How do you repair a turret as engineer?

[JayTuut (not cat)]

aaaaaaa

[Hiroko]

bungus

[Banana Slamma]

Basically any healing item. Bustling Fungus (bungus, as it is known) is ideal because it creates a healing circle while standing still. Your turrets can’t move, so they are always healing. Just make sure to avoid the void equivalent (weeping fungus/wungus) as it will corrupt all of your bungus.

[Light0234]

you typically dont you have items for that

[Pizzarugi]

As other have said, Bustling Fungus is perhaps the most powerful healing item for turrets. You get enough of them coupled with things like Tougher Times, and you've got turrets that are invulnerable to all but the hardest 1shot hits.

In my experience as an e8 engi main, getting lucky to have one drop makes it too unreliable to depend on as you could go an entire cycle without seeing it. With every major update and DLC that gets added, the pool of white items grow more diluted, making it increasingly difficult obtaining this precious item. Decarbonizer turrets have become a better option as their ability to move around helps add a lot to their survivability.

That said, the new DLC might make that a lot easier with the rebirth pool. If you get lucky and find a bungus, you can sacrifice it into the pool and have immediate access to it in your next run. Though in retrospect, you'd probably be better off sacrificing a Lysate Cell. They're arguably a lot harder to obtain, and getting access to a third turret at game start could be a gamechanger.

[Fren]

Originally posted by JayTuut.ttv:

aaaaaaa

[Draconic Creature]

Any sort of healing items, on-hits that cascade a lot are very good for them because of the high firerate.

Also, mobile turrets are surprisingly capable too, you can't bungus or wungus them, but once you get some mobility items going they tend to last a lot longer during stressful situations than standard turrets because of how much they constantly move around, including strafing targets.
Definitely pair those with the engineer's harpoons if you have them, definitely the walking mines too.