Yeah a lot of the stuff I've seen is just the imposter stuff. Though cheaper, I think it does look quite tacky.
What would the difference be between the Epoxi and the Phenol? I'd rather it dries/tacks/hardens just in room temperatures because although we do have a vacuum pump which has a built in heater (probably the closest thing to an autoclave besides the large furnace we have) it probably would annoy the teachers if it had to run for many hours.
On an episode of 'How its made' I saw them use vacuum pumps and heat, much the same as I could achieve, but they had to leave it for a while.
I don't mind if it isn't the toughest composite, chances are it won't come out fantastic anyway due to my lack in skill, but I am looking for something that will have a decent appearance and some durability.
For Phenol hartz, you have to have an autoclave, several hundred degrees, a vacuum and a lot of time. The easier way for you would be epoxi hartz. That you can use at room temperature. You can accelerate the hardening with a little heat and you do not require an vacuum, but it would help in the impregnation of the hartz into the web of the fabric. Talking of which, carbon web is directional. You only have strength in one direction, so when laying it up, you must take note of the indication threads that show this. This is important if you buy sheet. If it comes of a roll, then the strength direction is that of the roll direction You will need to layer your work in alternate directions to gain uniform strength. One very important thing about epoxi hartz is that is burns readily and gives off seriously poisonous fumes from the moment of ignition. Phenol hartz is relatively fire proof, though with time does burn but is not as poisonous, but then you have to producion problems to overcome. If I was in your place, I would seriously look at using GRP as fiber glass can be got in just about any DIY or auto repair shop. Jumping in with Carbon you are setting yourself up with a whole lot of costs and trial and error to get your end product just to look good when you could also get the same result with glass all be it another colour and not a trendy black weave.
ALSO to note are the heath aspects of carbon and hartz. They can ruin your day. You cannot sand carbon, the dust if breathed in will enter your lungs and stay there and slowly block you lungs up if enough is inhaled...... No matter what anyone tells you about carbon, please, please believe me on this one point!!! It goes for drilling it to. Also the dust can conduct electricity and cause short circuiting in any electrical component it touches. It can also act as a dialectic and cause corrosion on any metal it comes into contact with if it becomes damp. Lastly, if you get a carbon splinter in your finger, then it is operation time. Due to the form of carbon it acts like a fish hook. The best way to describe this is in comparison with a wood splinter. You body will, given enough time repel said splinter from you finger (that's it you left it alone and did not take a pair of tweezers to it). Carbon worms it way into the skin and would not be naturally expelled. If you got a splinter and could not remove it, you must seek medical advice. If the doctor tells you it will come out given time, thank him and go to another one. In fact keep going from doctor to doctor until you find one who knows about carbon and removes it.
"A bit of a pickle" - British translation: A catastrophically bad situation with potentially fatal consequences.
PETA
People Eating Tasty Animals.
B1 (Cat C) licenced engineer, Boeing 737NG 600/700/800/900 Airbus A318/19/20/21 and Dash8 Q-400
1. Captain, if the problem is not entered into the technical logbook.........then the aircraft does not have a problem.
2. And, if you have time to write the fault on a napkin and attach to it to the yoke.........you have time to write it in the tech log....see point 1.
by machineman9 » Sat May 30, 2009 11:31 am 
