The performance art exhibit in Bethnal Green, east London, has been a year in the making, but recent events have lent a certain poignancy to the gradual erosion of Her Majesty's face.
"We're not going to smash the state," remarked Mr Stawman, 29, continuing to tap while looking up from his work. "The way it's going to go is drip, drip, tap, tap. It's that feeling of it disappearing. I don't think it's going to be like the Bastille, it's going to be more like this."
The hammer just happens to be By Royal Appointment and the floor painted red (as in carpet), but there is, apparently, much more to this solo performance than a simple comment on the Queen. The work is entitled Pecu, as in the root of pecuniary and peculiar, the European currency plus a "P". It is, in Mr Stawman's words, a "peculiar, pecuniary performance".
Visitors to the disused belt factory, where Mr Stawman has been hammering away in the squat position for 16 hours a day for the past nine days, have paid their pounds 1 entry fee and then watched their coins dented and mashed along with the rest. "What is this?" they ask. "A remark on the meaning of money, of art, of what?"
Mr Stawman mentions Black Wednesday and makes a few suggestions. "What is money? The quidity of a quid, the essence of a pound, the crashing of the pound? ... It's about spending all your time working for virtually nothing ... It's about artists in their studios doing their stuff - for love, not for money ... If you so wish, you could see it as anti-contemporary art."
Some people have found the solo performance harrowing. Although Mr Stawman, looking part-monk, part-prisoner, has developed a repertoire of swings, strokes and swipes, the monotony of his work has got to them. "They've just found it too much," he said. "They think: `He's doing this all the time. Is he mad? They've scarpered pretty sharpish."
Perhaps it takes a fellow artist to appreciate the exhibit. For when Phillip Harvey, a 31-year-old painter, entered the room, he was enthralled. "When I do things many, many times, patterns emerge," he began. "It's about process. The way things start to coalesce and have a certain logic. Bridget Riley said the secret to art is in the materials."
For Mr Stawman himself, the hammering has been an "empowering" experience. Over the course of the week, he has changed his attitude to money. He says he feels "much lighter" towards it now.
And what of the defaced coins? He has not quite decided whether to bury them or keep them, but is edging towards the latter option. "Maybe they'll take on a value as an art commodity," he debated. "Yeah, that would be handy."