Fire cement recommendations

[antdad]

I've tried most, is there anything out there that's just a little more elastic and can handle thermal expansion.

 

[SimonG]

High temp silicone.

 

[antdad]

That's only rated at 300 degrees max isn't it?

 

[kris]

Here .

http://www.google.co.uk/aclk?sa=l&a...z-cYCFWNw2wodqV0Iig&ei=IiS1Va6PHOPg7Qapu6HQCA

 

[kris]

So is that one . But u do get higher .

 

[SimonG]

Aye 300. What you sealing?

 

[antdad]

Solid flue of multifuel stove.

You think HT silicone would survive(Optimum op temp 150 - 250 deg C)?

Gives me an idea though, use a mix HT silicone with fire cement.

 

[SimonG]

Dont think the silicone would last on its own tbh.

 

[lame plumber]

Solid flue of multifuel stove.

You think HT silicone would survive(Optimum op temp 150 - 250 deg C)?

Gives me an idea though, use a mix HT silicone with fire cement.

stick with the fire cement, been fine for the last 50 years or so.

 

[Best]

No don't use heat resist silicone. I find it won't even last on standard efficiency oil boiler flues near the boiler- it just falls to bits eventually.
There are better quality fire cements, but not sure what they are. Most seem to crack eventually. It might be possible to add fine mica well mixed into the fire cement.
It is just one of those things to be redone every year or two on the wider joints, like at top of stove. Give the area a soak with water before you apply the fire cement, as that makes it last longer.

 

[newcastle phill]

Have you tried ready made stuff from screwfix. Cheap as chips. Easy to apply. Never had a problem with it but i havent managed to raise the temp of the houses ive worked in to 300 degrees yet [emoji12]

 

[antdad]

Thanks for replies.

Yes usually use that and leave to dry for a week before lighting anything.

This stove flue is rear entry (rather than straight out the top) so I have more joints than usual and as Best says it's something I usually have to redo every couple of years or so because it always cracks eventually but I'd rather not.

Might try adding some lime to the fire cement, it may have the same effect as it does to cement render.

 

[kris]

Here are sealants made for stoves @ 1250degrees

https://www.woodburningstovesandflu...-p-281?zenid=85459c94df1c49ebcbb67e8979b98da6

 

[lame plumber]

Thanks for replies.

Yes usually use that and leave to dry for a week before lighting anything.

This stove flue is rear entry (rather than straight out the top) so I have more joints than usual and as Best says it's something I usually have to redo every couple of years or so because it always cracks eventually but I'd rather not.

Might try adding some lime to the fire cement, it may have the same effect as it does to cement render.

lime and sand gives a soft porous mortar, not what you want with a flue joint really, dont think the manufacturers would support you when the lounge contents dont wake up!

 

[antdad]

Exhaust paste?

 

[lame plumber]

Exhaust paste?

not using it for its proper purpose, be it on your own head

 

[Roger Welton]

KOS fire cement for me, seems to go one more nicely than the cheaper stuff.

 

[LaMont5way]

Another vote for KOS, didn't know people used anything else.

 

[antdad]

Thanks...KOS looks good, it has some plastic in it so I hope it's less likely to crack.

 

[Geyser]

Vitcas range. I used outdoor oven cement which was left over. Didnt swell, crack and good to 1250c I think. Ready mix powder so mix as you need it, no more gone off pots of fire cement in van. I'm going to try others in range to test.

 

[wetdrip]

Heat Resistant Plaster, Fire Bricks & Cement | VITCAS

Vitcas Fire Cement-Ready Mixed Rated to 1250ºC. For patching and repair fire bricks, fireplaces, solid fuel ovens, range cookers, boilers and central heating systems. Colour: Buff / Grey

Or
http://shop.vitcas.com/vitcas-heatproof-mortar-10kg-19-p.asp