Boiler insulation

kaowool is rated to higher temps, easier to deal with, and stays in a cohesive mass better. Kaowool may be stabilized by the addition of rigidizer.

Rockwool is, I think- a better insulator, works up to pretty good temps (also known as accoustical fire batts), sound dampening, and pretty darned cheap. It falls apart when you look at it wrong, so it can be a mess.

Of the 2, I'd use the kaowool for that, but is it a problem- I dunno. Are you sure it's not kaowool "board", rather than kaowool blanket?

This is like the baffle board in a wood stove. They use it for a target in some oil furnaces.

The fire is touching the 1" roll material, check this part #93315k74 at Mcmaster-carr it comes in a 1" x 24" x 25' roll between this and the skin is the 2" mineral wool this crumbles easy pn 9328k43 at Mcmaster-carr
when i replaced mine I ordered 10pcs of the 2" and 2 rolls of the 1" worked well with a bit to spare for $350 to my door.

J =)

welded SS hex head bolts to the inside of the skin.

Josh

I used the rock wool held on by bolts with fender washers screwed into nuts welded to the skin. Then used mechanics wire to criss cross between bolts. Worked very well, but as stated above....will fall apart is your not careful with it. Did my boiler for $68 with some left over.

I used the rock wool held on by bolts with fender washers screwed into nuts welded to the skin. Then used mechanics wire to criss cross between bolts. Worked very well, but as stated above….will fall apart is your not careful with it. Did my boiler for $68 with some left over.

so your top is single layer and 2" thick? is there much heat loss when its up to temp?

I have used kaowool inside my boiler with no problems. Last night I glued 1/2 board to the inside of my firebox door using gasket glue-crack sealer. the stuff even stays white inside the fire box.

Jroz said:

so your top is single layer and 2" thick? is there much heat loss when its up to temp?

Click to expand...

The material I have shown is 3" thick mounted to 3/16" top skin and you can hold your hand on the top when it's running full bore.