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Poor mans exhaust silencer

Discussion in 'Technical Discussion' started by Capt Ralph, Oct 5, 2014.

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  1. Capt Ralph

    Capt Ralph Senior Member

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    Bert 1.JPG

    Poor mans exhaust silencer.


    Note the 10" rubber elbow. Clamped on and the suspension bracket from the platform is also bolted to the 10" tube further capturing the elbow.
    Holes in the side are for idle pressure relief. Rev 1 without the holes sprayed water everywhere. Now just a little spray out those holes. Next time I'll know not to drill holes to the outside and keep the docks dry.
    The downward part of the 90 I cut off. You can just see a little leading lip and the back edge about 1 inch higher like a bow thruster tube brow.
    Does a great job reducing noise and the 1000/1100 rpm howell. At speed, the elbows are out of the water just deflecting the noise down toward the water. No back pressure. At low speed, they just blub blub and we can talk in the back of the boat and to/from the dock.
    Exhaust rubber, nothing sticks to them but some grass.

    I was looking for 10" pvc to experiment with but found these at a surplus shop. If your exhaust is smaller, say 5 or 6", give that PCV idea a try and experiment before you plunge into the rubber exhaust part$.
    Factory 10" exhaust tube came out to swim platform back edge. The back edge of the swim platform had 35 years of abuse, Rebuilt it and added another 18" to boot.
    So this is a twofer, exhaust and bigger deck project.
    Last edited: Oct 5, 2014
  2. weto

    weto Senior Member

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    SWEET ! Adapt and over come as my dad ALWAYS says. :)
  3. K1W1

    K1W1 Senior Member

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    Geez Ralph, If you hadn't dumped those bits you drilled out you could have stuck them back in with 5200 and had no more problems spraying the dock.
  4. Capt Ralph

    Capt Ralph Senior Member

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    You remember The Wizard of Oz movie, where the ScareCrow was singing;
    If I only had a ,,,
  5. P46-Curaçao

    P46-Curaçao Senior Member

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    Nicely made Ralph, but curious what others think of back pressure issues on a SF, our sterns go down when we push the throttle…
  6. Capt Ralph

    Capt Ralph Senior Member

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    Well, the stern does go down (it is the Bertram 58 hull), worse at the end of those tube extensions. Right when the resonance of the motors ring in the ears and drive me to drink (another good excuse).
    Closer to a SF hull, I think they would work better.
    Often wondered why Bertram put those tube extensions on the MYs.
  7. dennismc

    dennismc Senior Member

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    How about turning the 45 ell inboards might keep it enough out of the water to be effective ?
  8. Old Phart

    Old Phart Senior Member

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    I dunno
    Mod the holes with an elbow - Street 45 or 90, angled back.

    RCExhaustElbows_Sch40Fittings.jpg
  9. Capt Ralph

    Capt Ralph Senior Member

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    I only had two elbows and in 10". I had a lot of after thoughts and you kids are there and thinking also.
    So, Let me say, it works and any improvements are up to the next generation of poor kids with a exhaust noise issue and plan.
    Keep us all up on the next generation of redneck exhaust.
  10. Old Phart

    Old Phart Senior Member

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    I dunno
    Only noticed two drilled holes on the outside.

    Figured two x two = four small pipe elbows glued-in,

    would divert the flow from the dock.

    Actually, thought you might have some

    in your collection of rainy day odds and ends.
  11. SomeTexan

    SomeTexan Member

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    If you want it more redneck, paint the pipes red and call them cherry bombs... Looks like a good solution as is.
  12. Capt Ralph

    Capt Ralph Senior Member

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    It's not my feet getting wet, I'm driving das boot where it's dry.
    Something like a plug is on the list,, near da bottom of da list ,, way down da list,, need a flashlight to read it.
  13. Capt Ralph

    Capt Ralph Senior Member

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    Some call it pink, you may accept red, I called it SHRIMP and sticking to it.

    Bert on Hill  Nov 2012 060a.JPG
  14. SomeTexan

    SomeTexan Member

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    Lol, I like it. Add white candy cane stripe to the propshaft and it would be perfect.

    On a only somewhat related topic, I used to paint u-joint, ball-joint and tie rod ends pink on my off road toys because I could blame the pink part when it broke.
  15. Capt Ralph

    Capt Ralph Senior Member

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    I was experimenting with hard bottom paint on the running gear. The kids at Huckins has some white & some red Vivid and offered it to us. This pic was in November 2012. While diving under Josea the next summer off of Taloo Kay, most of it was intact. It's still SHRIMP, not pink.
    Our diver reports this summer that most of it is gone now and he is cleaning the hardware as usual.
    The Pettit Pro is still in great shape on the hull.


    Bert on Hill  Nov 2012 023a.JPG
    Last edited: Oct 8, 2014
  16. SomeTexan

    SomeTexan Member

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    I will accept shrimp, works for me for a light-ish red color. I wasn't calling it pink, just explaining how this 100% masculine, 6'4" southern boy justified the use of straight up flamingo pink on my rock crawler.

    Have you tried powder coating? I know a local lake marina offered an anti-fouling powder coat for lower units and aluminum hulls that were stored in the water. I don't know if it would be worth the time/effort/expense, just curious.
  17. Capt Ralph

    Capt Ralph Senior Member

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    Well, I'm a lil taller, wider, heavier (I'm sure) and wish I was from Texas. And, YES, I think I'm 100% masculine until my wife wanted that light-ish red,,,, I mean SHRIMP paint that the kids mixed up on there.

    Powder coating I had thought was baked on, like in an oven... Somebody can put a boat in an oven?

    Here in south Georgia (N Florida with pine trees), the silt, sand, tannic, gators and manatees is hard on the running gear and it usually does not last long (the paint). I thought it was cool for the hard paint on the gear to last 8 months and 600 miles.
    Last longer than that d$%m speed prop stuff.
  18. SomeTexan

    SomeTexan Member

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    They can us infrared heaters to bake it on. Reflective covers on stuff that doesn't need the heat. And there are shops around that have ovens you could put a stack of semi truck flatbeds in.

    I have zero experience with under the waterline coatings in saltwater. I thought you were looking for a more permanent solution, so I offered a suggestion. I am curious as to how different stuff holds up, and how well it resists fouling.

    As for props, the last one I messed with got magna fluxed after every pass, and "cleaned up" after every weekend. Throwing a blade sucks...
  19. Capt Ralph

    Capt Ralph Senior Member

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    I had thought about porcelain coatings but could not get any interest. Outboards and I/O drives I think are powder coated already somehow and hold up (with use and cleaning) pretty well. I'll have to think a lil more about your idea and see what I can experiment with, ya know these budget constraints I have to live with only allow so much past shrimp paint.
    ,rc
  20. SomeTexan

    SomeTexan Member

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    Porcelain could be neat. I would think it would have a better wear resistance than most powdercoats, but lose larger chunks with impacts. I am looking for a classic steel boat to refit/restore, and have wondered how viable of an option doing the whole hull, inside and out, with powdercoat would be. Probably a dumb idea, but one of those random thoughts I have started looking into. I would have to be seeing longterm advantages before I would throw much money at it though.