Autoclaves?

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Richied76
Richied76
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Joined: 18 Aug 2010, 21:04

Autoclaves?

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This may sound like a stupid idea to many of you, but i have an idea to construct an autoclave to the size capable of curing a 2/3rd size F1 monocoque, What i need to know is what pressure and temperature will i need to be reaching for it to make a possitive effect? If...funds dependant....i am able to make it work possitivly enough i will be using epoxy and twill carbon fiber. If not, polyester and Eglass/fiber glass. Both using vaccume bagging techniques.

My idea consists of a bespoke 12mm thick, steel plated heagonal tube with a 45mm box section frame, braze welded on the exteriour, with a layer of 25mm celotex boading on the inside with a highly polished face, and a 2nd layer of 65mm celotex on the exteriour. i have a compressor capable of 1000psi and a suitable heater element that in an open atmosphere can generate 200c. I would be greatfull for the feedback and your idea's. the second i find how to put pics on here, i'll show my designs

Oh and the ultimate goal is to be able to produce a minture? vastly simplified F1 car using a honda GS230 engine for my son....and if he grows up faster than i can build...to sell!

conni
conni
0
Joined: 07 Jan 2010, 22:09

Re: Autoclaves?

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if you stick to polyester you wont need a clave or oven much simpler

conni

Jersey Tom
Jersey Tom
166
Joined: 29 May 2006, 20:49
Location: Huntersville, NC

Re: Autoclaves?

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I would think it would be easier and safer to do as a steel frame with appropriately looking fiberglass bodywork on it, rather than a full tub.
Grip is a four letter word. All opinions are my own and not those of current or previous employers.

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747heavy
24
Joined: 06 Jul 2010, 21:45

Re: Autoclaves?

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it will depend on the resin system you use.
an example curing cycle for an aerospace part is shown here:

Image

So I would say 200°C and 6 bar pressure (for monolite parts) will be sufficient.
If you use a honeycomp core material, the pressure is lower ~2.5bar
For simpler "hobby" style parts curing temps are around ~120°C .

Another cure cycle for Hexcel 8552 resin

Image

For any quality or high stress part you will need to use a prepreg systems, as you wont get the desired quality and strength for a monocoque with wet layup - IMHO

some informations which are maybe useful for you, can be found here:

http://www.4spepro.org/pdf/003343/003343.pdf
http://www.ltt.de/uploads/pdfs/Events/I ... C_Nutt.pdf

Hope this helps a bit

(as for the photos, you need to upload them to a photo hosting side, such as photobucket etc, and then link them to here)
"Make the suspension adjustable and they will adjust it wrong ......
look what they can do to a carburetor in just a few moments of stupidity with a screwdriver."
- Colin Chapman

“Simplicity is the ultimate sophistication.” - Leonardo da Vinci

riff_raff
riff_raff
132
Joined: 24 Dec 2004, 10:18

Re: Autoclaves?

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Richied76,

Making your own autoclave would be a very risky undertaking. The autoclave and controls would cost several times what your tub will cost. If you really need an autoclave, there are composite manufacturing companies that will gladly autoclave your parts for you (for a price).

Here's a suitable autoclave for sale:

http://cgi.ebay.com/Autoclave-304-Stain ... ltDomain_0

Otherwise, you can get very good results with modern, out-of-autoclave resin systems. They only require a low temp oven and vacuum bagging. Both of these can be achieved in your garage.

http://www.cytec.com/engineered-materia ... 205320.htm

Good luck.
riff_raff
"Q: How do you make a small fortune in racing?
A: Start with a large one!"

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flynfrog
Moderator
Joined: 23 Mar 2006, 22:31

Re: Autoclaves?

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Why not just look at out of autoclave process. You probably dont need the void content and compaction provided by a clave

Jersey Tom
Jersey Tom
166
Joined: 29 May 2006, 20:49
Location: Huntersville, NC

Re: Autoclaves?

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Again.. I say.. if you're just making something fun for you son.. don't do a carbon tub. There is absolutely zero reason.

Steel frame, fiberglass body.
Grip is a four letter word. All opinions are my own and not those of current or previous employers.

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ringo
230
Joined: 29 Mar 2009, 10:57

Re: Autoclaves?

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The question is; can you afford the energy bill?
For Sure!!

riff_raff
riff_raff
132
Joined: 24 Dec 2004, 10:18

Re: Autoclaves?

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"Again.. I say.. if you're just making something fun for you son.. don't do a carbon tub. There is absolutely zero reason."

JT,

Zero reason? It's all about having fun with his son. What better reason could there be?

Richied76 can do a carbon tub with his son, but it just will need to be an out-of-autoclave material. I wish my dad would have tried such a project with me when I was young.
"Q: How do you make a small fortune in racing?
A: Start with a large one!"

marcush.
marcush.
159
Joined: 09 Mar 2004, 16:55

Re: Autoclaves?

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forget Autoclave. resin infusion and films plus vacuum will do a very nice job.Maybe even syntactic expanadalbe films alone will carry you a long way .Modifying a household kitchen oven will provide the means for tmperature curing ....so not much in terms of hardware to be bought apart from a decent Vac pump .

Jersey Tom
Jersey Tom
166
Joined: 29 May 2006, 20:49
Location: Huntersville, NC

Re: Autoclaves?

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riff_raff wrote:"Again.. I say.. if you're just making something fun for you son.. don't do a carbon tub. There is absolutely zero reason."

JT,

Zero reason? It's all about having fun with his son. What better reason could there be?

Richied76 can do a carbon tub with his son, but it just will need to be an out-of-autoclave material. I wish my dad would have tried such a project with me when I was young.
Safety comes to mind as a reason for me. Seems like it's much more straight forward to build a SAFE chassis, around SCCA rules for example, out of steel, than it is to make an impact-safe and load bearing tub with the right structural equivalency.
Grip is a four letter word. All opinions are my own and not those of current or previous employers.

marcush.
marcush.
159
Joined: 09 Mar 2004, 16:55

Re: Autoclaves?

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I´d say learning to weld and fabricate is for sure not easier than learning to laminate especially when it comes to dry layups it is for sure something you can do at home.

autogyro
autogyro
53
Joined: 04 Oct 2009, 15:03

Re: Autoclaves?

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Good luck to them I say. For to long carbon fibre has been looked on as out of reach to anyone without millions to invest.
This attitude IMO has prevented many other uses for the material.

marcush.
marcush.
159
Joined: 09 Mar 2004, 16:55

Re: Autoclaves?

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In my book it´s not the cf ..you could as well use glassfibrecloth ,wich is also available in aero qualities and a lot cheaper to learn how it is done..the construction methods and resin systems are the interesting bits.

gridwalker
gridwalker
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Joined: 27 Mar 2009, 12:22
Location: Sheffield, UK

Re: Autoclaves?

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Marcush, I note two uses of the magic words "for sure" in your last comment : now I am starting to suspect that you are actually an F1 Driver ...

For news on the "For Sure" world championship, please see http://www.f1network.net/main/s169/st146795.htm
"Change is inevitable, except from a vending machine ..."