Description of the issue:

2 Immersive Engineerers Hammers can be duped into nearly infinite hammer when combining them in a crafting table.
The 2 original Hammers use up durability and create a new one.
This has been Tested on an Instance with just IE

Versions & Modlist

IE Version: ImmersiveEngineering-1.18.2-8.0.2-149.jar
Forge: 40.1.52

Additional Information

This has been reported to the FTB Modpack Issue tracker:
FTBTeam/FTB-Modpack-Issues#1004

Probably just an oversight on my part, feel free to toss it

@BluSunrize do you remember where isRepairable came from in 990c06e? From a quick search that's only used by the vanilla repair recipe (which is what causes this issue) and the grindstone, while your commit was about the anvil. We have our own impl of repair recipes that doesn't have this issue, but with that method implemented on the hammer the vanilla reicpe also matches and it's essentially random (hash map iteration order, I think) which one is used.