View single post by Huw Griffiths
 Posted: Wed Jan 27th, 2010 10:53 pm
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Huw Griffiths



Joined: Wed Oct 21st, 2009
Location: Cwmbran, Wales, United Kingdom
Posts: 263
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W C Greene wrote: Huw-I wasn't trying to get someone to use something dangerous!  Most all my model airplane builder friends make stuff from carbon fiber and they swear by it. Sure, you have to observe proper safety procedures to work with it..most stuff modelers use needs some safety procedures. You can make your own by using what is called carbon fiber tow-looks like fine threads-and lay that into epoxy or other resin. The guys I know use industrial epoxies, not the cheap stuff from the hobby shop. When done properly, it is hard as h#$$ and for something like a locomotive frame, it would probably be fine.


Don't worry, I wasn't trying to suggest that you were encouraging people to take risks.

I was merely hoping to warn people that they need to be careful with carbon fibre. As some people might have guessed from my comments, I had some painful splinters from this stuff - I wanted others to be able to avoid them.

I recall that, when I worked at the university, some people in another department used carbon fibre matting (probably the stuff you're talking about) - this stuff had some flex in it, so was less likely to "spear" you (well, at least until you added the epoxy). Even then, my friends were still wearing 2 sets of rubber gloves!

I also remember the industrial epoxies - we used one of them to bond the ready made sheets to concrete beams - these were real adhesives, which put the mass market stuff to shame.

From what my friends told me, they got best results from the epoxies (and carbon fibre stuff) when joints or encapsulation was done under pressure - weights on top, that sort of thing - this reduced the chance of voids in the epoxy. This was also the case with other adhesives, being used for other purposes.

Since these guys were doing PhDs based on their research into adhesives, I think they probably knew what they were talking about. However, there is a difference between what you can do in a lab and what you can do in the real world.

 

It's interesting that you mention about the need for safety precautions with many things connected with modelling (and life in general). I had my fair share of accidents when I was younger - most of them very minor, often soldering iron burns (which healed fully after a few days). I don't doubt that there will be others.

The accident which had the most effect on me was also one of the silliest and most minor. As a 7 year old, I tried my hand at card modelling - unfortunately, I was stupid enough to use a stapler for fixing things together - and I ended up stapling into my left thumb. The next day, I was in school, being taught joined-up handwriting (that was the theory), so I was forced to start writing with my right hand. A week later, my thumb healed up and I picked up a pen in my left hand. I was told to keep using my right for writing and I complied - a big mistake, which I've regretted for the last 37 years. Since then, I decided that I wasn't going to allow myself to be pushed around so easily in future. These days, I'm something of a maverick (albeit a law-abiding one).

 

There's another reason why I brought up this stuff. In my last job, I was the only "electrical" guy in my department - so I ended up doing a lot of health and safety enforcement. This started off as electrical safety testing on plug-in equipment - and progressed to include keeping students away from test beams that were about to break - and holding safety details of all the chemicals used there. I didn't enjoy having to tell people what they couldn't do, but it wasn't as tedious as all the paperwork that could have followed an accident.

This sort of stuff would obviously make anyone risk-averse - I hope I didn't cause any offence by jumping in.

Anyway, that's more than enough from me.

Regards,

Huw.

Last edited on Wed Jan 27th, 2010 11:10 pm by Huw Griffiths

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