Six-10 is pre-mixed with something like Cab-O-Sil and is meant for bonding and patches. It can also be used for tacking between stitches. It is very good at this but has its limits. The main problem is although the two parts don't mix until the tip, enough must stay in the tip so that in about 30 minutes it starts to gel up and it becomes almost impossible to pump and you will need to change tips.

This leads to the second problem. Expense. It takes about half an ounce to charge the tip and about as much is left in the tip when the tube is empty. You could put the same tip on a new tube but it won't be usable for long. (see first paragraph). Since each tube yields about six and a half ounces of mixed product, minus what is lost in the tip, it costs about $4.50/oz. If cost is not a problem it is great stuff.

The thickening agent in Six10 is silica.  

In last year's build-your-own-Cocktail-Class one-week classes, we found the speed and ease of dispensing fillets with Six10 to be indispensable.  It really came out quickly and neatly.

The relatively small quantity of material in each Six10 tube is a limitation imposed by existing caulking guns.  Everybody has the same caulking gun in their toolbox, and the geometry of cramming resin, hardener, filler, and a static mixing device into a tube that fits everbody's caulking gun means that you just can't get another single ounce out of it.

In years past, we have tried other epoxy-in-a-tube schemes.  One involved two tandem tubes, yielding twice as much.  But this required a special expensive caulking gun, and the plumbing required to combine resin and hardener at the end of the tandem tubes resulted in a high failure rate.  

I'd like to see the large-size contractor caulking tubes turned into pre-mixed epoxy dispensers.  Those guns are more available and affordable.