Jul 17, 2024 #1 BFstr Structural Jul 20, 2009 54 Colleagues Anybody know what these marks might be? Are they black mold???? Thanks https://files.engineering.com/getfile.aspx?folder=c11c6c1f-35a5-4b21-bb87-74057dadcc3a&file=Black_marks_on_steel.pdf
Jul 17, 2024 #2 Heaviside1925 Mechanical Jun 7, 2024 431 OP, My first thought (if you hadn't said mold) would be soot marks from an oxyacetylene torch. Upvote 0 Downvote
Jul 17, 2024 #3 Tomfh Structural Feb 27, 2005 3,377 Water staining from when the beams were laid on site. Upvote 0 Downvote
Jul 17, 2024 Thread starter #4 BFstr Structural Jul 20, 2009 54 Tomfh (Structural), May I ask water makes "black stains"? I thought water makes rust brownish marks? Shall I do anything about it? Is it bad? Thanks Upvote 0 Downvote
Tomfh (Structural), May I ask water makes "black stains"? I thought water makes rust brownish marks? Shall I do anything about it? Is it bad? Thanks
Jul 17, 2024 #5 bones206 Structural Jun 22, 2007 1,950 I think it’s probably just dirty. These PEMB columns get transported on their sides and remain on their sides in lay down areas on site. Water can pool at a low point on the web and concentrate dirt in that area. Upvote 0 Downvote
I think it’s probably just dirty. These PEMB columns get transported on their sides and remain on their sides in lay down areas on site. Water can pool at a low point on the web and concentrate dirt in that area.
Jul 17, 2024 #6 RPGs Structural Oct 20, 2022 130 Try to clean it (your hand, a paper towel, a wire brush) and see if you have loss of corrosion protection or section. Upvote 0 Downvote
Try to clean it (your hand, a paper towel, a wire brush) and see if you have loss of corrosion protection or section.
