Mast step Compresion?

skyamsen · #1 (**permalink**) 12-17-2002

I have just purchased a 1980 C&C 25 Mk2 It has about a 3/4" of deck compresion at the mast at deck level. The boat was surveyed by a good surveyor and he said that it souldn''t be a problem as it wasn''t stuctuaral. Does anyone have any suggestions? Should I fix this soon and if so how? Do I need to get a shop to do it? Or should I just leave it alone. there are no cracks in the gelcoat at all. Thanks for any help. Is this a HUGE problem????

pirateofcapeann · #2 (**permalink**) 12-17-2002

I had the same problem on my C22. There was a strong-back in the companionway under the mast step and some other rigs had been installed that were supposed to support the mast. But my suspicion was that the core material under the mast step was degrading and no shoring up from down below was going to help. I opted to take care of the problem at the deck level, with out tearing the deck apart.

I made a strong-back by laminating 6 pieces of ¼ inch thick oak, just wider then the mast step fitting and long enough to span the width of the companionway below. This allowed me to spread the compression load over good coring and to the up-rights on either side of the companionway that were originally meant to take this load. I molded it to fit the crown of the cabin top and finished it when it had cured.

This was epoxied and fastened in place with screws from below. The mast step fitting was through-bolted to this and through a doubler below. The indentation where the mast was originally stepped was filled with marine bondo. I hacked 1-½ inches off of the mast so that the rigging length would remain the same.

Now, my new mast step was far stronger then the original and it served as a great place to attach the turning blocks for the halyards to be lead to the cockpit too!

Incidentally, while I was making this piece, my step-dad and I got into a “discussion” as to its strength. To prove each other’s point we took the thing into the yard and set it up on wood blocks at each end and set another on top at the middle. On top of this, my step-dad lowered the bucket of one of his backhoes and in an attempt to break it, put on the pressure! The thing didn’t even flinch and the backhoe’s rear end was lifted clean off the ground!

You can show me all kinds of test results and paperwork from the epoxy manufacturers, but when it comes to my boat, that test superseded them all!

Jeff_H · #3 (**permalink**) 12-17-2002

Pirate, the problem is these are short lived materials and while they may have held in the shorthaul, this is not a permanent fix. Bondo in particular has very poor charactreristics when exposed to flexing over time. Soory Dude, this is very bad advice on how to solve the problem at hand.

Jeff

pirateofcapeann · #4 (**permalink**) 12-17-2002

All I can tell ya'' is that it worked and held up well. 5 years and showing no signs of fatigue when I sold the boat, and I wasn''t one to baby her either. The bondo, a marine type, was used as a filler only and was not under any pressure or movement. In fact, the entire original mast step area was bridged by the new piece and all of the forces were transferred to different areas of the deck. That spot was filled only to keep moisture out from causing further damage. The oak held up well as it was laminated and sealed with epoxy, then all was sealed and painted over to match the scheme of the boat.

I suppose the other action would be to remove the fiberglass around the step and remove and replace the degraded materials and re-glass it over. Still, unless the area is built up, it would never be as strong as the original step.

Sorry to disagree with you again but if I was presented with a similar problem, I’d still respond exactly as I did then. But that’s highly unlikely as my Jes is keel stepped. What would you do if faced with this problem?