Sodium bicarbonate in air intake manifold - cleanup?

[ScottMeilicke]

I had a little fire today when the wires of the air heater on our Perkins 4-154 burned. I put the fire out with a sodium bicarbonate extinguisher. Since the air heater is just below the air intake, significant bicarb got into the manifold. The engine was not running. When I took off the intake hood to vacuum it up, I got most of the powder in the manifold.

My question is how thorough do I need to be? My plan was to vacuum, then mist the interior of the manifold with a vinegar/water solution, wipe it out, and repeat.

Any other advice?

One last thing - my neighbor has the same engine, but no air heater. Any reason I cannot just disconnect mine and cap the fuel line at the secondary fuel filter and the heater? Or I guess just pull the heater and cap the opening in the manifold.

Pre - vacuum:


Post vacuum (you can also see the heater):





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The Meilicke Family | Sailing Mango

[tkeithlu]

A pure sodium bicarb dry chem Type K extinguisher? Most type K (as in kitchen) extinguishers have some mica, calcium carbonate (chalk) and kaolin (clay) in the mix. Usual B-C dry chems found in boats, houses and everywhere except computer centers have a bunch of silicates, as well. I'm asking, because what was in your extinguisher makes a difference here - sodium bicarbonate by itself is not very abrasive, although it is used as a "soft" blasting medium, but the others are very gritty, and the extinguisher you are describing is a rare bird not often seen on boats. If it really is pure sodium bicarb, your plan sounds OK, but if not, I'd take the intake manifold off and clean it carefully - you don't want what amounts to sand in your cylinders.

[jamhass]

From the looks of the photos, the heater took the brunt of the powder and you cleaned it pretty well.

Is the heater removable to gain better access to the manifold behind it? If so, might be a good idea to try.

If you want to be a bit more thorough, maybe removing the manifold? but I suspect that might be getting a bit anal.

Some years ago I had an automotive engine fire at the carbs. Kinda similar to your situation as the air cleaner elements had burned away, so the throttle plates were all that stood between the fire extinguisher and the manifold. Nothing got past the plates. As in your case, the engine was not running.

I'm guessing you are likely good to go, but an extra effort will not be wasted, even if it only lets you sleep a bit easier...

[ScottMeilicke]

Contents (from the canister):

"Regular dry chemical / HMIS 1-0-0 magnesium aluminum silicate, sodium bicarbonate / nuisance dust, irritant"

The front says it is B:C, marine usgc approved. The canister further states "sodium bicarbonate based".

I did not clean the manifold any further, just vacuumed. I cleaned the air filter thoroughly, as it was about 25% clogged. I also vacuumed the entire engine, then blew air on the areas I couldn't reach, vacuumed, blew, etc, and finally sprayed down the engine with a very weak vinegar solution, maybe half a gallon worth.

The Mg Al Si had me worried now. I should have done more research.








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www.sailingmango.com

[sartorst]

Do everything that you can to clean the area up and as you know it gets in places you have not found yet I had an accidental discharge cause multiple corrosion problems including corroding a hole in an aluminum line to my refrigerator in just a mater of days this stuff is highly corrosive Afterwards I wished I had sprayed the area down with some type of oil like WD40 even if it would also be mess in itself
As far as the intake goes I would jury rig a small hose down to a size that could be inserted further into the intake runners and vacuum as best I could and as far as the heater goes it all depends on the temperatures you operate in and how old the engine is there will come a time when it may be needed

[sy_gilana]

I would remove the manifold and clean clean clean. That stuff will score the bores in no time, it turns into a solid abrasive layer, of carbonized gunk, picking up metal and it turns into a file. I have seen the damage it does.
Small cost of prevention vs. big cost of repairs.
Get rid of the heater, and if you need it, you can always use a hairdryer on those cold days.

[ScottMeilicke]

Originally Posted by sartorst

Do everything that you can to clean the area up and as you know it gets in places you have not found yet I had an accidental discharge cause multiple corrosion problems including corroding a hole in an aluminum line to my refrigerator in just a mater of days this stuff is highly corrosive Afterwards I wished I had sprayed the area down with some type of oil like WD40 even if it would also be mess in itself
As far as the intake goes I would jury rig a small hose down to a size that could be inserted further into the intake runners and vacuum as best I could and as far as the heater goes it all depends on the temperatures you operate in and how old the engine is there will come a time when it may be needed

Is it the baking soda that is corrosive? I know the chemicals in an ABC fire extinguisher are nasty, but didn't think the backing soda was bad.




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www.sailingmango.com

[reed1v]

Originally Posted by sy_gilana

I would remove the manifold and clean clean clean. That stuff will score the bores in no time, it turns into a solid abrasive layer, of carbonized gunk, picking up metal and it turns into a file. I have seen the damage it does.
Small cost of prevention vs. big cost of repairs.
Get rid of the heater, and if you need it, you can always use a hairdryer on those cold days.

Kind of like putting salt in a gas, or diesel, tank. Of course not quite like sugar which will really kill an engine. Good news is that you probably got most if not all of it with the vacuum. Given how dirty the air is that goes into a diesel, probably not the end of the engine by a long shot.

[dougal]

Think I'll stick to my old CO2 extinguishers. Useful for runaway motors too.

Sent from my SM-G900F using Cruisers Sailing Forum mobile app

[model 10]

I'm pretty proud if my good sized Halon tank, nice sunbrella cover, the works.
I was under the impression that if your engine was not running a dry powder exh is OK. Don't use water for clean-up inside the manifold because it creates a corrosive goop. I've cleaned up a number of aircraft engines that caught fire on start-up. If they had gotten it started it would probably put out the fire but they chicken out usually and stop cranking. I don't think I ever heard of someone doing more than an external clean-up.

[tkeithlu]

That's an unusual dry chem only in that it includes sodium bicarbonate. The problem is the magnesium aluminum silicate, "silicate" being gritty as in silicon, and magnesium aluminum silicate when wet is corrosive. Sodium bicarbonate when wet is also a salt and promotes corrosion, but it will neutralize any strong base or acid present. In all, it's nasty stuff to have in an engine, and instantaneously destructive in electronics. I consider dry chem extinguishers to be last resort in my boat given the damage they can do. The gritty corrosive powder gets into everything, which is what it is supposed to do, but it's so darned indiscriminate, as you found out. My first line of defense is 40 pounds of CO2 in a "sprinkler" system that floods the engine room; #2 is Halon through ports into the engine room or in the wheelhouse, and then fresh water for class A fires. I love the post about using CO2 to stop a run-away engine! I had not thought of that, and old Detroit Diesels like mine have a reputation for running away, and then eating their gaskets when you slam the air door shut. I have a hand-held CO2 - they are rare nowdays; I may move it to the boat! As you probably have guessed, I teach fire extinguishers to emergency services people as a volunteer, and am married to a chemist.