ROO - Black Soot on Rear of Boat !!!

RogerRat

RogerRat

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As per recent post last week, I said watch this space as I was about to trial a mod to the exhaust outlet.

The back of Panache is similar to all flybridges and I quickly came to the conclusion that they have similar characteristics to the rear of a 4x4 or an estate car. This means that a low pressure area of air behind the boat sucks any exhaust gases back behind the boat and some of the soot sticks and is a pain to clean off. /forums/images/graemlins/mad.gif

Panrearlow.jpg


I took a closer look at what was happening to the airflow around the rear qtrs. and you can see quite clearly that the fastest moving air is moving past the side very fast when planing.

I thought it may be worth making up a fairing to expel the gases out further into the fast moving air. I acquired some thick 8mm latex (stiffish) rubber and cut a template to create and extension the the exhaust outlets. The rubber was red, so I antifouled it so it would look less like a pig with one ear.

Portexhaust.jpg


This gave an extension of about 40-45mm further out and soon after it was fastened, I noticed that this fairing is standard on the Squadron. Hey I thought, this might work!

There was good news and bad, the starboard one fell off. /forums/images/graemlins/blush.gif /forums/images/graemlins/crazy.gif

Strbdexhaust.jpg

Sorry, a bit dark this morning.

The good news was that after a trip to Cowes and back, covering just over 30 miles, the Port side area was virtually clean and the starboard side smutty.

Realistically, the improvement was 90% ish, and the blessing was that by only having one fitted when we returned, I could see and compare the improvement.

MarkII will follow and when I've found the optimum, I may have it glassed in as permanent. The nice thing about a rubber extension is that if you do knock it when berthing it will just bend and not cause any other damage. /forums/images/graemlins/cool.gif

Not bad eh?
 
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who's a clever rat then. nice one.

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/forums/images/graemlins/blush.gif /forums/images/graemlins/blush.gif /forums/images/graemlins/smirk.gif

But then if I'd been really clever, they both would have stayed on. /forums/images/graemlins/crazy.gif
 
Thanks Roger, seems like you might have cracked it!!...on your boat at least!
Don't know about yours, but my exhausts are actually underwater at cruising speed, and the smoke seems to surface, be sucked up around the corners, across the transom and under the dinghy /forums/images/graemlins/frown.gif
Local Volvo place told me to try putting dinghy on foredeck to reduce turbulence, good idea but not very practical long term...
What glue did you use, would have to be very strong for permanent job!
 
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But then if I'd been really clever, they both would have stayed on. /forums/images/graemlins/crazy.gif

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But in all the best experiments they have the product under test and a control so they can see if there are any improvements ergo you have been clever.
/forums/images/graemlins/laugh.gif
 
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1. my exhausts are actually underwater at cruising speed, and the smoke seems to surface, be sucked up around the corners.

2. Local Volvo place told me to try putting dinghy on foredeck to reduce turbulence...


3. What glue did you use, would have to be very strong for permanent job!

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1. If your exhausts are under the water then it should be easier to crack, option of extending outlet as per 'hlb' (not 100 yards though) or you need my mark III idea which I will try if MarkII doesn't work. (MarkII = mods to exhaust. Mark III = mods to airflow)

2. Removing the dinghy certainly helps but doesn't stop soot so don't bother, it's not worth the agro. Keep looking at 4x4's and estates' with clean rear windows and mentally note the spoilers you see and we can compare notes. /forums/images/graemlins/confused.gif /forums/images/graemlins/grin.gif

3. The glue I used was just an evode contact adhesive. I wanted to use a 3M product called '1888V' but they stopped making it. I used to attached centre board gaskets to GRP on Tornados' and Div II boards so I knew it would hold in a salt water environment, but there must be some alternative. If the proto-types work then I shall find an adhesive or may even go to resin. These were attached reaching over from the swim deck so not too disappointing really. /forums/images/graemlins/blush.gif
 
Very impressive Roger.

I'm following this with great interest. Got the same problem on Suprendo, as have many other Phantom owners that I have met. There MUST be a market in aftersales on this one.

Don' tell Fairline, otherwise they will start fitting them as standard or an expensive extra!!
 
I'm not so sure that this a Fairline problem, most boats are blunt at the rear and as such will suffer with black soot contrasting on white hulls. But atleast we know they created a fairing for the Squaddie 56/59 so they may know more.

The nice thing about the rubber outlet wing is it's not overly sensitive on size. Most of the exhaust outlets I looked at were all different sizes. Possibly one size will fix all.

Sunseeker seem to get the exhaust out earlier, about 3/4 back along the hull into the fast moving air, interesting eh?


BTW. "It's hard to be a winner in a society dedicated to the glorification of the loser."

Losers are just as important as winners, there's more of 'em and you can't win without 'em! /forums/images/graemlins/crazy.gif /forums/images/graemlins/wink.gif
 
Unfortunately exhausts are on side of boat, so bit hard to extend with 100 yard pipe, or even 10cm pipe without them getting ripped off! /forums/images/graemlins/frown.gif
Think your idea of airflow and spoilers better idea and much cheaper than having exhausts re routed, although it may eventually come to that!!
Or perhaps when you've fixed yours, we could just swap boats /forums/images/graemlins/laugh.gif
 
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