TheSamba.com :: View topic - Exhaust system clean up and rust prevention

Sun Jan 29, 2006 6:31 pm

I just bought a used exhaust system off of ebay. It came with the cross over pipe, elbow pipe, cat, muffler, and tail pipe. It seams to be in pretty good shape. Or at least in better shape than my old exhaust. Obviously its got some surface rust. The PO had it wrapped in some sort of cloth heat wrap material which as you can imagine did wonders to help the rust.

Any way I'm in the process of cutting the cloth off and scrapping the rust clear as best I can. Most of the rust is flaking off easily in big thin sheets and there are no deep pits or holes penetrating through the surface.

Is there a material I can use to seal the surface after I'm done scraping the loose material? It would have to be able to stand up to the heat of the exhaust. Has anyone tried powder coating there exhaust? Is it pricy$$$? Any preparation and restoration tips would be appreciated.

Thanks

Sun Jan 29, 2006 11:15 pm

Putting it in a bead blaster and peening it all off is best. Powder coating is a heat activated material, and would not be the best choice. There are exhaust coating systems, but are best used when the part is new (and pricey). You can try regular old exhaust high temp paint, but it flakes off if there is any rust.

Cheers,
James

Mon Jan 30, 2006 12:21 am

POR 15 makes a paint for exhaust. I have some but haven't used it yet but suspect it is pretty good. Their flyer says you can coat inside the pipes as well.

Mon Jan 30, 2006 12:30 am

Hmm I'll have to look in to that. Thanks

Mon Jan 30, 2006 7:21 am

Any tricks to getting these rusty bolts off this tailpipe aside from soaking them in WD-40? I Don't have access to a welder.

Mon Jan 30, 2006 8:24 am

WOW MAN JAY!!! :shock:

YOUR WIFE IS GUNNA KILL YOU :twisted:

but anyways.. invest in a battery operated sawzall, extremely handy for those junkyard runs too. to 'pull' seized studs/bolts you either have to use heat.. (cherry red heat) or good luck and penetrating oil.
if you have enough room on the stud, you can double nut it put one nut on then a 2nd, tighten the 2 together to each other, then they bind real tight on the stud and sometimes it'll come out, sometimes itll break..

I REALLY like my small 110volt lincoln MIG welder. it's perfect for this kind of work, and it runs off a regular wall outlet (likes a 15-20amp breaker though). I take a nut screw it on or place it over the seized/broken stud and the heat from the welding goes right where you want it to go.. gives the neighbors a good light show as bonus.
these are 'suitcase' sized and sold in homedepot/lowes for under $300. but only buy NAMEBRANDS in small scale welders, never a "harbor freight" brand for this work.

you should be quite able to have it powdercoated, they'll strip the corrosion off as part of the service, either sandblasted or chemical strip.

I've been wanting to make a 'reverse-electrolisis dip tank for my garage. maybe this year.. google = " electrolysis rust removal "
http://antique-engines.com/electrol.asp

dan from syracuse NY
1980 Tan Riviera camper with Turbo diesel conversion

Mon Jan 30, 2006 9:08 am

Thanks Dan

The wife is in Canada visiting family \:D/ :twisted: While the cat is away the mice will play :wink: I actually managed to dig in there with a couple of wrenches and yank those bolts loose by hand this morning. ARRRG! :twisted: After a big bowl of wheeties :lol: I'm taking the cross over pipe to get sand blasted this after noon. The guy quoted me a price of $45.00 over the phone. Not to bad a guess. Then I think I'm gona try some of that high temp POR-15 walrus suggested. I'll post some pics later.

Mon Jan 30, 2006 10:47 am

The right way of treating the exhaust system so it will not re- rust is to have it ceramic coated.

I've exhaust system heat POR-15ed my tail pipe & exhaust and the results are sort lived.

I know of one guy that swears that coating the system yearly with peanut oil prevents rust.

Go Figure--- ~: )

Mon Jan 30, 2006 10:55 am

There are places that will "aluminize" your parts. Still others will ceramic coat them. Pretty much anything you put on that is self applied seems to be problematic. Over the decades I have tried several things. Most are so, so.

One of the best things you can do for yourself is to be sure the exhaust is well installed. That means, the flanges are filed flat, use good gaskets, use copper plated pinch nuts and use plenty of antisieze. That way the prime exhaust killer will not happen. That is an exhaust that breaks because if vibrated and rattled. If they vibrate and rattle, they tend to break and fall apart.

Mon Jan 30, 2006 11:07 am

r39o wrote: There are places that will "aluminize" your parts. Still others will ceramic coat them. <<Pretty much anything you put on that is self applied seems to be problematic. Over the decades I have tried several things. Most are so, so.>>

Or more like No-No
Whatever the can claims it isn't going to stay on for long, that's for sure.

The heat seems to eat it up.

Just figure it this way----

If you don't pay to have it done, it isn't going to last.

<<One of the best things you can do for yourself is to be sure the exhaust is well installed. That means, the flanges are filed flat, use good gaskets,>>

Use a piece of glass to verify if the flanges are flat--absolutley, and do use new gaskets.

<< use copper plated pinch nuts and use plenty of antisieze. That way the prime exhaust killer will not happen.>>

I passed on the copper plated nuts.
They do wok ok, but under than copper plating is just plain old mild steel, and they will eventually rust up.
Especially when the coppper cust off the threads on the way down.

I replaced every nut, bolt, washer, , & head stud with stainless, and still gave them a copious coat of anti seize.

Now lets see the hardware fight me when it's time to do some work down yonder-- ~: )

Boy--I almost hate to go near the exhaust system--it's alway's a pain.

That is an exhaust that breaks because if vibrated and rattled. If they vibrate and rattle, they tend to break and fall apart.

Mon Jan 30, 2006 11:56 am

Although many stainless steels are great for not rusting, a materials guy showed me in an envirnoment that tends to be hostile (salt) you do not want to mix in stainless and non stainless. Reason is, you will promote the non stainless to corrode. So what good is a beautiful stainless fastner when the flange you are holding on has had the corrosion accelerated causing it to fail prematurely?

The point of the pinch nuts comment is to use NEW hardware. It is what is used on new VWs and if you use the never sieze, the parts actually do come apart years later. Seen that time and time again.

BTW: The best exhaust is totally stainless, if you can get it and afford it.

Mon Jan 30, 2006 5:35 pm

Well step one is complete \:D/

Sand blasting only cost me $30.00. Even cheaper then the quote I got over the phone :wink: I think that deserves a free plug:

Haward Corp.
31 Porete Ave.
North Arlington, NJ 07031
Phone: 800-342-9041
Fax: 201-991-1903
http://www.haward.com/

Ask for Keith

Absolutely no signs of rust. Its so clean it looks like I painted it :wink:

Mon Jan 30, 2006 5:46 pm

Wow! That looks good. I just ordered the POR15 Black Velvet ($34 Cdn). Let me know how yours works out.....

Mon Jan 30, 2006 7:43 pm

Beaker wrote: Wow! That looks good. I just ordered the POR15 Black Velvet ($34 Cdn). Let me know how yours works out.....

Me to :wink: I went with the manifold gray how about you? They say its good up to 1,400 Deg. F :twisted:

Mon Jan 30, 2006 8:36 pm

Follow the instructions. If you want streak free application, use a cheap foam brush. Toss when done. Also, use the smallest jar you can. It is near impossible to keep the stuff once it is opened. In other words, if you do reseal, it won't really be good later. This is EXPERIENCE talking.

BTW: I noticed it is rusting already. Better hurry!

Mon Jan 30, 2006 8:54 pm

r39o wrote: Follow the instructions. If you want streak free application, use a cheap foam brush. Toss when done. Also, use the smallest jar you can. It is near impossible to keep the stuff once it is opened. In other words, if you do reseal, it won't really be good later. This is EXPERIENCE talking.

BTW: I noticed it is rusting already. Better hurry!

Thanks for the tips :wink: I'll post a pic when its done.

Mon Jan 30, 2006 11:34 pm

Burn those photos! Photshop them so that the exhaust is on the driveway. Otherwise, when your lady gets home, you are going to hear about it every time you sit down to dinner.

THE KITCHEN TABLE??

The subject will be difficult to exhaust.

Rigging Winston for his new radio wiring. Tapped into the "YOU LEFT THE KEY IN, IDIOT!" circuit.

Tue Jan 31, 2006 12:07 am

They say you can also do the inside of the exhaust by pulling a swab thru the pipe.

Tue Jan 31, 2006 6:23 am

msinabottle wrote: Burn those photos! Photshop them so that the exhaust is on the driveway. Otherwise, when your lady gets home, you are going to hear about it every time you sit down to dinner.

THE KITCHEN TABLE??

The subject will be difficult to exhaust.

Rigging Winston for his new radio wiring. Tapped into the "YOU LEFT THE KEY IN, IDIOT!" circuit.

Driveway?? :lol: What's that? :roll: I wish I had one :cry: Trust me I would have used it if I did. I live in a 900 SF. apartment in the city so I have to improvise. Would you believe I once replaced the floor pans in my old 72 Beetle out on the street? In December? I couldn't use the dining room table for that one.

I sucked all the rust up with my shop vac as I scraped it off. And my wife wouldn't even know how to find this forum. No worries the crime scene has been contained :wink:

Tue Jan 31, 2006 9:20 am

Por-15 might hold up on that, then it might not.
The black velvet I used on my steel "extractor" exhaust lasted about a week and a half, some of it's still there most of it flaked off.
It was thinner than the stock system, so it may get hotter.