Thread: hummingbird epoxy

Use a slow cure epoxy...12-24hr cure...

It should state on the package...

Be sure and test the spot first with the "hold down and add water to the bilge" test...

Rickie

i want to test it with a putty or somthing , will that hold up in water for awhile?

If you're looking for something to hold the ducer while finding the right spot, try plumbers putty, kayakers use it for long term installs of their ducers inside the hulls. After you find the right spot, use the epoxy.

I bought a single packet of the epoxy from HB less than 2 months ago, might want to try again with a different sales person.

Any slow cure two-part marine grade epoxy will do. The key is in the slow cure part. Stay away from anything with less than a 1 hour cure time, the 12 and 24 hour cures are best. Try to keep the air bubbles out while mixing it and always pre-test the installation location first.

I would think that plumbers putty would have small air bubbles in it and so would not work well under a transducer. Maybe to help build a dam to hold the water in but not under it. I would use a plastic storage bag with some dry dirt or sand in it to hold the transducer in place while testing.

Maybe I missed something. What are you going to use the epoxy for? If its for setting a transduce (TD) where are you going to mount it? Understand the TD sends out the sound and also receives the reflected signal back when the sound wave hits an object. Water is a great medium for transmitting sound . Air sucks and will attenuate the sound so that your reflection will be near Zero. Another thing you need to understand is the angle of incident is equal to the angle of reflection. So if the sound impacts something at say 45 degrees the reflected sound will be reflected at 45 degrees. That why you want to make the sound enter the water perpendicular to the surface of the water. This give you maximum reflection back to your unit. The sound is also scattered because surfaces are not perfect so the sound reflects in all directions but most is at the angle of incidence. You also have beam spread going on think of that as a flashlight and the area of the sound increases the further your away from the light source.The main strength is at the center so that s where we focus on.

Sound travels though different objects at different speeds. Starting from the transducer each interface you have will reduce the sound some what. The greater the difference in the materials ability to transmit sound the more sound you will loose. As air is a bad transmitter, thats why we cant hear each other from long distances and wales can hear each other for very long distances. Select materials with little air in their makeup.Thats also the reason you don't want air in the epoxy or what ever medium your going to use. You lose sound. Plastics, glass, metal, etc have little air in them while wood, concrete and bricks have lots of air in them. I would try using a silicon first as this would allow you to remove the TD should you decide you wanted to do something else. you could also try the set with Vaseline or petroleum Jelly as a temporary set up. It will let you couple to the surface and see how it will all work. Hope I didn't confuse or make this more difficult than necessary. If you have question you can PM me.

hi knot ....yea gonna mount it in the rear of hull(shoot thru) I did use some putty to hold it in place and went out the other day for a trial run and seemed to work pretty good but that was with the trolling motor only. motor wouldn't start due to corrosion on the ring terminals(fixed now). I have a small bilge area and limited space to put ducer so I basicly put it in the same spot as the last one, the other one worked good in that same spot. gonna do one more trail run with motor WOT and see what that does. I just bought some Loctite 2 part epoxy for marine use it says 2 hr. cure but it says full strength is at 24hr.(goog?bad?) before I epoxy it i'd like to tack it down the ducer first so it stays in place before doing the final epoxy....any suggestions.?

I have not used that epoxy before but know that the longer the cure time the better off you will be. Just make sure you are using it in the temperature range specified by the epoxy manufacturer. If you use it in at a cooler temperature the cure times will typically be longer and shorter if it is hotter.
I would use a plastic bag filled with dirt/sand/pea gravel to hold the transducer in place both while testing and while waiting for the epoxy to cure.