Can i use furnace sealant to replace a gas heater firebox sealant

matthew_rogers

quick feedback wanted.
i just cleaned the burner tubes in my gas heater
i removed the back hatch and slightly weakened the back firewall calking while removing a stubborn screw.
(this firewall piece is abt 6"x8" and soft: resembling soft kaowool and the color of firebrick)

there was a white sealant applied to the top of this small pad
this sealant insured a tight seal between the top of the pad and the base of the metal radiator sections.
this white sealant was loose when i first noticed it, and fell off as i removed the back plate.

i have furnace sealant on hand (black) but i know its 2000 degree rated and hard curing.
i figured the hard sealant that has fallen off (white colored) was essentially the same material.

i am about to:
#1 put a bead of my black furnace sealant on the firewall pad to replicate the pre-existing white sealant.
#2 i will slide it up to meet the radiator and screw the back plate back on.
#3 I will let it air dry 1hr
#4 and then fire up the heater.

am i making a decent 1:1 fix? (temperature is dropping here in MA)

matthew_rogers

i went ahead with the sealant patch, a Plumber/Heating contractor looked at it, shrugged and said it was fine. I'd prefer a bit more chemistry in his shrug.

does anyone know what sort of MSDS i could pull to identify the compound used to seal the seams in a forced hot water boiler?

I will then compare it to the furnace sealant i used to seam my boiler.

Tim McElwain

Go to a plumbing and heating supply and bring what ever you used and ask them if it is acceptable for what you did. That is for your sake the simplest approach.

matthew_rogers

thanks, will do

matthew_rogers

only feedback i get from all plumbers and vendors is a shrug.

firebox is tight now and sealant is hard.

specs on the product i used did specify ratings for repairing fireboxes and the like.

besides its just functioning as a tiny bit of air sealant (2000 degree caulking)

Tim McElwain

What is the exact information on what you used and I will look it up for you as to application. Need manufacturer name and perhaps a picture of the tube, can etc.

matthew_rogers

Tim McElwain said:

What is the exact information on what you used and I will look it up for you as to application. Need manufacturer name and perhaps a picture of the tube, can etc.

product i used:
rutland furnace cement
upc: 022624000655
product name: No65

outer frame is nice and cool for last couple days since i introduced this product to replace the cracked/loose/missing material.

Tim McElwain

Furnace cement does not work well with high temps it will dry out and you will have the same problem. You need a refractory cement for what you did.