New to fireplaces and worried I cleaned incorrectly

[Jodamuto]

Hello, I started using a fireplace in my home that I bought a few years ago. It is a superior b1038. It has a grate on the top and bottom of the fireplace. I looked behind the top grate and saw probably decades of dust. So I removed the grate to clear it out. In addition I dusted the top of the firebox which has a rectangular-pyramid shape also accessible from behind the grate.

When the dust came off its was pretty clean metal underneath. I am pretty sure it was just dust/soot but I am also slightly worried I may have swiped away some type of insulation. I didn't do any heavy cleaning on it, just a light dusting.

Is it normal for metal to be exposed like this? Is there even such thing as a "dust insulation"?

Sorry if it seems like a silly question, just want to make sure my fireplace is still safe. I can't find any documentation online for this brand/model fireplace.

Pictures included is of the exterior of the top of the firebox as seen through the opened top grate.

Thank you.

 

[begreen]

It looks like the top of the firebox should be exposed as a convective heat exchanger so I wouldn't expect it to be insulated. There should be a grille in front that normally hides this area.

 

[TomMcDonald]

The first picture shows what looks like insulation up above where the chimney goes.

Are you sure that top plate is metal? Looks more like some type of fibre board from the pictures.

 

[Jodamuto]

It looks like the top of the firebox should be exposed as a convective heat exchanger so I wouldn't expect it to be insulated. There should be a grille in front that normally hides this area.

Thanks that makes sense, yes there is a grille that covers it

 

[Jodamuto]

The first picture shows what looks like insulation up above where the chimney goes.

Are you sure that top plate is metal? Looks more like some type of fibre board from the pictures.

Yes there is insulation that goes where the chimney.

I think it is metal, but I could be mistaken. it's still just a little dirty since I did a light dusting. The main reason I was concerned because the dust/soot was so evenly spread, and since some remained that wouldn't come off, I got a little worried that maybe it was purposefully applied.