I bought a Airmar depth sounder with an in hull transducer. The installation manual calls for adding propylene glycol to the housing after securing it to the inside of the hull. I can only find propylene glycol in gallon containers and the install calls for 2.4 ounces. Has anyone successfully tried a different substance as I certainly don't need all that extra propylene glycol?
In hull transducer
- Thread starter sigsgmret
- Start date
Propylene glycol is recommended to prevent freezing in the winter, which in Florida is not much of an issue. Water will work.
If the boat is left in the water, you'll never have an issue. If the boat is stored on a trailer in the winter drain the water from the fitting so it doesn't freeze.
Yes, it is at a marina in the water. I'm just wondering about evaporation. I saw a post about mineral oil as a replacement. Maybe, I can try that.
It should seal well enough to avoid evaporation. If the water evaporates you'll know immediately upon turning on the DS, it won't read any depth. Pour some water in it. I had one once that had a slow leak that I couldn't stop, I'd prefer water sloshing around in the bilge than mineral oil.
So what does a gallon of propolene glycol cost? $5 or $6? Dump the rest out. It's safe to dump down the drain. You can also ask a marine repair shop for a cup or two.
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Buy a 1.98 wax toilet ring and make a flat oval of it, stick to inside of hull, and stick transducer in it.
It is the same stuff you put in your car as anti-freeze. Put the left-overs in your radiator... if your car is newer and has a closed cooling system, offer it for free on craigs list and someone in an old beat up car will come take it off of your hands.
Well I used plumbers putty and it worked great for a few weeks, now my transducer is dead. Coincidence? I dunno. Any the boat is locked up in a boatyard at the moment. What happens if they go bankrupt? So lets say got bigger things to worry about now.
Cars use ethylene glycol, which would also work provided it did not cause the plastic casing to deteriorate.
If a solid or sort of solid substance, like a wax ring or plumber's putty, is used it must maintain good contact with both the hull and the face of the transducer. The DS works by sending out a very high frequency ping, anything that attenuates the pinging will reduce the DS accuracy. Even air bubbles in the wax ring or plumber's putty.
The simplest cheapest option is water. That's what I used on my last boat with an Airmar in hull transducer. If the water evaporates or leaks, it is easy enough to refill it.
That is still true but more and more it is moving into the realm of "used to be true" as more and more cars are moving towards the more environmentally friendly propylene glycol.
ethylene glycol is toxic, propylene glycol isn't I bet mineral oil would work OK too or maybe olive oil or baby oil, perhaps KY but I suspect plumbers putty doesn't.
Installed one inside my previous boat, an '88 Hunter 33.5. Read about it in a sailing rag. I glassed a PVC coupling to the interior liner and then used a reducer to adapt the transducer to the glassed in coupling ( in the event that I needed to remove the transducer in future). Filled it with mineral oil and never had a problem with it.
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Plumbers putty works. You have to sand lightly to bare fiberglass and literally immerse the transducer in it and let it set in place overnight
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,843
The issue I found with Plumbers putty is they use linseed oil in the putty. This lasts for a while in a sealed environment but when left in the air tends to evaporate over time.
Toilet bowl wax “bees wax” has a longer exposed life span. I used it on my 15ft trailer sailboat.
Mineral oil does work, it was used in the transducer I have on my boat.
Some folk go the Epoxy path. This has the challenge that you need to assure no air bubbles occur in the mix between the transducer and the hull.
Toilet bowl wax “bees wax” has a longer exposed life span. I used it on my 15ft trailer sailboat.
Mineral oil does work, it was used in the transducer I have on my boat.
Some folk go the Epoxy path. This has the challenge that you need to assure no air bubbles occur in the mix between the transducer and the hull.
I have never understood why folks don't follow manufactures advice and epoxy it in place- Has worked on both my boats for years
It is a one-way street. And if you plan to sell the boat someday, broken remnants of old equipment permanently affixed to a hull are kind of a negative.