Print

Please login or register.

[scgunner]

So that's a big thumbs up from the crew for the GTU. I would like to use the GTU but my concern after reading Noah's posted article is the possible galvanic problem as I just spent $1,000 for a new S/S prop shaft.

Right now I've got three rings of 3/16" flax and after an hour it's still running hot. While I've got you guys here is everyone using 3/16" and three rings? Right now I'm wondering if I should go with two rings of 3/16" or try 1/4" packing.

[Noah]

In my stuffing box I used 1/4 in. GTU. Sorry but I can’t remember how many layers. As far as corrosion concerns, I would be “slightly” concerned if you had the old bronze shaft—not so much with the SS one. I have had NO issues with corrosion (that I can see anyway). I had my SS shaft removed two years after installing it using GTU because I needed to replace my strut. At that time I walked it back over to the machine shop that made it for me 2 yrs earlier, to inspect (because I could so why not). He said it “was still in brand new shape” but checked it over on his “truing equipment” too—all was good! My shaft is A22 SS alloy.

[Jim Hardesty]

Right now I've got three rings of 3/16" flax and after an hour it's still running hot. While I've got you guys here is everyone using 3/16" and three rings? Right now I'm wondering if I should go with two rings of 3/16" or try 1/4" packing.

Packing size and number of rings depends on the manufacture of the shaft log.  I don't think Catalina always used the same ones.  FWIW Shamrock takes 3/16 and two rings.  Tried to put in third ring but wouldn't fit.
Not a difficult job at all.  Don Casey describes very well how to in "This Old Boat".  My personal favorite how to fix boat book.
Jim

[KWKloeber]

https://marinehowto.com/re-packing-a-traditional-stuffing-box/

[scgunner]

With much information and helpful suggests provided here's what I've done. The yard installed three rings and it ran hot I thought due to being overly compressed, I replaced them with three rings and the nut installed loosely it still ran hot. So following Jim's post I removed the third ring and that did the trick, it's now running cool although I'll still have to adjust the drip rate, but that's just a matter of walking in the packing nut to achieve the best possible drip rate.

Thanks again guys for all the help.

[Ron Hill]

Kevin : I believe that in the early production (1986-1990) Catalina uses a packing gland that needed 3 rings of 3/16" packing.  That's what I used.  After 10 years I added a 4th ring of Gore to mine and it's still basically dripless (warm, but not hot)!!  The key is in the spring to only make SLIGHT turns (maybe as small as 1/32) to retighten to stop any drips!!

A thought

[KWKloeber]

Interestingly, CD sells only 3/16” to replace prop shaft stuffin’

Makes ya wonder.

[scgunner]

Ron,

Yes, they certainly can be fussy little bastards!

Ken,

It's nice to know that's what CD recommends, although Jim might have a point about Catalina using different nuts, when I put three rings in mine there was almost no space left and I could only get one turn on the nut before it started compressing the packing.

[Noah]

Every boat situation is different. I used 1/4 inch in my stuffing box (confirmed by checking leftover packaging today).  However, don’t know how many layers. I remember some time ago I loaned Jon W. my set of stuffing box wrenches (bought from Catalina Direct) and they did NOT fit his… lots of variables there.

[Ron Hill]

Kevin : Over the years I have learned that in plumbing (boat or home) NEVER back up.  Always end with tightening!!

A thought

[KWKloeber]

Ron,

Yes, they certainly can be fussy little bastards!

Ken,

It's nice to know that's what CD recommends, although Jim might have a point about Catalina using different nuts, when I put three rings in mine there was almost no space left and I could only get one turn on the nut before it started compressing the packing.

To be clear I didn't say CD recommends anything, only that CD sells one size. 

[Stu Jackson]

Flax always gets a warm welcome.

In the over 25 years I have had my boat and all the Mainsheet articles since 1987, and all previous forum discussions and tech wiki articles, the conclusion is clear, as Noah said:

Each boat situation is different.

In my stuffing box wiki, I noted that my boat manual said a 1" shaft with 3 rings of 3/16" (Page 39, detail 4.4.2).  I also suggested checking your own boat manual, because there were reports of skippers needing 1/4" flax.  It's also easy to measure if you're in doubt.

[scgunner]

Just to correct a mistake I made, when I was referring to !/4" packing what I meant was 1/8" packing, there's no way I could get 1/4" into my stuffing box. Math never was my strong suit.

[Ron Hill]

Kevin : I was rereading this thread and am wondering if you really got all of the old packing out??  I took a close hanger, bent the end 1/8" 90 degrees and used that to probe and get all of the old packing out.

Maybe by this time you've solved your problem, but I'm sure that in Catalina's C34 1987 production they used the gland that needs 3 rings of 3/16" packing.  Again I recommend Gore dripless!!

A few thoughts

[Ron Hill]

Kevin : I forgot to add that I also took a #2 pensile shaved 2 sides, flattened the end 90degrees and made a packing tamper.  After each ring I made sure that that ring was tamped in place!!

A thought