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Cabin smoke

Guilhermepilot

Well Known Member
Hello captains

Sometimes during taxi/ runup the LH lower corner of my firewall allows smoke through (white warm smells oil)
it takes a minute then is over
I think I will seal my Firewall I did not during construction, could be an oil over ehxaust?
 
Why would you do this Steve? Any reason other then easier disassembling?

Vlad,
As I understand it the ball joint on the exhaust needs to stay free (lubricated) so the exhaust can flex. If the ball joint freezes up then they will flex (break) somewhere else.
 
Vlad,
As I understand it the ball joint on the exhaust needs to stay free (lubricated) so the exhaust can flex. If the ball joint freezes up then they will flex (break) somewhere else.

Got it. I somehow thought the hanger hoses were the main flexers. Replaced all of them recently but never touched the ball joint.
 
Steve,

I will check my ehxaust, you gave a clue, that maybe a crack could lead smoke to firewall, anyway, I will seal it off

Thanks
 
I'd seal it off.

It's not just a fire wall, it's a smoke wall and a CO wall of sorts, too.

I've gotten very accustomed to the odor of scorching oil in the cockpit after an oil change and the inevitable spillage of a few drops into places like the heat muff, where wiping up isn't easy.

This condition inspection I noted a few tiny gaps of daylight along the curved top of the firewall while "in the position" checking wiring, avionics, etc under the panel: gaps that had been left unsealed for nearly 20 years. I bought a fresh tube of red RTV and went to work on them. Ounce of prevention.

-Stormy
 
I would get this sealed befor another flight!
Think Carbon Monoxide poisoning. This could really ruin your day.
 
Why would you do this Steve? Any reason other then easier disassembling?

Vetterman actually recommends putting mouse milk on the ball joints every time the cowl is off. I think when that joint can move freely it puts less stress on the exhaust hangers,
rubber cross-ties, and generally less stress on the whole exhaust system.
 
Vetterman actually recommends putting mouse milk on the ball joints every time the cowl is off. I think when that joint can move freely it puts less stress on the exhaust hangers,
rubber cross-ties, and generally less stress on the whole exhaust system.

I agree with Jeremy. I use mouse milk every time the cowl comes off.
 
I sealed my firewall, it is very complicate to access all spots, my back hurts! Let's see if it stops, fact is I was worried about source, but aft a long research I found no evidence of anything wrong.
Some smoke build up and gets its way to cockpit on ground with low speeds and RPM, smoke don't dissipate like in the air when you are fast, I also tightened some bolts on engine and checked my ehxaust.
 
Veering a bit off topic. Mouse Milk is a penetrating oil. 50% or more of it is Toluene, a solvent. We are not really lubricating the joint. A petroleum based lubricant, another 30 or 40% of the make up of Mouse Milk, will just burn off.
What we are doing is breaking down the carbon build up from the oil laced exhaust that will creep in and freeze up that joint.
 
Preventing seized joints

Since we are off topic; after buying my 6A I discovered the exhaust ball joints seized. When the exhaust came off to attend to an oil leak I went to work on the ball joints with a wire brush. It was a slow process of working the contamination out of the joint where the brush wont reach, but with about an hour of effort the joints were free and smooth. I now apply mouse milk to the exhaust joints every time the cowl is off.
 
Thanks for mouse milk :)

I sealed my firewall, it is very complicate to access all spots, my back hurts! Let's see if it stops, fact is I was worried about source, but aft a long research I found no evidence of anything wrong.
Some smoke build up and gets its way to cockpit on ground with low speeds and RPM, smoke don't dissipate like in the air when you are fast, I also tightened some bolts on engine and checked my ehxaust.

What about CO? Is anyone using a CO Detector? I am thinking to install this one:
http://www.aircraftspruce.com/catalog/pspages/fds_gd40carbondet.php?clickkey=2026276
Any better advice? :eek:
 
Domestic CO detectors

I wont comment on dedicated aviaton CO detectors, but if you're still using an old black-spot type I'd suggest that domestic CO detectors have improved and some are worth considering for use in experimental aircraft. Any CO detector that complies with the performance requirements standardised in EN50291-2010 will have appropriate exposure levels and response times.

My RV now has a hardware store CO detector like this positioned on the lower right side near the heater outlet:
http://www.quell.com.au/collections/carbon-monoxide-alarms/products/carbon-monoxide-digital-display-alarm

Not saying don't use an aviation CO detector, but I don't think a compliant domestic CO detector is any less safe, and would surely provide a better level of safety than a black-spot type. And the independent 10 year power supply is nice.
 
Beware of generalisations about CO detectors

Mike Busch has a great webinar on CO monitors, and why home monitors are *not* a good solution for aviation.

http://www.eaavideo.org/video.aspx?v=4598110268001

Saw the webinar some time ago and I encourage people to watch it. As always, Mike presents some very good information. But Mike is up front that he is giving his own opinions about alarm thresholds, and for that reason, that aspect of the webinar warrants some critical evaluation. That's what led me to a domestic CO detector that is right for my aircraft and that I have a high level of confidence in.

The basis of Mike's criticsm of domestic CO detectors is they have an alarm threshold of 70ppm after 4 hours, which he says is too high and I don't disagree.

That high alarm threshold may be true of all domestic CO detectors sold in the US, I don't know, I haven't studied their specifications. But it's not true of the domestic CO detector that I have in the RV, nor is it true of any CO detector that complies with the European standard, which will alarm at 50ppm after 60 minutes or at 300ppm in less than 3 minutes. Certainly more sensitive than 70ppm after 4 hours.

My CO detector is designed for mobile use (boats, campervans etc) so it's robust and a much better alternative to the black spot type. For less than $50 I think a domestic CO detector with appropriate alarm thresholds presents a compelling safety argument for renters or owners not wanting a panel mount.

Coincidentally, the CO detector in my RV alarmed for the first time today. The engine was not running at the time. I was about to take an aircraft mechanic for a local flight and as he was climbing into the passenger seat the CO detector chirped twice. He had just come from ground running a radial engine and I'm assuming he brought a cloud of CO along in his clothes. That's sensitive enough for me.
 
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Brand ?

My CO detector is designed for mobile use (boats, campervans etc) so it's robust and a much better alternative to the black spot type. For less than $50 I think a domestic CO detector with appropriate alarm thresholds presents a compelling safety argument for renters or owners not wanting a panel mount.

Malndi,
What brand/model is your CO detector? Would you mind to give us a hint where it is from? Thanks !
 
CO detectors are not a bad idea, but I think a firewall leakage test should be higher priority.

In a dark hangar, have someone pan a bright light over the entire fwd face of the firewall while you are inside looking from the rear. There should be zero light penetration to the back side,
 
Thanks Malndi,
for your help! 11ppm indication is really good. I ordered one unit from Kidde in the UK , looked good for 38 ?. We'll see what will happen.

All the best and always happy and CO free landings
 
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