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Posts posted by BMW56

  1. I built a new exhaust manifold and mixer from stainless 2 years ago. I made a template from PVC water pipe first then fabricated from off the shelf bends. Worked out well and no issues so far. Bends and tube from Steel & Tube Stainless. Price was reasonable and their rep was very helpful. Had a mate help with welding. Only downside was the time it took but I had no other option as the old manifold was badly corroded and no original replacement available.



    IMG_20210220_122616626 2.jpg

    • Upvote 2
  2. Hi all,

    Not sure if anyone else on here has their boat moored at Cass Bay or Corsair Bay in Lyttelton Harbour. Unfortunately there have been multiple breakins to boats in the last couple of days, so it would pay to check your vessel.

    Also be on the lookout for any cheap boating gear offered for sale as is could be stolen property. I'm missing a Raymarine tiller pilot and a 5KW inverter as well as a few other bits.

    Cheers, Barrie

  3. I promised I would share some photos so here they are. New exhaust manifold fabricated from Schedule 40 pipe and the exhaust pipe and mixing elbow. Fitted it all up and tried it out on Saturday and it works perfectly.


    Mixing elbow.jpg

    • Like 1
  4. Talking about sanding antifoul, I have found using a tungsten blade paint scraper really handy for tidying up after water blasting. I have previously sanded (using No 5), but one of the guys in the haulout yard suggested I try this, and it worked a charm. Just takes a light run over to shift any lumps and bumps. I should say I'm not looking for a mirror finish but it was a huge time saver.


    Linbide Scraper 50mm

    • Like 1
  5. Thanks again for the replies. 

    Fish, the contact for The Engine Room sounds worth a follow up and Frank, that was a useful link you provided. All good info.

    I'm breaking the job into two parts. The first is to fabricate a new manifold for the engine, replicating the original one as closely as possible, but in stainless.  While we are doing that I'll investigate the options for the riser and mixing elbow. There's a bit of a plan taking shape, so I hopefully I'll be able to share some photos before too long (and be back on the water).

  6. Thanks for the replies.

    I have somebody lined up to help with the fabrication. He's a first class welder and machinist, though not much marine experience. We have a plan for making a new manifold and intend to keep that separate to the riser and mixer to make future repairs easier.

    I'm still not happy with the idea of hot salt water sitting in the bottom of the riser and condensing into the exhaust manifold as the engine cools, so I'm keen to see if there's a better way to do it. The previous owner had exhaust valve problems and had to do a head overhaul, so I suspect the current setup is causing problems. Bigal, I'll be interested to hear how you get on with the aftermarket Yanmar elbow. It could be a possible option. Otherwise we will have a go at building something.

    I've been wondering if a mixing elbow alone will be sufficient, and do away with the riser. One concern is getting enough cooling before the plastic muffler. It's quite close to the elbow and can't easily be moved. Any thoughts on how far away the muffler should be for the mixer to have done it's work? I checked the Vetus manual for the muffler but it wasn't much help - just says to keep below 70 deg C and connect to metal exhaust via a reinforced rubber pipe.

    There are some good options for bends and fittings at ANZOR and Steel & Tube stainless. Any thoughts on using standard seamed bends verses Schedule 10 or 40 seamless, or just threaded BSP pipe fittings like the one Frank made?

  7. Sadly the exhaust manifold and mixer on my engine has reached the end of its life and has failed fairly dramatically.  The engine is an older Isuzu and the original cast iron manifold has corroded fairly dramatically to the point where it broke (fell) in half while dismantling. You will see in the attached photo there is a stainless water jacketed riser and mixing elbow which are custom made. The water jacket is really just a second point of injection into a well which the exhaust gases flow through, rather than a proper jacket.

    Parts for the Isuzu are hard to come by, so it looks as if we will need to fabricate a new manifold. An engineer mate who looked at the current setup is worried that salt water sitting in the bottom of the hot riser causes water to condense inside the manifold when it cools, and has rotted it from the inside out. It certainly looks as if that could be the case.

    I'm wondering if this sort of exhaust setup is very common, and whether there might be a better way of doing it given that I am pretty much going to need to start from scratch.

    Thanks for any thoughts or advice. (The engine is in reasonable condition apart from this, so not considering a repower.)

    Exhaust 2.jpg

    Exhaust 1.jpg

  8. I have the same unit and while it's working OK the aluminium plate has become quite corroded. I had a go at removing the whole unit but gave up after removing the screws on the face plate and finding it was still well attached. It was going to be more complicated than I had time for that day so it's gone to the to-do list, but some maintenance is probably well overdue. To save me some mucking around, is somebody able to advise the best way to detach and remove the unit please? I'm thinking it may be fastened from behind where I can't see. Thanks.

  9. I'm also looking for a new insurer since Youi sold out to Tower. Have just received notification from Tower that they will no longer provide cover.

    I have checked with Nautical and they won't provide cover on a swing mooring. No luck either with State who I have my car and house with. Some helpful info in this thread, but I get the feeling it may be going to take some time and research to get this sorted. Boat is a Spencer 28 built in 1979.

    I also have had suggestions to check with Mariner and Club Marine. Does anyone have experience with them? Good, bad or otherwise. Any other suggestions of recent experience?


  10. I have my now 40 year old boat insured with Youi. No unreasonable questions asked, no survey required, happy to insure on a swing mooring, and the price seems competitive.


    It looks like all insurance premiums are taking a hike though. My business insurance (through State) jumped 25% this year. No claims and it seems other companies have made similar increases. Always worth shopping around.

  11. I had a break in last year. Toolbox stolen, and a torch, but the electronics weren't touched. Whoever it was broke the hasp off the hatch cover - probably with a large screwdriver. Not hard to get in if you really want to, and I agree with Puff about more damage if you make it harder.


    Since than I have put in an alarm siren that will sound if the washboards are lifted. There is a concealed switch in the cockpit to set it. Also a sign to say the boat is alarmed. No trouble since then. No longer leave a full toolbox on the boat either.

  12. Hi Kevin,

    3M make some good outdoor quality tapes. There are various types depending on whether you need stretch, strength or self amalgamating properties. I suggest visiting an electrical wholesaler as they will carry the professional quality products and should be able to advise on which one to use. Be prepared to pay a bit more than your standard insulating tape from the local hardware shop.

  13. I have a 12V Akai TV I picked up from The Warehouse that works well and cost a lot less than similar models from the RV shops. Built-in DVD player which gets used quite a bit, and both VGA and HDMI inputs to use with a laptop.


    I see The Warehouse currently has a 19.5" Veon with DVD for $179, and I think it runs on a 12V external power adaptor too. Could be a nice cheap option.

  14. When I did mine I made templates out of mdf which the plastics company was able to scan to make a digital file and then laser cut from. When I first approached them they suggested the mdf templates which I presumed they would cut around with a bandsaw, but they said it's faster and cheaper to laser cut. They turned out really nice and were a perfect fit.

  15. I'm not sure of confessing somebody else's sins counts, but if it adds to the thread....


    A few years back I set off for a weekend away on a mate's launch. We arrived a the Havelock marina quite late on Friday night and decided to fill up with fresh water before we headed out. In his tired state my mate managed to fill the diesel tanks with fresh water! Needless to say we spent all of Saturday at the dock pumping the fuel tanks. The only redeeming factor was that water and diesel don't mix well, so we were able to salvage most of the fuel. Lesson learned.

  16. You can get flap discs for an angle grinder that clean up stainless quite nicely. They come in various grades so you can start coarse and finish fine. They aren’t as aggressive as you might think. Bunnings should have them, but my local Mitre 10 doesn’t. Otherwise wet and dry sandpaper. Then you can use a kitchen pot pad to finish off. NOT a Steelo pad - never use steel wool on stainless as it will start it rusting. The synthetic pads like Scotch Bright work well but you will need to use some elbow grease. Then you can buff up using Autosol.


    If you are doing the work on the boat make sure you clean up any dust if you use a flap disc or sand, otherwise it will very quickly rust and stain paintwork.

  17. Once you have it nicely polished a wipe down with some olive oil will slow down any future tarnishing or staining. You can't use any coatings that keep oxygen away from the surface of the stainless, but the olive oil provides an oxygen permeable barrier to any salt and keeps the finish nice. It only needs a very thin film, but be careful not to make anything slippery that shouldn't be.

  18. I went with Youi.  1979 Spencer 28 on a swing mooring.  No need for a survey and the premium was quite affordable.  They were one of the few interested in insuring on a swing mooring, so I didn't have many choices.  Their only condition was that mooring inspections are kept up to date and done by an independent party (i.e. can't self certify).


    I checked out the policy against one offered by State Insurance (who did require a survey and would have required them on an ongoing basis) and the terms and conditions were very similar. State's premium looked like it would be half as much again, but they wouldn't provide a formal quote without a survey. I've not needed to make claim, so can't comment on my experience in that respect.  My other comment is that Youi's salespeople are quite aggressive keen.

  19. If you blow the engine room will be under slight pressure and fume laden air could be forced into the cabin via various fortuitous paths if there isn’t sufficient ventilation. On that basis it’s probably better to suck, then you can direct any fumes and odours safety outside.

  20. This stuff may be worth a try: www.ghostgloveusa.com


    It was originally developed for working with carbon fibre and epoxy resin. I got some from Mitre 10 locally, but can't find it on their website.  I found it in the cleaning products section.  I see it's also available on Amazon.


    There's also another one called Handshield Liquid Gloves that I have used in the past.  I think it is supplied through the professional drywall supplies outfits.  A mate gave me some to try, but I personally think the Ghost Glove is better, especially for mechanical work (grease, oil, etc.). 

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