Changing transducers — “So you have a 5200 problem?”

Ben Ellison

Ben Ellison

Panbo editor, publisher & chief bottlewasher from 4/2005 until 8/2018, and now pleased to have Ben Stein as a very able publisher, webmaster, and editing colleague. Please don't regard him as an "expert"; he's getting quite old and thinks that "fadiddling fumble-putz" is a more accurate description.

16 Responses

  1. Mark Morwood says:

    After struggling to enlarge holes with a hole saw in the past, I recently discovered this: . It makes enlarging holes with a hole saw much easier.

  2. Don Joyce says:

    I suppose you will be doing inshore surveys with the vast array of depth sensors you have now. It will be interesting to see the charts you produce.
    Also an excellent time to remind everyone to check seacocks regularly. I check mine during haulout by hooking up a garden hose to the inboard end to see how bad they might leak.

  3. Ben Ellison Ben Ellison says:

    That’s clever. The tools lets you chuck two hole saw blades at once, with the smaller diameter one forward to act as the guide. Thanks, Mark!

  4. Anonymous says:

    I lecture friends ever year… only use Sikaflex 291 or 291 LOT (Long Open Time) or 3M 4200 for transducers.
    Do the work two weeks before launch, dry fit everything first to ensure the hole is square. Then once you are ready for sealant, don’t fully tighten things up, wait a day or two, then apply the final torque to it.
    5200 is for permanent bonds, and 5200 Fast Cure, while good isn’t as strong. I used to use 5200 FC because I was in a hurry on a hull/deck joint, failed after 3-4 years, Regular 5200 never fails… to stick or break misfitted transducers.

  5. Ben Ellison Ben Ellison says:

    Good point, Don. That seacock looks fine, and its valve stem seems to turn smoothly with the handle. But water was shooting out of the hose at the same rate no matter which way I put the handle. I’m having a hard time imagining what is broken inside. I’m also unfamiliar with that particular type of seacock. Anyone know what may be happening?

  6. Richard C says:

    I have used heat on a bronze transducer through-hull to get 5200 to release. With the transducer removed, apply heat with a propane torch to the inside of the bronze through-hull opening. Use a handheld type of propane torch used by plumbers. When 5200 reaches 500 degrees F it will release and the through-hull can be removed with a few hits from the mallet, (from inside the boat).
    The tricky part is not allowing the bronze to heat the fiberglass hull it is mounted in. This is why you need to keep a charged hose at your feet. The sequence goes like this – heat – try the mallet and heat again until a few hits start the bronze to move. Once it starts to move stop heating and keep extracting the through-hull. Once you get it separated from the hull by a half inch you can usually get a pipe wrench on it from outside and rotate it out of the boat. Having an assistant do the hitting from inside the boat while you are heating from the outside helps make this a quick process, however I have done it singlehanded. Just be very careful with the heat and keep it off the fiberglass.

  7. Uh, Ben – How are you going to hook up all those transducers for testing? Don’t they all have specific connectors on the sounder ends depending on which sounder you’re using? I assume you have a plan to operate only one transducer at a time to avoid echo interference from each other….

  8. Richard C says:

    One more thing: The fumes from heating 5200 are highly toxic so use a mask.

  9. Don Joyce says:

    Can’t enlarge the photo showing the seacock, but it looks like a GROCO. From your description, it appears that the shaft and the ball have separated….hard to say. In general GROCO seacocks are very good. They did have the miserable experience of having castings made overseas and I understand that the supplier didn’t adhere to the GROCO specs. GROCO replaced all seacocks already sold, so I would trust them.
    Good luck!

  10. Bill Bishop says:

    Good Job Ben, the $4 saw was an excellent idea, I just bought one. It will be useful for other things also methinks. Adding to the tool list, I have collection of wedges made out of Starboard, cat paws (I de-claw them first so I don’t get scratched) and a 4″ angle grinder to remove recalcitrant transducer nuts in tight areas where I can’t get any leverage. An extensive pejorative vocabulary is a must for these jobs. I’m interested in the results you’re going to get. The Interphase stuff was always a little too inscrutable for my taste.

  11. Butch Davis says:

    In an emergency or when you cant put your hands on a pocket saw a steel fishing leader with a large key ring on each end may help get the job done.

  12. Allan Engler says:

    I would be concerned about turbulence affecting the aft transducer even at low speed

  13. Ben Ellison Ben Ellison says:

    Hope to be testing soon, Allan, but am not too concerned. Do you realize that the large Interphase transducer (photo #2) was the most forward of three for the last four seasons? A StructureScan and a DST800 transducer worked quite well behind that big lump, except for the paddlewheel. They always performed up through the 10-12 knot range and often faster if not too rough.

  14. Reed Erskine says:

    Hi Ben,
    I mounted the Interphase forward looking sonar on our 42 sailboat hoping it would be useful for gunk-holing in shallow coastal areas. With the boat at rest in calm water it would “see” underwater objects with satisfying clarity, but when the boat was moving, or there was any turbulence, its ability to see things diminished rapidly. It turned out to be of little use and I replaced it with a conventional Airmar sounder. I hope your experience is better.

  15. Avery says:

    Bears repeating: “An extensive pejorative vocabulary is a must for these jobs.”

  16. Jeff Field says:

    Hi Ben,
    I just wanted to let your readers know that there is another alternative for removing 5200 called Unhesive. It is a 5200 remover developed by a chemist in Florida. It doesn’t use stinky or slick solvents or petroleum based materials, but rather a mild water based chemistry which releases the adhesive bond between 5200 and the substrate. Can’t hurt wood, fiberglass, aluminum, etc., and doesn’t leave an oily residue or stains on the deck.
    You also get a big 8 oz bottle rather than a tiny 1oz spray can, so it is great for larger projects. Also removes expanding foam and some other adhesives. Great stuff. See http://store.marine

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