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Ceramic coating?
- Thread starter N941WR
- Start date
Ceramic coating
I don't have any personal experience with ceramic coating, but I'm going to get my exhaust coated. I spoke to a lot of the exhaust guys at OSH and they all said it's a good idea. Some even said that they used to not recommend it, but now they say they've been converted. They all said to make sure you get the coating that goes *inside* and outside. Don't just do the outside. Also, make sure you get the 2000?F coating, not the 1200?F version.
I don't have any personal experience with ceramic coating, but I'm going to get my exhaust coated. I spoke to a lot of the exhaust guys at OSH and they all said it's a good idea. Some even said that they used to not recommend it, but now they say they've been converted. They all said to make sure you get the coating that goes *inside* and outside. Don't just do the outside. Also, make sure you get the 2000?F coating, not the 1200?F version.
Dad's RV-10
Well Known Member
gmcjetpilot
Well Known Member
Cabin heat?
(And dont tell me your water heater core, Mickey
)
Where ya going to get your cabin heat from? GN941WR said:
(And dont tell me your water heater core, Mickey
)
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When having the pipes coated, you need to supply the heat muff and all clamps that you will have on the exhaust pipes to the person doing the coating so they can be coated, too.
The portion of the pipes where the heatmuff will be installed should not be coated if you want heat.
I talked to Cradin Industries (830 249-9580) about this and I intend to take mine there.
By the way, there is more than one type of coating. One to hold heat in & one to keep heat out. (Per Cradin) And, they come in chrome or black and maybe other colors as well. Their product is weldable. Go look at their site and you will see that they have quite a background in this stuff.
It's possible that ceramic coating can provide added HP, to some degree, but my main goal is to keep the interior of the cowling cooler. A friend of mine has this on his RV 4 and he is happy with it keeping cowling temps down; however, any boost in power is yet to be determined.
The portion of the pipes where the heatmuff will be installed should not be coated if you want heat.
I talked to Cradin Industries (830 249-9580) about this and I intend to take mine there.
By the way, there is more than one type of coating. One to hold heat in & one to keep heat out. (Per Cradin) And, they come in chrome or black and maybe other colors as well. Their product is weldable. Go look at their site and you will see that they have quite a background in this stuff.
It's possible that ceramic coating can provide added HP, to some degree, but my main goal is to keep the interior of the cowling cooler. A friend of mine has this on his RV 4 and he is happy with it keeping cowling temps down; however, any boost in power is yet to be determined.
gmcjetpilot
Well Known Member
Can you do that?
G
Cobra: I told you not to tell me that.
Hummm will having coating on the pipe cause a problem (thermal stress) where the coating starts and stops? I don't know I am just asking. Anyone try this, because I would like to do that but was afraid of this coating discontinuity. Thanks cool stuff, I mean hot stuff.sf3543 said:
GCobra: I told you not to tell me that.
Tandem46
Well Known Member
Exhaust question for RV8CH
RV8CH,
I'm also interested in coating my exhausts, I think there is entirely too much heat down there. You said "I spoke to a lot of the exhaust guys at OSH" May I ask who these "exhaust guys" were?
If the exhaust is coated inside and out, I don't see why Vetterman is worried so much about it. Coating just outside would seem to trap heat inside the metal, but coating in and out seems to me would only give heat only one way to go, out the end of the exhaust. Sound reasonable?
Tobin
RV8CH,
I'm also interested in coating my exhausts, I think there is entirely too much heat down there. You said "I spoke to a lot of the exhaust guys at OSH" May I ask who these "exhaust guys" were?
If the exhaust is coated inside and out, I don't see why Vetterman is worried so much about it. Coating just outside would seem to trap heat inside the metal, but coating in and out seems to me would only give heat only one way to go, out the end of the exhaust. Sound reasonable?
Tobin
dan
Well Known Member
And where's the heat?
I agree that coating inside & out is the way to go. People have mentioned "masking off" the exhaust where the heat muff goes, but that only works on the outside. If the inside is coated, then I would expect that the heat muff would barely extract any heat, even if the outside is not coated where the muff goes.
I use my heat pretty rarely but I do use it. I'm curious how people have tackled the heat thing when they've ceramic coated the INSIDE of the pipes.
Has anybody on this forum actually done this, or are we all just talking out of our ?
)_( Dan
RV-7 N714D (622 hours)
http://www.rvproject.com
I agree that coating inside & out is the way to go. People have mentioned "masking off" the exhaust where the heat muff goes, but that only works on the outside. If the inside is coated, then I would expect that the heat muff would barely extract any heat, even if the outside is not coated where the muff goes.
I use my heat pretty rarely but I do use it. I'm curious how people have tackled the heat thing when they've ceramic coated the INSIDE of the pipes.
Has anybody on this forum actually done this, or are we all just talking out of our ?
)_( Dan
RV-7 N714D (622 hours)
http://www.rvproject.com
gmcjetpilot
Well Known Member
I think I have a solution...
Then I was curious about thermal stress (#7). Exhaust cracks are a critical thing.
I kind of answered my own question. (Dan, this is where I talk out of my.... ) Just don't ceramic coat the entire pipe with the heat muff for the entire length. This may not work for the cross-over exhaust pipe, but I have a 4-into-1 (pic below).
My heat muff is on # 1 cylinder. Since the 4-into-1 is just four seperate pipes going to a collector, I could just not ceramic coat the #1 pipe. The collector is just a slip joint and held on with floating links. I could even ceramic coat the #1 pipe from the exhaust port flange to the slip/ball joint. The section of pipe should get as hot or hotter. Since the exhuast heats the metal and it is this hot metal that heats the air thru convectioin it should work. My pipes from AET (Aircraft Exhaust Technology) has the heat studs. These are like welded on with special equipment used in other stainless aerospace exhaust applications. (click to enlarge)
I love the idea of ceramic coating keeping under the cowl heat down. One side point is for us carb guys, is carb ice. Part of the reason Lycoming engines have little problem with carb ice is the heated sump and the fact the carb is cooking under the hot cowl. Heating the body of the carb itself no doubt contributes to anti-carb-ice. May be I am overthinking it or just talking out my...... Any ideas, or as Dan asked someone who has done this?
G
I ask the same question above on #4 Dan and the reply was mask the area off.dan said:
Then I was curious about thermal stress (#7). Exhaust cracks are a critical thing.
I kind of answered my own question. (Dan, this is where I talk out of my....
) Just don't ceramic coat the entire pipe with the heat muff for the entire length. This may not work for the cross-over exhaust pipe, but I have a 4-into-1 (pic below).My heat muff is on # 1 cylinder. Since the 4-into-1 is just four seperate pipes going to a collector, I could just not ceramic coat the #1 pipe. The collector is just a slip joint and held on with floating links. I could even ceramic coat the #1 pipe from the exhaust port flange to the slip/ball joint. The section of pipe should get as hot or hotter. Since the exhuast heats the metal and it is this hot metal that heats the air thru convectioin it should work. My pipes from AET (Aircraft Exhaust Technology) has the heat studs. These are like welded on with special equipment used in other stainless aerospace exhaust applications. (click to enlarge)
I love the idea of ceramic coating keeping under the cowl heat down. One side point is for us carb guys, is carb ice. Part of the reason Lycoming engines have little problem with carb ice is the heated sump and the fact the carb is cooking under the hot cowl. Heating the body of the carb itself no doubt contributes to anti-carb-ice. May be I am overthinking it or just talking out my...... Any ideas, or as Dan asked someone who has done this?
G
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Heat From ?
I am very interested in the exhaust coating idea, but my exhaust is from Sky Dynamics, and coating them would void the warranty. Every single "car performance guru" is a big proponent of coating, but all car engines are water cooled. I would think that the bare metal pipes radiating heat, would help keep cylinder head and exhaust gas temps lower.
As for heat. We will be taking the hot air from the oil coller. I did not want to have to worry about exhaust leaks and the plumbing is shorter.
My 2 cents...
Wade Lively
I am very interested in the exhaust coating idea, but my exhaust is from Sky Dynamics, and coating them would void the warranty. Every single "car performance guru" is a big proponent of coating, but all car engines are water cooled. I would think that the bare metal pipes radiating heat, would help keep cylinder head and exhaust gas temps lower.
As for heat. We will be taking the hot air from the oil coller. I did not want to have to worry about exhaust leaks and the plumbing is shorter.
My 2 cents...
Wade Lively
gmcjetpilot
Well Known Member
Why is it not approved?
I would worry about getting enough hot air from the oil cooler to be effective. Have you "engineered" this? Exhaust gas is well over 1,000 degrees F and is transferred directly to the air thru conduction and than convection. We know this works but even this can get over taxed at altitude and cold temps .
An oil cooler is only about 210F oil and has a very limited area? So you have cold 30F inlet air going to cooler. You raise the temp of the air to (X?). By the time you get it into the cockpit the air temp is (Y?). Is it enough volume/temp to offset the heat loss in the cabin thru air leaks and thru the canopy and fuselage? My point is there may be some mis-matched requirements here. I know the Long-EZ guys do it, but their cockpit is smaller and more insulated, plus I don't know how well it works for them in winter at 8,000 feet. Also as you fly higher the oil gets cooler and thus you have less heat.
G
Yes I heard that, but so many swear by the coating. I know wrapping the pipes with fiberglass wrap is a NO NO. It cooks the pipes. Also the wrap can get oil soaked and be a fire hazard.RV8RIVETER said:
I would worry about getting enough hot air from the oil cooler to be effective. Have you "engineered" this? Exhaust gas is well over 1,000 degrees F and is transferred directly to the air thru conduction and than convection. We know this works but even this can get over taxed at altitude and cold temps .
An oil cooler is only about 210F oil and has a very limited area? So you have cold 30F inlet air going to cooler. You raise the temp of the air to (X?). By the time you get it into the cockpit the air temp is (Y?). Is it enough volume/temp to offset the heat loss in the cabin thru air leaks and thru the canopy and fuselage? My point is there may be some mis-matched requirements here. I know the Long-EZ guys do it, but their cockpit is smaller and more insulated, plus I don't know how well it works for them in winter at 8,000 feet. Also as you fly higher the oil gets cooler and thus you have less heat.
G
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Exhaust guys
I didn't ask the question about how the ceramic coating affects the operation of the heat muff - sorry, it just didn't occur to me, but it's a good question.
The interesting thing I learned was that they felt ceramic coatings was no longer voodoo, but something worthwhile. As others have mentioned, it's not just for the exhaust systems, either.
I spoke to several different people, they were all over in the "fly market" area of OSH, and one was inside one of the buildings. I only have cards for two - Forsling Aviation out of Parker, CO, (no website) and Aircraft Exhaust Technologies, Inc. out of Barnesville, MN. I didn't get a card or brochure from anyone else. My main reason for visiting them was to find parts for hooking up the muffler on my exhaust. At least one, I believe it was Forsling, had a ceramic coated header in his booth, on an engine, and said it was for an RV10. That's what got us talking about the coatings.tobin said:
I didn't ask the question about how the ceramic coating affects the operation of the heat muff - sorry, it just didn't occur to me, but it's a good question.
The interesting thing I learned was that they felt ceramic coatings was no longer voodoo, but something worthwhile. As others have mentioned, it's not just for the exhaust systems, either.
Oil Cooler Heat
Interestingly, the guys that are already flying with this solution say it's not even necessary to have an on/off valve for the radiator - just let the hot water flow through there. If the fan is off, no heat is felt on your feet. It seems like it could work for oil...
I'm plumbing hot water to go into my cabin and run through a little radiator with a three speed fan - just like in your car. I guess running hot oil through there would not be more complicated.gmcjetpilot said:
Interestingly, the guys that are already flying with this solution say it's not even necessary to have an on/off valve for the radiator - just let the hot water flow through there. If the fan is off, no heat is felt on your feet. It seems like it could work for oil...
N941WR
Legacy Member
I do have ceramic coated headers on one of my cars and they do get hot. Hot enough to burn your hand on so I'm thinking they will still transfer enough heat for your carb and cabin but I'm not sure.
With the heater stubs G has on his header, they could leave those uncoated and I'm sure they would work fine, but don't ask me for a refund if I'm wrong.
With the heater stubs G has on his header, they could leave those uncoated and I'm sure they would work fine, but don't ask me for a refund if I'm wrong.
Tandem46
Well Known Member
Coating temp data
This is very interesting. Kinda old, I remember seeing it over 4 yrs ago. Click on site, then scroll down to table.
http://www.performancecoatings.com/benefitdata.htm
Tobin
This is very interesting. Kinda old, I remember seeing it over 4 yrs ago. Click on site, then scroll down to table.
http://www.performancecoatings.com/benefitdata.htm
Tobin
RV7Guy
Well Known Member
Coatings
Okay, maybe I'm missing something. Does anyone have any real information that this stuff works? Sounds like marketing to me.
Here are some of the quotes from this thread with my thoughts intermixed:
I spoke to a lot of the exhaust guys at OSH and they all said it's a good idea. Some even said that they used to not recommend it, but now they say they've been converted.
Where were these guys? I must have missed them...... What makes them feel converted?
I had them dropped shipped to Jet-Hot and was very happy with the final product.
Same question, what did it do for performance?
It's possible that ceramic coating can provide added HP, to some degree, but my main goal is to keep the interior of the cowling cooler. A friend of mine has this on his RV 4 and he is happy with it keeping cowling temps down; however, any boost in power is yet to be determined.
I would ask for evidence. What did your friend do to compare before/after temps?
I'm not trying to be confrontational on this issue but it definitely appears as if there is some good marketing out there. If it is so good why haven't the various exhaust manufacturers put their arms around this concept. Additionally, how much difference in temps is there? Is it a difference between 250 degrees without and 235 with the stuff. (Just throwing numbers out there). I'm not an engineer but it seems as if it would be better to let the metal do its natural thing and cool on its own.
I believe it we wanted to lower exhaust metal temps (actually, dissipate them quicker) we could have heat sink fins welded on them. The temps coming out aren't going to be changed so just how much temperature drop could be realized in a couple of feet exhaust.
Darwin N. Barrie
Chandler AZ
Baffles done/airbox work UGH!!
Okay, maybe I'm missing something. Does anyone have any real information that this stuff works? Sounds like marketing to me.
Here are some of the quotes from this thread with my thoughts intermixed:
I spoke to a lot of the exhaust guys at OSH and they all said it's a good idea. Some even said that they used to not recommend it, but now they say they've been converted.
Where were these guys? I must have missed them...... What makes them feel converted?
I had them dropped shipped to Jet-Hot and was very happy with the final product.
Same question, what did it do for performance?
It's possible that ceramic coating can provide added HP, to some degree, but my main goal is to keep the interior of the cowling cooler. A friend of mine has this on his RV 4 and he is happy with it keeping cowling temps down; however, any boost in power is yet to be determined.
I would ask for evidence. What did your friend do to compare before/after temps?
I'm not trying to be confrontational on this issue but it definitely appears as if there is some good marketing out there. If it is so good why haven't the various exhaust manufacturers put their arms around this concept. Additionally, how much difference in temps is there? Is it a difference between 250 degrees without and 235 with the stuff. (Just throwing numbers out there). I'm not an engineer but it seems as if it would be better to let the metal do its natural thing and cool on its own.
I believe it we wanted to lower exhaust metal temps (actually, dissipate them quicker) we could have heat sink fins welded on them. The temps coming out aren't going to be changed so just how much temperature drop could be realized in a couple of feet exhaust.
Darwin N. Barrie
Chandler AZ
Baffles done/airbox work UGH!!
Tandem46
Well Known Member
Reply to RV7Guy
Darwin,
Did you even look at the table two posts below your latest? Look at this table, here it is again: http://www.performancecoatings.com/benefitdata.htm
Wrapping/coating is definitely going to lower under cowl temps, no marketing about it. As for HP increase, I don't think RVers are interested in it for that.
Obviously the biggest exhaust guy in the Rv arena is Vetterman. I don't know why he hasn't embraced this, but probably for the same reason as others who don't embrace new technology, liability. There is no way Vetterman can control who/where/how coatings are done to guarantee they're done right, so he simply recommends not doing them at all. Wraps are a different story because they can retain moisture and lead to corrosion if not done properly. I need to talk to Vetterman because I don't understand how it could possible hurt the pipes if you coated BOTH inside and out. That should increase metal longevity, not decrease it.
Tobin
Darwin,
Did you even look at the table two posts below your latest? Look at this table, here it is again: http://www.performancecoatings.com/benefitdata.htm
Wrapping/coating is definitely going to lower under cowl temps, no marketing about it. As for HP increase, I don't think RVers are interested in it for that.
Obviously the biggest exhaust guy in the Rv arena is Vetterman. I don't know why he hasn't embraced this, but probably for the same reason as others who don't embrace new technology, liability. There is no way Vetterman can control who/where/how coatings are done to guarantee they're done right, so he simply recommends not doing them at all. Wraps are a different story because they can retain moisture and lead to corrosion if not done properly. I need to talk to Vetterman because I don't understand how it could possible hurt the pipes if you coated BOTH inside and out. That should increase metal longevity, not decrease it.
Tobin
mlw450802
Well Known Member
I think that functionally you are correct here. The issue with the oil cooler is that when you need the heat in the cockpit the least is likely when the oil cooler needs to be rejecting the most heat (It's hot outside..) so just turning the cooler fan off won't do. You would have to fabricate some sort of ducting that could be switchable from summer to winter.rv8ch said:
It may become a pain.
-Mike
gmcjetpilot
Well Known Member
Several things
If there is any significant HP increase from using ceramic exhaust coating, I believe it is more from turbo charger installations, which benefit from keeping heat inside the exhaust system, not for normally aspirated engines.
If there is any HP increase to be had in an Atmo engine, I guess it's keeping the engine compartment cool, which helps keep the fuel density higher (since the induction tubes are close to the exhaust). Cool air is denser air.
Also ceramic coatings may have less friction allowing less exhaust backpressure? However I agree the main goal is just to keep the temp down which has obvious benefits on wear and tear on the components under the cowl. I think it is an accept fact that ceramics will lower the radiant heat off the pipes. Is it worth it? All I know my old RV-4 would just COOK the top of the cowl after a flight, and I have seen other RV's with scorched or bubbled cowl paint from engine / exhaust heat.
As far as pipe longevity, leaving them alone is likely the best thing to do. We know that works. There are 30-year-old stainless steel pipes out there. Vetterman may have no interest in recommending it, since his product works without the coating, and there may be some down side yet determined. It is a fairly new thing for aircraft exhaust (no ceramic coated pipes with 30 years service around). If the ceraminc coating is not done well there is a chance of creating more problems than solving.
Welding heat sinks on the pipes, as was suggested, may not be a great idea since it might make hot spots and thermal stresses. Besides, you are still heating the engine compartment and the worst spot to have a heat sink is next to the induction tubes. Cracks tend to happen around welds. Again leaving the pipes alone is best from a "pure goodness to the pipe" standpoint. 321 stainless can get red hot, over and over for years with out degrading. They (the pipes) don't need cooling, it is the under cowl area that needs to be cooled. The RV's have very tight cowls and everything is very close to everything else.
From what I heard if you should get ceramic coating, get it inside and out coated and to the higher temp rating. G
If there is any significant HP increase from using ceramic exhaust coating, I believe it is more from turbo charger installations, which benefit from keeping heat inside the exhaust system, not for normally aspirated engines.
If there is any HP increase to be had in an Atmo engine, I guess it's keeping the engine compartment cool, which helps keep the fuel density higher (since the induction tubes are close to the exhaust). Cool air is denser air.
Also ceramic coatings may have less friction allowing less exhaust backpressure? However I agree the main goal is just to keep the temp down which has obvious benefits on wear and tear on the components under the cowl. I think it is an accept fact that ceramics will lower the radiant heat off the pipes. Is it worth it? All I know my old RV-4 would just COOK the top of the cowl after a flight, and I have seen other RV's with scorched or bubbled cowl paint from engine / exhaust heat.
As far as pipe longevity, leaving them alone is likely the best thing to do. We know that works. There are 30-year-old stainless steel pipes out there. Vetterman may have no interest in recommending it, since his product works without the coating, and there may be some down side yet determined. It is a fairly new thing for aircraft exhaust (no ceramic coated pipes with 30 years service around). If the ceraminc coating is not done well there is a chance of creating more problems than solving.
Welding heat sinks on the pipes, as was suggested, may not be a great idea since it might make hot spots and thermal stresses. Besides, you are still heating the engine compartment and the worst spot to have a heat sink is next to the induction tubes. Cracks tend to happen around welds. Again leaving the pipes alone is best from a "pure goodness to the pipe" standpoint. 321 stainless can get red hot, over and over for years with out degrading. They (the pipes) don't need cooling, it is the under cowl area that needs to be cooled. The RV's have very tight cowls and everything is very close to everything else.
From what I heard if you should get ceramic coating, get it inside and out coated and to the higher temp rating. G
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