We've just had a quieter can fitted. However, now there is more resistance it's finding out the gaps up front! Between the headers and the collector is the main culprit. As the exhaust is semi-rigid any attempt to seal this joint using typical hardening exhaust cement simply pop's out upon contraction.

Is there such a thing as flexible exhaust sealer that can withstand the 600oC+ temperature at that part of the exhaust?

Second to that, it means mounting the rear of the exhaust can using a more flexible method...

Steve

The man who fabricated my system recommended the flex. silicone sealant used by central heating installers - suggested beer tokens to your local British Gas van man would resolve it. Can't say it will work as I haven't fired it up but he does everything incl. old F1 cars so knows a trick or two. Cheers, Pewe

Yep, silicone (bathroom type) sealant is the stuff to use. Pongs a bit tho!

Ive used bathroom silicon to seal back box to manifold (stainless system) but would be hesitant about using it further forward. Is it really Ok in high heat applications?

The "proper" exhaust silicone (at least the tube I was looking at) said it was good up to 360 degrees. Obviously different brands will probably say different temps...

I've found this product...

http://www.intek-uk.com/XTS320data.html

Possibly the highest temperature adhesive/sealer on the market and high very high percentage of Silicon so stable'ish at VHT... waiting for a price.

We've tried Silicon Bathroom Sealer - it just breaks down to a powder and drops off.

Steve

Think i've got some Silicone sealant in the Garage thats rated to 400 or even 600 DegC Called Plumba Flue, as the name would suggest for sealing flues

Thats stays as flexible as silicone and is good stuff, definately worth a try.

If thats not high enough there's Boiler Assembly mastic (not sure of a trade name and harder to get hold of) thats used imbetween the sections of Cast Iron Boilers to prevent combustion chamber gases leaking so thats even higher temps. Not sure how flexible that would remain.

The Plumba flue should be available at your local PlumbCentre etc but the boiler mastic may be harder to find.

i need some of this stuff too, along with a tig welder keep us posted!

I'm suprised at the bathrom silicon sealer not working as I use it all the time for sealing exhausts from the manifold down to the back box. I've used it on turbo's and bikes with no probs. It may be down to the different brands.....

can you remember which brands have worked for you and not turned to powder?

There is a wood burning stove showroom next to my work and the lads there use that plumaflue stuff when fitting woodburners, thats what i will be using on my exhaust too.

Just been out to the other Garage and found the PlumbaFlue, its rated to 300 Deg Max and 250 Deg Sustained Temperature.

There's also a substance called FJC Flue Jointing Compound thats rated to similar temperatures with a texture like putty but not sure how that holds up over time, just a little bit better than Fire Cement really for what we use it for.

I used some Dow Corning firestop 700 , it is used to fill gaps around fire doors etc and has a 4 hour fire rating in that application.It is a silicon type but never actually sets fully. It is sold bt RS components.
Paul.