High temp silicone wont adhere to stainless

3650

Minister of Fire
May 8, 2011
669
midwest
A few days ago i put a storm gaurd on my flashing for my stainless double wall. I went up to look at it this morning and it had completely delaminated from the stainless chimney. It was well adhered to the galvanized storm collar. I re applied a bead under the collar and slid it down over the bead then laid another bead over it. Ill check it tomorrow and see what i have.

The brand is Meecos rated for 500 degrees. Its all that is available locally. Hope it works this time. Cant understand why it wouldnt stick to stainless. I thought silicone sticks to anything.
 

begreen

Mooderator
Staff member
Nov 18, 2005
84,325
South Puget Sound, WA
No need for high temp in that location. I think that Meeco's is more of a sealant than adhesive. Regular silicone is ok. Choose one with good adhesive qualities and meant for outdoor use. GE Silicone II window/door is good stuff. Wipe down with alcohol first if there is any oil on the pipe or flashing.

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Last edited:

brenndatomu

Minister of Fire
Aug 21, 2013
5,399
NE Ohio
Wipe down with alcohol first if there is any oil on the pipe or flashing.
I bet that was it...I have learned to wipe down almost everything that I'm going to glue/seal...much higher success rate.
 

begreen

Mooderator
Staff member
Nov 18, 2005
84,325
South Puget Sound, WA
I bet that was it...I have learned to wipe down almost everything that I'm going to glue/seal...much higher success rate.
Same for stove painting too. FWIW, I have been impressed by the bonding strength of GE Silicone II.
 

brenndatomu

Minister of Fire
Aug 21, 2013
5,399
NE Ohio
Same for stove painting too. FWIW, I have been impressed by the bonding strength of GE Silicone II.
Definitely…most painting is all about the prep work
 

LONDONDERRY

Member
May 23, 2008
133
New Hampshire
Wipe down the substrate with IPA to remove all oil or dirt. Most of the run of a mill adhesives at hardware stores have a temperature threshold of 500 degrees.. beyond that and you're into specialty adhesives.
 

begreen

Mooderator
Staff member
Nov 18, 2005
84,325
South Puget Sound, WA
Wipe down the substrate with IPA to remove all oil or dirt. Most of the run of a mill adhesives at hardware stores have a temperature threshold of 500 degrees.. beyond that and you're into specialty adhesives.
Make that most silicone adhesives. There are many others (latex, polyurethane) that would not be appropriate due to lower service temps.
 

Highbeam

Minister of Fire
Dec 28, 2006
17,681
Mt. Rainier Foothills, WA
Oh and I recommend clear silicone for the Stainless chimney. I thought grey would look better but it doesn't.
 

begreen

Mooderator
Staff member
Nov 18, 2005
84,325
South Puget Sound, WA
Yes, clear, with good UV resistance and strong adhesion. I looked at our flashing after 15 yrs and it looked good.