The whole "detonating a fireball in an enclosed space" thing was a concern of mine also, and why i suggested a metal firing chamber. Apparently though, we are already doing so with the boilers, so it should be fine.
The boilers boil. We essencially use pressure cannons combined with combustion cannons. It is somewhere in between the two. And, of course, both are fundamentally pressure cannons, just with different attitudes to pressure generation. I absolutely agree tht it would be more powerful if we could do it, but I see no reason to believe that things havr improved that much since we were having issues with pressure cannons exploding. Ehh, regeneration is a big step, they won't develope progressive weakness, but still, it is a lot to ask to go from a boiler-sized combustion chamber to a gun-sized combustion chamber. I expect that we are already at the limit of what our materials can reliably withstand, so we will not gain any power without something exploding. Though I am willing to concedet hat I may have been a little overzealous at removing the steam. It is a big risk as we are gaining a lot from the large steam chamber, but it is not impossible that removing it might reduce power consumption with no appreciable downsides.
Also, we do not "summon the crystal over air" we replace/displace the air with crystal, attempting to summon crystal over steel would simply result in a crystal jacket. By definition, you can't form an alloy with crystal. Crystal is heavily reliant on structure, and an alloy is changing the structure.
We know that our wasps do not explode, so we know that some re/dis-placement occurs, but they do not expel unnatural gasses either. Therefore it stands to reason that the gasous content is what was there originally. The crystal is light because it has a low density, it should be possible to have a crystal grow around another material, even at the elemental level. Certainly not an alloy, a crystal alloy is an obviously ridiculous concept, but using magic to force the crystal to grow into a dense material ought to be plausible and ought to result in a version of the crystal that loses its low weight but gains compression-resistance. It is rather absurd an idea, but seems well within the bounds of magic to my mind.
I feel like you just disagree with CW designs on principal now.
Nom it is just the constant stream of nonsense that the poor G.M. has to translate into a working concept. Like calling my crystal-gorwn-through-metal thing an alloy. C.W. insisted that creating an alloy was too difficult, I insisted that comaring it to an alloy was ridiculous and C.W. insisted that it was very definitely an alloy and was very definiately allow-level difficult even though alloys are dificult because you need to get the measurments and cnditions right and if you just get the crystal to grow through a material then there are no measuments or conditions.
And we get crystalworks that are an assembly line to improve the production of things that come into being fully formed from a single act. Fortunately we ended up with three-dimensional printing instead of an assembly line and so it would actually work and be of benefit rather than just sending 5 wizards to do a job that one could do.
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This is what I have to deal with, this is where "Crystal alloy" came from.
It is just combiningthe two, in a fashion that is plausible. We have never explained what happens to whatever is in the place that a summoned thing is summoned into. This just places something other than air where the crystal is summoned and has the crystal summoned around it. Normally this would just be heavy crystals, as lead doesn't really do anything to improve crystal other than maybe increase its shock resistance, but in a very very much less weight-efficient way than you would get from just adding more crystal. What it does achieve, however, is making the lead rigid until it impacts, which is pretty much the only thing that matters. Hardness is basically irrelevant in such forces and structure generally loses out to things like blast-waves. This just holds a liead-projectile's form so that it all piles onto a single point instead of behaving like a liquid and spreading out.
You want to make a crystal-lead alloy.
We have never done anything like this before. At best this is a revision of its own. You're seeking insane overcomplication here and I frankly don't know why.
Spontaneously we have, from nowhere, that it is an alloy, and that alloys are hard to do. It is not an alloy, and it either works or id doesn't. Possibly it takes more power to get it to summon in a dense environment. Maybe it even requires a special magic to overcome the material's presence. Maybe it just doesn't work and we are left with a lump of normal lead that still would have worked well enough and we would have learned something. But no, apparently I am making the mystical lead-crystal alloy that is so difficult instead of just making a simple mass increase to our existing crystals by summoning them into a high-density environment and letting their low-density nature be filled in.
C.,W. just has a gift for adding bizarre things that obviously won't work. In this instance we put a lot of effort into making the steam work and now it is being removed. It certainly could work, this is not a particularly unworkable idea, it is just that what is holding us back right now is materials, also, a fireball requires a lot more magic than the current ammunition provides so we are obviously looking at a greatly reduced spell in there, Which means that it is developing an entirely new fireball spell. Now this idea could actually work. It will do nothing about the airships which will murder us next turn, but it would actually do what is advertised, which is more than can be said for some of the other ones.