[Though there are no halos around any of the tacks, the screws holding the keel on were about half-length, corroded away, with almost nothing left of the cone washers.]
The above is a quote from the post I made on 11 Aug regarding OT 20147. Weeks later the little lightbulb flashed on with this thought: "No zinc, no dezincification". The original tacks used to build OT 20147 in 1912 have a very dark red appearance, closer to silicon bronze than to the bright golden brass canoe tacks we use now, and those old tacks are just as solid as they were 100 years ago. So what was the composition of the tacks that Old Town was using in 1912? Just copper, copper/arsenic brass, some other brass alloy lacking zinc? And those screws which had been used to hold the keel on must have been a copper/zinc alloy, and so were badly decomposed. Any other thoughts? Tom McCloud
The above is a quote from the post I made on 11 Aug regarding OT 20147. Weeks later the little lightbulb flashed on with this thought: "No zinc, no dezincification". The original tacks used to build OT 20147 in 1912 have a very dark red appearance, closer to silicon bronze than to the bright golden brass canoe tacks we use now, and those old tacks are just as solid as they were 100 years ago. So what was the composition of the tacks that Old Town was using in 1912? Just copper, copper/arsenic brass, some other brass alloy lacking zinc? And those screws which had been used to hold the keel on must have been a copper/zinc alloy, and so were badly decomposed. Any other thoughts? Tom McCloud