swim platform

[Florida Man]

i have a swimplatform on my boat believe its aluminum tubing with stainless bolts.im having bad pitting on the part that goes under water boat doesnt stay in the water.its fairly new took it back and they replaced the foot on it but after one time in the water seeing signs of pitting again.dont know if its electrolysis or just disimiller metals.it doesnt have an anode but engine anode is 12 inches away any help would be great maybe ground the bracket thank you

 

[Lyle29464]

Re: swim platform

The stainless should not be a problem on a trailered boat. I would run a ground wire to a through bolt for the platform and see if that takes care of it. I would watch the drive very close to make sure it's just the platform. You might have a missing ground to the drive.

 

[Fireman431]

Re: swim platform

You didn't say if the boat was a fiberglass or aluminum hull, so I'm going to assume fiberglass. You have a definite electrloysis problem if you're seeing pitting after 1 time in the water. I had an issue like that, so here's what I recommend.

First, check the thru bolts to see if the bolt or washers are pinching any wires on the back side of the transom.

With the battery(s) on, put an ammeter on the ladder bracket and see if you get any current through the metal rails.

Put the boat in the water and try the ammeter trick again. I have actually seen 0.8 amps in the water behind my old boat. The zinc was actually bubbling like an alka-seltzer!

Does your battery(s) have a kill switch (OFF,1,2,BOTH). If so, remove the cables and see if that stops any stray current. My problem was a shorted battery switch.

The posts of the swim platform are usually stainless steel. Even so, aluminum with SS bolts shouldn't be so dissimiliar that pitting starts after 1 time out, especially in a trailered boat.

 

[metriccrescentwrench]

Re: swim platform

Everything Fireman said is good advice. As far as how long aluminum should last, I'm rebuilding a 31 year old Checkmate and the original swim ladder (stainless tubing with aluminum steps) is still in good condition. However, if you really wanted to it wouln't hurt to either run a ground wire back to the engine (that's the only way the zinc anode on the engine is going to help), or bolt a piece of zinc in some out of the way place (that's submerged when the boat's in the water) on your swim platform.

 

[Fireman431]

Re: swim platform

Everything Fireman said is good advice. As far as how long aluminum should last, I'm rebuilding a 31 year old Checkmate and the original swim ladder (stainless tubing with aluminum steps) is still in good condition. However, if you really wanted to it wouln't hurt to either run a ground wire back to the engine (that's the only way the zinc anode on the engine is going to help), or bolt a piece of zinc in some out of the way place (that's submerged when the boat's in the water) on your swim platform.

Adding an anode wouldn't hurt, but the problem he has to find is where the current is coming from. Most anodes are in place to protect metal parts from energized electrical sources that are leaching stray current. Aside from the engine/outdrive, a trailered boat shouldn't require any zincs or bonding wires. That's why you don't see zincs on the trim tabs and ladders of trailer boats.

If there is pitting of the metal after a day on the water, the boat is leaching. Don't add a zinc or bonding wire...find the problem and fix it! The ladder will be the least of the problems. He'll be replacing engine and outdrive anodes, propellers, trim tabs, etc.

If you get a current measured, disconnect the battery and check again. Start adding wires back to the battery and check after each one to see when your problem starts and then fix it.

After my initial issue with my switch, the only anodes I ever ran on all of my trailered boats was the lower unit zinc(s).

 

[metriccrescentwrench]

Re: swim platform

Adding an anode wouldn't hurt, but the problem he has to find is where the current is coming from.

Not disagreeing at all. I should have added "AFTER the initial problem is fixed".

 

[Florida Man]

Re: swim platform

thank you all for your suggestions.tried the amp meter on the tube part of swimplatform nothing no amps.all conections are good no splices that i seen, all original wires and connectors.even filled up copartment with water were electrical connections are.some other questions i have are do the wire that might be an issue does it have to be touching or in the water to cause electrolysis?could i ground the bracket?engine anodes dont have issues could it be just needs an anode? thanks again to all. i take good care of my boat so my family could enjoy and this is bothering me and would like to fix it.

 

[Florida Man]

Re: swim platform

went back out there and checked out further i believe my bielge pump is bad.pump will not run with water filled up put volt meter to platform screws had about 3.5 dc volts on them disconected pump and drop down to about 0.356 nonsense voltage.checked voltage to deck screws that are isolated and seeing same voltage of 0.356.i will be buying new pump and keeping and eye on it. thanks

 

[Fireman431]

Re: swim platform

Nice find. Honestly, I wouldn't have thought to look at the bilge pump wiring. But if you didn't have water in your bilge originally, I wonder where the current was coming from?!?

Might consider (just a thought) cutting back to known good wire and rewire the bilge pump. You might find wires abrated through and grounding out. That would cause not only the bilge not to work, but also your current source.

Good job on the short. Those are tough to find.

 

[SteveRoss]

Re: swim platform

Pitting, corrosion, etc. can be solved by keeping it out of salt water. Come to Gainesville !! Plenty of fresh water lakes here, and we can always use the tourist's dollars !! LOL !!!