4703]

This video should be on your shops learning section! I was just looking for exactly this video there and was about to comment somewhere that you should make one, but here it is :D Man great channel!

[@easycompositestv]

Hi, thanks for your comment, glad you enjoyed the video! All of our videos can be found on our website here; www.easycomposites.co.uk/learning.

[@foolwise4703]

@@easycompositestv Oh, thats where I looked, but it seems like I was just blind. Sorry^^

[@stevesloan6775]

Best videos in the webs! You have taught me so much over the years. Thank you. 🇦🇺🤜🏼🤛🏼😎🍀🍀🍀

[@easycompositestv]

Thank you for the feedback Steve, good to hear from you.

[@remkojerphanion4686]

That was a really interesting and clear video, thanks! As a RC boat fanatic, I find these video's a veritable gold mine of information!

[@easycompositestv]

Thanks Remko, glad you enjoyed it!

[@remkojerphanion4686]

@@easycompositestv I'm already looking forward to the next video.... :)

[@ddegn]

I was hoping to find videos of your RC boats on your channel. No such luck. I think it would be a lot of fun to see your boats. I agree with you about these videos. They're great.

[@twowheelsabove]

11:20 loved that prepreg introduction! =)

[@hallkbrdz]

Great video, and very useful for what I'm doing. I need to construct a battery box for a sprint kart with 420 18650 cells. Impact strength and structural strength are key, along with light weight. Kevlar looks like the best choice of these, and is much superior in terms of weight compared to thin welded aluminum plate, plus it's almost non-conductive.

[@PaukSK]

You have a lovely and clean shop. Thanks for the test results.

[@easycompositestv]

Glad you enjoyed :)

[@TechnoComposites]

Very vivid and transparent shown.

[@MechGuyver]

Awesome video and great info within. Kudos.

[@dersebbler9452]

6:10 Yes you see carbon fibre in the crash structures but these are designed to break - the total oposite of what we are trying to do here. They work by inducing as many cracks as posible in order to absorb as much energy as possible. They are one use only. Also here you can see barely no visible damage but if you would look at delaminations, you would see a total different pictuere. If you would load it afterwards, it wouldn't be able to carry nearly as much load.

[@qcnck2776]

I'm glad to see the friction testing after sanding. I would have thought that this would be a big concern for the sled. The runners or other gliding surfaces may become abraded after several tens of miles of hauling, and testing the friction results of pristine surfaces may not reflect changes with use.

[@easycompositestv]

Yes, that’s what we thought too, although, as mentioned in the video, the Dark Ice team said that generally the underside of the sledges come back almost as new.

[@AH-ns2wh]

If you avoid rock/grit, the gelcoats usually end up with almost no abrasion over ice and snow. I have a sledge that's done over 1500miles, and has a perfect 'as new' gloss surface still. Oddly, here we found the sanded graphite-filled resin was lower in friction, so an improvement compared to unsanded/glossy, filled epoxy.

[@ddegn]

@@AH-ns2wh Darn, no videos of your sledge on your channel. I think it would be fun to see your sledge.

[@AH-ns2wh]

@@ddegn Aha! It's heading out onto the ice this winter. Stay tuned.

[@andreywrubel8186]

So many knowledge and experience in one video.. thanks your team so much!

[@CarbonGlassMan]

We've used Innegra before, but if I remember right, ours was white. To cut the dry cloth we had to tape both sides and use a cut off wheel on a die grinder to cut it. We couldn't cut it with scissors. It's what they're using as the tether material for Indycars to tether the wheels, nose, etc to the tubs.

[@easycompositestv]

innegra and aramid based fabrics will cut with dedicated aramid shears

[@ErtsenPlayGames]

next episode maybe test more materials like basalt , glass comparsion 0/90* to 45/45* etc , weight to stiffness etc

[@annakquinn7084]

Basalt is the future

[@espacesX]

Alpine Skiers have highly molecular Graphite sintered contact surface to the snow. The contact surface get an structured surface finish. The same when you apply wax on it. You brush the wax to reintroduce the structured surface. Structuring reduces adhesion and friction. Well on the slides for the expedition you will have the gelcoat, and you won't do waxing, but better think about microstructured surface. Furthermore there is electrostatic charging and the resulting brake effect. The Graphite in the contact surface of an Alpine Ski is most important here. There was the Blizzard V20 RS (Giant Slalom). Originally highly oversaturated with graphite. The FIS requested Blizzard to reduce the amount of Graphite even in the serial production Ski. I still have one pair before the Change of the recipe. This Ski is infernal fast. My proposal would be to experiment with gelcoat which is saturated with Graphite and get an structured finish. A company which could be on your wavelenght regarding Innovation and Challenge is e.g. Völkl / Voelkl (Straubing, Germany). Maybe they have an idea how to structure a gelcoat. They've invented the Speedwall(s), which is(are) the Sidewall(s) of the Ski. This Speedwall is structured as well and gets waxed as Well. Just think about this Speedwall in gelcoat. That could be a explanation, which the Völkl / Voelkl Experts understand. Would be Teflon /PTFE too soft for the Skids?

[@AH-ns2wh]

Thanks for the considered input here, and it's something @easycomposites and I have discussed prototyping in future, but where there's time to test/break and not on a critical expedition. The impact resilience of PTFE meant it was discounted.

[@edsuver1]

The first thing I'd do is ask what the ski and snowboard builders use for the bearing surface and do that, including the waxing process directly before use. That's not a new technology, and if you wanted to make sure your resin bonds well to it, just test a piece. The difference between skiing on wax thats seen just a few days of use is noticeable when you rewax them, it's way more slippery.

[@EZ_shop]

Extremely interesting video

[@danielwlodawer1282]

I would like to see which results a combination of a flexible structure (Innegra/Diolen) and a high load structure (Kevlar/carbon) compares.

[@MatthieuLibeert]

Great video! Nice testing and well explained! Was just a bit disappointed not seeing the carbon/Kevlar hybrid in the testing as I assume it is designed to solve the problem of having to chose between Kevlar or carbon for stiffness or impact! Keep up the good work, can't wait for the next video 👌

[@easycompositestv]

Hi Matt, thanks for your comments. Maybe we should have included carbon/Kevlar but we had to decide to stop somewhere. There were lots of other fibres we could have tested (PBO, UMHMPE etc.) and then there are hybrids of all of these fibres. We could probably have tested 20 laminates and still missed some obvious combinations. To address carbon/Kevlar specifically, although it might seem an obvious choice, the problem with a hybrid like this, for this application, is the failure mode: because Kevlar offers less stiffness and has a higher elongation than the carbon, in the event of a heavy impact on a carbon/Kevlar hybrid the Kevlar can (potentially) elongate past the maximum strain of the carbon, the carbon will break, leaving the Kevlar holding things together but possibly doing only that, holding it together. If you had another 2 months to drag a compromised sledge across the ice, you'd probably wish you'd made it all out of Kevlar.

[@shanewilson3653]

UHMWPE will require mechanical fixing to the sled, It is very hard to get adhesion to UHMWPE in surfaces that flex. If you wanted to attach a sheet of it to the sled I would recommend milling fine dovetail grooves at a 50% material fill rate or impregnating a stainless exposed mesh to act a a "keying" material. If it was something rigid than Loctite and other corporations offer primers for low energy plastics but in practice the suffer from adhesive release in high impact or inconstant surface stretching situations. Silicon spray or CRC 2-26 are both great Hydrophobic lubricants and coatings that flex and won't damage Most** plastics. WD40 and CRC5-56 will yellow and damage plastics but will temporarily act as a good hydrophobic coating but is still not recommended.

[@evolutionxone]

Any worries with silicone spray contamination of the shop/paint booth/molds?

[@manudehanoi]

fantastic vid, thanks guys, this is what good sales is about.

[@easycompositestv]

Glad you enjoyed the video Manu!

[@fabricebrun9287]

Great video nice to see some tests of different fibers 👍

[@easycompositestv]

Thaks Fabrice, glad you enjoyed it

[@gmtzholmes]

Thank you KZbin Algorithm I needed urgently to know what's the best material for a sledge

[@easycompositestv]

Hey, you never know when it might just come in handy :)

[@rohanpuri1989]

Good one. Please make a video on split mold infusion and rtm

[@easycompositestv]

Hi Rohan, yes, we’ll do this. The next video is a very in-depth infusion guide, it’s not split so won’t cover what you’re after, but certainly will have a lot of useful information for you.

[@francoisrochefort5759]

Love those videos

[@easycompositestv]

Thanks François :)

[@amirfathirad2965]

i cant wait for the next video and really wish you make more videos

[@easycompositestv]

Thanks Amir, we're doing our best! The final part on this one won't be long.

[@amirfathirad2965]

@@easycompositestv thank you so much also if you can make a tutorial about composite planes please, thank you so much for all your hard work

[@amirfathirad2965]

@@easycompositestv you are the best, i almost learned all i know about composite with your toturials and matthieu libert page, your page gave me enough confidence to make parts myself and i never can thank you enough for it, you and matthieu

[@hannesaltenfelder4302]

That's a very professional material comparison. I hope you make a comparison for a hangglider, too. I really wonder what would be the lightest options for a Klingberg mk2. Also, if there is a signifant difference between high pressure carbon fiber vs laminated vs braided(?)

[@easycompositestv]

Hi Hanes, that might be a bit too specific for a general audience but we’ll try to keep providing more general guidance that would be applicable to projects like a hang glider.

[@bigbothoee8617]

Beautiful simply beautiful

[@texaswildcat2000]

I've learned more through this company than any videos I've watched from U.S. based companies..Extemely informative.....Now, the question is, what combination of these materials will give you the best strength to weight ratio in all areas....I'm thinking a layer of carbon as outer for initial impact strength, then a layer of kevlar, and finish with 2 layers of diolen....let the carbon takes the initial hit, the kevlar backing that up and then the diolen as a method of extending the overall strenth with some flexibility should the carbon and kevlar completely fail on impact....oh, the ideas that come to mind...I bet it would be great fun making and testing various combinations of these materials...as well as educational...OR, maybe diolen exterior layers, 2, then kevlar, then carbon....hmmm...ideas....

[@easycompositestv]

It entirely depends on the design of the part, there is no set answer. You would ideally need to do comparative structural calculations or testing to sort the best combination.

[@texaswildcat2000]

@@easycompositestv Couldn't agree more...I think it would be enjoyable, along with educational, to do a lot of various testing combinations for various applications...

[@Talisman-tb6vw]

This is great info as I am making parts for sports cars and needed to know what material would have the best resistence to impact - primarily rocks thrown up by the tires into the fender well. Currently the cars have ABS, but when it gets cold it fractures. Having a combination of materials would probably be the best and I've settled on carbon/kevlar for the wheel side and carbon fiber for the engine side. Thanks for the series - I'm looking forward to the next one to see how you lay up the sledge.

[@easycompositestv]

Great, glad it's been interesting/useful. We hope your project goes well :)

[@SianaGearz]

I'd love to see more guidance on choosing material for various types of projects. For example this video doesn't include fibreglass, and while it might have been a priori not the right choice for this, it is my understanding that being inexpensive is not its only advantage, it also has distinct durability advantages in some uses. It is obviously comparatively dense, but sometimes the weight disadvantage doesn't matter and envelope is more important.

[@easycompositestv]

You're right that fibreglass can have advantages over carbon fibre in some key areas, it's much better at not blocking RF signals for instance in use with model planes etc. We do want to cover more videos with material choice in mind, one of the issues are keeping it relevant. A guide covering every material choice for every possible application would be very long indeed.

[@mollyjohnson6517]

Very interesting. Much of this applies to canoes as well. I would love to learn more about how combining layers would impact weight and strength of a 16 foot prospector canoe. The work horse of the north.

[@easycompositestv]

Hi Molly, well, you might be very interested to see one of our forthcoming tutorials where we make a 16ft canoe! Make sure you’re subscribed 😀

[@fredygump5578]

Excellent! I don't want to sound greedy, but I would sure like to see more about engineering propeties of composites. Maybe even principles for controlling directional strength and flexibility? I'm trying to combine light weight and flexibility, with localized rigidity. I've taught myself a couple tricks so far, but I know there is a lot I don't know!

[@easycompositestv]

Hi Freddy, thanks for the feedback and suggestions. We’d like to do more on these subjects too so we’ll keep this in mind.

[@JunoW712]

Very interesting video! What about the carbon fiber and kevlar blend ?

[@RubyByte]

Would love this as well

[@CameronCarter1]

Excellent video. Thanks.

[@easycompositestv]

Thanks Cameron, glad you liked it!

[@CKOD]

What did you have in mind for bonding the UHMW film? Ive used scotchweld DP-8005 with great success for bonding 3d printed brackets to pelican cases (polypropylene blend) but thats not exactly a laminating resin. IIRC it has a rather potent chemical that was a cross linker to allow it to cross link the acrylic adhesive base to typically chemical resistant plastics (UMHWPE, POM, PE, PP, PTFE, etc) but it was also good at cross-linking DNA and being carcinogenic, so I would actually make sure to use it in a fume hood, be mindful of gloves, rather than the more casual way that something like JB weld may get used.

[@billfromgermany]

Brilliant video!

[@hello7gods362]

More tec info like this please.

[@chrisklimek1613]

Can we just take a moment and appreciate Paul's "chopped tow" hair cut style ?:)

[@tejeshwvardhan1165]

Use UHMWPE sheet to reduce friction!

[@msheremet]

waiting for the next video!)

[@AboutComposites]

excellent study

[@easycompositestv]

Thank you.

[@crapisnice]

good video that show that kevlar attributes are a myth when is just only a good sacrificial material that absorbs energy without being shattered as it happens with carbon. Also this video reflects the good mechanical properties of thermoplastics even with thermoset matrix, however I would choose thermoplastic matrix and carbon fiber

[@easycompositestv]

Thanks for the comments. I'm not sure about Kevlar attributes being a myth, Kevlar is a remarkable material but like any material it has advantages and disadvantages. After all, we did go on to make the sledges out of Kevlar so, out of all these materials, it offered the performance and handling we preferred for this project.

[@crapisnice]

@@easycompositestv Yes, they all have attributes but I thought kevlar was a strong material against impacts (what I refer a kevlar's myth) and is totally contrary due its low compressive strength, but thanks to that low compressive strength it absorbs the impact energy and most important, without shattering. But again it easily loses it's structural integrity that it's not desirable for boats for example where kevlar can be used as a material to be destroyed to save a carbon fiber structure. The bullet proof properties of kevlar exist only without matrix and with several layers, and the thing is that kevlar could be used with some flexible thermoplastic instead with no flex and brittle epoxy for better impact sacrificial properties where other fibers just would shatter.

[@jacobbuxton932]

Excellent video

[@mr.robert1416]

THIS IS SO INTERESTING!

[@easycompositestv]

Thanks Mr. Robert

[@burakgul5508]

Now I know what my dream job is

[@jeremymcginnis7258]

I'm interested in how fiberglass would compare.

[@MrNinjaManrocks]

I'd love if you guys could perform the same friction tests on the coatings, but in regards to liquid water. I've been looking online for days for how graphite added to different coating will affect a boat's performance through water.

[@jdrissel]

I wonder if you should test molybdenum disulfide and/or teflon? Is it even comparable with gell coat? I have heard of using teflon filled epoxy as an anti adhesive surface. It is just about impossible to repair though, and I have always wondered about the moly...

[@realAlpha]

a drop test with a puncture device would be interesting to see

[@conniestevenson226]

Love the experiments.

[@easycompositestv]

Thanks Connie, glad you enjoyed them.

[@entritur]

Lawl a company is trying to sell me stuff by teaching me how all this stuff works. Genius.

[@pogcarr]

When comparing the various material samples it would have been wonderful if you had included a simple fiberglass sample as well, as most of us are familiar with fiberglass and could better use that to gauge how these other materials compare to the most common composite that we run into. Maybe next time.

[@easycompositestv]

The video wasn't about general property comparison but specific to this individual project hence the fibreglass was ruled out very early on. It is possible in the future we may do a general materials comparison video.

[@pogcarr]

@@easycompositestv Understood. It was just such a GOOD video but I thought it could be made more relatable by inclusion of a fiberglass sample as the "baseline" instead of carbon as the baseline. Looking forward to a video on materials in a more general sense to help us newbies pick a good material for our projects. Keep up the great work!

[@curvs4me]

I'm reviewing here and I'll venture that wet sanded and buffed graphite infused resin would be slickest in both categories. Of course kevlar is often used as an outside layer because it's unbeatable against grinding friction. Incredibly difficult to wear through a kevlar splitter where a carbon one will disappear with every passing contact. A kevlar outer layer, followed by a few layers of innegra, and stiffened on the inside with carbon is the best multicomposite mix. If you have a human on the inside, layers of kevlar prevent carbon fiber intrusion in your soft parts. High end carbon aircraft line the cockpit with kevlar for that reason. In the multi layer I described previously, the layers of innegra diffuse the impact over a larger area. Material combinations absolutely work and are frequently used in aerospace.

[@christopheb9221]

I was also thinking about mixing these materials but not just multilayered; what about using a different material threads in a weave or mixing the materials fibers one process up when being spun into a thread

[@curvs4me]

@@christopheb9221 you can get it. Spread tow triaxial fabric carbon/kevlar is as light as it gets with stiffness but a little flex before breaking.

[@williamduffield4964]

The issue with Kevlar is it does not join to inself at all well so i would be using it as the core material. And you cant sand it, it just fluffs up.

[@justinw1765]

Another issue with carbon is that is highly thermally conductive. The epoxy resin will lessen this quite a bit, but one of the things that can happen with carbon is that as the water is melting on the surface from friction, it may start to refreeze faster increasing friction. On the other hand, kevlar, polyester, and polypropylene are much less thermally conductive and would insulate the sled from the above better. But with the epoxy resin, there probably isn't that much of a difference between all of them in this regard since the resin can make up a good percentage of the overall material, and epoxy resin is much more similar to kevlar, polyester, and PP in that regard (since these are all essentially plastics).

[@easycompositestv]

The layer of epoxy and the prolonged time in the cold environment for the sleds themselves mean they will likely be close to the ambient temperature for most of the in service usage so the material differences is not such a big issue.

[@patrickradcliffe3837]

From what I remember in my days as Air Frames Mechanic in the Navy you could get better bend strength of the composite structure, with the correct choice of the resin matrix that has a good bending strength at lower temperatures. The longer the resin matrix maintains adhesion with fiber layers the better bend strength.

[@nishithkishore9841]

Mr. Patrick, I have a doubt... For having better bending strength, u have to layup fiber in that direction, but how bending strength is dependent on resin system.

[@patrickradcliffe3837]

@@nishithkishore9841 the resin is the stiffening and binding agent. Without it there is no rigidity. There are two failure modes for a composite structure, one is failure if the fiber, second is failure of resin to hold the fibers in the matrix.

[@nishithkishore9841]

@@patrickradcliffe3837 ...Sir, can you share your email ID , I want detailed discussion on it. I am struggling with a component to increase its bending strength.

[@Pushyhog]

mix in some innegra w/carbon, is great stuff.

[@Reptile789]

You guys need to try a test with Innegra mixed with carbon. I’ve been told by Innegra that it is best to mix it with other reinforcements as it is not that good by itself.

[@easycompositestv]

Hi Alexander, well, yes, there's certainly some truth in that but it depends what you want to achieve. If you wanted maximum damage tolerance then you wouldn't combine the Innegra with anything else, if you wanted to add some stiffness then combining with a higher modulus material (like glass or carbon) can make sense. The problem with a hybrid like this, for this application, is the failure mode: the Innegra offers little stiffness and has a high elongation. In the event of a heavy impact on a carbon/Innegra hybrid the Innegra will offer little tensile strength, putting all the work onto the carbon, the carbon will break, leaving the Innegra holding things together but most probably doing only that, holding it together. If you had another 2 months to drag a broken sledge across the ice, you might not thank us!

[@camwillie6827]

I rarely comment on KZbin videos but I must say I am incredibly impressed by this and all your videos. I've watched about ten tonight alone, and plan to finish the series and review as needed. Thank you so much. Could you elaborate a little on the method (calculation) for obtaining bending stress data from (I presume) force data provided by the testing rig? I seem to remember doing some of that in school but I cannot remember the process.

[@easycompositestv]

On our testing machine, depending how you set it up, it will actually give usable stress and strain data without doing further calculations and will give the data needed to draw the graphs seen in the video.

[@ifell3]

Great video!!

[@rnichol22]

So many people think carbon is king of everything and used purely for strength and weight not realising that it is its stiffness that is its big advantage and in fact other fibres are in fact stronger but less stiff

[@AlitaGunm99]

I'd be curious to see the same tests on S-glass.

[@St0RM33]

You should have tested fiberglass too; E-glass and S-glass fibers

[@AH-ns2wh]

Having hauled glass sledges before, it's not something I want to repeat! Approaching twice the density of aramid/carbon/diolen - so it's cheap but heavy.

[@St0RM33]

@@AH-ns2wh You'll be surprised how effective s-glass fiber is considering the cost. I can't talk about your experience but i'm pretty sure a well developed composite made via infusion vs wet lay-up (that you probably had) is a good choice.

[@AH-ns2wh]

@@St0RM33 It's strong, for sure. I've tested S-glass. But the problem is the density. In a weight-critical world it's just out-competed by kevlar etc.

[@unzippedcomposites7966]

Kevlar is still the better choice here though. S-Glass has a higher tensile strength but these sleds aren't really carrying a tensile load - they need to be stiff enough to carry their load without deflecting too much which will mean their tensile strength is more than high enough to carry that load without breaking. Kevlar still has a higher Youngs Modulus, so it is stiffer than S-Glass. To achieve the same rigidity as Kevlar, you would need to use more S-Glass - and at almost twice the density of Kevlar, that would make the sled significantly heavier for the same rigidity. Agree it would have been cool just to see the performance of fibreglass in the tests though, seeing it is so common. But - this is advanced composites! Unless you are looking for ultimate tensile strength or outright lowest cost; there is always a higher performer than fibreglass.

[@St0RM33]

@@AH-ns2wh yes i know but it would be worth added to this video even though it's not the ideal application. Probably because (i assume) Easy composites doesn't sell it

[@dimitricherny]

Some company has a hybrid fabric weaving innegra with basalt fibers. Basalt fibers have about the same strength as e-glass. But the combination of the two seems to provide the durability of the innegra with strength of fiberglass. It would be very interesting to see you two destructive tests done on that material.

[@easycompositestv]

Hi Dimitri, thanks for the comment. Indeed there are hundreds of different 'hybrid' fabrics which combine properties of different fibre types, unfortunately it would go on almost forever if we'd tested all of these materials! Basalt/Innegra could be interesting, as would basalt/glass. Maybe we'll do a video all about hybrid fabrics in the future which would allow us to dive deeper into those type of reinforcements in paricular.

[@filippaoronto3880]

You people are awesome ! Thank you!!!!!!!!!!!!!!

[@easycompositestv]

Hi Filippao, thanks for your comment! Glad you enjoy the content!

[@FlexDRG]

Very nice tests. And here's the But... What about hybrid composites? Layering the white fibers with keflar in the center? Don't know how many layers were used but putting about a third of them as Keflar in the middle of the stack would make for an interesting test I would think. And on a side note, testing impact with the outercoat applied would be important to. To see how the coat gets damaged in the process and what that would do for the friction with the ice and snow.

[@easycompositestv]

The tests shown were designed specifically for the sledge and its expected use so we have had to limit the scope of what was tested and shown. But yes there could be a lot of different combinations tested that might have different results.

[@slimtabka]

Hello, thx for all the different videos, can you please make a video about all different kind of release agents and how to apply them on glassy or normal surface to be as smooth as possible and without haziness?or how mant layer needed .?? etc .... I think it's nice subject for a video

[@easycompositestv]

Hi Slim, thanks for the suggestion. Yes, that would make quite a useful video. Not likely to be a million-viewer but certainly of interest to those actually working with composite materials. We'll keep it in mind.

[@slimtabka]

@@easycompositestv thanks for taking into consideration my proposal, it might not get 1M views but who knows since there's no video speaking about the subject in detail, you might be suprised. and Since there a lot of types of releases so you can cover a lot of topics (which purpose for each release agent?, how to apply? which one to choose for each case?) etc ... it will definitly be a good learning material for beginners and people with intermediate level.

[@guigui78340]

would be interesting to see the yield results on those materials based on similar density rather than similar thickness to take advantage of their properties

[@capnthepeafarmer]

Your drop test is actually pretty close to an actual test method. Look up the "Gardner Impact Test" reference, ASTM D5420. It's essentially the same test as what you've done except there are set weights, and the geometries for impact. It is very simple to perform and gives some valuable data. The only caveat is that you must be consistent in your definition of "rupture" or "crack"

[@easycompositestv]

Thanks, yes, we improvised based loosely on existing test standards. For comparative results (rather than ‘absolute’ numbers) tests like this produce very reliable results, often more reliable than - for example - comparing manufacturers’ own published data.

[@vargasaidan7366]

Could we get a video about making a front or rear bumper out of carbon fiber? Or other car parts. The complex shapes and angles of a aerodynamic body kit would be amazing to see come together! Myself and many others I’m sure would greatly appreciate it.

[@easycompositestv]

Yes, this is certainly something that we'll aim to cover in a future tutorial, something like a full clamshell.

[@KJ7JHN]

Have you tried wax on the substrate? Works for surfboards, may work with colder weather too.

[@easycompositestv]

Hi Damon, yes, indeed, waxing PTEX (as found on skis and snowboards) used for the runners on the sledge would reduce friction so I guess the team probably do do that on the runners but potentially could do it on the belly too.

[@ghislaindevouton5301]

Great video ! I'm wondering what would be the outcome of the impact test if the constraint is to keep the integrity of the structure behind the laminate. My use case is a carbon sandwich sailboat bow with a sacrificial shield to protect from log strikes). Deflection become a more important factor which may place the carbon back on top of the leaderboard.

[@easycompositestv]

You would probably want some kind of foam between the two surfaces so that the foam absorbs the deflection of the outer layer to prevent excess energy being transmitted into the structure behind.

[@philipwilkie3239]

I'd be interested to know your view on basalt fibre. It's main feature is a very high impact resistance.

[@easycompositestv]

To be totally honest Philip, we don't have much experience of basalt fibre. We'll bear it in mind for the future.

[@somannacs]

I just click thumbs up even before watching the video.

[@easycompositestv]

Ahh, well, I hope we don’t let you down!

[@notsonominal]

Now I know why my Diolen sandwich kayak appears to be indestructible.. SKUK FTW!