Carbon Fiber mold
Carbon Fiber mold
(OP)
Tube Construction:
I'm in the process of making a 2.5 inch tube with a gradual 90 degree bend on both ends for the purpose of creating a custom cold air intake for a Miata MX5. This cold air intake has to serve a dual task. One is to reach downward to the air dam and bring in cold air upward to a resevoir blasting across a high flow air filter. This filter takes the cool air to the injection system via the 2.5 inch tube previously described. My problem is that being new to using fiber, I'm accustomed to metal and intended to use aluminum but fiber caught my attention, what should I use for mold material and how can I get the two 90 degree bends and all of this being one piece? Anybody!
Great admirations to those minds in the sky,
Dipstick
I'm in the process of making a 2.5 inch tube with a gradual 90 degree bend on both ends for the purpose of creating a custom cold air intake for a Miata MX5. This cold air intake has to serve a dual task. One is to reach downward to the air dam and bring in cold air upward to a resevoir blasting across a high flow air filter. This filter takes the cool air to the injection system via the 2.5 inch tube previously described. My problem is that being new to using fiber, I'm accustomed to metal and intended to use aluminum but fiber caught my attention, what should I use for mold material and how can I get the two 90 degree bends and all of this being one piece? Anybody!
Great admirations to those minds in the sky,
Dipstick






RE: Carbon Fiber mold
RE: Carbon Fiber mold
RE: Carbon Fiber mold
Then you use your model to make a fibre mould.
After you have made a fibre mould you can hand lay up your fibre to make your parts.
You will probably find that this part is better made in 2 parts. Before you stick the 2 parts together you can smooth out the inside.
Making it in 2 parts would also make it easier to core.
For a first project not an easy thing to do, maybee better going to an expert with your model.
Good luck
RE: Carbon Fiber mold
info@rotousa.com
RE: Carbon Fiber mold
RE: Carbon Fiber mold
First make a "buck" by making a model of the intended shape and get it as smooth as possable then lay fiberglass or pour a durable plastic material around your model,making sure you can seperate it into two halves when cured.Pop out your model and you have a mold in which to lay up your Carbon piece.
RE: Carbon Fiber mold
RE: Carbon Fiber mold
Anyone done this yet???
email me at wildman@xwindow.ath.cx with any info you may have.
RE: Carbon Fiber mold
Thanks for the help
RE: Carbon Fiber mold
RE: Carbon Fiber mold
CF does not have to be vacuum-bagged after wetting it with resin, but you can achieve a lighter, more attractive part by wrapping the wet laminate with heat-shrink tape. Here's a site with tube making instructions, and some good epoxy information: http://www.info-central.org/construction_heattape.shtml
RE: Carbon Fiber mold
An easy way to make an odd shaped tube is to build a core in the shape of the interior, entirely from paraffin wax, wrap the wet laminate over that, and wrap the whole assembly in Saran Wrap to debulk it. When the Saran is easy to peel off, the resin has cured.
Directing air from in front of a chin spoiler/ air dam into the engine also directs water from deep puddles into the engine. Several bent connecting rods detract seriously from the resale value of a Corvette.
-Mike-
RE: Carbon Fiber mold
Yes, but he's working on a Mazda MX5... P-)
RE: Carbon Fiber mold
The original post is very ancient history, so come on guys, play nice.
Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Carbon Fiber mold
From what I have gathered, my best and cheapest route would be to making a foam core from swimming noodles, and wrap that in CF. the question is.....
how many layers of CF do I need to apply?
I'm using west systems epoxy is that sufficient?
how will I be able to to release the foam core?
I have some PVA, Peel ply, and silicone spray, How should I utilize those releasing agents?
I have problems w/ bubbles in my epoxy, how should I deal w/ that problem?
i think vacuum bagging will bring out the best product, can I use a conventional vacuum, with a filter to catch the epoxy, and by wrapping the pipe with peelply?
I was also thinking of going to a muffler shop and have them bend me a tube to my specs, Then wrapping it w/ CF to achieve the look, is that feasible?
***Thats all I believe, I'm only 18 years old and I'm eager to learn more about fabrication. Hope one day to be able to produce this tube in quantities and resell them to make a profit, with as low of cost as possible
any help will be greatly appreciated
RE: Carbon Fiber mold
If you use exhaust tubing, you will not be able to remove it from the moulding, unless you split the moulding then glue the 2 halves together, a process I would not recommend for reasons of both strength and aesthetics.
I am sure that West Systems are good epoxies, and you need to work the air bubbles out with a roller or pressure, by say,wrapping with plastic film layered on in a similar manner to applying a bandage.
The easiest way might be to buy some carbon fibre prepreg, then wrap a styrene foam core, then cure the prepeg, then dissolve out the core. You would need to verify that the curing temp was below the deflection temperature of the core.
Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Carbon Fiber mold
RE: Carbon Fiber mold
Even if you do, you risk drawing some resin over and ruining the machine.
Wrapping tightly with plastic film will expel the air. The cure temperature and the strength of the wrap and the mould at those temps will be the main concern
Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Carbon Fiber mold
I need advice on super smooth CF asthitic surface finishes.
Im attempting a complex shape specifically for load bearing therefor the former need not be removed but it also needs to look dam sexy so bandage style wrapping is out.
I need a way to have sheet CF finish without joins you know the ones where you cant see the fiber edges under the resin(like the pros:)how is that acheived?
It feels like i should laquer the inside of a one piece mould and somehow feed in sheet CF in in perfect cut shapes then inflate a thick baloon inside to form it but thats dum...is it?
RE: Carbon Fiber mold
If you want a woven carbon look, you can't have complex shapes without joins.
Just pretend you are a Tailor or an Upholsterer. Could you get your shape in a suiting fabric or upholstery fabric, without seams. If not, why do you imagine you can get it in a carbon fibre fabric.
Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Carbon Fiber mold
I dont imagine it, I have a two car parts infront of me now which to the naked eye seem to have no join. Now maybe they have a mechanical method of weaving a knitted jumper style sheet which could be inflated from within, are hand made or an advanced mechanical technique has been used...i do 0's and 1's not nuts and bolts so just dont know.
My frame needs strength in a flexing plane and to a lesser degree in a tortional plane.
It is a recumbent cycle frame therefor the load is my mass from above plus cornering vectors and the tortional is for stability.
I will mail you a stock shot of the advised foam former for this frame as there does not seem to be a way to attach it here. The advised finish is body filler sanded and sprayed but i would like a fine CF finish.
The fillament sounds time consuming but i imagine it to be very neat could you describe the process.
RE: Carbon Fiber mold
Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Carbon Fiber mold
How would i reenforce areas.
i sent an image of the former to your mail does it seem like a realistic process for that shape?
RE: Carbon Fiber mold
It Will be difficult to wind the filaments through the hole in the centre unless you make a small spool and do it carefully by hand. You do it just like a bandage, but using single yarns. they are wound very close and parallel to get full cover, but can be criss crossed at a wider pitch on the surface to get an aesthetic effect.
The helix angle you use when winding will significantly effect the reinforcement as it will only reinforce along the axis of the yarn.
Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Carbon Fiber mold
RE: Carbon Fiber mold
Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA
RE: Carbon Fiber mold
do this and here is what i am currently getting ready to do. I purchased 3" I.D. pvc water piping in straight tube and some 90 degree elbows for the moment to get things started. You will go to this site to get your carbon fiber sleaving (or CF Kevlar hybrid sleeving) http://sollerpaddles.com/composites/
He also sells West epoxy at a very good price. The pvc piping is shapeable after a 30 minute soak in the oven at 200 degrees. Get your misc shapes that you need, split the pipes that you have created, so this will be a 2 piece mold. Now comes the cool part! I found a company that makes sail boat steering wheels this way. You create a plastic bladder that will slide into the the initial 2 or 3 layers of the CF sleeving (prepregged before mold insertion of course) and you will inflate this bladder so it pushes the sleeving against the inside walls of the pvc piping. Hold until it sets up, and remove it from the 2 part tubing mold. Bake for
an hour at about 200 degrees. Now if your first prototype is too thin in the wall, you can always go back and add another
layer of CF sleaving. I do believe this this will work for this application. And i also know that i will maintain a cooler air charge as opposed to alluminum. CF has a lower mass by something like 1.5 compared to alluminum so there is definitely going to be less heat transfer. Good Luck on your projects! Also, the guy that has bubbles in his epoxy after mixing, go to the plastic store and pick up some of that large diameter clear acrylic tube ( the 6 or 8 inch stuff). Make a chamber that your cup of epoxy will fit in, make a sealable lid and attach a vacuum hose (i use a vacuum pump from a scrapped mini fridge : )) and this will suck the bubbles to the top of the cup of epoxy.
RE: Carbon Fiber mold
///////////////////////////////////////////////
Yea the tube ends need to be beefed up for sure.
There will be a decent flange on there to prevent
slipoff, but since the clamps have a uniform
force
around the pipe... i might be able to wrap
unidirectional CF at the clamping points. I think
that could prevent crushing forces. But to answer
your question, they are making kayak paddles with
a form that you slide your prepregged CF sleeve
over... then they slide on a low temp heat shrink
to give even pressure and it squeezes out any
excess epoxy. Now applying this to the IC piping
idea: Lay up one sleave layer only and cure it.
Split it to remove off the form, then put the two
halves back together with maybe just epoxy to
fuse
the seams back together. So you have a tube now
in the shape you want that is about 1 mm. thick,
next you prep however many sleaves you plan to
use. Put those sleeves over the tube and then
slide over the low temp heat shrink tubing. Heat
the heat shrink starting at the center to let the
excess epoxy flow outwards to the tube ends. Cure
it and remove the heat shrink. Now you have a
perfect tube. : ) And it will have a super
smooth finish.
RE: Carbon Fiber mold
RE: Carbon Fiber mold
area. For a variety of high temp epoxies, check out JD Lincoln
in Costa Mesa Ca. http://www.jdlincoln.com/ they also prepreg
for customers large or small. But i think you are one the right track with the plate because it will handle the bolts better.
Mike
RE: Carbon Fiber mold
Check out the latest engine cover parts for clarity of carbon fiber.
ht
RE: Carbon Fiber mold
That idea for the innertube came to me a few weeks back when i was racking my brain over a good inflatable bladder for the tube mold. I cut the tube as you describe and was amazed how well the tube worked! I had a flat tire on a bike in my garage so i thought what the heck, and tried it. Great pic of your work BTW. I am making CF mirror covers for the 240SX and working on some other parts as well. My work http://
I am tooling up for the 350Z and Scion right now for parts.
RE: Carbon Fiber mold
Thanks, By the way, how are yur customers reacting to your prices?
RE: Carbon Fiber mold
Mike
RE: Carbon Fiber mold
Ive got some questions about mold construction though.
Kognition- Are you still using pvc? What did you do about imperfections between the straight pieces and the pre-made bends.
Basically, Im trying to find a fairly easy, cheap way to make several different pipe designs. They need to be mandrel bent style and easy to modify and remake.
I was going to use the foam tubing style, but I figured where it bent there would be a crease. Also, how could you shrink it without crushing the foam?
Thanks again
RE: Carbon Fiber mold
RE: Carbon Fiber mold
What brand did you decide on for the silicon.
Also, did you first mold the part in one piece then split it, or did you make 2 seperate molds? The reason I ask is because Im making pipes that bend on more than one axis and will have to do it in one piece, then carefully split it along the center.
When you say "existing piping" Im assuming you mean factory steel/aluminum pipes. Im trying to find a cheap product that I can build plugs cheaply, without having to fabricate a steel pipe before hand. I liked the idea of pvc, but theres just too many imperfections in it and no real way to repair them.
RE: Carbon Fiber mold
I take a pipe and mount it on a flat plane, build up a layer of modelling clay halfway up. Build a dam around it to hold the rtv when it is poured. I used 1.5" thick sheets of styrofoam available at Home Depot to quickly build dams and adhese them together with silicone caulk. Wax your clayed up surface with car wax paste using the soft sponge pad and dab the surface completely. A couple layers will do. Pour rtv. Let set. Now you need to very carefully flip this whole thing upside down. Carefully remove clay. Wax the new rtv surface and exposed remaining pipe surface very good. Build another dam and repeat the process. From this point to can reinforce the rtv shape integrity by glassing it. Then splitting that. Now you should have a workable shape to make parts from that will have the original surface finish.
Hope this helps.
RE: Carbon Fiber mold
Anthony
makaveli200369@aol.com
RE: Carbon Fiber mold
It does take a little getting your mind around it, but if you are new to composites... i suggest getting to know the materials first so you get a handle on it. Making tubes is indeed a task for those with experience. I for one do not post images of our manufacturing processes (and most companies do not. But i have explained above how you can do it. And there are a few different ways to do it. I would check google again
this time adding the domain extension "EDU" for the Universities which do post video and images of course projects.
Mike
RE: Carbon Fiber mold
If you are new to composites, it really has nothing to do with mold making. Both are completely different realms. But wanting to learn one, will force you to learn the other eventually. But once you get the basics down for both, you are really only limited by your imagination and budget.
RE: Carbon Fiber mold
RE: Carbon Fiber mold
This should give you a basic idea of the process, you just need top apply it to making a pipe.
Kog, have you had any problems with the seams between the 2 mold halves. I havent started yet but I would think it would be difficult to get it seamless. Thanks
RE: Carbon Fiber mold
RE: Carbon Fiber mold
RE: Carbon Fiber mold
RE: Carbon Fiber mold
RE: Carbon Fiber mold
Basically they expand cf within a mold by use of a bladder like an inner tube. But the bladder i think remains in the part permanently so they must be making low cost bladders out of plastic or something.
RE: Carbon Fiber mold
RE: Carbon Fiber mold
a mold release is suggested. Then you just strip the mold release from the cured part with mineral spirits.
RE: Carbon Fiber mold
Mike Halloran
Pembroke Pines, FL, USA
RE: Carbon Fiber mold
RE: Carbon Fiber mold
RE: Carbon Fiber mold
Paraffin also makes an excellent core for parts like intake tracts. You can wrap wet fiber on it to make a tube directly. It gets more difficult if the tube needs ears at the ends.
Mike Halloran
Pembroke Pines, FL, USA