PREPREG Carbon Fiber? Where do you source it from?

Triathlon Forum
1

Hello. I’m attempting to make a carbon fiber nutrition box and then a carbon fiber tool box for behind the seat. Of course wanting both boxes to be super light, super strong and aero. So. Rather than buying carbon fiber sheets and the epoxy, where can I find, or where did you find PRE IMPREGNATED CARBON FIBER SHEETS that you can form to fit and then you bake and or let them cure and BAM the stuff is as hard as nails.

I don’t want to mix epoxies, I have seen a hundred youtube videos showing guys using this stuff and I have already sent a PM to the fella that made the CF seat on this site, but he seems to have ignored the email after nearly a week. He wasn’t using prepreg anyway, but he still ignored me, which really hurts deep inside. :slight_smile:

So where can I get this stuff? Please feel free not to answer if your answer includes: “Google it dumb ass” “Ebay”, or “Amazon” or some other vague answer. If anyone has links to specific sites that would be very helpful.

Thanks.

2

You dont let carbon cure like you can do with fibreglass, you have to bake it. Well, I guess you could use fibreglass resin with Carbon, but then you might as well just use fibreglass.

3

You dont let carbon cure like you can do with fibreglass, you have to bake it. Well, I guess you could use fibreglass resin with Carbon, but then you might as well just use fibreglass.

Ok. thanks. Sorry for my terminology mix up. Bake/cure…

Do you have any sources for the stuff?

4

I buy all my carbon fiber products from Fiber Glast.
That said… I don’t know that what you are asking for is going to do the job. I’d contact them and ask though.

5

Have you watched the video’s on youtube? Just type in prepreg carbon fiber and you’ll stumble upon a slew of videos of guys pulling this stuff out of their freezers, letting it warm a bit, forming it, some other details etc etc, putting it in vacuum bag etc etc…bake it, and BAM…

It’s good stuff, I’ve seen it work in video, and even Koenigsegg cars uses this stuff to make rims…

It’s bulletproof stuff and it is the right stuff.

Sources?

6

cleaned up link
.

7

cleaned up link

Very cool! Thank you! I hope to get a few more sources to help other folks and also because living in Austria, some of them will not want to post it all the way over here for less than the cost of the product. I’m going to send them an email now.

Anybody else?

8

I don’t want to mix epoxies,.

That is like the easiest part of what you want to do.

Using pre-preg is going to be much more expensive for what you want to do, with no real advantage and with several disadvantages. First, pre-preg is going to require planning ahead of time of exactly what you need to cut and also know how you are laying up ahead of time. If you do not use pre-preg, you can cut your shapes first and verify that they are right and have them all set up before you layup. Plus, you can use a room temperature expoxy, so that you do not need to bake it (there may be pre-preg that does not temp to cure well or maybe a room temp cure will be good enough for what you need).

Second, you are making a very small thing that will require very little material, but are going to need to order a couple meters of fabric. You are going to have alot of extra material and pre-preg does expire, so unless you are making a bunch of these, pre-preg will cost you. If you do not use pre-preg you can keep the extra fabric and use it months later when you come up with another project.

Or you can just use fiberglass. If you are not actually analyzing the structure, why would carbon fiber be any lighter?

9

Id agree with your thoughts on going with fiberglass instead - CF looks cool & all, but if you are just making a toolbox or something similar, you need almost zero strength.

10

Do you understand the difference between prepreg and separate cloth/epoxy? You can make what you are talking about with the stuff from home depot (non-structural) very cheaply and easily. Prepreg really only helps get the resin/fiber ratio correct; and then you have to vaccum bag (a pain in the butt without the proper stuff), and also cook it (which you also do with separate cloth/epoxy as well; although it is not necessary for non-structural stuff).
This company sometimes has clearance prepreg if that is what you REALLY want: http://www.shop.protechcomposites.com/clearance-items/
I have also dealt with prepreg unidirectional boron. Interesting stuff, but not worth the expense for the silly stuff that I play with making.

Stephen J

11

I don’t have any pre-peg sources in Austria.

Just so you know pre-peg has a shelf life in the 1-2 week period and you usually have to buy it in large rolls. This is when you keep it in the freezer. So if you don’t use the whole roll you will be throwing a lot of money out.

12

You don’t need to use pre-preg. For your purposes there is no way the costs will outweigh the advantages in any sort of objective or logical sense.

Fibre Glast carbon fiber and room-temp cure epoxy + a vacuum bagging system will be more than sufficient.

Not to be a negative nancy, but it truthfully sounds like you are in way over your head on this one…you’ll need to design a mold of some description, and you’ll probably end up laying up this mold with…surprise…fiberglass + epoxy (so having to do this step will already defeat your idea of making something without mixing epoxy). This is really the most difficult part of the process. If you go the plug and mold route, you have to design the part you intend on making and manufacture it out of something else (wood, plastic, metal, foam, etc). Then, you treat the plug (i.e apply really smooth coatings, and finally some mold release film) and lay up your mold materials on top of it. Your mold cures and then you’ll end up needing to post-process it (i.e polish it, fix edges, apply wax and mold release coatings). Then, you lay up your part inside the mold using the carbon fiber, vacuum bag it, and wait.

I’m not trying to burst your bubble, but I’d hate for you to spend a bunch of money on supplies and things only to realize you have no idea what you’re doing.

Here’s what you’ll need:

Carbon cloth
Fiberglass cloth
Epoxy
Special scissors for cutting the fabric without screwing up the loose fabric weave
Peel Ply
Absorbent cotton or flow material
vacuum bagging plastic
clay
mold release film
sprayer for mold release film
vacuum supply (or a high flow compressor plus a venturi system for generating a vacuum). The more powerful the vacuum is, the better your result will be.
pneumatic tubing and fittings for the vacuum tube interface with the vacuum bag
large flat work surface for layup and vacuum bagging–must be very clean–dust, dirt and other contaminants can create voids or surface imperfections in your end product.
Dremel tool (pretty much mandatory for any kind of cutting, mold or part trimming)
Sand paper of all kinds
Bondo
Lots of mixing cups
Lots of tongue depressors or popsicle sticks to stir the epoxy

Plug/Mold-making tools (this is really an entire subcategory of its own–if you draw up a design in CAD and 3d print it, even on the highest resolution you will still not get the kind of quality required to produce near-mirror finish carbon parts. You’ll need to sand it, coat it, etc. Since the tools required are so dependent on exactly how you intend on making the mold I’m not even going to list them. Same deal with the plug. Lots of time needed here. The mold needs to be stiff enough to resist the vacuum forces, but not so stiff as to prevent your part from releasing. Depending on the shape of your tool box and whether you want more than one side to have a cosmetic finish to it, you may need to look into molding halves separately and subsequently joining them.

If you don’t own an autoclave you are ill-equipped to use prepreg anyway. You have to have your mold+part layup inside the vacuum bag inside the autoclave, and I’m not sure you could safely cure the epoxy in a home oven with a vacuum system hooked up. I’m guessing some Macgyver out there has done it, but for home projects you really should be using room temp cure products. It’s way more practical.

The biggest expenses are the vacuum bagging tools. You need a ~$200 compressor (minimum) to do the job, and the venturi is $120 IIRC. The sprayer for the mold release film will run another $75 to $100, and it’s important because a shitty mold release layer will give your part a poor finish, or may prevent it from releasing from your mold at all (really bad news–lots of wasted time).

Working with composites is cool and it’s do-able at home, but I just want you to understand that it really is not as simple as your original post makes it sound like you think it is…

13

As someone who has made commercially sold composite parts…I would like to agree with this post 1000 times. Start small, learn what you don’t know, and work your way up to ‘how pagani does it’. There are reasons the ‘big boys’ do it a certain way, but you can get 90% of the way there with a lot less money invested and using techniques that are a lot more mistake friendly.

14

You are spot on with your Post…great response!

CJ
33 years in the Advanced Composites Business
2xIM

15

For what you are doing (nutrition and a tool box) I’d suggest 3d printed plastic. You don’t need a lot of strength and, if you spend enough time on this forum, you’ll learn that weight means very little in a TT setting. If you design your parts right, you’re talking 1lb of plastic max.

16

Hello. I’m attempting to make a carbon fiber nutrition box and then a carbon fiber tool box for behind the seat. Of course wanting both boxes to be super light, super strong and aero. So. Rather than buying carbon fiber sheets and the epoxy, where can I find, or where did you find PRE IMPREGNATED CARBON FIBER SHEETS that you can form to fit and then you bake and or let them cure and BAM the stuff is as hard as nails.

I don’t want to mix epoxies, I have seen a hundred youtube videos showing guys using this stuff and I have already sent a PM to the fella that made the CF seat on this site, but he seems to have ignored the email after nearly a week. He wasn’t using prepreg anyway, but he still ignored me, which really hurts deep inside. :slight_smile:

So where can I get this stuff? Please feel free not to answer if your answer includes: “Google it dumb ass” “Ebay”, or “Amazon” or some other vague answer. If anyone has links to specific sites that would be very helpful.

Thanks.

Check Amazon. If you don’t find anything, I’m sure Ebay will be have something. If all else fails, Google it, dumb ass.

17

dude…

carbon fibre is alarmingly similar to fibreglass. It is a woven fabric (in this case). The woven fabric has very little inherent usefulness. To be useful in needs to be combined with an epoxy to combine to make a moldable product that when finished, makes a rigid 3 dimensional product.

In its most basic form you take the cloth, soak it in epoxy and leave it to cure (harden) after it’s cured, you have a rigid product to use. Voila! Ok so it’s messy and time consuming, but it works great. Lots of carbon fibre products are made this way. Boats, cars, all sorts of things. This is cold molding.

Some clever soul figured out another way and that is to pre-impregnate the carbon fibre cloth with epoxy. To avoid it curing into unusable flat sheets, they impregnated it with a special kind of epoxy that only cures/hardens at high temperatures (generally around 150deg C). In this case you cut the pre-preg into suitable shapes and put it in a mold. In many cases it gets vacuum formed inside a plastic bag and heated. When cooled, it is a solid 3 dimensional product of the shape you want. This is autoclaving (heat and pressure)

The OP is looking to use pre-preg to make his items as it’s more controllable (the pre-preg is easily cut to the exact shape required) and less messy. Most times it also takes less finishing time.

As for carbon vs fibreglass, they are quite similar and quite different. :slight_smile:
In this discussion, they are both woven cloths using multiple tiny fibres. The fibres give the strength to the finished product. They are very strong in tension, but not very stong in compression. When either type of cloth is combined with epoxy, they are quite rigid. The cured epoxy provides very good compressive resistance (the epoxy used for wet layup, cold molding can be exactly the same for carbon and fibreglas, ie the West System range). You are right that the OP could just use fibreglas, but only if he wanted to use wet layup/cold molding. As they wanted pre-preg. as far as I know, he has to use carbon (I’m not aware of any pre-preg fibreglas but I could be wrong)
Fibreglas and carbon are different in some ways however. Fibreglas is…glass :-). In woven form, it appears white, because each individual fibre reflects white light. When epoxy is added, it takes away the glass surface and as epoxy is arguably clear and so is glass, it becomes almost completely clear. I made a fibreglas covered cedar strip canoe years ago and the fibreglass is all but invisible, and everyone assumes it’s just varnished. Fibreglas is strong.
Carbon cloth on the other hand, is black. As the epoxy is clear, the carbon cloth remains visible through the cured epoxy. Carbon fibre is really strong (stronger than glass fibre)

18

Hello. I’m attempting to make a carbon fiber nutrition box and then a carbon fiber tool box for behind the seat. Of course wanting both boxes to be super light, super strong and aero. So. Rather than buying carbon fiber sheets and the epoxy, where can I find, or where did you find PRE IMPREGNATED CARBON FIBER SHEETS that you can form to fit and then you bake and or let them cure and BAM the stuff is as hard as nails.

I don’t want to mix epoxies, I have seen a hundred youtube videos showing guys using this stuff and I have already sent a PM to the fella that made the CF seat on this site, but he seems to have ignored the email after nearly a week. He wasn’t using prepreg anyway, but he still ignored me, which really hurts deep inside. :slight_smile:

So where can I get this stuff? Please feel free not to answer if your answer includes: “Google it dumb ass” “Ebay”, or “Amazon” or some other vague answer. If anyone has links to specific sites that would be very helpful.

Thanks.

Check Amazon. If you don’t find anything, I’m sure Ebay will be have something. If all else fails, Google it, dumb ass.

I’m sure you’re a sparkly bubbly positive person in real life when you’re not near your keyboard behind your monitor. I knew there would be one “clever” person that did that.

19

UK company Carbonmods here, they ship worldwide. Well, through their e-biz portal.

For example, their carbon fiber “starter kit” here.

20

UK company Carbonmods here, they ship worldwide. Well, through their e-biz portal.

For example, their carbon fiber “starter kit” here.

Exactly what I was looking for! Excellent links and thank you.