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Lessons Learned

Started by jaguaretype, September 27, 2004, 08:05:52 PM

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jaguaretype

In July 04 I purchased a 1990 Com-Pac 23 D and trailered it from
Minnesota to Arkansas. After a bottom job (epoxy barrier coat and
anti-fouling) and other "freshening up", I launched the boat for the
first time this last Friday on Lake Ouchita. Saturday was spent
fine tuning the rigging, storing equipment, bleeding the diesel fuel
line, and motoring the boat about 14 miles from the launch site to
its slip. When I arrived Sunday afternoon for the first sail, I
discovered to my horror that the bilge and boat to a level a few
inches above the teak/holly sole was filled with water. Had I not
taken off work Friday, thereby enabling the first sail on Sunday, I
would have arrived this weekend at the lake to find that the boat
had sunk. I checked the bilge, all seacocks, all thru-hull
fittings, and the propeller shaft stuffing box for leaks, and turned
the electric bilge on auto before leaving Saturday, and was clueless
as to what could have caused the leak. After draining the water I
discovered that the leak was the result of hairline stress cracks in
the bottom of the bilge, which is in the aft part of the keel.
Apparantly, the barrier coating and antifouling paint was able to
keep the bilge dry for a day or two, which was why the leak did not
start until Saturday night. Also apparantly, the bilge pump came on
ran, failed to stop when the level of water fell, and thus ran until
the battery was drained, at which point the boat again started to
fill with water. Before applying the epoxy barrier coat, I
dertmined that the gelcoat on the keel was in original condition
with no gouges or other evidence of the keel having ever been
grounded. At this point, I believe the keel stress cracks occurred
as a result of the thinness of the fibreglass laminate in bilge area
of the keel combined with the stress of trailering. Specifically,
the Magic Tilt trailer, which was supplied by Hutchins with the
boat, was outfitted with 5/8" shaft, 12" length, 3 3/4" black
rubber "V" hull keel rollers, which seem to be original to the
trailer. The weight of the boat sets on the relatively narrow ends
of the "V". Depending if the boat is centered squarely on the
trailer, there could be a fair degree of stress applied to the keel
when hauling the boat some distance over less than smooth roads. I
don't believe the thickness of the fiberglass in the keel bottom was
designed to take this kind of stress. My lessons learned are 1)
carefully check the bottom of the bilge area for tiny hairline
stress cracks after each time the boat is trailered; 2) as it may be
difficult to see the cracks, filling the bilge with water and
checking for dampness on the outside of the hull may be adviseable;
3) have Hutchins reinforce this area if purchasing a new boat (in my
humble opinion the unreinforced fiberglass in this area will not
withstand a good grounding or constant trailering); 4) don't rely on
the auto bilge to function properly (the float will stick at the
most inopportune time); 5) inspect the bilge carefully and
thoroughly investigate any dampness, and; 6) spend more than a
couple of days on the boat after a bottom job before assuming there
are no leaks. Again, in my humble opinion, the bottom of the keel
below the bilge is the boat's weakest structual area. As a
preventative measure it wouldn't hurt to reinforce this area even if
your boat currently has no leaks. Jay, 1990 Com-Pac 23 D, 'Fabi'.

bro t

Hi Jay, bummer :cry: about the leak, but a good thing :) for your timely arrival!  I have a cp16, for four seasons now, and I didn't do a lot of trailering, but my general inspections neglected to discern some major flaws in how the trailer was functioning the first two seasons, until part way through the second year and we couldn't launch at ALL, and ended up unhitching the trailer IN the water and rolling, (1,2,3, HEAVE!) to the point of floating the boat off of the trailer.  I knew then that I had to have a change!  I don't know how, but as I did several improvements to the trailer, including new v-rollers and new galvanized locking bolts for the height adjustment of the v-rollers, I realized that the tuning was in the rollers.  The following summer began with a coat of bottom paint, and it was then that some important observations were made, and NOW the trailer is properly adjusted and works so well, the last two places I have trailered, both designed for stinkpots at the launch, launch and retrieval is a bit of work at these, but only because I was literally 8 to 10 inches above the waterline.  Maybe I'm stupid, but I refuse to put the tires in more than 4-6 inches, and prefer to stay high and dry.  Also the trailering is AWESOME stable.  The secret?  First, the bunks were released, as I realized they were putting undue pressure on the hull, and actually deforming the normal curves of the hull.  With the boat in the bow roller, I actually reset the three v-rollers so that they were in a horizontal line, and because the type of rollers I had bought had end-caps which fell out and allowed the rollers to drop, I put some thick (1/2 to 3/4 inch) 2" by 2" squares of plastic (HDPE) on each end of the roller shafts to prevent the end caps from coming out again.  (I regretted not having spent the extra $ on the solid polyurethane v-rollers at that point).  With the rollers thus properly set (on well greased shafts), I was convinced that the boat would rest on the keel while trailering, as it should: the bunks are NOT supposed to carry any weight.  Finally, I actually reset the bunks to the boat (propped up in a perfectly level position, and resting on the properly adjusted v-rollers) by putting them only so high as I could lift them with maybe 20 or 30 pounds of lifting force.  I never could have accomplished this without the acetylene torch I have, simply because the locking bolts were reduced to small gobs of rust.  One final note on this season's lessons, but I think I'm going to try to lift the rear roller (not carrying weight while trailering) slightly, in order to assist the boat over the bunk ends as the maximum beam of the hull comes through (when the boat is about half on).  I wish we had more tech. info on how these are supposed to be set, as I realized that I had been fortunate not to damage my hull, which was deflecting as much as two or three inches at the max. point.  In your case, unfortunately, the extra weight of the 23 was enough to do damage.  I hope this helps you, and anyone else who is wondering, a quick check to see if the boat is resting on the KEEL is really a good idea, if you haven't checked, or if you have any troubles at launch.  Good sailing, happy trails!
bro t. from Upwest Maine

Gil Weiss

I have 1 1990 CP16/3 that sits on  a Hutch trailer all winter. I put new rollers and bunks on too plus some other parts so my trailer is in first class shape. My dealer told me that the boat weight sits on the two forward rollers and to only adjust the bunks upward to stabalize the boat, not really take any weight. That seems to look a bit odd since the bunks only touch the hull in one spot, but it does seem to work fine. I don't think forcing the bunks to curve by putting lots of upward pressure is a good idea.

I see lots of large power boats and sailboats at my local boat yard stored in similar fashion. Two or three spots on the keel take the weight and side supports keep it upright.

jaguaretype

Don't almost all Com-Pacs have flat bottom keels?  If so, why does every Magic Tilt trailer come with "V" keel rollers instead of striaght rollers?  Isn't the entire weight of the boat supposed to rest on the keel?  Isn't the side rollers' only function to keep the boat from tipping to one side?  I think the reason why the stress cracks occurred in the bilge on the 23 D is because the weight of the boat rests on the end of the "V"s.  While the concrete filled portion of the keel can stand the stress, the aft bilge portion of the keel cannot due to the thinness of the fiberglass.  The problem is probably compounded by the 300 pound weight of the diesel above the bilge and two 200 pound plus men going up and down the ladder on the transom while the boat is on the trailer to step the mast, load equipment, set the rigging, etc., prior to launching.  Jay.

jaguaretype

I thought I'd update the forum on my leaking keel.  There are some hairline stress cracks in the bottom of the bilge that become evident when looking inside the bilge with a high intensity light outside the hull.  But apparently the epoxy barrier coat that I applied to the hull was enough to seal the hairline cracks.  As the fiberglass seems to still be structurally OK, I decided to ignore the hairline stress cracks for the time being.  When I pulled the boat and took it to Ouachita Marine Service the real leak became apparent from an examination of the outside hull.  There was crack in the bracket that holds the stern tube (also known as a shaft tube or log) in the keel.  I'm not sure it was standard on all 23 Ds, but welded to the starboard and port side of the tube is a flat bracket about 1" wide by 6" long through which a bolt and screw on each side attach to the hull.  The bracket cracked at the point of contact with the tube.  It may have been cracked when I bought the boat, but I didn't notice the crack when I painted the hull. Alternatively, when I first started up the diesel, the engine ran rough until I was finally able to get all the air bled from the fuel line.  The initial rough running combined with the 14 mile trip from the Crystal Springs launch site to the Brady Mountain slip may have caused the crack to form or widen.  In any event, the seal between the stern tube and the fiberglass hull broke during the motor trip to Brady.  A white rubbery compound was used for the seal, and from the looks of it, it had never been replaced since the boat was purchased.  I checked the stuffing box after launching the boat and before I leaving the boat for the day.  As it was not leaking, I thought it safe to leave the boat in the water.  Unfortunately however, the water from the leaking seal around the tube was almost impossible to detect, because there was no drip and because the water ran down the inside of the keel in the V at the very aft end of the bilge.  The boat did not leak the first night after being launched.  And me being brain dead did not consider that the operation of the diesel might have caused the seal to break.  I noticed that there was some water in the bilge after the trip, but incorrectly assumed that it was harmless having come from the normal turning of the propeller shaft in the stuffing box. In any event, after I pulled boat and noticed that the bracket had cracked and the stern tub was loose, I removed the tube.  Ouachita Marine Service had it repaired at the local propeller shop, which does stainless steel welding.  They then installed the tube, propeller shaft, stuffing box, propeller, etc. last Saturday.  I'm going to give the sealer another day to set, and will hopefully get the boat back in the water Monday.  I've learned a good lesson.  If the bilge at any point is not completely dry, you'd had better be completely certain as to why not.  Jay.