Hull deflection under cradle pad

[Sparrow496]

I am in the market to buy a cs 36 t.
When viewing one for sale I noticed an obvious hull deflection caused by the rear starboard cradle pad.
The broker assured me this was a non issue and that the deflection would correct itself when launched
How does one ensure this is factual and no hidden damaged has occurred?

 

[Joe]

Hire a surveyor.

 

[Sparrow496]

Most definitely a surveyor would be used.
I was wondering what comments the group would have. Have others had experience with this issue? How common is this?

 

[Prime Time]

Depends

On my old mirage, thin non cored hull, this never happened. On my Bristol, during the short haul for the survey, they miss placed a jack stand and lowered the boat onto it accidentally. The stand broke like a toy, with no hull deflection.

Another old racer at my club had this deflection every yr. The hull had delaminated from the stringers. They cut it up for scrap this winter.

I'd be very Leary. Save your money and survey another boat without obvious issues. It is a buyers market.

 

[sandpiper10471]

The cradle pad should be under a bulkhead. If the travellift operator missed this structural support, the hull might well deflect. Sometimes this deflection will cause the bulkhead tabbing to let go. Now there is a structural concern but is not that difficult to repair stronger than new as long as there is internal access. I would make sure the surveyor does a really good job inspecting ALL the grid and bulkhead tabbing. Each should be sounded with a phenolic hammer. CS's didn't have cored hulls, do rely on structural grids to spread loads to the skin and are sometimes prone to osmosis issues. They are, though, fairly well made boats which sail beautifully.

Prime Time - the "old racer" that was scrapped must have had some other issues. It is just not that challenging to do a good bonding job on delaminated tabbing.

 

[RON20406]

Sandpiper said it very well, but I would like to add one thing: When a vessel is placed on jackstands it is not only the improper placement on a thinly built hull, but also can be the amount of over-torque on a thicker hull that causes the deflection. The broker is not incorrect to say on a solid glass boat that the deflection usually disappears once in the water but I would have a competent fiberglass repair specialist (in lieu of a surveyor) do the assessment. CS has a bullet proof reputation and I would not let something like this, if diagnosed with a bill of clean health, prevent your purchase of a potentially quality vessel. Many boatyards are quilty of improper placement of jackstands on a regular basis since the average boater really doesn't have a clue. Good luck and good sailing, Ron

 

[CharlieCobra]

The stands are there for balance, not really weight bearing so if there's deflection, either the hull has issues at that point or the yard screwed up and over tightened the stand. Have the boat surveyed (a normal thing to do anyway) and make sure the surveyor checks that area for Delam.

 

[Prime Time]

Nope

The cradle pad should be under a bulkhead. If the travellift operator missed this structural support, the hull might well deflect. Sometimes this deflection will cause the bulkhead tabbing to let go. Now there is a structural concern but is not that difficult to repair stronger than new as long as there is internal access. I would make sure the surveyor does a really good job inspecting ALL the grid and bulkhead tabbing. Each should be sounded with a phenolic hammer. CS's didn't have cored hulls, do rely on structural grids to spread loads to the skin and are sometimes prone to osmosis issues. They are, though, fairly well made boats which sail beautifully.

Prime Time - the "old racer" that was scrapped must have had some other issues. It is just not that challenging to do a good bonding job on delaminated tabbing.

The owner is a friend of mine. The boat had major structural issues and needed lots of work to rebond many of the stringers.