Thruster zinc problems

[wa7pug]

I have been struggling with the replacement of zincs on thrusters of our R-25SC. Contacted manufacturer and local reps and bottom line is that it is ugly. I read all of the posts thus far, but can share a little bit of information:
1 suggestion was to take it to a boat shop - there are none close by and they will not be able to do much different than an individual does .... it is a function of time. I have more than they do, and I do not charge myself huge prices for my learning curve.
1 suggestion from mfg of thruster was PB Blaster .... doing that now but that does not solve the problem ... at least not yet.
I did get a very good article from JMark@imtra.com and I will try to post it somewhere (it is a pdf, so if somebody can tell me how to upload it to where you folks can find it, I will post it).
Looks like I am going to have to put a mask on and take a dremel and cut the remaining piece of zinc off and dress for a new one, but one other thing to note: all of the zinc mfgs have said to NOT use a "loctite" method because it can affect the galvanic path. I did read where someone had used 3M or Sitkaflex to affix the bolt - don't do that.
Anyway, you can see I am in a very frustrating point in this but I have learned a lot (that I didn't really want to know).
If someone can tell me how to upload a pdf file, I will share the article that I was sent which might help someone else.
Many thanks for your patience ....

 

[wa7pug]

One other detail I forgot to mention: when I say to not use a loctite method, that applies to the set screw going into the soft metal of the thruster. If you are replacing that with a stud that protrudes and you use a washer and nut to secure the zinc, then something like Loctite 262 or something like that is probably recommended (not sure about effect of salt water). If you can find them, before you put the stud in, you might want to put a hole in the bolt so you can use a castle nut and safety wire ..... not sure what I am going to do in the end yet - still struggling with getting it apart at this point.

 

[zekeandboone]

We had a'17 R25SC. I kept it on the trailer in the barn. I couldn't get the thruster zincs out with my T handle hex breaker bar. I contacted the manufacturer (Imtra? been awhile). Someone high up in the company called me and gave me several suggestions. He indicated that having it dry out on the trailer led to the difficult removal. 3 days of nightly PB Blaster and then he said remove with a long basin wrench.... Worked great!... I now have a R31 that I keep in the water. I hauled out in July and the first thing I did was to change the thruster zincs. No problem.
Hope this helps!

 

[bails023]

Beware of breaking off the hex bolt "in" the thruster driveshaft. Soaked it in PB Blaster, let it sit, and tried (a little too hard I guess) to loosen it and the bolt snapped flush with the shaft. Result - expensive thruster arm replacement. Technician said it was a pretty common occurrence.

 

[wa7pug]

Thanks Steve and also thanks for the caution note. I will let you guys know how it turns out.

 

[wa7pug]

I have about 60% of the zinc left on back thruster / have not yet looked at bow thruster but after reading Steve's comment, I may be smart to leave it alone until next fall and pull it right when I put boat on trailer to bring home .... I had no idea these were going to be such a PITA.
The article I wanted to share is from imtra, and it recommended replacing the hex screw with a stud permanently, and affixing the new zinc with a nut and washer .... as noted earlier, I am not convinced loctite is the do-all fix-all so if I have to do that, I will use castle nuts (nuts with the slots in the top) and safety wire .... maybe the thruster manufacturers will someday figure out better. Thx for your notes guys ... this forum is pretty amazing. Too bad more component manufacturers do not read forums for ideas for improvements. Sure a lot different on a drawing board than in reality. Merry Christmas All!

 

[wa7pug]

Gavin sent the following link to his onedrive: https://1drv.ms/b/s!Auy2KJTFDgidkM12nWW ... g?e=DRGDoS
I tried it and it got stuck at the 3 dots and disappeared into the ether. I asked him to try another way, meanwhile:
Here is my personal email pugwerks487@gmail.com
Email me and just put in the subject line something about the 'zinc mod" and I will copy it to you ....Doug