NOW what do they use?

[Firelock76]

Hey everybody, I've got a question.  Back in the old days asbestos was used as boiler insulation (i.e. "lagging")  in steam locomotives.  Since asbestos is dangerous stuff what's used now for insulation, especially in restorations?  Anyone know?

[wholeman]

I'm no expert on asbestos but, as far as I know it is still legal for it's use in certain applications. I know someone will correct me on here, but that's ok. The only regulations officially is working around it. Many brake pads and shoes no longer use it.

[selector]

In the video showing the restoration of CPR Hudson #2816, they do show the crew chief/supervisor using what is clearly a very sharp filleting knife, or something like it, to trim what appear to be maybe 2" thick dense fiberglass batten panels.

I have no recollection of the narrator actually saying what they were...perhaps I should take a look again.

[SD70M-2Dude]

That's exactly what we use for CN 1392 at the Alberta Railway Museum, I'm not aware of anything asbestos is legal for in Canada, but then again I've never checked.

[daveklepper]

Fiberglass is widely used for both thermal insulation and sound-absorption and is not toxic in any way.  There are also polyeurathane products that can provide excellent heat insulation and are not toxic, but they may melt with too mch heat.

[Firelock76]

Thanks all for your responses!  I suspected fiberglass insulation might be used, but something a bit more rugged than the stuff we put in our attics.

Thanks again!

[daveklepper]

Yes, Fiberglass is made  in varying densities, the lightest used for insulation between inner and outer walls on aircraft, and the most dense to provide sound and vibration isoilation in floor-ceiling structures, such as a concert hall located over a railrroad tunnel (Seattle's Benaroya Hall is one example, and cirtain hall near the IRT at Lincoln Center, Manhatan, are others) or over a rehearsal room, using what is called a "floating concrete slab."  But all densities provide thermal  insulation, and the degree depends on thickness and what structure is on each side.  In the case of the "floated slab" the Fiberglass actually provides the structural support in many cases, and in others it is supplemented by srpings.

[Harwit]

Hmm, if the insulation was cut with a bread knife, that would be mineral wool.  I used it at home for heat and sound insulation.  The brand name was Roxul.  This grey stuff is more rigid than the pink or yellow fibreglass stuff and will not melt when in contact with flame.  Not as itchy to work with too.