15 replies to this topic

[samt88]

I've got a slightly rusty exhaust that I'd like to try and clean up - would hammerite red oxide primer stand up to the heat?

[HUBBA.HUBBA]

which end?

[samt88]

Just after the exhaust manifold

[mini670]

Id say not,

after painting the welds on my silencers in zinc rich paint.... It hasn't come off yet (30mins running) but im sure it will.

[SMP]

What is hammerite red oxide primer! Do you mean the special primer used over aluminium, copper etc ? Anyway years ago I used to paint my exhausts with hammerite. I think it used to last quite well. However it lost it's colour very quickly because of the heat , I think it used to turn to a golden colour and produce a lot of fumes until it had gassed of sufficiently.

[cal844]

Red oxide has no lead, just a dye!!

[mini670]

its bilt hamber electrolux. It has changed colour, but it hasnt had the test of time to see if it comes off or not

[Dusky]

i used heat resistant hammerite, didn't come of yet ( have driven a few hours now) Only came of at the exhaust manifold because there already was a non heat resistant paint on the manifold..

[johnR]

why not use a proper exhaust paint like Sperex or Hycote designed to cope with 6oo degress or so?  Not much difference in price.

[dklawson]

I cannot comment on "Sperex or Hycote" as mentioned above as I don't think they are for sale here in the U.S.  However, we do have many brands of "high-temperature exhaust paint".  Most have very, very, little binder to hold the pigment to the pipes/castings.  Therefore, they look great until the first time you drive the car in the rain and the coating literally washes off.  (Not completely... it is most likely to wash off in patches giving a camouflage appearance). 

 

Many of us in the old-car hobby over here simply use "barbecue paint" like you would apply to an outdoor cooking grill.  As long as you are OK with black, you will find the paint holds up to the heat and has enough binder to keep it in place.  It is also relatively inexpensive.  Over here it is available in both spray and pint cans.

[tiger99]

Barbecue paint sounds like the ideal stuff for the job, considering what a barbecue has to endure. I have never seen it but imagine that it will be available in B&Q.

 

Sperex is indeed not very tough, although I don't think it usually washes off in the rain. But it has very limited adhesion, and I have been very disappointed with it in the past. I would suggest not using any other kind of paint at the hot end of the exhaust, because the inevitable fumes may be toxic, certainly unpleasant, and the fire risk may be quite considerable until the paint is well and truly cooked. Definitely not Hammerite.

 

There are also ceramic and similar coatings, for which I recall something like zircotec as a leading brand. Due to the high cost, only worthwhile on a new exhaust system, and more commonly used on the manifold.

[Tamworthbay]

Go on eBay and look for Granvilles engine black. It has been used for decades to repaint motorbike cylinders and is brilliant stuff. My freeflow was done in it two years ago and still looks like new.

[HarrysMini]

Go on eBay and look for Granvilles engine black. It has been used for decades to repaint motorbike cylinders and is brilliant stuff. My freeflow was done in it two years ago and still looks like new.

This stuff http://www.ebay.co.u...=item51bbe518c1 ?

 

I was going to get some of that for my engine, so it would be useful to know if it is any good. I might also paint my LCB as that is the only part of my exhaust system that isn't stainless.

[Dusky]

why not use a proper exhaust paint like Sperex or Hycote designed to cope with 6oo degress or so?  Not much difference in price.

Hammerite heat resistant goes to 650 degree celcius

[Ethel]

Red lead oxide is just a colour these days. You could deliberately get surface rust on it then "black" it with phosphoric acid, paint on top is probably a good idea