Best Way Of Rust Proofing A Mild Steel Exhaust?

[cRaig 273 1 Cars]

Hey there,

 

Ive just bought a new exhaust centre section from peugeot, and I was wondering if anyone had any experience trying to prolong the life of an exhaust with paint etc? It looks well made, but already I can imagine the welded joints rusting pretty quickly, and given its cost, would like to prolong its life for as long as possible! Im guessing some kind of zinc treatment and then a VHT paint? anyone have any specific recomendations?

 

IWas also thinking, if anything was up to resisting the temperatures involved, painting the downpipe divider, to try and make it last.

 

Craig

[eddie bullit 37]

What about the VHT paints from Frost? I know they do some HTemp original look exhaust paints as well. I've always been under the impression that they rot inside out due to condensation after use.

Hope this helps Craig.

Edd

[cRaig 273 1 Cars]

Yeah, I understand there will always be internal corrosion that there isnt much I can do about, but with the exposed welds on the outside, my old exhaust was starting to rot apart at all of the welded joins, so if I can prevent that for a while I will be happy.

 

So far I have come up with Flameproof VHT which might be better for further up the exhaust near the manifold

 

orFrosts exhaust paint and I have always been impressed with Frost's stuff, but it does only go up to 150oC

 

Craig

[Tom Fenton 1,542]

Cold galvanising spray is what I'd look for. Also weld the split in the downpipe, the small gap between parts fails and splays out over time, until it can nearly block off the entire exhaust.

[cRaig 273 1 Cars]

Thats a very good idea welding up the gap between the two pressings- I can see how it is a potential weak point.

 

 

Need to find someone locally to weld it up now

 

I shall research some cold galv spray, my initial research suggests it is a very zinc rich paint spray, which does sound ideal but nice and straightforward, it is only an exhaust after all.

 

Thanks

 

Craig

Edited January 30, 2012 by pug_ham
image filesize, 160k max please or usse the thumbnail code imageshack supply!!

[sensualt101 31 1 Cars]

i used to work as a lift engineer years ago and we used a galvanising paint called "galvafroid" i dont know how much it costs or even if its available now though i am sure there must be a similar product on sale if its not. hope that is of use mate

[sensualt101 31 1 Cars]

take a look at this pdf craig

 

http://www.nwepaints.co.uk/acatalog/Galvafroid%20Data.PDF

 

i remember it being very efective as we used in in areas that were always damp to prevent corosion on all ferrous metal surfaces

[EdCherry 34 1 Cars]

Id be be careful with VHT used on exhausts, as it often comes out with a primer like finish which absorbs the moisture.

 

I run a couple of race cars where we regularly respray the exhaust after a race in the rain as it just starts to get surface rust quickly.

[Tom Fenton 1,542]

Galvafroid was what sprung to my mind as a trade name, don't know if its still available, but I'm sure there is a modern version.

 

Welding the split, if you can find someone with a TIG they should be able to do a very neat job that doesn't interfere with gas flow or fitment. Otherwise MIG weld and dress it back afterwards.

[SurGie 54]

CAM COAT will sort it out

[cRaig 273 1 Cars]

haha! it was expensive enough having the manifold coated! wouldnt even like to think what a full centre section would cost!

[SurGie 54]

Yeah it is but it will last a long time and will match your manifold. Because the exhaust is under the car it needs to be very well done, if you don't want it to rust within a few years then i think this is the only worth while way.

[Tom Fenton 1,542]

Surgie have you personally used either Camcoat or Galvafroid?

[cRaig 273 1 Cars]

Yeah, Im curious, have you had your exhaust done? Because to do it inside and out (my manifold was indeed done by camcoat) is surely the only way to do it properly - it could well cost more than the brand new exhaust has! I am all for prolonging the life of the car, but the line has to be drawn somewhere! I think it would be more financially viable to just buy a stainless exhaust!

Edited January 30, 2012 by cRaig

[welshpug 1,657]

Given how long o.e exhausts tend to last I would just fit and forget about it

[Batfink 201]

paint the outside and it will just rot from the inside instead. Save your money.

[jackherer 543]

Given how long o.e exhausts tend to last I would just fit and forget about it

 

Mild steel exhausts can last for years on regularly used cars but when they are cold for long periods and condensation forms they rot from the inside out in no time.

[cRaig 273 1 Cars]

Mm, Im hoping the fact that the garage is dehumidified will be enough to prevent condensation forming when its not being used for longer periods. Time will tell I guess!

[welshpug 1,657]

best just use the bloody thing then

[pug_ham 244 3 Cars]

Also weld the split in the downpipe, the small gap between parts fails and splays out over time, until it can nearly block off the entire exhaust.

I've done this on the last few standard exhausts I've fitted, just seemed like a good idea after seeing the state of a couple I'd removed.

 

g

[SurGie 54]

Iv not driven with mine yet Tom but was told by their technical adviser's that they are 'very rust proof' as well a its good heat properties. That was enough for me in deciding to get mine done.

 

Mine was under £250 for the 6 manifold alone.

 

Dont bother trying to use stuff that wont work for very long, waste of time trying.

[Tom Fenton 1,542]

So you have the testimonial of a company that wanted to sell you its product, and you have never used Galvafroid, yet armed with this information you are fully qualified to comment?

 

I refer you to the forum rules.

[SurGie 54]

Cold galvanising spray is what I'd look for. Also weld the split in the downpipe, the small gap between parts fails and splays out over time, until it can nearly block off the entire exhaust.

 

Have you tried this long enough to say it works ? Galvanising does not last long when under a car, fact, which is why i dont use the stuff on any chassis metal.

 

Compared to all the other suggestions that look like they haven't tried it themselves, you felt the need to tell me that.

 

Just because they want to sell things does not mean that they are lying, do you have proof they do rust when under a car for a long time, i think not. It would be pointless in having this coating to keep the heat down if it were to rust quickly, the rust would stop this from working, common sense really.

[Tom Fenton 1,542]

Yes I have used Galvafroid on an exhaust, it worked very well for the 3 years the system was on the car.

 

I refer you back to the rules. I suggest instead of arguing the toss you read them, in particular the bit about only relaying 1st hand verified information.

[harryskid 193]

I have a tin of galvafroid left over from when i did industrial heating and as an engineer i have only ever used it for brackets and such like. I have never used it on extreme hot surfaces or for that matter seen it used on hot surfaces!