[BUILD] Making a Carbon Fibre Bonnet: The Part
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- เผยแพร่เมื่อ 29 มี.ค. 2019
- My second installment of making a carbon fibre bonnet for my friends race car.
Part one can be found here: • [BUILD] Making a Carbo...
Please keep in mind this is for a street sprint track car, not a show car or anything like that. The surface finish of the part is not perfect, but in terms of time taken and cost to manufacture this part is perfect for the job that it is going to do.
I recorded a bit more this time and ended up with far more footage than I could use. I probably should have cut this down into two videos, but you guys get what you paid for, so no complaining.
I still expect this will be a three part series, with part three showing the install; maybe a road trip montage in there too.
How good was that photo by Ben? That photo is actually of Cecil Plains after some rain, it looks deceptively nice.
His channel is here: / @bgersey9
The bonnet is for him and his dad, have a look through his channel.
Music: "Ukulele", "Summer", "Going Higher" and "Enigmatic" from bensound.com
![[BUILD] Making a Carbon Fibre Wing: Part 4 - The Rest](http://i.ytimg.com/vi/gVBfY7gclQs/mqdefault.jpg)
![รวมเพลงลูกทุ่ง 6 หนุ่มไทบ้าน ฮิตติดกระแส ชุดที่ 1 l มนต์แคน ไมค์ ไผ่ เสถียร ไหมไทย พี [Longplay]](http://i.ytimg.com/vi/GD2v1OjMw5I/mqdefault.jpg)
Sharing your "failures" is often the most informative and useful part of a tutorial. Thanks for doing so. Excellent work!
G'day Dave, glad you appreciate it. I think one of the the best ways to learn is by overcoming problems. If I can help others know what the problems are I'll be happy.
Great job, the resin flows better when warmed to 24 degrees and hard points can be fitted before the lay up , use aluminium blocks
That tool you used to perforate the core is genius! I'll be making a version of that.
Glad you liked it, check out the build here: th-cam.com/video/l0DVsNQ7JUQ/w-d-xo.html (the first 30 seconds of the video show where I got the concept from (so do the comments) if you want to use someone other than me as a source.
I will suggest that you don't drill straight into the ends of the dowels like I did, maybe bond them in as well or put some straps over the top of them to hold them together, I've had mine come loose recently and when I get some time they are on my list to fix (it's still functional as it is, just a bit annoying at the moment).
Great video. Love the core design. Good job. Yeah, tempature is key.
Great tool for making holes in foam!
Glad you like it, there is another video there on how to build it.
Amazing work Iv just started doing skinning and it’s not that easy first one was flat bottom steering wheel I cut and fitted a pipe then covered the top and bottom was hard to keep in line and smooth. I found spray glue helps when laying try keep the ends not pulling out
WOW this looks awesome ! I would love this for on my 74 Te 27 Corolla !!!
Mate, if your in Aus I'd be happy to either make one (cost involved obviously) or if your a Brisbane local, give you some pointers in the right direction.
Awesome job
Thanks mate, glad you liked it.
Good info!
The louvers looked like a pain to lay over. Good job.
Cheers, they really were a pain, but I get there in the end.
Great vid man, keep it up
Cheers, I should have a F3 sidepod cover video coming soon (I have all the footage, just needed to finishing editing this one first).
CEW.Manufacturing Great! Can’t wait
@@CEWManufacturing Hello mate how much does this cost ?
The bubbles are most likely due to the different flow speeds of the resin above and underneath the core, which leads to trapped air wherever you have reflow. this is especially important as you have windows with no core. For an aesthetic part like this the safe route would be to infuse the first skin against the mould, carefully remove the peel ply without pulling the part out the mould, then bond in the core, and then a final infusion with the second skin.
Unlike others suggested, letting the pump run for longer will not lead to less porosity, as it only leads to the resin and core degassing! The big air pocket is just because of bridging i would bet! with the vents it is a tricky part to get right, would get easier with the method described above.
Furthermore, a core with smaller cells like rohacell would improve the weight a lot. alternatively use microbubbles mixed with resin to fill in the porosity on the surface to save some weight.
And finally, i would strongly suggest backing your part to get the glass transition temperature as high as possible. a dark part in the australian sun will get very hot, might even get too hot for whats possible with most infusion resins...
I like your thoughts there with the different flow rates, that is something to consider for future work. I do take exception to this being an "Aesthetic Part" though ;) It's a functional part, the mould was no-where near nice enough for it to be an aesthetic part, it was a relatively low cost, one off part, making it look pretty would have cost more and taken more time.
If I was doing this again, I would be looking at doing the outer skin and all of the vent layers in the first layup, then follow it with the core bonded in with micro and a wet layup on the back in a single second layup. I think this will remove chances of bubbles and drop some more weight out of it, there was a lot of resin uptake.
What do you mean by "backing the part". Coming from an aerospace background I am familiar with heat mitigation methods for composites in the sun (white paint is a great one), but I'm not sure what you're referring to there. This resin is good for a 100 degree Celsius Tg, while the Australian sun is hot, and the black part will amplify this, I believe it will not get to that temp (80 wouldn't surprise me though, which is one of the reasons I do not use west systems resins, when I last looked into them they didn't have the best Tg even with post cure).
@@CEWManufacturing sorry was a typo, meant baking not backing... 100°C Tg is good, but be aware that onset it's probably no more than 50°C and needs post cure according to datasheet to get to 100°C. Without that you will end up with fibre print through in the best case, and a warped part in the worst case...
@@RetoAebischer I'm tracking the post cure requirements. The part received a dodgy (janky? junk yard style?) post cure and has been holding up well in use. The methods I have used here served a purpose and have worked well in this application, I would not use them for something more structural or aesthetic.
Love the music
Those nut plates are supposed to go under the carbon, not on top of it. I suppose for a race car it's functional. But for the record, that's why you should make 2 moulds, one of the top, one of the bottom, and then epoxy the 2 halves together, with the nut plates set in from behind the bottom half, for maximum support. Bang up job though, not bad.
I wrote out a massive reply to this comment and then it seems to have gone walkabout. So here we go for a take 2.
I fully understand that the nutplates are meant to go under the skin, I did some calcs behind it and the failure loads in this configuration are high enough that I am happy. I was going to pot in some inserts (like from wooden furniture) but decided that I didn't want to have to destructively test them, it would have been nicer and cheaper so I should have done it.
As for the two moulds side of things, I can see the need for that from a show car perspective, but to me it is a lot of extra cost and extra time that doesn't provide any real benefit. I would have to double my moulding materials, and probably have to double the amount of carbon and resin I used. This bonnet is only a total of 4 layers (3 layers in the vents). If I was to use a second mould I would realistically need (please correct me based on your experience) 4 layers on each side of the mould, then cut out the un-needed areas and bond it all in. I think at least a 70% increase in cost over what I have here and a heap of extra time. with a 10-20mm thick core this part is plenty strong enough as it is and only the outside surface really matters for shape.
If you have some good reasons that I have failed to think of please let me know. Robust design discussion is a great way to learn.
Matt
Yeah it would look better with two molded halves. But fuck the time for that. It's gonna get abused on the track. Just do a 45 degree X patters for core imo. Would be easier to do with less time. And it's more structural. Then build hard points up for mounting with a material of your choice. Bad ass hood though. Not knocking your work at all. It's fucking beautiful.
Few pictures below
You also have to perforate the foam to avoid air bubbles and infuse slowly.
Sure do. The foam was perforated using the perf tool I made previously. It works well.
I think the surface imperfections were as a result of the super 77 being used to hold down the carbon and no clear coat
I'm getting ready to make a carbon hood for my C6 Corvette. I'm trying to decide between making a two-piece mold - top (outer) and bottom (engine side) - or just going with the method you show here. Did the final part exhibit any weird flexing or craziness at speed on the track? Mine is mostly a street car with the occasional track day. (I'm lucky in that the C6 hood is nearly flat with no funky returns on the edges.)
It didn't exhibit anything weird. Though I would suggest doing it slightly differently from what I have done.
Do the outer layer (top skin) as an infusion and then with the top skin still in the mould do another, wet, layup with nomex honeycomb and the bottom skin.
That will give you light weight and strength for days.
In my opinion, the only benefit you get from two moulds is easier attachment points and knowledge that it's not going to have any fit issues. A sandwich structure (foam/honeycomb) is mechanically superior.
Why go the infusion route? What made you choose that over perforated and breather cloth? Also why so much core? Seems over kill and more stiff than you'd really need? I make my own stuff too. (Aerospace background) just curious as to why you choose the methods you did.
G'day Mate, good to see another aerospace person around here! Are you in the design or manufacture side of things? (or maintenance, or flying or any of the other aspects).
I went the infusion route because I didn't want to be working against the clock with a wet layup. I wanted to take my time getting all of the fabric laid up and then introduce the resin later. I find there is a lot less pressure with this method. I would like to step it up even further and move on to prepreg stuff, however at this time I don't have an oven suitable and to be honest this is a side job / hobby and I cannot justify the cost of my own oven.
As for the core, this is my first bonnet, I figured it was better to be safe than sorry. Its a poor engineering decision I know. What would you have done?
What kind of stuff do you make?
Great video mate! Loved the process, but would like to hear you talking through some of it to know what you were doing and with what tools and equipment. I really enjoyed watching. Thanks!
How long did the entire process take from start to finish? How much did you charge your mate for the work?
Thanks for the feedback mate, I'll try and talk a bit more when I'm working. It's surprisingly hard to talk and work at the same time, I frequently just end up working and forget to talk.
The total process took me around 7 months from commencement to install. This is not a realistic timing for most people. I spent over 30 weeks away with my full time job last year and more time seeing family overseas. If I had more time around the house it would have taken a lot less calendar time to complete.
As to the cost; for the bonnet to act as a plug, the materials for the mould the materials for the part and some consumables it cost around $1200 Aussie. My mate only paid cost (plus some timber).
where did you get the nut plates you epoxied into the bonnet for the hinge mount?
They are by a company called Bighead, they cost me around $5.50 AUD per nut plate. I picked them up from these guys (Gold Coast based) www.yardeng.com/bighead-fasteners
Could you tell me what spray adhesive did you apply between the mold an the carbon fiber ?
Thanks
I used 3M super 77, however I suspect that caused some of the surface imperfections I had. There are other infusion adhesives out there I would consider using them instead.
Awesome stuff, a great inspiration to finally get off my arse and make my aero parts.
I'm curious as to why you're using easy composites cloth though, isn't it super expensive getting it from the UK compared to local suppliers?
Hey mate, glad that you liked it. If you were around the Brisbane area I would have offered to give you a hand, sadly the cost to travel the 2,000km and 20 years backwards in time is a bit too much...
At the time that I purchased that cloth from the UK (2016) it was not cheaper than getting it locally, particularly as the bi-axial stuff there was purchased for ~9GBP per linear meter (~7GBP per sq/m). There are now some competitors in Australia that are selling carbon that is comparable value for money.
I find that easy composites is still the king for consumables with some of their products being 50% cheaper than locally with duty and GST. When you include shipping it comes to be ~30% cheaper (I made a spreadsheet to assess it all). They also have some things that you cannot get in Australia easily in small batches (like small qty tooling board). So when I have done bulk orders of certain products they are cheaper from EC than locally.
If you are looking for local products, check out beyond materials (AU). They have good pricing for their reinforcements, and I really like their infusion resin. (You would be the 5th or so person I have recommended them to, I should get a cut)
While you are in Adelaide, if you want to collab on anything let me know. I just subbed to your channel. I do a bit of routed products for F3 cars (wing endplates, wing supports, side pod covers etc) , as well as some drone components and other engineering plastic stuff. Have a look at my latest video as an example.
Now now no need to be salty that we took the crown of newest track in Aus from you ;) That said I'd love to give QR a crack sometime.
Amazing that the cost was there but will happily believe you, there's a few suppliers locally that are a bit nicer than $75 sq/m now! I discounted looking at EC but will definitely check them out again. I've seen beyond materials before and they were nicely competitive with our local ones.
Would definitely love your opinion on a few things :) have watched all your wing videos voraciously as that's what I'd like to attempt next, was thinking of making a lattice support rib and then fill in the rest with PVA printed parts, infuse then dissolve the PVA. Was thinking it might be a gamble but after seeing that F3 wing I think it may be possible. Just depends if the PVA can hold up to the cure temperatures.
Good work! -one mere suggestion. have your shop vac sucking near your cuts!
I did for some of them, but it was hard to work with the hose around the camera so I dropped it out for some shots. Always use PPE though!
Great work! How many cfm is the vacuum pump?
It's only a 3 cfm pump from memory. 2 stage, from ebay. If it breaks (it hasn't yet) I'll look at buying a brand name one.
Great! Thanks for sharing!
can you estimate how much materials would cost me if i want to copy my oem carbon fiber hood? not including tools
From memory it was around $600 Aussie.
How does more foam add strength?
It provides a path for shear transfer between the top and bottom skins. Check out this other video I did on the topic (complete with very average animations that took me forever....) I hope that's useful, if not hit me up and I'll try and answer it better.
Can you make a video for a fender
At this stage I don't have anyone who wants one/is willing to pay for materials for one. So right now, no I can't. If my channel grows and I can pull in some money from that, I'd be happy to put it towards doing a fender (bumper in Australian). Likewise, if someone near me wants one and is willing to pay for the materials, I'd happily make one.
I hope you understand.
Hi, what is the difference in weight in this case?
About 10kg, I only just saw this question, sorry
if you keep the pump on for more time and let some resin to the catch pot you probably will fill those voids and bubbles!
Thanks for the suggestion, I'm probably never going to do a full infusion like that again for a race part, it came out too heavy. I think I'll infuse the skin against the mould surface; then bond on the skin with an epoxy/q-cell slurry and wet the back skin in one activity.
I'll try leave the pump on for longer next time though.
@@CEWManufacturing nice! have you seen this video: th-cam.com/video/EHLSzEmWzJs/w-d-xo.html
That is a beautiful bonnet. How much to make a normal carbon fiber bonnet for a E36? Maybe with just the front air ducks ... I'm serious. I want one lol
I'm glad you like it mate! If you're in Australia and you want some work done, hit me up through my website chapmaneng.com/
Indicatively, there is around $650 of raw materials and consumables in the bonnet itself (plus the mould and labour, etc). It's not the cheapest option, but costs can be varied based on materials and design and a bunch of other parameters, I don't really do large production runs, so I'm flexible with the final product to meet requirements.
My friend, what is that spray you apply to the Carbon Fiber? Cause the carbon seems a bit hardned?
I used 3m super 77 between the layers to stick them down
My question is: did you apply something to the carbon fiber before cutting it? Because it doesnt seem to be as soft as cloth... It seems a bit hardned...
@@41Paulocesar Hey mate, I didn't apply anything, it was just carbon straight from the roll...
Beautiful job. Ambitious project esp due to louvers. The foam inner core is brilliant, saves moulding underside of hood and looks good. What else would you need to do to put this on a car, painted? Would have thought there would be a greater weight savings than 17kg->6.5.
G'day Roy, The part will not be painted, they will throw some stickers on it though for their sponsors (check out the making of the mould video, it shows the car in the first minute). I assume that it will need some more edge sanding, I'm pretty sure it is back to the original dimensions but you can never be too sure. It will also need the holes for the bonnet locking pins to be bored out in the correct location, there are hard points in the front to accept them, but I didnt want to make the holes without it being on the car. The hinges will also need to be lined up and probably shimmed to make it sit perfectly.
So not too much in comparison to the build, but still a bit.
Matt
Good job👍🏾
Why didn’t use a surface coat before applying the carbon?
Couple of reasons, 1: this was meant to be a low cost, functional part. A surface coat is additional labour, and more material costs.
2: a surface coat adds additional weight
3: I haven't used a surface coat before, I didn't want to try it on a part that size, fail and ruin the part.
I should get some and give it a go, but right now I don't have a project it's needed for and I don't really want to go spending the money just for the sake of it.
Do you use surface coats?
CEW.Manufacturing no problem just thought I’d ask.
Yes I do use a surface coat. If you were going to be showing raw carbon in the end of everything you’ve done the last thing you want to do is more prep work to clear/sand clear/sand, that’s too much work.
If you use a surface coat you wouldn’t have to worry about the pinholes and repairs. Once the part comes out all I do is a light sand, if I want it more shiny than the mold, then a finish buff, that’s it!👍🏾 I don’t even use clear coat, just resin.
It just saves you a ton of headaches.
You shouldn’t have to do extra repair work.
It adds a lil extra weight but not what you think, it doesn’t really take much at all, I guess I’m more obsessed with the look 😂
How many vacuum pump power do you use?
I believe it is a half horsepower dual stage vacuum pump. It's not very big. I wish I had have gotten a bigger one, maybe in the future!
It does work well though, it will pull a good vacuum.
@@CEWManufacturing thankyou for information.
What is the weight difference between steel and carbon bonnet?
10kg.
The original bonnet was 16.5kg, the final was 6.5kg. It wasn't quite 1/3 of the weight, but it was getting there.
I think if you laid up and infused the first two layers (with 4 layers on the vents) let that cure then did the foam and the back layer together (not as an infusion but a wet lay under vacuum) you may get it down near 5kg. That is my suspicion at least.
@@CEWManufacturing yeah, core probably soak bit more resin.Great job 👍
Ah, Monsieur, you have misspelled "Le bonnet au crabon fibré"
I have always been bad at French, I'll work on it ;)
can you make one for me?
If you wanted. Obviously it would have an associated cost, but sure can.
yea it would be lighter if you didnt use a foam core lol
If there was no foam core it wouldn't have much strength at all. I'd have to use a lot more carbon and resin to give it the same strength, which would have made it a lot heavier.
CEW.Manufacturing carbon fiber is lighter than foam cores and the resin that the foam cores absorb but i got ya its an efficient way of making the hood while maintaining effectiveness i guess
@@2k5mike Sorry Mate, I'll have to disagree with you there. Foam is a hell of a lot lighter than carbon. Almost two orders of magnitude in fact. Polyurathane foam does take up more resin than is ideal, a proper closed cell (like dyvinacell, probably spelt wrong) would be better and take up less resin. a nomex honeycomb core would be the best, but then I couldn't do an infusion part and it would cost a heap.
If you want to see some maths and theory behind it: th-cam.com/video/1GhGyr3Wn0k/w-d-xo.html
CEW.Manufacturing yea i guess you would no more i just based my judgement off of this video but it was the 12k carbon that was equal in weight to the foam at 2:30 in this video th-cam.com/video/YdH4Xj2K1Bc/w-d-xo.html :D but the regular carbon was much heavier lol woops xD