The Steamboating Forum

what is the hard fiberglass like white stuff on the receiver?

I am curious too.... Got a link for where that pic came from?

Cheers
Scott

Steamboat Midship

I assume this is typical insulation covering used by many of us. Piping insulation, using ordinary pre-formed pipe insulation, or ordinary fiberglass home insulation bats, applied at about 1 inch thickness.

The outer covering is cotton fabric, saturated with Plaster of Paris, the same as medical casts of decades ago. Cotton strips about 2 inches x 30 inches are soaked with wet Plaster of Paris, and wrapped around the insulation. The stuff hardens rather quickly, only about 2 minutes working time from wetting the Plaster of Paris until the wrap is in place. Do not use polyester blended cloth, use only pure cotton. Good idea to put some guard plastic sheeting around when doing this job, it gets pretty messy, but works well.

The white surface can be left as is, or painted.

I don't think its plaster, I recently saw it on someone's engine and it feels like plastic

Might it be regular insulation wrap coated with something like what used to be called Arabol? Arabol was a milk-derived heat resistant lagging adhesive used back when pipes were covered with asbestos. I suppose when the asbestos went south, so did Arabol. It was made by Borden's Dairy Co. They no longer make it and nobody has found a replacement for its use with "yellow jacket" as a deck covering which was a popular home remedy for leaking decks on workboats maybe thirty to forty years ago. It was very similar to another product they made, a white glue called "Elmer's Glue." I suspect it contained tributyl tin oxide to retard mold and mildew and so was outlawed by our friends at the EPA. There are, I believe, similar high-temperature lagging adhesives available today that look much the same.

I've used mobile home rubber roof coating as lagging cement with good results. Easy to find, repels water and is reasonably heat resistant.

- Bart