This thread is a continuation of sorts of a previous thread "Experiment Poly-U Glue vs Epoxy" http://www.skibuilders.com/phpBB2/viewtopic.php?t=3024
But since I'm not using Poly-U glue in the CF test and comparing CF vs FG I thought it be better to start a new thread.
We can be fairly confident from the start that pound for pound (ie ounce for ounce) CF is stronger/stiffer/lighter than FG. This allows you to make a lighter ski yet just as durable as a FG ski. But how much lighter, stronger, durable?
Here's the test I conducted with CF sample layups and comparing them to the FG layups I did in the "Experiment Poly-U Glue vs Epoxy".
A few notable Ooops.....
1. In the CF test samples I forgot to use VDS which I used in the FG test samples (argh).
2. The CF samples I used poplar veneer instead of maple. I thought I had used poplar in the original FG samples.
3. I did not do a CF and metal layup. Instead I did a CF and FG layup and compared that against the FG metal layup. WHY? Chances are I won't be using metal (titanal or AL) in a ski any time soon. The comparison results of the 2 are intriguing though.
All materials below measure 3in wide x 36in long (76.2mm x 914.4mm).
Material list for the FG layup:
FG - Triax 20 oz with 7 carbon fiber strips
Core - maple 1/16in thick (1.6mm) 2 layers in each sample
Cork - .8mm (www.corkstore.com)
AL - .24mm thick (sanded using 80 grit to increase adhesion)
Epoxy - QCM EMV 0049 resin ECA 032 hardener
VDS
Ptex base
Material list for the CF layup:
CF - 9.4oz Uni
FG - Triax 22 oz
Core - poplar 1/16in thick (1.6mm) 2 layers in each sample
Cork - .8mm (www.corkstore.com)
Epoxy - QCM EMV 0049 resin ECA 032 hardener
Ptex base
30lb weight (13.6 kilo)
Wixey Digital Angle gauge model WR300 to measure angle of deflection
All samples were pressed and cured at room temp.
As you can see the CF is a little bit lighter, slightly thinner and retained more camber out of the press with 1 exception.
Defelection Test Results:
I used the BOW method to conduct the Deflection test... Bucket Of Weights :-) See my hi-tech method in the above link.
Here you can see how much stronger the CF is when 30lbs of weight is applied to each CF sample. Hands down it is stronger. The CF/FG layup deflected less than the FG/metal layup which was a little bit of a surprise.
Torsion Test Results:
The torsional tests are fairly close. I'm assuming this is because the FG is triaxial/heavier and the CF is only Uni. The FG Cork is a very weak layup and the cork does nothing for torsional stiffness as expected.
CF FG Comparison:
These charts are just the above charts combined.
So, as expected CF will create a lighter, stiffer ski. You can bet I will make at least 1 ski that is just CF and 1 CF/FG ski this season!
Well that's it for now.
