Composite lessons

During my undergrad studies I had the opportunity (and curiosity) to play with as many materials I could get my hands on. Thanks to a very supportive professor, I spent years (seriously, like 2.5 years) devoting every afternoon and late night to design, create (or replicate), work and process every material and alloy that I could imagine. From LDPE injection molding to high alloy steels. From CNC milling the face of a friend on an acrylic plate to using state of the art foundry facilities to replicate ancient alloys, and with incidents that ranged from clogging a spindle with the wrong resin, or getting aluminum chips playing on my underwear, to leaving a permanently red iron oxide stain on a concrete floor (still there 6 years and counting) due to a over-sized thermite. Fun.

The only family of materials I didn’t have the opportunity to work with was composites. I don’t know if the reason was due to my professor not knowing how to handle them (which I seriously doubt, the guy was a walking encyclopedia), or just due to not having the raw materials or facilities available.

Anyways, if I’ve learnt something while working on Polaris (LINK) it’s been about working with composites, and more particularly, with unidirectional CFRP or Carbon Fibre Reinforced Polymer(boom!).

Yep, during the past 10 months I’ve spent around 500 hours cooking the whole tamale: designing and making molds, wet-laying up layers of unidirectional carbon fiber on quasi-isotropic patterns after carefully calculating the number of layers, high-temp curing the low-offgass, space-relevant resins on a vacuum assisted autoclave, trimming the resulting parts to their final awesome shape with a bad ass ABB industrial robot arm and obviously, testing (to failure FTW!).

Loving the suit, goggles, gloves and respirator

Being completely new to the material and fab process, one of the first things I did was to look at what OSHA had to say about it. You know, getting lung cancer or losing the skin of my hands weren’t on my 2012 resolutions. But soon, during the layup of the parts, I found out that everything I needed to know was that I was gonna have to sacrifice a pair of jeans and a long sleeve t-shirt; that I was gonna have to wear a bad ass respirator and that using nitrile gloves would allow me to get faster to my lunch instead of having to spend valuable minutes scrubbing my hands with liberal amounts of the award winning* GOJO.

Later in the game, during the trimming of the parts, I learnt that I was gonna have to fall in love with that respirator, no matter what; that no long sleeve was tough enough to contain the wrath of those micro carbon bitchy particles; that my ears also wanted some protection; and more important, that nitrile gloves are not enough to contain the rage of carbon fiber splinters. I also learnt that a shower late at night is preferable than a rash in the morning. Always.

An last, I remembered that the inch can and will be divided by the thousands and that more than 5 of them off is not acceptable. I remembered that “ideal” and “real” are not always the same. I learnt that wobbly and skinny tubes can be surprisingly strong if assembled propperly, regardless of what a horde of PhDs have to say; that breaking stuff on purpose is always FUN and that sleeping at night can sometimes be more a luxury than a need.

I’ve learned so much during the past months that it’s been like drinking water from a fire hose. But the most valuable lesson I’ve had is that the skills you earn by working hard on a project are there to stay with you for life.

* I have no idea if Gojo has actually got any award or not. Or if there’s even any award that Gojo would win. But I promise I’ll keep one of those orange bottles (with pumice, of course) close to my heart and to my shop’s sink till the day I die.

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