High-temperature penetrating sealant?

[Grifter]

I've got a leak from the exhaust of my engine, from a collar between two muffler boxes that has been welded in the past. The weld is bad - just little patches of pigeon **** - but I can't really grind and re-weld as there's no space, and don't have suitable power. So... 

I'm looking for some kind of sealant. I think the putty would sit in the fillet of the joint and would be liable to blow off with the vibrations over time. Does anyone know of anything that would be a bit more "searching" and would work its way into the joint a bit more?

Cheers,
Joe

[BEngo]

Try one of the really  high  temperature silicone sealants.  Plumba flue might work depending on how far away from the engine the joint is.

You could always bandage over the wet sealant  with some glass tape and a jubilee clip or two.

N

[ditchcrawler]

How about this https://www.toolstation.com/shop/p17590?r=googleshopping&rr=marin&utm_source=googleshopping&utm_medium=feed&utm_campaign=googleshoppingfeed&gclid=CjwKCAjw5ZPcBRBkEiwA-avvkzqg1la5--Jne2LCIAqhigrQBMQDLNNIGgecKAcFgLCLKxLebdf0bBoCbwEQAvD_BwE

[Grifter]

Looks ideal. Cheers. I'll give it a go.

[Onewheeler]

Might be worth trying this stuff: Envirograf Sealant. It's not "penetrating" but stays flexible and might be able to be worked into the joint. Good on flues. Maybe cover with a tight binding of fibreglass tape? It needs a while to cure.

[Arthur Marshall]

I tried that heat wrap stuff on my bike exhaust. Found it impossible to get tight enough & it just fell off. 

[Ian F B]

JB Weld is good stuff, used it for various difficult repairs in the past,check out the spec sheet?????

Oops, no longer available due to EU regs,but link replacement product from JB site!!???

 

Edited August 28, 2018 by Ian F B

[sharpness]

Can you still get Gun Gum & asbestos type bandage in Halfords. Long time since I got down under a car to use it but I seem to remember it worked well.

[David Mack]

14 minutes ago, sharpness said:

Can you still get Gun Gum & asbestos type bandage in Halfords. Long time since I got down under a car to use it but I seem to remember it worked well.

Yes.

[WotEver]

2 hours ago, Arthur Marshall said:

I tried that heat wrap stuff on my bike exhaust. Found it impossible to get tight enough & it just fell off. 

Yeah, you have to wrap that wire around it and twist it into place to hold it firmly while it sets. It’s still never been very satisfactory in my experience. 

[blackrose]

On 28/08/2018 at 15:57, Onewheeler said:

Might be worth trying this stuff: Envirograf Sealant. It's not "penetrating" but stays flexible and might be able to be worked into the joint. Good on flues. Maybe cover with a tight binding of fibreglass tape? It needs a while to cure.

That would be a better bet than Plumba flue as it goes up to 1200C. Plumba flue only goes to 350C I think?

21 hours ago, Ian F B said:

JB Weld is good stuff, used it for various difficult repairs in the past,check out the spec sheet?????

Oops, no longer available due to EU regs,but link replacement product from JB site!!???

 

I've used JB weld for several jobs, but it sounds too brittle for this one as there'll be lots of vibration.

20 hours ago, sharpness said:

Can you still get Gun Gum & asbestos type bandage in Halfords. Long time since I got down under a car to use it but I seem to remember it worked well.

That is the product made for the job, so might be better than the Envirograf?

[bizzard]

The bandage is the thing, Holts made it, but there are others. Comes with a thin metal patch to put over the hole then you soak the bandage in water for a bit, wrap it around the job securing with the wire, I never found the wire supplied enough and so used some thin soft iron wire to finish the job.

Edited August 29, 2018 by bizzard

[reg]

I used gun gum back in the day. Worked well

https://www.holtsauto.com/holts/support/gun-gum-product-i-use/

Above link shows product range and uses.