Oilcanning of later CD hulls?

[Dick Sisson]

I recently looked at and placed a deposit on a 1982 25D. The survey went pretty good, there were some minor cracks/crazing in the deck and cockpit but no detectable delamination, and the hull turned out to have no blisters. Except.

The fly in the ointment was that the hull was susceptible to being oilcanned/deflected under firm hand pressure, most noticeably in an area forward of the shrouds maybe a foot or so below the waterline. The surveyor first detected this situation. I also happened to be present when the boat was blocked. Discernable local deflection occurred when the weight was placed on the stands. Regrettably I did not go over the entire hull to determine the approximate extent of the situation, it was late in the day at that point and I was fatigued. I still, at that time, had a mindset in the direction of acquiring the boat.

I am now wavering in the direction of retrieving my deposit and letting this hull sit on the back burner while I look at other options.

I cannot imagine being able to oilcan the hull of my 1970 Typhoon. On the other hand, obviously, that is an earlier, much smaller boat.

This basically boils down to: Should you be able to oilcan a 25D, or any Cape Dory for that matter, with your hand? Maybe they went light on the layups of some of the boats, or perhaps just inadvertently on that one particular hull?

I would be very appreciative of any and all opinions and advice.

Regards, Dick Sisson



dickee@crosslink.net

[Lou Ostendorff]

Hi Dick,
I own an '82 CD25D, and everything I know about and have seen about this boat cries "overbuilt". That doesn't mean that certain hulls don't have weak spots, or that the boat was abused or neglected before you surveyed it. The standing rigging could also have been over-tensioned, however, the tendency is to under-tension, thinking you might break something. I'm interested in the exact definition of the term "oilcanning"...all I can envision, is the boat flexing from 'stem to stern' because of severly tightened fore and backstays. Any thoughts from others on this?
Lou Ostendorff
s/v "KARMA"



louosten@ipass.net

[D. Stump, Hanalei]

Dick,

I'll be interested to hear what other 25D owners say about this one, but to me, being able to deflect the hull inward with hand pressure below the waterline and in front of the shrouds just doesn't sound right! Maybe it was a Friday boat, and CD hadn't finished the layup. I would be real concerned. Maybe you can find a Naval Engineer that could alleviate your fears, but if it were I, at this point, I'd go for the deposit or maybe ask the owner to get someone to explain why this would be acceptable.

It just doesn't sound right!

Dave Stump
Captain Commanding
s/v Hanalei CD-30

[Harris]

My guess would be that jackstand pressure damaged the glass. What you failed to mention is if the surface that you mention is horizontal, verticle, or 45%. My guess because of the hull shape is 45%. I have seen alot of abandoned sailboats that have the jackstand pads depressing as much as 6 inches into the glass with time. One that comes to mind is a long abandoned triton....certainly a heavily built boat.



hg@myhost.com

[John R.]

My guess would be that jackstand pressure damaged the glass. What you failed to mention is if the surface that you mention is horizontal, verticle, or 45%. My guess because of the hull shape is 45%. I have seen alot of abandoned sailboats that have the jackstand pads depressing as much as 6 inches into the glass with time. One that comes to mind is a long abandoned triton....certainly a heavily built boat.

I totally agree with Harris. Far too many boats in a yard or storage can be found with the boat stands way too tight against the hull. Those stands should bear no weight of the boat. They are there simply to steady and balance the boat. All the weight should be totally on the keel. The pads of the stands should just touch the hull and that is all.

Sounds to me that the CD25 you are considering has been damaged by the stands. You do not mention the size of the areas that seem to flex. If it's roughly a foot square you can almost rest assured it's stand damage. Should be able to repair it.

[Kurt]

When I purchased my 1985 CD26 in 1993 it had been sitting on a wooden cradle for 5 years. During this time the cradle had sagged allowing the cradle poppets to push into and deflect the hull approximately 1/2" in six different spots (where the cradel uprights contacted the hull). Initially, there were six 'flatspots' in the hull but as the next couple of years went by and the boat was returned to normal use and proper storage, the flatspots disappeared and the hull returned to its normal shape!!! I have never noticed or felt any weakness or oilcanning anywhere within the hull. The boat is very strong and well built other than too many gelcoat cracks in the deck/cockpit area.



kjlgpw@aol.com

[Bill Cochrane]

The below line indicates the yard guy didn't know what he's doing, or the hull is very flimsy (doubtful). The stands don't carry weight, they steady the boat. The weight should be virtually all on the keel and the jackstands just screwed up enough to keep the boat upright. If it's level side to side and the keel is properly supported by a timber, there should be very little weight on the pads.

occurred when the weight was placed on the stands.

cochrane@clark.net

[Dick Sisson]

The situation was initially detected by the surveyor when the boat was hanging in the slings. He pointed out that he could deflect the hull (in various areas below the water line) with his hand. This was after he had sounded the hull, he said there was no detectable delamination. I do not believe the hull had been damaged, my opinion is that for whatever reason, the layup of this particular hull was light in places. Not at all in the lower portions where the hull is concave, but more where it goes flat and then convex.

So Bill, what size Cape Dory do you have? Are there any areas on your hull that you can oilcan with your hand?




dickee@crosslink.net

[sloopjohnl]

oil-canning is pretty much what an oil can does when applying a squirt of oil to something. the surface flexes in and out (athwartships). the cure generally involves adding stringers inside the hull to firm up the structure, which ususally invloves removing the interior on anything larger the a small daysailer.

Hi Dick,
I own an '82 CD25D, and everything I know about and have seen about this boat cries "overbuilt". That doesn't mean that certain hulls don't have weak spots, or that the boat was abused or neglected before you surveyed it. The standing rigging could also have been over-tensioned, however, the tendency is to under-tension, thinking you might break something. I'm interested in the exact definition of the term "oilcanning"...all I can envision, is the boat flexing from 'stem to stern' because of severly tightened fore and backstays. Any thoughts from others on this?
Lou Ostendorff
s/v "KARMA"

[Don Sargeant]

Boy, I couldn't agree more with Dave. My 25D #189, the last one built, is solid as can be. Not as solid as my 1963 folkboat was but, hey, the science of construction has progressed a lot since then. But when the boat's in the water it is suspended all around and a soft spot, if it doesn't leak, shouldn't be a big problem. IMHO

Don Sargeant
~~COQUINA~~
cd 25d #189
Lying in the rain in Greenwich Cove

Dick,

I'll be interested to hear what other 25D owners say about this one, but to me, being able to deflect the hull inward with hand pressure below the waterline and in front of the shrouds just doesn't sound right! Maybe it was a Friday boat, and CD hadn't finished the layup. I would be real concerned. Maybe you can find a Naval Engineer that could alleviate your fears, but if it were I, at this point, I'd go for the deposit or maybe ask the owner to get someone to explain why this would be acceptable.

It just doesn't sound right!

Dave Stump
Captain Commanding
s/v Hanalei CD-30

don.sargeant@scp.com

[Neil Gordon]

>>But when the boat's in the water it is suspended all around and a soft spot, if it doesn't leak, shouldn't be a big problem.<<

That doesn't sound right to me. The hull is under lots of stress... from the rig as well as from the sea. And the boat isn't suspended evenly in the water... waves lift the bow, stern, etc. A hull might be sound enough despite a weak spot (we put all sorts of through hulls in), but at some point, it won't be.


Regards, Neil
s/v LIQUIDITY
Cape Dory 28 #167



neil@nrgordon.com

[Bill Cochrane]

Dick, I have the 36, #114 built 1984, and there is nowhere on the hull that I can detect flexing. Different boat but same yard and presumably same standards.

Did the surveyor venture an opinion on the reason? How large were the areas? Still could have been caused by jackstands at an earlier date as opposed to a light layup. I suspect that the only way to know for sure is invasive testing...removing a plug from the hull.



cochrane@clark.net

[Dick Sisson]

The surveyor was of the opinion they had gone light on the layup.

I would assume damage from previous inappropriate setting of jackstands would have been evidenced by some delamination or cracking, he did not detect this when he sounded the hull.

[Ross Williams]

We recently purchased a CD26 also. Hull #3. We've had a great 1st season and really love the boat. We sail the Maine coast out of the Portland area. Anyway, ours has what the surveyor called significant gelcoat cracks in the deck areas. His opinion, based on sounding and moisture meter was that these cracks are cosmetic at this point. He could find no evidence of moisture getting into the underlying laminate. I feel these cracks need to be corrected or water will intrude at some point and cause deck delamination issues. We've seen other CD26's with all the same gelcoat cracks so we know that we're not alone on this one. Since we like the boat so much, we are currently getting estimates for an over the winter repair to the decks. This involves repairing the deck areas with excessive cracks and then having the whole deck repainted (awlgrip). We're getting several estimates on this but the 1st person to look at it recommended re doing the whole deck with awlgrip after repairs have been made since it would be very difficult to match gelcoat repair to 7-8 various areas needing repair on the decks. This quote was for $6,000. We could save approx. $700 of that if we remove and re-install all the deck fittings that would need to come off for the awlgripping job. Has anyone else gone this route? Thanks for any suggestions... Ross and Sandra Williams



rosswilli@aol.com

[Jay Ankers]

I agree with the comments about the stands being improperly placed. I block my own boat (cd-30 #344) and put a substantial amount of weight on a bow stand with a "V"...and I spread the load there with wood blocks.

I just completed a full bottom strip and recoat and found areas similar to what you found on your hull. Not really flexible by hand..at least that I noticed...AND I WORKED ALOT ON EVERY SQUARE INCH OF OUR BOAT.

Cape Dorys are actually 4 fiberglass parts that are bonded together. The inner liner on the bottom adds structural strength to the outer hull and may have either not been completely bonded to the hull or the hull expanded away from the liner. in either case, I would not worry about a light layup UNLESS you can really push on the bottom with your hand and see it deflect.

Jay



jankers@pii-cgmp.com