Diesel Heater Exhaust Sealant

goeasy123

Active member
Joined
10 Nov 2018
Messages
705
Visit site
What's the best paste/product to seal the joint between the exhaust stub and the exhaust pipe on an Eberspacher diesel heater?
 

goeasy123

Active member
Joined
10 Nov 2018
Messages
705
Visit site
The HeatMate looks like the right thing. Is this similar to FireGum or similar products I could buy in a car parts shop?
 

Old Harry

Well-known member
Joined
29 Sep 2017
Messages
4,022
Visit site
The HeatMate looks like the right thing. Is this similar to FireGum or similar products I could buy in a car parts shop?
It is a flexible mastic, same as sanitary sealant but takes heat & remains flexible
its available on fleabay
 

goeasy123

Active member
Joined
10 Nov 2018
Messages
705
Visit site
Heatmate is good to 300C. I'm not sure that's enough for where the joint is... right on the exit of the flame chamber. What do you think?
 

lw395

Well-known member
Joined
16 May 2007
Messages
41,951
Visit site
It should not need a gap filling gunge.
Use parts that fit, a bit of copper grease and do it up properly.
 

goeasy123

Active member
Joined
10 Nov 2018
Messages
705
Visit site
It should not need a gap filling gunge.
Use parts that fit, a bit of copper grease and do it up properly.
Unfortunately, it's a bit of a crap design. Tube over tube with a nut welded on one side, through which you put a screw to clamp the items together. There's bound to be a gap.
 

Yngmar

Well-known member
Joined
6 Dec 2012
Messages
3,060
Location
Gone cruising
Visit site
Ours has the same (original Eberspächer) crap design as Andy's. I've previously used exhaust paste (such as Firegum) and while that initially worked, it didn't cope well with the vibrations from heater and/or boat and crumbled away slowly. So this time (new China heater - whole kit cheaper than the Eber parts would've been) I used a high temperature silicone sealant, which stays flexible.

Apply carefully and only over the exterior of the inside tube (the one you slide the other over), else you risk it forming a lip inside which restricts exhaust gas flow.

Example product link (I've used one from a Lidl sale, but essentially the same): 85G GREY HIGH TEMPERATURE SILICONE GASKET Heat Resistant Glue Adhesive Sealant 5906534001443 | eBay
 

goeasy123

Active member
Joined
10 Nov 2018
Messages
705
Visit site
Ours has the same (original Eberspächer) crap design as Andy's. I've previously used exhaust paste (such as Firegum) and while that initially worked, it didn't cope well with the vibrations from heater and/or boat and crumbled away slowly. So this time (new China heater - whole kit cheaper than the Eber parts would've been) I used a high temperature silicone sealant, which stays flexible.

Apply carefully and only over the exterior of the inside tube (the one you slide the other over), else you risk it forming a lip inside which restricts exhaust gas flow.

Example product link (I've used one from a Lidl sale, but essentially the same): 85G GREY HIGH TEMPERATURE SILICONE GASKET Heat Resistant Glue Adhesive Sealant 5906534001443 | eBay
This product is good to 350C. My guess is that the heat at the joint is much higher than that. How long has it held out for so far?
 
Top