I finally got around to testing this stuff over the long weekend, and the results were not as good as I expected.
This stuff is no replacement for fiberglass/resin, but it may be useful for a few things. If you have ever tried resin jelly, this stuff is very similar.
Cons:
Cost - $54.00 a gallon at my local autoparts store, plus it didn't come with hardener cream. I usually pay about $35.00 a gallon for resin. If you could use this stuff without glass, the cost might balance out, but it does not have the strengh by itself to be used on wearable armor.
Strength - Not as good as glass / resin. All test strips were 2 inch by 6 inch strips if resined cardstock and were allowed to cure overnight.
For the first round I applied about 1/8th inch coating of tiger hair to one, and 1 layer of fiberglass mat & resin to another. When I tried to bend them in half, The tiger hair one bent easier than the glassed one and snapped cleanly in half at about 70% bent. The glassed one did not break and was harder to bend.
For the second test, I applied a 1/8th inch of tiger hair, then layed on a strip of mat. I covered the mat with another layer of tiger hair. The other piece got 2 layers of fiberglass mat & resin. The TigerHair / f.g.mat combo was just as strong as the glass/resin piece. Both were difficult to bend and neither broke, however, the tiger haired strip was thicker and heavier by about 50%. (guestimate)
Ugly - You will definetly want to paint the inside of your armor if you use this stuff. Not only is the green/brown color ugly, but you cannot see the glass thru the tiger hair. You have to really pay attention to not leave un-glassed areas during layup.
*note* When I opened the can, the stuff had seperated into two parts. According to the instructions this is normal and it needs mixing. That turned into a very slow messy task, as the can was full to the top, and the liqiud part was almost as thin as water.
Pros:
User friendly - No brushes, no mixing containers to clean. Mix it on a square of cardboard and apply with a spreader like bondo. Also the hardener is the same red colored cream that is used for bondo, so when you mix it, you can judge by the color how fast it will set up.
Predictability - Unlike resin, which seems to go from a liqiud to a congealed, unuasble mess with almost no warning, this stuff sets up alot like bondo and you can continue to use it until it gets too hard to spread.
Quikness - Many times I have fiberglassed or resined a piece and have had to wait until the next day for the resin to cure, even if I tried significantly increasing the hardener, I have had to wait. The Tiger Hair was rock hard and sandable in 15 minutes - 1 hour depending on how "hot" or "cold" I mixed it.
No bubbles - When you spread this stuff on it fills in all the sharp angles inside your piece that always give me problems with glass/resin. Also, because of its paste like consistancy, once you push the glass into it, it stays put, no going back to push out air bubbles.
Bottom line - The strength to weight ratio of glass/resin blows tiger hair away, IMO. I will use the stuff that I have, but with fiberglass mat to strengthen my other thigh piece. Also I like Loess's idea of using this stuff by itself to fill in sharp corners and inverted details inside to lessen the chance of air bubbles when applying glass/resin. In the meantime, I'll continue to work on my fiberglassing skills.