There is no permanent fix for a cracked block except replacement.
There are some things that will get you some extra time, but due to the pressure and vibration of an engine nothing lasts and more time causes even more damage.
Sometimes. It depends on how large the crack is. There are much better sealers than liquid glass. Glass isn't used much any more and can be very hard to find. If you choose this type of "TEMPORARY" repair I would get one labeled "Block Sealer" as they seem to work best.
One way to fix a crack in a glass globe is to bring it to a glass blower. It may be fixable that way. However if the crack is too big or deep, it may be better to simply purchase a new one.
A surfboard should stay waterproof until you crack the glass. If you do crack the glass, then there are quick and cheap ways to fix it.
only if crack under 6 inches
The repair is most likely more money than the car is worth, you need a new engine block.
If the crack is weeping water (crack is next to water jacket) you could try temp fix products like chemiweld or irontite
It can be done but unless the block is rare or an antique, it isn't worth it. Buy a new or good used block to replace the cracked one.
As long as you let it. It will not fix itself. I'm not sure this was your complete question.
this is a sign of a major problem you either have a cracked head or block or a blown head gasket. there is a product called liquid glass you can use to fix this but bear in mind this is a tempoary fix at best. However, check the water pump blades to see if they may have cut a circular hole leading water into your engine, depending on the design of the assembly. It may not be noticeable at first unless you thoroughly inspect areas wherever possible. A crack in the engine block is rare by the way.
I'm not sure, but I have a cracked corner on a glass block that I plan to use clear epoxy to fix. I will let you know how that works!
Your best bet is to FIX the leak. You are asking for real trouble if you add liquid glass. It will coat the sensors and they will not work properly.
Depends on where it is cracked. If it is a small crack, J.B. Weld, found at any hardware store, can be used as a quick and temparary fix. Otherwise it would be better to get a new block altogether.