Cold galvanising exhaust pipe

[Tigershark1976]

Found my wife's Matrix exhaust badly rusted. Tried VHT paint but work only for a few months and the paint flakes....thinking to galvanise it using galvanising paint. Search from google for more details but found that there are different comment.. Some says cold galvanise doesnt work for exhaust because the zinc will melt beyond 700+ FH..... but the others says that it works very well and easily last for a few yrs...

 

Wanted to check with expert in the forum on their comment before doing anything cause its a very tedious process for DIY preparation work scrub & sand off the existing paint and rust process)for spray paint....

[Briansoh]

It flakes because the surface is not prepped well. You will need to sand off the rust and then apply some sort of rust converter to stop whatever rust left from spreading. You then need to use a high temp etch primer to prime the surface before applying the high temp paint. Alternatively, you can try this product called POR-15. Very popular in the USA and less work as it treats rust and protects it at the same time (you will still need to sand off most of the rust). Shipment into Singapore would be rather expensive though. How much does a new exhaust cost? Would it be more economical to just replace?

[Watwheels]

Just bring it for chrome. Galvanizing will oxidise and turn matt grey after a while.

 

I dunno whether those doing industrial chrome will do just one item coz usually they go by weight. Maybe those smaller companies will entertain. Galvanizing has 2 types, one is cold which is done by electroplating, the other is hot dip which the metal will be dip into molten zinc.

 

But i got a feeling it will be cheaper if you buy an exhaust chromed attachment off the shelf. It will also save you time as most likely you will have to come back on other day to collect your item becoz it won't be done within a day.

[Tigershark1976]

It flakes because the surface is not prepped well. You will need to sand off the rust and then apply some sort of rust converter to stop whatever rust left from spreading. You then need to use a high temp etch primer to prime the surface before applying the high temp paint. Alternatively, you can try this product called POR-15. Very popular in the USA and less work as it treats rust and protects it at the same time (you will still need to sand off most of the rust). Shipment into Singapore would be rather expensive though. How much does a new exhaust cost? Would it be more economical to just replace?

 

 

prep job done very well.... brushed off all the old paint and sanded off all rust... but spray the VHT paint directly without primer cause I cant find any primer thats high temp rated... Thats Y thinking to use cold galvanise method instead...

[Tigershark1976]

Just bring it for chrome. Galvanizing will oxidise and turn matt grey after a while.

 

I dunno whether those doing industrial chrome will do just one item coz usually they go by weight. Maybe those smaller companies will entertain. Galvanizing has 2 types, one is cold which is done by electroplating, the other is hot dip which the metal will be dip into molten zinc.

 

But i got a feeling it will be cheaper if you buy an exhaust chromed attachment off the shelf. It will also save you time as most likely you will have to come back on other day to collect your item becoz it won't be done within a day.

 

 

chrome the whole exhaust??? I might as well buy full set stainless steel exhaust.. ...

 

The cold galvanise I refer to is DIY type.... its in paint form. got 2 type, paint brush and spray type....

[Tigershark1976]

double post...

Edited June 24, 2012 by Tigershark1976

[Briansoh]

Hi there,

Okay i just used a rust converter solution on my car. The paint can then be applier over it directly. So far the paint sticks but im not sure whether it will work for you as the exhaust pipe is so hot.

[Tigershark1976]

Hi there,

Okay i just used a rust converter solution on my car. The paint can then be applier over it directly. So far the paint sticks but im not sure whether it will work for you as the exhaust pipe is so hot.

 

 

care to share more about your "rust converter" ?? what brand, how much and you bought from where. Have been spending a lot of time and $$ on all sorts of high temp paint.... haiz, the longest only last for a few weeks.... money is still okie but the preparation work its really killing... scrubbing off the old paint and rust is really no joke. Especially at the exhaust where I have to work on it in an awkward positions.... damn tiring...

[5936]

Zinc galvanising is not anti rust treatment.

 

 

if already rusted, need to remove loose rust, use rust convertor, apply primer 2 coats and finishing coats of VHT at lease 3 coats.

 

if you really want to try galvanising paint you can get from hardware supplier in industrial estates- Crown brand is not bad. wear a mask or avoid breathing in zinc particles.

[5936]

Dont get rust convertor from auto shop or DIY shop. small and expensive.

 

Go to industrial supplies; Bok Seng, or Homely hardware. They sell in 1/2, 1 or 5L plastic container. If I remember correctly it is called Redox, local chem company.

[Briansoh]

You can get Pies rust converter from most hardware shops in small bottles. Around 7 bucks i think for 100ml or so. Its a liquid product that you just apply with a brush and wait for it to dry then paint it. As what the fellow forum member mentioned above, you will still need to prime and paint accordingly with vht.

[5936]

He needs many 100mls bottles for the exhaust pipings. I reckon at lease 500-1000mls.

 

[Briansoh]

Yeah easily. If can find in liter bottles go ahead and grab them as theyll definitely be cheaper. TS, Let us know the outcome.

[Oregon]

I think if your exhaust is corroding there's not much you can do to stop it. Its like cancer, the only way is to cut it out. Firstly, moisture comes from the combustion process and so there is always water inside the exhaust. If you do not warm up the exhaust enough from your daily use, it will build up and rust inside out. Secondly, if your exhaust is rusting on the outside, I'm sure it is rusting from the inside out too. This is probably due to inferior metals or rust proofing. Depending on how long you wish to keep the car, I would bite the bullet and replace it.

[Tigershark1976]

Dont get rust convertor from auto shop or DIY shop. small and expensive.

 

Go to industrial supplies; Bok Seng, or Homely hardware. They sell in 1/2, 1 or 5L plastic container. If I remember correctly it is called Redox, local chem company.

 

 

thanks for the info bro...

[Tigershark1976]

Bro, just to confirm, whether those ruct convertor are heat proof? cause many primer and paint that I came across doesnt works will under high temp... even some VHT paint is only good enough to paint on exhaust pipes near to the muffler, whether the temp is lower. those nearer to cat converter and center muffler usually gone very fast....

[Tigershark1976]

I think if your exhaust is corroding there's not much you can do to stop it. Its like cancer, the only way is to cut it out. Firstly, moisture comes from the combustion process and so there is always water inside the exhaust. If you do not warm up the exhaust enough from your daily use, it will build up and rust inside out. Secondly, if your exhaust is rusting on the outside, I'm sure it is rusting from the inside out too. This is probably due to inferior metals or rust proofing. Depending on how long you wish to keep the car, I would bite the bullet and replace it.

 

 

 

Yup, rusting from inside is mainly caused my short trips.... for me, Its not too bad cause the distance I travel daily is min 20km, my office to home is around 28km...

 

The rust from outside, is the one I try to tackle. In SG, exhaust pipe cannot be repair, any non factory weld mark on the exhaust will carries a $500 fines. and replacing the whole exhaust is also not cheap. Why delaying the rust issue, I believe the exhaust could easily last 10 yrs.

[5936]

Hi Tiger, rust convertor is not coating. it is chemical that "kill and stop the corrosion".

 

After rust converting worked. you have to remove the excess liquid.