I know exactly how to weather that hammer, find some Orcs and get to bashing. Depending on what you want the outcome
to be there are a few ways to get the job done, first and easiest way is to .... ask Fred
Or you could do some drybrushing if you know how, i have used graphite (shaved pencil lead) and rubbed it on
if your looking for some blood i have used a paint brush and dipped it in paint and flicked it on to the weapon.
The handle is plastic i believe, a light sanding and new paint would be nice, a base coat of the color you want the handle to be
and then a wash of a darker color over that. And then before you try any of these suggestions , ask Fred

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Coose fraba, coose fraba...Goose Blah blah .... No no, not Goose Blah blah...cooooose fraba....