+Spoo Posted September 5, 2005 Share Posted September 5, 2005 Today, I went looking for two Mountain top Triangulation Stations and an associated Azimuth Mark. (Found all three.....YAYYYYY!) I have found many brass, copper and bronze marks......no known aluminum or Titanium.......but what is this disk material? OC2706 It is very black and I do not think the black is associated with age. Could it be Anodized Aluminum or a form of Black Oxide finish? Just curious. Quote Link to comment
Z15 Posted September 5, 2005 Share Posted September 5, 2005 (edited) Tarnished brass. I have seen them turn dark like this. That style disk came on the scene earyly 70's. Edited September 5, 2005 by Z15 Quote Link to comment
evenfall Posted September 5, 2005 Share Posted September 5, 2005 I will second Mike's Tarnished Brass comments. There are a number in the Seattle area, Vintage 1973 than look just as tarnished. Rob Quote Link to comment
mloser Posted September 6, 2005 Share Posted September 6, 2005 I will third the tarnished brass comments. I have seen a number like this--often older USGS ones on the sides of buildings. Matt Quote Link to comment
2oldfarts (the rockhounders) Posted September 6, 2005 Share Posted September 6, 2005 Spoo They are all wrong! It is algae staining on the disk. Did you notice all around the disk on the rock is fungi and therefore that MUST be what is causing the coloration.... John It's a joke son, it's only a joke! Quote Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.