Rust on my Unit!


KJRGT

GT Owner
Mark II Lifetime
May 4, 2006
2,840
SoCal
My OEM muffler unit that is. :biggrin

My stock muffler has spent nearly 10 years in storage and has developed surface rust on the box and a heavier level of surface rust on the curved exhaust pipes.

I want to clean it up and then store it with some kind of rust prevention/protection.

Evapo - Rust is the best surface rust remover I have used, but the muffler is too big to sit in an Evapo-Rust bath.

What products and procedures do you recommend I try for rust removal and rust free storage?

Thanks!
 

Art138

GT Owner
Mark II Lifetime
Jan 4, 2011
624
Weston,FL
I sprayed mine with a light coat of white protective lithium grease (made by WD40) and placed a reusable dehumidifier bag (pingi.com).
 

KJRGT

GT Owner
Mark II Lifetime
May 4, 2006
2,840
SoCal
I sprayed mine with a light coat of white protective lithium grease (made by WD40) and placed a reusable dehumidifier bag (pingi.com).


Sounds good for after rust is removed. Thanks.
 

TO AWSUM

Ford GT Owner
Mark II Lifetime
Jul 4, 2007
1,506
Niceville FL
Put Ospho on it to dissolve the rust, then oil it or put a rust inhibitor on it.

Ospho can be purchased at Home Depot, Ace Hardware, etc., etc.

Sent from my SM-N920V using Tapatalk
 
Last edited:

Rick Mustang

GT Owner
Mar 29, 2016
102
Central Texas
BoShield is what Boeing and all the classic car guys use on bare metal parts to prevent rust and it looks natural. Spray on and let dry 24 hours. Rick
 

djs

GT Owner
Mark IV Lifetime
Jun 7, 2007
2,082
" Rust on my Unit!"

Does your wife know about this?:lol

(Couldn't resist).
 

KJRGT

GT Owner
Mark II Lifetime
May 4, 2006
2,840
SoCal
" Rust on my Unit!"

Does your wife know about this?:lol

(Couldn't resist).

Only cuz it's been raining a lot this week.
 

KJRGT

GT Owner
Mark II Lifetime
May 4, 2006
2,840
SoCal
Put Ospho on it to dissolve the rust, then oil it or put a rust inhibitor on it.

Ospho can be purchased at Home Depot, Ace Hardware, etc., etc.

Sent from my SM-N920V using Tapatalk

Their website seems to say it inhibits/stops rust and it is used as a primer for painting over rust. Will it remove rust?
 
Last edited:

PeteK

GT Owner
Mark II Lifetime
Apr 18, 2014
2,267
Kalama, Free part of WA State
Their website seems to say it inhibits/stops rust and it is used as a primer for painting over rust. Will it remove rust?
Ospho is a brand name for diluted phosphoric acid. Yes, phosphoric acid removes the rust and inhibits further rusting by converting it to ferric phosphate. FYI, 2 H3PO4 + Fe2O3 → 2 FePO4 + 3 H2O. But that won't give you a smooth shiny stainless steel appearance. It probably will leave a cloudy etched appearance. The only method I know of to get back to that state is polishing with a machine and lots of elbow grease. Start with regular steel wool or stainless steel wool if you can find it. that will rub off most or all of the rust stains. If you want to try a chemical, you better try it on a small area first and see what results you get.

I second the suggestion to use Boeshield. It leaves a waxy coating that can be removed much more easily than cosmoline.
 

KJRGT

GT Owner
Mark II Lifetime
May 4, 2006
2,840
SoCal
Ospho is a brand name for diluted phosphoric acid. Yes, phosphoric acid removes the rust and inhibits further rusting by converting it to ferric phosphate. FYI, 2 H3PO4 + Fe2O3 → 2 FePO4 + 3 H2O. But that won't give you a smooth shiny stainless steel appearance. It probably will leave a cloudy etched appearance. The only method I know of to get back to that state is polishing with a machine and lots of elbow grease. Start with regular steel wool or stainless steel wool if you can find it. that will rub off most or all of the rust stains. If you want to try a chemical, you better try it on a small area first and see what results you get.

I second the suggestion to use Boeshield. It leaves a waxy coating that can be removed much more easily than cosmoline.

Thanks for the detailed explanation. Very helpful.
 

TO AWSUM

Ford GT Owner
Mark II Lifetime
Jul 4, 2007
1,506
Niceville FL
The Ospho I use doesn't leave a discoloration or change the rust to iron phosphate. It dissolves the rust and leaves it clean looking. I have used other products that convert the rust but my Ospho dissolves it leaving shiny metal. A Web search shows that Ospho now has many products so you may be describing one of their other products. Mine is a light blue liquid.

You may have to polish after the Ospho dissolves the rust depending if it's a deep rust or a surface rust.

Sent from my SM-N920V using Tapatalk
 

KJRGT

GT Owner
Mark II Lifetime
May 4, 2006
2,840
SoCal
The Ospho I use doesn't leave a discoloration or change the rust to iron phosphate. It dissolves the rust and leaves it clean looking. I have used other products that convert the rust but my Ospho dissolves it leaving shiny metal. A Web search shows that Ospho now has many products so you may be describing one of their other products. Mine is a light blue liquid.

You may have to polish after the Ospho dissolves the rust depending if it's a deep rust or a surface rust.

Sent from my SM-N920V using Tapatalk

Aahhh. Thanks I'll research it some more.
 

Simon

GT Owner
Mark II Lifetime
Feb 19, 2013
1,230
Houston
 
Wait a minute - if it's good stainless, it shouldn't rust ....
 

KJRGT

GT Owner
Mark II Lifetime
May 4, 2006
2,840
SoCal
Wait a minute - if it's good stainless, it shouldn't rust ....

Agreed. But there is light rust on the box and much more on the exhaust pipes.
 

PeteK

GT Owner
Mark II Lifetime
Apr 18, 2014
2,267
Kalama, Free part of WA State
Aahhh. Thanks I'll research it some more.

Just be sure to try it on a small area first.
 

SYCO GT

GT Owner
Mark II Lifetime
Sep 9, 2006
4,974
California
I sprayed mine with a light coat of white protective lithium grease (made by WD40) and placed a reusable dehumidifier bag (pingi.com).

Good idea. Thanks for the tip.
 

SYCO GT

GT Owner
Mark II Lifetime
Sep 9, 2006
4,974
California
Aahhh. Thanks I'll research it some more.

Keep us posted on your uitimate solution. I have a muffler box to go check on...
 

Tomcat

GT Owner
Wait a minute - if it's good stainless, it shouldn't rust ....
I believe there are grades of stainless that are harder (due to % of carbon steel) that do rust...at least that is what my outboard motor guy said about my prop.
 

KJRGT

GT Owner
Mark II Lifetime
May 4, 2006
2,840
SoCal
Hi guys.

I apologize for not following through.

I started out old school and started working it by hand with steel wool. Began on the tail pipes and the rust came off pretty easily. Mind you the tail pipes are discolored from heat, but the rust came right off.

So I just worked the rest of the underside, which is also discolored, and the rust was heavier than the muffler ends, sides and top, the can itself.

Bottom line I used steel wool on the whole unit so never tried any rust cleaning products. It took a couple hours but the job is done and looks good.