TheSamba.com :: View topic

Sun Nov 29, 2015 9:53 am

On my pipe, I feel that it is burning off.
It has not seen snow, salt or even rain yet, just heat.

We shall see.

Sun Nov 29, 2015 9:53 am

Thanks ptjjb for your step by step procedures. It wil help future people to try that method.

Thanks insyncro, that is different than last time! I will check mine...

Sun Nov 29, 2015 9:59 am

pedrokrusher wrote:

Thanks insyncro, that is different than last time! I will check mine...

I have talked to a bunch of people about this.
The Walmart oil is very cheap.
If we think about olive oil, the first pressing is the highest quality and carries the highest price.

This oil was $3.50 for a quart...by far the least expensive I saw at just a couple stores and I didn't want to waste $.
Perhaps a better quality oil will hold up better???

I'm not saying this doesn't work, but a few pictures are one thing, by eye and in person, it looks to me like the top of the pipe has lost the entire layering of the three coatings.

I have coated complete other WBX exhaust systems with this brand of oil.
They look great, BUT havent seen any road miles, just heat cycles to have the pipes change color at idle, at full operating temp, for 15 minutes each.

Just sharing.

Sun Nov 29, 2015 10:01 am

hi! glad youre interested ( iam a total dork about metal!)

metals are made up of tightly packed crystals,theer is a 'space' between the crystals that allows both moisture and other fluids(oil,especially hot oil because it becomes less viscous) to penetrate beneath the surface so to speak. this is why polishing a piece of metal will help keep it 'watertight' becasue you are tightening the grain structure on the surface. eventually ambient moisture makes its way into the metal and hangs out there causing rust etc on ferrous metals. if you fill the voids with the oil and the oil when burned leaves behind a fatty residue this essentially blocks and slows the penetration of moisture into the same spaces. we use linseed oil to bond sand for casting but there are reasons that we woudl use other oils for this process. wax is also used but that obviously burns off over 175 degrees. for the exhaust scenario you have a piece of mild steel being repeatedly heated and cooled which wreaks havoc on the structure and causes annealing to occur and softening of the metal among other things, that is why exhausts have a short lifespan and also why using stainless steel(nickel) changes the operating temps of the metal thus prolonging its service lifespan. the idea of imbuing the steel with peanut oil which has a very thin viscosity compared to linseed oil even when hot, is a solid example of outsmarting the structure of the steel and winning the war against rust :)

Sun Nov 29, 2015 10:08 am

oh also just to be clear even though this trick will slow the process down of rusting it wont stop it. the metal also undergoes 'spalling' from constant reheating and that is caused by the shrinkage that occurs when a metal is heated and then cooled. the crystals actually 'push away' from one another when heated. the atoms are leaving their 'ground state' when that happens the metal almost has to 'put itself back together' each time it cools back down. this leaves the surface to cool at one rate and the interior to cool at another rate thus pushing off a small layer of material in the process. because of this we will always need to replace our exhaust systems :x

Sun Nov 29, 2015 10:44 am

I think this;

insyncro's pipes that he treated had plenty of patina on them.
He scuffed them up a little to knock off some of the heavy crustations.
That's OK.

However, I do believe that the well rusted pipes & then knocking it off opened up the steel a little more to cause it to be more porus than new pipes.
I do believe it'll take more seasoning than if it was treated when there were no rust pits in the pipes, from new.

There is going to be a point of eventually filling them up to where the seasoning won't burn out of the surface of the tubing so fast--

Oiling them up again would be my suggestion, there will be a point of no return to rusting up.

Working backwards from rusted up, rather than starting the seasoning from new will take more oil applications to maintain the pipes to a rust free surface I'm sure.

Sun Nov 29, 2015 11:54 am

I have some new pipes, only heat cycles a few times to remove the grey factory coating.
With time, I will treat them and show how they hold up.

This J pipe I am showing could be original.
The fasteners have only tiny bits holding them together, the muffler was replaced at some point, but tell tale for me is that the original Syncro exhaust fire shield is still there.
Not many vans have those intact and most rusted away and were not usable any longer.

Yes, this pipe was beat to begin with.
I was just trying to get some more involved by showing how simple this process is.

It can't hang with an interior and exterior Jet Coat from day one...but also doesn't cost hundreds of dollars for just the basic industrial coating.

I am doing all sorts of rust experiments currently, so for now, this will have to do with the peanut oil.

Sun Nov 29, 2015 6:06 pm

This is how mine looks like after two weeks.
One mini snow storm, a couple rainy days and thats it.
Really not much different from two weeks ago.
The bent pipe has a little bit dryer look, and dry to the touch.
The muffler has that oily touch...
And it unfortunately still smell burnt vegetable oil... Less but still smells.

Sun Nov 29, 2015 6:27 pm

The reason the muffler is still tacky with the peanut oil is it can't get through the zinc plating to bond, leach into the metal.
This is a good sign though, giving you a sign it isn't burning off.
Perhaps it is because the muffler doesn't get as hot at the end of the line.

The pipe looks pretty good considering you did nothing to prep it, just slapped on the oil.

Interesting.

Sun Nov 29, 2015 7:00 pm

outcaststudios wrote: hi! glad youre interested ( iam a total dork about metal!)

metals are made up of tightly packed crystals,theer is a 'space' between the crystals that allows both moisture and other fluids(oil,especially hot oil because it becomes less viscous) to penetrate beneath the surface so to speak. this is why polishing a piece of metal will help keep it 'watertight' becasue you are tightening the grain structure on the surface. eventually ambient moisture makes its way into the metal and hangs out there causing rust etc on ferrous metals. if you fill the voids with the oil and the oil when burned leaves behind a fatty residue this essentially blocks and slows the penetration of moisture into the same spaces. we use linseed oil to bond sand for casting but there are reasons that we woudl use other oils for this process. wax is also used but that obviously burns off over 175 degrees. for the exhaust scenario you have a piece of mild steel being repeatedly heated and cooled which wreaks havoc on the structure and causes annealing to occur and softening of the metal among other things, that is why exhausts have a short lifespan and also why using stainless steel(nickel) changes the operating temps of the metal thus prolonging its service lifespan. the idea of imbuing the steel with peanut oil which has a very thin viscosity compared to linseed oil even when hot, is a solid example of outsmarting the structure of the steel and winning the war against rust :) outcaststudios wrote: oh also just to be clear even though this trick will slow the process down of rusting it wont stop it. the metal also undergoes 'spalling' from constant reheating and that is caused by the shrinkage that occurs when a metal is heated and then cooled. the crystals actually 'push away' from one another when heated. the atoms are leaving their 'ground state' when that happens the metal almost has to 'put itself back together' each time it cools back down. this leaves the surface to cool at one rate and the interior to cool at another rate thus pushing off a small layer of material in the process. because of this we will always need to replace our exhaust systems :x
Outcaststudios, im very very very interested in hearing more about this metalurgy!!!
If there is anything else you would like to add, please let us know, tx!!!
My dad was a machinist, now retired, and i was always fascinated with the parts he fabricated, built and all.

Thank you in explaining that the metal is like thighly packed crystals and oil can feed the voids. Excellent. And yes that there is also metal fatigue that enters the equation.

One thing i had in mind while applying the coats of peanut oil is... am i in any way weakening the metal in long term? Is there any harm to the metal? Like maybe shortening the metal life expectancy if we stop seasoning every year? Or softening the metal? Thanks in advance!

Sun Nov 29, 2015 7:12 pm

insyncro wrote: pedrokrusher wrote:

Thanks insyncro, that is different than last time! I will check mine...

I have talked to a bunch of people about this.
The Walmart oil is very cheap.
If we think about olive oil, the first pressing is the highest quality and carries the highest price.

This oil was $3.50 for a quart...by far the least expensive I saw at just a couple stores and I didn't want to waste $.
Perhaps a better quality oil will hold up better???

I'm not saying this doesn't work, but a few pictures are one thing, by eye and in person, it looks to me like the top of the pipe has lost the entire layering of the three coatings.

I have coated complete other WBX exhaust systems with this brand of oil.
They look great, BUT havent seen any road miles, just heat cycles to have the pipes change color at idle, at full operating temp, for 15 minutes each.

Just sharing.

Thanks for sharing insyncro. Most probably is that i applyed much thicker peanut oil coatings and my bend pipe was way rustier. That is probably why mine is "more darker"... Like i said in another post, my pipes still smells burnt vegetable oil... Bummer...

Sun Nov 29, 2015 7:22 pm

Terry Kay wrote: The reason the muffler is still tacky with the peanut oil is it can't get through the zinc plating to bond, leach into the metal.
This is a good sign though, giving you a sign it isn't burning off.
Perhaps it is because the muffler doesn't get as hot at the end of the line.

The pipe looks pretty good considering you did nothing to prep it, just slapped on the oil.

Interesting.

Ah forgot about the zink plating still visible on the muffler... And combined with the lower temperature the peanut oil does not reach a very high temperature to burn off.

Sun Nov 29, 2015 7:28 pm

Hopefully I will have time to keep applying the oil.
We dont have any nasty weather in the 10 day forecast.

If I do I will update with some pictures.

Mon Nov 30, 2015 12:50 am

You guys have me convinced. I am going to lather up my vans, and my dodge truck. I will take some pics. the syncro exhaust is fairly new, the 2wd is old and ready to replace, the dodge still has plenty of life.

I mainly want to see how much time it buys me on the 2wd vanagon exhaust.

Mon Nov 30, 2015 7:50 am

pedrokrusher- i think the reason youre having the smell linger is that the oil was applied very thick. the trick to the process is applying many VERY THIN coats and letting each coat fully burn in. the end result should have a gummy feel to it and not be shiny. if its shiny then odds are the oil is still burning in. i will take pictures of my doka exhast later on as the coat of oil on mine is from about four months ago and is plenty burned in. i sometimes just apply the oil and then use a small propane torch to burn it in, it takes less time i think and you can see the results happen before your eyes without getting smoked out running the motor. anything that the torch misses usually gets taken care of by the first few trips,;)

Mon Nov 30, 2015 7:56 am

I don't think a torch is a good idea after the application of the oil, for the simple reason , you stand a real good chance of buring the oil off.

Your not heat curing it as the entire pipe gets hot from the inside & evenly--your exterior heating it, and I'll bet that your torching the oil off where your flame heating it at any given moment.

Not a good idea.

What is wrong with starting the engine to allow the entire pipe to get hot evenly--from the inside out?

This is how this seasoning job is supposed to get done.

Mon Nov 30, 2015 8:48 am

tk- you are correct it is important to have the burn happen evenly, but in this case i am not burning the oil off, i am heating the pipe up FIRST then applying a thin coat. this way the metal is already "open" when the oil hits the surface. im sure either way works just the same. the oil nees to be burned off to leave behind the fatty acids that protect. so its pretty hard to over do it. but for those less seasoned (sorry bad pun) its important that if you do use a torch to not stay still too long in any one place,watch for hanging wires you dont want to char and also not to get the pipe too hot just hot enough to see some small smoke rise as you add oil. this is actually exactly how a traditional blacksmiths finish is applied which is exactly what this process is. so coming at it from a metalworkers perspective you woudl first get the metal up to temperature and drive off the moisture first either by running the motor or gently warming with torch ,thane after youre sure the temp is good begin applying small coats with a brush. after each coat simply run a torch along the areas and watch for the oil to start bubbling slightly and then move on you dont want to stay still and burn the heck out of it that isnt the idea here, it is to bake the oil into the surface.

Mon Nov 30, 2015 9:00 am

Outcast....does the oiling and color change on the J pipe I have shown look right?...worth continuing?...a waste of time?... need heavier coats?...lighter coats?

Curious?
Thanks.

D

Mon Nov 30, 2015 12:50 pm

insyncro-
looks good to me, if its a little 'wet' it will just burn in eventually,give us updates (even though i have been doing this for years and it usually lasts the season ymmv) you want to look for spots of oil dripping off really that's when you know its over saturated.

Mon Nov 30, 2015 2:30 pm

Cool, thanks.