Ride Plate Question

[camelpak]

I have an 2003 sportster 4-tec. I use it only in salt water & have noticed my ride plate is starting to pit & deteriorate. I clean the boat w/ salt away after every use, but the pitting has only gotten worse.

I would like to sand down the ride plate smooth & add an expoxy resin to it to build the thickness back up to spec & seal the pores to keep it from pitting any more - is there any reason I shouldn't do this or is there a better way to rectify this issue?

Also, is there any way to add a zinc to the boat to help w/ the corrosion on the rest of the jet pump?

Thanks in advance!

 

[Coastiejoe]

There are specific primers for aluminum items,,,, If the proper primer is not used, a few things happen. The paint will not stick and it will allow for the aluminum to have contact with the water, in this case salt water.

Even if you use an epoxy resin, I would think you would/should use a PROPER and a QUALITY primer. If not, the adhesion of the epoxy will be only as strong as the weakest link....

I think if you strip and clean your grate to bare metal, then paint it with the proper primer, then cover it with your epoxy resign, it would last for years...

As far as the zinc goes, I have put a decent amount of thought into this. In the case of a Jet Ski, you want the zinc to be in the water but not create a drag situation. Further, if the zinc in not in contact with what you are trying to save, then you really gain nothing by the zinc being on the ski. Like on a ship for example, many of them are wedge shaped to help with the drag issue and are bolted directly onto the metal hull. This design allows for less drag and saves the hull as it is the weak link...

This is hard to do with a fiberglass hull. If you want to save your grate, the zinc would have to be touching the grate. I would think in almost all cases this would create drag or change water flow to the impeller. I would bet you could get or build a washer made from zinc material. The issue with this is, your grate needs to be bolted VERY secure to the hull. As the zinc wears, this would allow for the grate to loosen....

 

[get_real]

I'm not that experienced with PWC but on my 96 XP I don't see hardly any corrosion on any kind of the grate, drive componets or ride plate. I'm thinking most skis aren't in the water enough to warrant needing zinc like a boat. If the ride plate is the only problem you're having I'd go with Coastiejoe's paint recomendation.

 

[camelpak]

Thanks Coastiejoe for your input.

Update - I sanded down the plate with some 100 grit on a D/A. Choose not to sand completely smooth because I didn't want to take off all the metal to even out the pitting. Instead I just sanded the rest of the paint off the high spots, cleaned up pitting with a wire brush, & wiped everything down multiple times w/ acetone.

I then used the "string, foil, & epoxy putty" method to fill in the ride plate recesses. Followed with marine text to fill the deep pitted areas. Once that was cured, I sanded & cleaned everything again and used an epoxy resin called Gluvit (no primer necessary) & painted on a coat to fill in the rest of the deformaties & seal the ride plate. Once that cured, I sanded the high spots in the Gluvit down to a "level" uniform state & then lightly sanded it down to 400 grit to make it silky smooth & waxed it.

 

[camelpak]

I also choose not to do anything with the zincs at this point - that may change in the future & if I come up with anything, I'll let everyone know how it goes.

 

[camelpak]

I just got back from taking the boat out.... I made it approx 3 miles from the boat ramp cruising at 6,000 rpms & the temp light came on. I shut it down immediately, let it cool for about 5 min. & headed back towards the ramp (I stopped at a place I couldn't anchor). Made it about about 1 mile back & temp light came on again; shut it down, anchored, drank a beer & let it cool for about 30 mins. Started up & made it back to boat ramp w/ no problem.

The only thing that is different from the last "trouble free" day on the water is the ride plate modification. So I have a question;

Does the ride plate act as part of the cooling system in the 4 stroke boats???

 

[mrfixitct]

Does the ride plate act as part of the cooling system in the 4 stroke boats???

Assuming you are referring to the plate beneath the jet pump, yes, it serves as a heat exchanger much like a car radiator..

 

[camelpak]

Assuming you are referring to the plate beneath the jet pump, yes, it serves as a heat exchanger much like a car radiator..

mrfixitct - yes sir, I just realized that right after I made my last post. Turns out the expoxy I used to fill & seal the plate doesn't tranfer heat at all. So - my IR angle grinder & I just had a few hour abrasive discussion with the epoxy and it is no longer on the plate. lol

 

[Coastiejoe]

Wow,, I am either shocked or impressed with the epoxy resin you are using.

I would not have guessed that it could have insulated as well as it clearly does.

Hope you have it solved,,,

 

[camelpak]

Took the boat out again today after taking all the epoxy off yesterday. Ran approx 10 miles at 6,000 rpms with no issues at all. I also felt the engine after the 10 miles & is was a lot cooler to the touch then yesterday after 3 miles. The only difference between the 2 days was the epoxy on the ride plate.

Today I also got to try out the new stereo system I put in the boat - was too worried about over temp issue yesterday. My mids & highs sound great, but may have to find more bass. I really thought 2 10's would be enough... LOL

 

[Coastiejoe]

Glad to here the over heat issue is gone,,,