Follow-up to my Float switch installation thread

[Jeff Hahn]

This is a follow-up to my thread on installing a float switch for my bilge pump https://www.bbcboards.net/showthread...9#post13442619.

I need some suggestions on how to fix the float switch to the hull. In order for the float switch to work correctly, it must be installed at the same level or slightly above the bilge pump. I'm installing this float switch in my small, 14 foot Lund. (The boat has a full floor, carpet, and a raised front deck. So, it's not a regular open floor type fishing boat.) The bilge area in the rear of the boat is divided in half by an aluminum panel with holes at the bottom to allow any water to flow from side to side. The starboard side takes up about 2/3 of the rear of the boat and houses two batteries (which sit on a small shelf), the bilge pump, and the livewell pump, as well as all of the hoses for both. The port side is where the 6 gallon portable gas tank sits on an elevated shelf. But, there is a section about 8 inches long and 6 inches wide at the center of the boat that is open down to the hull. There is no room to install the float switch on the starboard side so this area on the port side is the only area where I can install the float switch.

I have cleaned the grime from this area and am down to the bare metal. The question becomes how to install the float switch to the metal. In order to get the float switch level with the bilge pump, I need to elevate it. It turns out that a small piece of 2 X 4 is perfect for this. I will screw the float switch to the top of the 2 X 4. But, how should I attach the 2 X 4 to the hull? My idea is to use RTV silicone. But, to allow the silicone to grip the hull I will need to rough up the aluminum. Instead of doing that, I thought about installing a small piece of anti-skid material (the kind used on steps...see link below) on the bare aluminum and then using silicone on top of that to attach the 2 X 4. The glue on these anti-slip pieces is SUPER sticky, so I doubt that it would every loosen up. Then, I can also drill some holes in the bottom of the 2 X 4 in order to help it grip the silicone.

https://www.lowes.com/pd/SKID-GUARD-...p-Tape/3185621

(I wish I could simply use screws through the divider panel between the two bilge areas to hold the 2 X 4 piece in place. But, to do that I would need to remove several hoses, etc. to get access to the starboard side of the panel. Too much of a PITA if the silicone will work just as well.)

Whatcha think?

[Jeff Hahn]

Maybe some pics would help.

Starboard side
Attachment 546374


Port side
Attachment 546375


Small trough to mount float switch
Attachment 546376

[Lightning 6]

Again, I would simply replace the current bilge pump with an auto sensing bilge pump.

[JohnN]

I used JB Weld for this purpose in an older boat and it worked well. You do need to be careful not to use too much.

[bassnman81]

Again, I would simply replace the current bilge pump with an auto sensing bilge pump.

This simplifies everything you're trying to do.

[Jeff Hahn]

Again, I would simply replace the current bilge pump with an auto sensing bilge pump.

While this might be the simplest solution, I don't want to get into dismantling the current system, rerouting hoses, etc. I'll look into this if/when my current bilge pump breaks.

[Jeff Hahn]

I used JB Weld for this purpose in an older boat and it worked well. You do need to be careful not to use too much.

JB Weld would create a very permanent bond, right? Maybe I should use something that could be removed...just in case.

[5keepers2]

I like what your doing and why except one thing. I would not use wood 2 x 4. Get a piece of composite 2 x 4.

[Bill Reynolds]

What about sticky back Velcro? I use it to attach the battery to the side of my DIY Kayak transducer pole and it is very strong.
Have not tried it under water though.

[Jeff Hahn]

I like what your doing and why except one thing. I would not use wood 2 x 4. Get a piece of composite 2 x 4.

Good idea. I wonder if a store would have some scrap/ I'll have to call and see.

What about sticky back Velcro? I use it to attach the battery to the side of my DIY Kayak transducer pole and it is very strong.
Have not tried it under water though.

Velcro was one of my first ideas. I tried it, but I didn't think it was stable enough and I wasn't sure that the glue would stick well enough not to come loose.

[catdude28]

Jeff, as mentioned above, I would also use a piece of composite instead of wood. No worries with rot later on. To fasten, I have used a good 2 part epoxy (permanent though). BCB uses a product called Euroflex to fasten down many things. It is removable. I have also used a silicone ADHESIVE with success and it is also removable. Just put something heavy on top of the plastic piece until your product bonds. Velcro may not stick well in a wet environment.

[Jeff Hahn]

I got some composite material today on which to mount the float switch. I went to a local hardware store and ask what they had. Of course, everything was in a length longer than I wanted. I told the clerk that all I needed was a 6 inch piece. He took me out to their dumpster, picked out a couple small pieces and gave them to me, no charge! Good deal!

[CJ1]

3m makes a couple different types of marine adhesives just for this purpose. Silicone falls apart after a few years. Lexal is one that will work. Cj

[Rudeman]

I think you're overthinking it. Just replace the current pump with the automatic one. They usually have a manual override built in that you can activate using a switch. Use the same manufacturer's auto pump and it'll be virtually plug and play.