I have seen cotton string used as steam line insulation and I have used some soft ceramic material on some of my stationary model steam lines and under the boiler lagging of all my models except Newbie which has wood lagging.. I should think cotton to be the string of choice and I am not stringing you along here, but I am all strung out now and going to bed. Jesse Reckon we'll have a hemp of a good time, Terry.... Anyone use string for boiler lagging and/or to wrap steam pipes on their models? If so, what kind? Cotton? Fiberglass? I think nylon would probably melt and really get strung out. See....we are back on topic.... Charles MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.