Old timer at the hall told me he tacks a strip of soapstone to his hard hat, and I've been lacing mine wrong for 6 years
Talked to him for 20 minutes at the union hall in Gary last Thursday and he said a chalk line on the shell beats soapstone every time for layout, so what's your go to for marking tube sheets?
That trick with the chalk line works even better if you snap it right on the tube sheet itself before you drill, then you got your grid locked in and you just wipe it off with a rag when the layout is done. I keep a small chalk box in my bucket with blue chalk for that, since the blue shows up good on the cold rolled but won't leave a stain like red does. Only thing to watch is a wet tube sheet, chalk won't grab worth a damn, so dry it off first or you're just smearing lines around.