View Full Version : Depth Finder Problems

09-25-2007, 10:35 AM
I'm having problems with my depth finder. It is a Lowrance model. The transducer (hockey puck looking thing) is mounted next to the V-drive transmission. It is a shoot through hull. The problem I'm having is the readout will be working fine one minute and then it will go to a dashed line -- I can flip the power switch off and on and sometimes that will fix the problem but most of the time it will just not work for quite a while. Then it will mysteriously start working again after a couple of hours. I've tried mashing the transducer down once it quits working with mixed results. Anybody got any ideas of what this is and how I can fix it? Thanks for any help you can give me.

09-25-2007, 10:41 AM
you need to have a good coat of epoxy between the tranducer and the hull. If you are able to mash it down that means there is air between the transducer and hull. I suspect it works when water fills the void between the boat and transducer. Take the transducer out, and reglue with waterproof epoxy. Do not use silicone glue.

09-25-2007, 11:46 AM
G-Man - you may be onto something there. It does seem to work better when my boat has water in the bilge (another issue I'm having).

If I were to remove the transducer and re-epoxy it how would i do that? Would I just pry it loose with a screwdriver or chisel and then use a two part epoxy to re-epoxy it? Do I need to clean the site and transducer before replacing it? How do I make sure I get all the bubbles out of the epoxy? Any tips/tricks for doing this? Should I put it in exactly the same spot or move it slightly?

I really appreciate the help.

09-25-2007, 12:25 PM
If you can mash it then definately something wrong there. It should be solid against the hull with no air bubbles. It will not read otherwise!!! I had recent problems with mine and the dealer re-mounted it and now it works great. There must have been an air bubble in the epoxy which was preventing it from reading correctly. My thread here.


09-25-2007, 01:03 PM
G-Man - you may be onto something there. It does seem to work better when my boat has water in the bilge (another issue I'm having).

Should I put it in exactly the same spot or move it slightly?

If you are not sure if it is located in the best spot, water in the bilge is a good way to test different locations before re-gluing. If you leave the puck in an inch or two of water, there will be no air and it can shoot through the hull (and the water) without problem. That way you can put it in a few different places and try it at speed and will moving slowly or not moving at all to see that it always gives you the best reading. The only issue with this approach is it will move around when at speed, so you need to weight it down with something to try each location.

Good Luck.

09-25-2007, 02:36 PM
When the boat is at speed and the depth finder is working (not giving me a -- reading) the depth finder gives me good readings except that every once in a while it will go from a normal depth to a really deep depth (e.g. 18' to 175') really quick when i know it's not that deep. So I'm fine with the readings its giving me when it's working it's just that it doesn't always work.

I was asking if I should move it mainly because I was worried about any epoxy residue that would have built up in the old area.

09-25-2007, 05:05 PM
I would not change the location of the depth puck, chisel it out, then clean off the surface area of the puck and bilge with a chisel and sanding tool. Make sure to not gouge the puck, you do want a nice clean surface at the bottom of the puck, get all of the epoxy off untill you see the black surface of the puck. After all epoxy is removed from the puck and "dry" bilge wipe both down with acetone. Use a good two part epoxy to bond the puck to the dry bilge, use 1/2 of the tube. Put a good amount of pressure on the puck with your hand to make sure that no air is allowed between the puck and the bilge as it sets. hold pressure for 3-5 minutes or untill you are sure the puck will not move. You should now be in back in business.

09-26-2007, 03:16 PM
this is good stuff.

My depth guage works most of the time, but sometimes it's jumps to 25' and even 275' when the deepest my lake gets right now is ~12'.

It's done this since I bought the boat last September.

It sounds like I may have a hockey puck problem.