You have a bunch of high tier ascended Ashbreakers you don't know what to do with? Here's a build to put them to use.

Incendiary and double Amplified Burning will get the most damage out of them. (Unless you want to use them on Schooner, in which case go for Combustion and Amplified Explosive)

Little Grace III with Machinist Table (Repair) I provides survivability. Add Empower for even more damage, Fix for more healing and Restorative so you don't have to worry about severe damage.

When it comes to furniture, Wyrm's Breath Churner provides a nice damage boost that's always there. Bombard Menuiserie I is also just a great damage boost that's a pretty much must have when your main damage is bombards, and so is Bombard Works I. Because this build will also have pretty good uptime on burning the enemy, it'll also get good value from Gunpowder Bench I and into the last slot we can toss Devil's Concoction for a bit more damage. Feel free to change this one with other furnitures of your liking though, for example with Beam Supports if you find yourself needing a bit more survivability.

Armor depends on your playstyle.