High temperature mastic

[monkeyhanger]

I have a Kabola E5 diesel boiler, and where the flue joins the main body the fire cement fillet has cracked and is loose. Do I just replace the fire cement fillet, or is there a better substance I could use?

[mrsmelly]

2 minutes ago, monkeyhanger said:

I have a Kabola E5 diesel boiler, and where the flue joins the main body the fire cement fillet has cracked and is loose. Do I just replace the fire cement fillet, or is there a better substance I could use?

Envirograf silicone comes in a tube. Great product. 1250 degrees.

Edited November 20, 2020 by mrsmelly

[BEngo]

If it is a big gap, say over about 8 mm, pack it  with fire rope then Envirograf on top.

 

N

[monkeyhanger]

28 minutes ago, mrsmelly said:

Envirograf silicone comes in a tube. Great product. 1250 degrees.

I've found  Mapei Mapeflex Firestop 1200 degree mastic at Screwfix. Do you have any experience of that product, please? I have a branch of Screwfix nearby.

[mrsmelly]

5 minutes ago, monkeyhanger said:

I've found  Mapei Mapeflex Firestop 1200 degree mastic at Screwfix. Do you have any experience of that product, please? I have a branch of Screwfix nearby.

Not personaly but that should do the job handsomely. It will flex ad never crack a once only job. Fire cement is deffo a thing of the past boat wise.

[monkeyhanger]

20 minutes ago, mrsmelly said:

Not personaly but that should do the job handsomely. It will flex ad never crack a once only job. Fire cement is deffo a thing of the past boat wise.

That's great. I'll get some of that Mapei stuff. Thanks to everyone who helped.

[mrsmelly]

2 minutes ago, monkeyhanger said:

That's great. I'll get some of that Mapei stuff. Thanks to everyone who helped.

Having just read the bumff on that one whilst it does say accomodates movement I would check wether it is as flexible as the high temp silicones which are ideal for boats.

[BEngo]

The blurb describes it as making a rigid seal.  Several of the reviews report similar and one says it is more like cement than silicone.  Another suggests it is like grout.

 

  I would stick to Envirograf.

 

That said, my Squirrel is sealed with Plumbaflue and that is lasting well.

 

N

 

[Sea Dog]

https://smile.amazon.co.uk/dp/B00OOO7PUG/ref=cm_sw_r_cp_awdb_imm_t1_UpaUFb0MX0SV5

 

£12.90 delivered from Amazon if you get stuck.

 

That said, if you get stuck just ordering sticky stuff, you need to get someone else to do the job... 

[Richard10002]

Just a bit of a warning regarding Envirograf. I've used it successfully on my stove/flue joint twice now in 9 years.

 

On both occasions, the first time I lit the fire, (after a few days for the stuff to cure), the boat filled with smoke/fumes. The first time, me and the dog were taken by surprise, but got out pretty quick. The second time I was prepared so lit the firelighter, shut the door, and made a sharp exit.

 

Be prepared.

[Mad Harold]

I used exhaust putty to seal the flue joint on my old boat.I think it was Hylomar.

It does set hard,but it was done some three years ago and still seems ok.

[Ex Brummie]

Pad the joint out with rope, then cover off with Purimachos Flue Jointing Compound. Stays firm but flexible.