Walt, I would choose to avoid fibreglass mat or cloth because:
1. It is difficult to cut accurately to small sizes and then it tends to pull apart. 2. It is difficult to handle and work a sheet of it without it changing shape and dimensions (as it pulls apart). 3. I have read that the fibreglass cloth meant for fibreglass/resin lamination (grp) is pretreated with materials to improve its adhesion to polyester resins (flammability?) 4. It produces nasty glass thread particulates (shards). Midwest provides a piece of fibreglass mat in its steam engine kit for boiler insulation. The yellow color and texture appears similar to kitchen stove insulation. I have used 1/32 birch plywood between the boiler and jacket on my RH Billy kit. I soaked it in water, formed it around a tin can, and let it dry. I don't know how much insulation it provides. It probably should be called a liner that backs up the thin boiler jacket. I am currently building a vertical boiler and using sheet insulation (ceramic?) from Sulphur Springs. The material is easy to form, cuts easily, and is dimensionally stable. It does appear that it would break down easily if subject to abraision, tensile, or shear forces. Steve -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] Sent: Wednesday, October 02, 2002 10:07 AM To: Multiple recipients of sslivesteam Subject: Re: boiler insulation Hi, Could Fibreglass (woven or matting) as used in boat building be used as lagging? Keep your steam up! Walt
