Cav plate cracking again!

[12Parker2320]

Looking for some kind of consensus or general opinion here. I posted previously that the wrong model and improperly installed permatrim cracked my cav plate on my f250 (4.2). I had the plate welded by an experienced welder who did good work. I ordered and installed the proper permatrim back on my fixed cav plate. After my last trip I noticed the exact same area on my cav plate was starting to crack again. My thoughts are, I don’t want to deal with this a third time and I am thinking of switching camps here and switching to a 4 blade and moving my motor up a couple holes. I love the performance from the permatrim but I think I am done with it. I contacted a respected marine welder who told me he wouldn’t guarantee his repair if I countined to run the permatrim. From what I understand the cast aluminum becomes more stiff and brittle after being welded with filler rod and mending dissimilar metals together. I know 4943 filler rod has a little more flex to it but I think after this next fix I’m going to fill in the holes and not run a permatrim. In my research I’ve landed on a couple props and want to get some thoughts.

Mercury Rev 4 15p (not sure if they still make it)

Powertech OFS4 15p

Thoughts? I fired off an email to Ken at prop gods as well

Thanks,
Andy

 

[plumsal]

I called Ken and he set me up with Mercury Enertia props. They provide lift, lower planing speed and better efficiency than my Reliance props. I originally was going 4 blade Powertechs but followed his advice, glad I did. Expensive props but well worth it for me.

 

[12Parker2320]

I called Ken and he set me up with Mercury Enertia props. They provide lift, lower planing speed and better efficiency than my Reliance props. I originally was going 4 blade Powertechs but followed his advice, glad I did. Expensive props but well worth it for me.

Are you running a 3 blade Mercury enertia then? What pitch and diameter?

 

[A-K]

Wow that totally sucks. I truly feel for you and your situation.

I had a crack in my bracket that was weld repaired. Shortly after the repair it cracked again in the same location. The bracket had to be replaced.

But I think the combination of the welding heat effect zone and salt water makes it difficult for a weld to resist cracking again. I had a friend who experienced the same problem with his bracket.

I’ve seen the same with salt water on 304 stainless piping systems. The chlorides get impregnated into the material, you can grind them out and re weld but the cracking often times reappear.

 

[plumsal]

Are you running a 3 blade Mercury enertia then? What pitch and diameter?

Yes, 3 Blade Enertia (not the Eco) 15x15. But I run twin f150s so you might run a different size & pitch on your motor. Ken will sort you out.

 

[12Parker2320]

Yes, 3 Blade Enertia (not the Eco) 15x15. But I run twin f150s so you might run a different size & pitch on your motor. Ken will sort you out.

Thanks

 

[Bodick93]

Man, I totally get you being done with Permatrims. I sure am sorry.
I have pulled mine off before and noticed there were areas of the AV plate that were proud and rubbed into the surface of the Permatrim. These high spots put additional stress on the installation, obviously.
Knowing that, along with your experience, may prompt others to disassemble and inspect.
In my opinion, it should be like bolting together two flat assemblies, and not causing stress while the bolts are tightened. Mine had flex as I tightened the bolts. I did use less sealant that I was supposed to during the first install, meaning only around the bolt holes. Glad I did now, because it revealed the stressed areas.

 

[Cman60]

I’m glad you are giving up on Permatrim. Myself and many others on here have debated their reliability in past threads. Moving the batteries out of the bilge combined with 4 blade made my 2300 dv jump on plane and run flat without having to drill holes in my engine. Seems like a much better solution IMO.

 

[Bodick93]

I’m glad you are giving up on Permatrim. Myself and many others on here have debated their reliability in past threads. Moving the batteries out of the bilge combined with 4 blade made my 2300 dv jump on plane and run flat without having to drill holes in my engine. Seems like a much better solution IMO.

Where did you install the batteries?

 

[12Parker2320]

Thanks you guys for the responses. Curious for those of you running 4 blades on 2320’s with 4.2’s what prop is working for you?

 

[Cman60]

Where did you install the batteries?

The console

 

[Bodick93]

The console

I misread...thought you had a 2320. I bet it handles beautifully.

 

[Cman60]

I misread...thought you had a 2320. I bet it handles beautifully.

Yup rides dead flat