TheHarvester
Premium
join:2006-08-25
Dana Point, CA
| reply to Doctor Olds
Re: catalytic converter causing fires
said by Doctor Olds 
Did you try picking any of it up with a magnet? I'll lay 20:1 odds it was ceramic material from the now damaged converter (melted and broken up inside from all the mis-firing) instead of metal. Otherwise where would the metal come from?[/quote :
No I didn't try picking it up with a magnet because I new what it was and where it was coming from. I said "it looked like cooled molten metal" to give you an idea as to what I saw. Some pieces were over 1 inch long and about 1/4 inch diameter. Converters DO contain metal, some of the most precious metals on earth.
quote:
Here is a poster with the same "tailpipe sparks" symptom in a Ford.
»www.fordforums.com/f648/sparks-c···e-18195/
They were not sparks and that post is basically worthless, no worthwhile info at all. Like most posts just a bunch of speculation and bullshit.
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StNickless
@tmodns.net
| Minor stupid mention....
Not all metals are attracted to a magnet, take 304 stainless for example (yes some stainless formulations containing carbon and/or iron are magnetic, 304 isn't).
I haven't a clue if Palladium or Rhodium are magnetic....but since gold, silver, and platinum (in pure form) are NOT magnetic, I would say they probably are not magnetic either.
Most rifle/pistol firing ranges these days say you cannot fire a round if it attracts a magnet....something to do with both overpenetration and fire risk....but it's a piss poor test at best.
It is, however, what made me think of how ludicrous testing particulates coming from an exhaust would be. Hell, even ceramic *bits* would probably pick up some magnetism from the friction of exhaust gases blowing over them for months/years/decades.
But I digress.....  |
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Doctor Olds
I Need A Remedy For What's Ailing Me.
Premium,VIP
join:2001-04-19
1970 442 W30
clubs:
1 edit | reply to StNickless
said by StNickless :The "active ingredients" in a catalytic convertor are Palladium and Rhodium. Umm....those just happen to be metals. The ceramic substrate is just that, a substrate, which in this instance means : "•any stratum or layer lying underneath another". It is the ceramic that makes up the honeycomb, the precious metals coat said honeycomb and are the first *items* to leave via the exhaust stream. Wiki quote quote:
2.The catalyst itself is most often a precious metal. Platinum is the most active catalyst and is widely used. It is not suitable for all applications, however, because of unwanted additional reactions and/or cost. Palladium and rhodium are two other precious metals used. Platinum and rhodium are used as a reduction catalyst, while platinum and palladium are used as an oxidization catalyst. Cerium, iron, manganese and nickel are also used, although each has its own limitations. Nickel is not legal for use in the European Union (due to reaction with carbon monoxide). While copper can be used, its use is illegal in North America due to the formation of dioxin.
» en.wikipedia.org/wiki/Catalytic_converterPlease, if you don't know what you're talking (typing) about, don't keep spreading false info. Thank you. That is funny as the 3 precious PGMs (platinum group metals) that are in a Catalytic converter don't melt until well above 2500° F (two of them have melt points above 3000° F) and the highest temp a converter reaches is around 1400° F to 1500° F (Full Cherry Red) so there is no molten metal, just more misinformation and FUD. The ceramic substrate is wash coated with aluminum oxide first then it is wash coated with the Platinum, Palladium, and Rhodium. Less than 10 grams total Platinum Group Metal is used for all of the 3 PGMs together in a converter. That is smaller than the normal weight for a clad JFK Kennedy half dollar which is a whoping 11.34 grams for reference to how much metal there is washed on to the ceramic honeycomb matrix making it a ultra thin molecular coating.
Platinum has a melting point of 3214° F
Rhodium has a melting point of 3567° F
Palladium has a melting point of 2830° F
Aluminium oxide has a melting point of 3761° F
Stainless Steel has a melting point of 2552° F
Now to melt that coating would require a furnace and is not something that even a severe misfiring engine can do to produce enough temperature to melt any of the PGM metals since it can't even melt the stainless steel body or the aluminum oxide that was used to coat everything first to help the PGM adhere to the ceramic honeycomb carrier. Only the ceramic can melt at those temps from the excess fuel of a engine malfuntioning.
»www.catalyticconverter.org/failure/index.htm
quote:
Thermal failure is most often caused when excessive raw fuel comes into contact with the catalyst, and "burns" in the converter instead of in the engine. The high quantity of fuel generates temperatures well in excess of the capacity of the converter, causing meltdown of the ceramic monolith.
Plus the PGM metals that are coating the ceramic substrate is minuscule at best meaning very little is used usually under 10 grams on a large converter. 10 Grams and it doesn't begin to melt until temps are way above the melting point for the converter's stainless steel body/shell would have melted away first and that doesn't happen. They remain a solid even though the ceramic has melted.
Please don't keep continuously spreading false info.
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Doctor Olds
I Need A Remedy For What's Ailing Me.
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join:2001-04-19
1970 442 W30
clubs:
1 edit | reply to TheHarvester
said by TheHarvester : No I didn't try picking it up with a magnet because I new what it was and where it was coming from. I said "it looked like cooled molten metal" to give you an idea as to what I saw. Some pieces were over 1 inch long and about 1/4 inch diameter. Converters DO contain metal, some of the most precious metals on earth. That is all ceramic melt though (looks like metal, but it is not metal), as the 3 base metals require special procedures to remove them from the ceramic. The metal doesn't melt, it is a molecular wash coating on the ceramic. Only the ceramic substrate melts. The metal remains a solid since the converter cannot reach temps high enough to melt the PGM metals (one requires 2500° F+ while the other 2 require over 3000° F to get their melting points).
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What’s the point of owning a supercar if you can’t scare yourself stupid from time to time? |
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3SGTE
ST215W
Premium,MVM
join:2000-11-23
there
clubs:
| reply to retired17
Re: catalytic convertor causing fires
Who cares what it is made of, red hot **** can come out of the converter.
Theharvester has seen it first hand.
I have shaken melted blobs out of mufflers.
The scenario in the story is very unlikely, but not completely impossible.
Put millions of cars on the road, and the unlikely will eventually happen.
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Striving for Parfection. |
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TheHarvester
Premium
join:2006-08-25
Dana Point, CA
| reply to Doctor Olds
Re: catalytic converter causing fires
said by Doctor Olds : That is all ceramic melt though (looks like metal, but it is not metal), as the 3 base metals require special procedures to remove them from the ceramic. The metal doesn't melt, it is a molecular wash coating on the ceramic. Only the ceramic substrate melts. The metal remains a solid since the converter cannot reach temps high enough to melt the PGM metals (one requires 2500° F+ while the other 2 require over 3000° F to get their melting points). HOLY CRAP man, one last time!! I just said it LOOKED LIKE MOLTEN METAL for a visual perspective and that is it. I saw the crap fly out of the tail pipe. At this point I wish I had saved some so I could send it to you so you could have it analyzed. I am not disputing that metal needs very high temps to melt, and converter substrates need far less. I never once said it WAS molten metal coming from the tail pipe. The only point of my post was to inform you that the impossible is possible and has happened, period.
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