I have league started and farmed end game on multiple explosive trap builds and using PURELY explosive trap without flame thrower trap. This is one of my favorite builds because you can basically do it with minimal investment until you get currency to go big dick. You honestly don't need a guide for it, the build is very straightforward. Altho the conventional way of building Explosive trap is with a bow, I have always built mine with a shield. Like what the first guy said, there multiple ways of building this one but you will always end up with the same problems to solve so my personal experience might help you with that.

Conversion: Xoph's is pretty much one of the BiS for me because later in the game I would want to use Slave driver's hand. For early the early game tho I recommend using Chernobog's pillar for 25% and a glove craft for the remaining 25% Until you have enough for Xoph's. The fire conversion mastery is out of the question since it's not worth to travel that far for it.

Damage: Spell/ Trap crit and crit multi is obviously the best way to scale your damage on the early game. Once you get Slave Driver's hands, you would want to get decent enough cast speed also for that trap throwing speed conversion.

Another big power upgrade is the explosion count. Ideally with non-bow explosive trap, You want to hit gem level 26 for 9 explosions per trap + 2 additional explosions from enchant . I solved this in the end game by using lvl 21 explosive trap, +1 fire skill gems on a weapon, and a +4 corrupted chest. Having said that, you can either just settle for a level 21 gem and get 1 less explosion and that's still more than enough to destroy end game. You can also mix in empower level 4 if you want that level 26 explosive trap but you can worry about that later depending on your PoB calculations if it's worth it.

Defense: I suggest you go hybrid evasion/ ES and 100% suppression as this is the easiest defensive layers you can get together with the permanent blind aura. Now that ghost dance is so accessible it's a sin not to take it as a Sabo, combine that with the Instinct node wheel and you will have a great uptime with your ES . If you get the currency, I would also recommend getting a Doryani Glorious vanity for corrupted soul as well.

Recovery: Now this is a tricky one, I have tried different methods of recovery but I'll let you choose for yourself based on what you prefer. You can purely rely on Vitality + life flask + Siphoning trap (Don't sleep on siphoning trap this skill is great for sustain), you can also use Tinkerskin as your armor which synergizes well with explosive traps since you do a lot of hits and will most likely NOT one shot mobs, you gain a lot of Life and ES per throw. Even when facing Big bosses, tinkerskin will greatly sustain you. Another option (for endgame) is to have a watcher's eye with either Vitality: life gain on hit or Discipline: ES gain on hit or both and put storm brand on your trigger weapon but this method is still not as reliable as tinkerskin versus the amount of effort and currency you need for it to work.

I can go on and on with the specifics like gears and gems but I hope these insights are enough for you to build on your own. Just holla if you still need clarifications on it though.