I have 2 year old solomon spks and I've cracked it on the toe. Boot still works fine but could blow up on me anytime now, I'm thinking of using jb plastic weld, any other glues or adhesive you think may work?
"your jackets too long, how can you even ride?"
- Unknown Gaper
Sadly this. Take them back to the shop you bought them from (or to an authorized Salomon dealer along with your receipt) and see if they can warranty them for you. Those boots have a 2-year warranty from purchase date, so it really depends on when you exactly bought the boots.
Don't try that. You will for sure void any warranty and potentially ruin the boots further and make them even less safe to ride.
If they are less then 2 years old and you got them new, take them to a salomon dealer and see about a warranty. If they are out of warranty start researching bootfitters around you so you can find the best place to get fitted next time.
With a crack at the shell overlap (which is common with boots) you can do this. But the OP said he has a crack at the toe. A crack in this area is quite the problem as tons of forces are put on the boot in this area. If the crack is at the toe on the main shell drilling a hole might stop the crack from spreading in one direction, but the boot may still catastrophically fail. If Salomon will not warranty the boots, the best bet is to replace the boot rather than risk serious injury.
Riding a ski boot that is cracked at the toe (aka, flexes at the contact points of my binding/knee preserving system) would make me very very nervous. You aren't taping pants to keep water out, that's what keeps you locked/unlocked to that ski as a function of your DIN.
Take this advice with a grain of salt but I rode a whole season with a 1/4 inch crack in my toepiece that you could see the liner of my boot through. Not the best plan for certain but I used it as a viable option (note: no shop will demo or rent you skis if you do this though).