Join the C34 Association Today!
[C34 Home] [C34Tech Notes] [C34 Tech Wiki] [Join!]
Please login or register.
Advanced search  

News:

Pages: [1] 2   Go Down

Author Topic: Stemhead Fitting Repair  (Read 1117 times)

0 Members and 1 Guest are viewing this topic.

Peter Kovacevich

  • Forum - Seaman Apprentice
  • *
  • Karma: 0
  • Posts: 3
    • View Profile
Stemhead Fitting Repair
« on: March 19, 2018, 11:59:32 AM »

Hi,

I'm the new owner of a 1993 MK 1.5,  hull #1234. It's a freshwater boat and it is in very good condition. One item that needs to be addressed are weld cracks in the stemhead fitting. It appears this is a common problem and there are a couple posts in the forum regarding the issue:

http://c34.org/bbs/index.php?topic=6250.0
http://c34.org/bbs/index.php/topic,9612.msg72644.html#msg72644

I  have a couple questions from anyone who has repaired or replaced the stemhead fitting on their boat:

   - I understand there are a couple sources (Catalina Direct, Garhauer) for a redesigned, thicker stemhead fitting, however I plan to have the cracks in the stemhead fitting welded and have extra material added below the tang to make it 1/2 inch thick between the shoulders (blue arrow in photo). Has anyone  performed this repair and was it successful in keeping the welds from cracking again?
   - Jon W indicated that he had to cut the aluminum extrusion holding the rub rail on his MK1 to remove his stemhead fitting. I know the bow roller is separate on the MK1.5. Will I need to cut or modify the aluminum extrusion to remove / reinstall the stemhead on my MK1.5?
   -  Jon W also indicated he removed the entire beckson deck plate, not just the cover to get better access to the nuts and retaining plates. Besides stabilizing the rig, are there any other  suggestions to make the job easier or safer?

I'm still getting familiar with the boat and I have a lot to learn. I really appreciate any advice on the best way to approach this repair.

Peter
Logged
1993 Catalina MK1.5
Hull #1234

Dave Spencer

  • Forum - Petty Officer 1st Class
  • *****
  • Karma: 2
  • Posts: 397
    • View Profile
Re: Stemhead Fitting Repair
« Reply #1 on: March 27, 2018, 11:29:58 AM »

Peter,
Welcome to the forum!  You'll find an enthusiastic and knowledgable group of people here who can answer almost any question... any question except yours apparently.  I'm surprised you didn't get a response to your well structured question.  I don't have first hand knowledge of how to replace or repair the stemhead fitting but after reading the links that you posted, I think Jon W's answer is the best one.  I've seen pictures of bent C34 stemhead fittings before but yours is fairly extreme.  Thinking about the forces acting on the stemhead fitting, I suspect the crack  may have been caused or exacerbated by inadequate forestay tension.  If the forestay is flopping around in heavy weather, it's easy to see how the stemhead could be loaded up to cause the crack that you have.

Hopefully someone with first hand knowledge will reply with their own experience.

Good luck and let us know how it turns out.
« Last Edit: March 27, 2018, 12:53:27 PM by Dave Spencer »
Logged
Dave Spencer
C34 #1279  "Good Idea"
Mk 1.5, Std Rig, Wing Keel, M35A Engine
Boat - Lion's Head, Ontario
People - London, Ontario

Jon W

  • Administrator
  • Forum - Chief Petty Officer
  • ******
  • Karma: 8
  • Posts: 768
    • View Profile
Re: Stemhead Fitting Repair
« Reply #2 on: March 27, 2018, 12:10:03 PM »

The rub rail extrusion interferes with the stemhead fitting because you can't drop it down vertically into place. It has to rotate aft to forward into place to match the chine of the bow. I had the bow rollers and mounting plate welded to the stemhead fitting so could not rotate it enough to get the lower strip through the rub rail and into place. My only option was to cut the rub rail extrusion the width of the fitting.

I've only done this on my MK 1 so am guessing here about newer models - If you're installing a 1/2" strip of SST formed to match the bow and the proper angle for the forestay to attach, I don't think you will have to cut anything. If something is attached behind the 1/2" strip like the C34 stem fitting Catalina Direct sells, you may have a challenge because the amount you can rotate aft to drop the angled strip through the rub rail extrusion is limited.

It would be worth a call to Catalina Direct to ask them the dimensions of the part they sell, then hot glue a wood mock-up together and see what happens.
« Last Edit: March 27, 2018, 01:55:32 PM by Jon W »
Logged
Jon W.
s/v Della Jean
Hull #493, 1987 MK 1, M25XP, Manson Supreme 35
San Diego, Ca

Peter Kovacevich

  • Forum - Seaman Apprentice
  • *
  • Karma: 0
  • Posts: 3
    • View Profile
Re: Stemhead Fitting Repair
« Reply #3 on: March 27, 2018, 08:00:36 PM »

Thanks Jon and Dave,

I called Garhauer and spoke with Doug. He said they can make a replacement stemhead to the specifications of the final version they made for Catalina; the tongue is 3/8", instead of 1/4" and it doesn't have the gussets on the side. Apparently the new design allows the stemhead to flex slightly as vibrations and loads are transmitted from the rig. The cost is about what I budgeted for welding the old stemhead, and it sounds like the redesigned stemhead is more robust, so I'm going to order a new stemhead from Garhauer.

I'll post an update regarding what I run into during removal / installation.

Thanks,

Peter
Logged
1993 Catalina MK1.5
Hull #1234

Jon W

  • Administrator
  • Forum - Chief Petty Officer
  • ******
  • Karma: 8
  • Posts: 768
    • View Profile
Re: Stemhead Fitting Repair
« Reply #4 on: March 27, 2018, 09:51:08 PM »

My new stemhead is also a constant thickness of 3/8”. It is welded on each side where it meets the top of the bow roller. You can see the weld bead in the photos. Good luck.
Logged
Jon W.
s/v Della Jean
Hull #493, 1987 MK 1, M25XP, Manson Supreme 35
San Diego, Ca

Paulus

  • Forum - Chief Petty Officer
  • ******
  • Karma: 4
  • Posts: 509
    • View Profile
Re: Stemhead Fitting Repair
« Reply #5 on: March 30, 2018, 04:43:02 AM »

Peter, if you order a new one be sure and tell them how many bolts go through the bow.  Some years ago I had my stemhead repaired and some of them came with 5 bolts and others with 7(?).
Paul
Just found the Proprietary Information that Catalina send me.  Shows 5 holes in the front.  This was the same stemhead used on the later C34 and C36 according the the Catalina people.
« Last Edit: March 31, 2018, 11:40:10 AM by Paulus »
Logged
Cool Change 1989 #944

rmbrown

  • Forum - Petty Officer 1st Class
  • *****
  • Karma: 1
  • Posts: 352
    • View Profile
Re: Stemhead Fitting Repair
« Reply #6 on: December 19, 2018, 04:20:07 PM »

I'm just about to do the same job on my own 1.5, a year or two older.   New part arrived from Garhauer yesterday.
  Did you end up having to cut your rub rail as well?

My original was backed only with washers.   Did you have a backing plate made?
Logged
Mike Brown
1993 C34 Tall Rig Wing Keel Mk 1.5
CTYP1251L293
Just Limin'
Universal M-35AC

Jon W

  • Administrator
  • Forum - Chief Petty Officer
  • ******
  • Karma: 8
  • Posts: 768
    • View Profile
Re: Stemhead Fitting Repair
« Reply #7 on: December 19, 2018, 05:01:12 PM »

Mine has a 1/4” thick aluminum backing plate on the stemhead fitting. Don’t know if it’s OEM, or a PO installed it.
Logged
Jon W.
s/v Della Jean
Hull #493, 1987 MK 1, M25XP, Manson Supreme 35
San Diego, Ca

mdidomenico

  • Forum - Petty Officer 2nd Class
  • ****
  • Karma: 1
  • Posts: 122
    • View Profile
Re: Stemhead Fitting Repair
« Reply #8 on: December 19, 2018, 05:39:56 PM »

my '89 has an alum plate behind the existing stem head and the bow roller.  and i'm positive the PO didn't install it, so it must have become OEM at some point.

i'm also replacing my stemhead, but it'll have to wait till spring, too cold here on the east coast for epoxy work.
Logged
1989 Cat34 #856, original MXP-25(ab?)

Paulus

  • Forum - Chief Petty Officer
  • ******
  • Karma: 4
  • Posts: 509
    • View Profile
Re: Stemhead Fitting Repair
« Reply #9 on: December 20, 2018, 05:20:16 AM »

My stemmed had a backing plate in the shape of a V(filled in) with matching holes.  I think this was original equipment.   I tend to think along the same lines as Dave, that  the crack  may have been caused or exacerbated by inadequate forestay tension.
Paul
Logged
Cool Change 1989 #944

rmbrown

  • Forum - Petty Officer 1st Class
  • *****
  • Karma: 1
  • Posts: 352
    • View Profile
Re: Stemhead Fitting Repair
« Reply #10 on: December 23, 2018, 08:36:37 PM »

Breaking plate sounds nice!  All I found behind mine is flat and lock washers, but they look original.
Logged
Mike Brown
1993 C34 Tall Rig Wing Keel Mk 1.5
CTYP1251L293
Just Limin'
Universal M-35AC

David Sanner

  • Administrator
  • Forum - Petty Officer 1st Class
  • *****
  • Karma: 5
  • Posts: 240
  • #611/1988 San Franscisco
    • View Profile
Re: Stemhead Fitting Repair
« Reply #11 on: December 24, 2018, 08:32:12 PM »


My stem fitting needs to come off as it has straightened as it "cut the corner" / flattened out a bit between where it leaves the hull and where it goes around the deck. 

This 'corner cutting' has lifted the stem about 3/16 off the deck ... over the years.  Apparently there wasn't enough/any solid backing material behind the gap in the transition from the hull to the deck.

My plan is pull off the stem, rework the angles of the strap/stem and fill the gap behind the strap with some sort of non-compressible fiber board and epoxy.
(I may call Garhauer before then to check their pricing for a new stem - and getting the 5 holes lined up presents a bit more work/planning)

I have the 1/4 inch aluminum backing plate on 4 of my 5 bolts (which has been more than adequate) ... assume the top one is screw from the outside. (see attached)

The 2nd attached image shows the backing plate and skewed angle of the stem strap that has cut the corner.

A review up and down my dock reveals some lifting on the stem fitting is more often found than not... regardless of manufacturer, even on boats less than 1/2 the age of my 1988 c34.
Logged
David Sanner, #611 1988, "Queimada" San Francisco Bay

rmbrown

  • Forum - Petty Officer 1st Class
  • *****
  • Karma: 1
  • Posts: 352
    • View Profile
Re: Stemhead Fitting Repair
« Reply #12 on: December 26, 2018, 02:45:08 PM »

For those that have had to cut out the rub rail, did you cut the aluminum and leave the rubber intact or cut both?  If you cut both, did you finish the ends somehow or leave them exposed?
Logged
Mike Brown
1993 C34 Tall Rig Wing Keel Mk 1.5
CTYP1251L293
Just Limin'
Universal M-35AC

Jon W

  • Administrator
  • Forum - Chief Petty Officer
  • ******
  • Karma: 8
  • Posts: 768
    • View Profile
Re: Stemhead Fitting Repair
« Reply #13 on: December 26, 2018, 04:02:45 PM »

I cut both. I thought about having an aluminum “cap” made to close the gap, but ended up putting a screw in each side to keep the rubrail from unwinding. Then I put adhesive caulk in the end of the rubber rubrail next to the stemhead fitting to seal the opening. Don’t remember what I used.
« Last Edit: December 26, 2018, 04:05:03 PM by Jon W »
Logged
Jon W.
s/v Della Jean
Hull #493, 1987 MK 1, M25XP, Manson Supreme 35
San Diego, Ca

rmbrown

  • Forum - Petty Officer 1st Class
  • *****
  • Karma: 1
  • Posts: 352
    • View Profile
Re: Stemhead Fitting Repair
« Reply #14 on: December 26, 2018, 06:09:19 PM »

If you come across a picture that shows those details, I'd be indebted!
Logged
Mike Brown
1993 C34 Tall Rig Wing Keel Mk 1.5
CTYP1251L293
Just Limin'
Universal M-35AC
Pages: [1] 2   Go Up