Black soot on stern from exhaust ..

[Refueler]

I've tried everything to stop the soot staining on stern from exhaust. I have extended the exhaust 3" out from stern to try and stop it staining. It blows into the water but I still get that horrid load of soot.
The line also shows the amount of stern squat when under power ...

Anybody found a cure ? (Ok - grease-buster cleaner get's it off ...)

 

[Cliveshep]

Change the type of coal you use?

Or fit an elbow to discharge under the water?

 

[MoodySabre]

I don't get this problem but the exhaust on a Moody 31 is under the water. Could this be the reason?

 

[willie4646]

Agree with cliveshep, i've seen a few boats using ordinary pvc drain elbows to over come this problem.
Willie

 

[clyst]

service your engine that will stop most of it . Black smoke too much fuel .

 

[ianat182]

Yes PVC pipe about 4"protruding and cut off at 45 degree angle longest edge at bottom. Shoots the smoke away from the the reverse flow of water which holds the soot to the hull.
Worked for me - well, the boat anyway!

ianat182

 

[johnalison]

My engine doesn't produce much visible smoke but the whole area around gets stained and a bit sooty. I just clean it thoroughly every now and again and polish in the hope that this will stop it staining the gelcoat. Not much of a solution, but the hull still comes up white after 10 years.

 

[SailJonah]

I think you are burning too Much Fuel. Service the engine. I had this, serviced / cleaned the Injectors (By a specialist) - lovelly nice Smoke.

 

[NormanS]

Well, it serves you right, you are always going on about rubbishy fuel that you use. /forums/images/graemlins/laugh.gif

 

[Refueler]

[ QUOTE ]
Well, it serves you right, you are always going on about rubbishy fuel that you use. /forums/images/graemlins/laugh.gif

[/ QUOTE ]

Yeh - I suppose I do deserve it ... I don't use the fuel we blend for you lot - I use my own concoction. Basically all the lab stuff that drops out of retention date. So my mixes can be 'interesting' ...

But the soot is annoying. Some here say it's because too much fuel injected / unburnt etc. Maybe .... but probably because I do have heavy heating oil mixed into my drums.

The exhaust is extended about 3" and is under water when motoring along, it's only just above surface when stationary.

It does clean off ok, but now with change of dock at the house, I can no longer get easily at it from pontoon. It's now a dinghy job.

Oh just to show that I'm now able to boat again out here ... yesterday (17th) we 'broke out' and had a marvelous day on the river ....

 

[chrishelen]

Re stern squat,

There is an interesting article regarding stern squat on the "Eventide owners" site,you can cure it quite simply but it involves drying out, re your sooty stern, i remember an article a while back about some RN MTBs i think with the same problem their solution was to paint the whole hull black, just an idea.

 

[sarabande]

would it be worth trying some of that miracle windscreenstuff that CSAIL is flogging ?

If it stops water adhering to windows and glassware, then it might be worth covering the transom with it.

Rainracer ?
http://www.rainracer.com/
is this the stuff. I think Roger Rat recommends it.

 

[Refueler]

[ QUOTE ]
would it be worth trying some of that miracle windscreenstuff that CSAIL is flogging ?

If it stops water adhering to windows and glassware, then it might be worth covering the transom with it.

Rainracer ?
http://www.rainracer.com/
is this the stuff. I think Roger Rat recommends it.

[/ QUOTE ]

I've used all sorts of polishes, coatings, all reckoned to stop staining and wipe away muck'able ... still there !!

Mmmmm local shop has same stuff for windscreens - never used that one ... worth a try !

 

[bluedragon]

Got the same problem as you. Got an extension tube from the exhaust, recent injector overhaul, no smoke from the engine. Still builds up over time no matter what I do. I think it's just a question of old gelcoat that's a bit porous. I do wonder if one of these acrylic sealer coats used on car paintwork might help? Might give it a try this year as I've just cleaned the trasnom.

 

[hlb]

Shouldnt need to tell you this.

Stick some Soltron in the tank. /forums/images/graemlins/grin.gif

 

[ksutton]

I really doubt that its anything to do with the quality of the gelcoat. I have a relatively new yacht, 1,500 sea miles and approx 150 hours on the engine. I also suffer from soot on the transom, my exhaust sticks out the transom by about 20mm only. Engine runs perfectly, is serviced properly and is proped correctly. Reading the amount of complaints here, it would point more towards fuel quality in my book. But interested if anyone has any other suggestions

 

[Mandarin331]

Is this really curable? I get black soot buildup on the chrome tailpipe of my car since new, serviced regulary, run on the very best BP roadfuel.

On the boat I just wipe down the transom with GRP cleaner every now and again.

 

[ksutton]

Agree, I doubt if it can be cured and yes most diesel cars exhausts are caked with soot at the outlet. I had a diesel estate car, which used to have a blackened tail gate after a longish journey. It may be more noticeable on boats with transom outlet exhausts and less with side outlets. A vacuum created at the transom and back flow of water is what causes the stuff to stick or hang around the transom.

 

[omega2]

Not too much fuel, too little air, is your air filter clean? has your engine room got enough vents, have you covered any airways up.

 

[steve28]

What about the propeller pitch, noone has mentioned this yet, i had a new prop that had 1/2 to 3/4 inch too much pitch and it created this result with the soot. Mainly when using the engine over 1/2 throttle.
I got the pitch taken off and it been perfect ever since.
Also worth mentioning is that if the batteries are quite discharged it will load the engine up even more and you get more soot.

Steve