Mast step repair

[Tom Cassidy 352]

Like a number of you, I've discovered a problem with my mast step and the surrounding deck. There has been some talk that a pro should tackle the repair because of the design of the step. Does anyone know if there is a scematic drawing of the cross section of the step showing the amount of taper so that I could give it to local pros? Does Tiara have it? Thanks in advance for any and all help. Tom Cassidy Gargle Blaster 352

[dave]

Tom, I am a pro and I don't really think it's that big of a deal. It IS a real pain in the a$$ but as far as getting things back the way they were, the two fairly critical aspects are to get the height correct where the mast plate sits and to make sure that said area is level side to side. For and aft isn't that critical because the mast base rocks fore and aft. You can build a simple template from another 7.9 to gauge the height/location/shape by making a frame that sits on the deck, inside the toe rails, "X" distance aft from the bow on both side. Run another beam across from these two uprights to indicate mast step level. You can then make a template of the shape if want to be that ticky, and mount it on the cross member with screws when needed.

THE most important and time consuming part of the job is getting everything dry. The moisture on my boat went WAY back on either side of the main hatch runners!!!!

[Tom Cassidy 352]

Dave,
Thanks for all the help. I'm thinking that I"ll remove any water soaked core at the mast step and deck and replace it with a combo of coosa board and epoxy/glass layup. Tom Cassidy

[dave]

Tome, it would be wise to go below with a drill and go up into the core to see how far the water goes. It may save you having to do it over, and you'll be able to hopefully do ALL repairs at once and NEVER have to go there again!

[dave]

Sorry for the "Tome".

What the heck happened to the edit feature?

[LarryE-old]

As a hands on engineer, for way to many years, I try to come up with a repair that is good so I never have to do it again.
First, my wood was mostly dry, just compressed, roughtly 1/4 inch. I went a completely different way and don't want to share it yet, until I prove it out. I wouldn't want someone else to do something dumb, just because I did. But I'm really happy with the way it came out.
No Dave, I didn't use the Alum or SS plate idea that we discussed.

[dave]

Good for you. If it didn't work to begin with there's not reason to do it over!

WHEN I ever get to mine I'm going to use Coosa board with carbon tube inserts supporting the compression forces. A wise man once said "Insanity: doing the same thing over and over again and expecting different results".

Albert Einstein

[LarryE-old]

Dave,
we are kinda on the same page. however we have issues with some of the PHRF guys rebuilding stuff with carbon and any carbon has become an issue.
I live on the Space Coast and you wouldn't believe some of the high tech stuff showing up on these PHRF boats.

[dave]

Larry, I have no formal education past the 12th grade, but even with that "limitation" it's just a common sense issue, or at least should be. Using carbon as compression struts in the deck laminate under the mast step adds NOTHING to performance and will save less than a pound in weight. Going with a carbon mast, that's a whole different ball of wax!!! It's typical though that their are loopholes in everything. Most OD keelboat classes allow carbon spinnaker poles. These are not only stronger, stiffer and lighter, making them easier to handle [which could make for quicker jibes], but because they are lighter the boat will have less weight on the bow/starboard side when on deck and sailing. This is moot in flat water but could be a BIG deal in waves. Funny, these boats aren't rated any differently than their counterparts with stock poles.....................................................................

The same thing could be accomplished with aluminum compression struts between the deck skins but the problem as I see it is that aluminum is what came out of there, albeit a plate. On my boat the galvanic corrosion between the SS mast base bolts and the aluminum plate [when combined with the moisture from the leaking mast step bolts, which turned the whole thing into a low grade battery] only exacerbates the problems once a leak starts. Also, the resin used in the repair and putty that's made from such to fill the voids will bond very well to the carbon tubes, as long as polyester isn't used. This will make for a very solid unit. The same can't be said for aluminum. Resin of any kind bonds with it until it doesn't. Once the resin bonds begin to release the whole repair is no longer a unit, just a bunch a pieces or sections that can move independently from each other. NOT GOOD!

[Tom Cassidy 352]

Thanks to everybody for your input. I spoke with a local pro and I'm going to sail this season but pull the boat early and get it to his shop. He'll let me do a lot of the brainless work with his direction so that the $$ don't blow the budget. He's worked on a lot of cored hulls esp T10s so he knows what he's doing. He wasn't familiar with coosa board but was interested in learning more about it. I'll let you know how it works out.If anyone has any other ideas, I'm open. With all the great advise this site offers, I still don't understand the people that won't pony up $25 for dues. Tom Cassidy 352

[Runaway#23]

Tom;

I used 1/2 inch Coosa Bluewater 126 to repair my step. The plate is not parallel to the deck step, making the step thicker forward than aft. I just posted a step-by-step repair to this site, but on the "daggerboard box" link.

As Dave said, it's not hard to fix, just get it dry first. Since you indicate putting this off now until the fall, you may want to caulk the plate bolts now just to avoid more water getting trapped over the summer.

Good luck!

[dave]

I would add to that: Drill some weep/breathing holes on the underside deck skin as far back as you find wet/damp balsa. Doing this and keeping some Damprid close by when the boat is put away at the end off the day may save you a bunch of work and time when you finally tackle the problem. The moisture just heeps on traveling further away from the original leak so anything you can do to stop and/or minimize that travel and at the same time start drying the core out now will only help in the long run.

[Tom Line]

I just finished this repair.

Step 1 - measured where the step should have been by checking three other 7.9's. No, sorry, I didn't save it. I made a template from the measurements and chucked it when I was done.

Step 2 - used a dremel to cut through the skin on the deck, then used a crow bar to peel it off in 1 piece.

Step 3 - Used the claw end of a hammer to peel all the crap wood out of the deck where it had been wet.

Step 4 - went inside the boat and peeled back the carpet. Drilled holes to test the balsa until I found dry.

Step 5 - Used same dremel to cut the interior skin surrounding the mast step.

Step 6 - Peeled the interior skin back with aforementioned crow bar (in the places it didn't just fall off EEK).

Step 7 - Let sit in a dry warm warehouse for 3 months while I and a friend removed every piece of hardware on the boat, filled everything, and repainted it top and bottom.

Step 8 - Grabbed some spare endgrain balsa and recored the inside deck from the inside.

Step 9 - Wetted out glass and stuck it up onto the still-wet balsa. Multiple layers, being careful to make sure it had prooper scarfing and thickness to match the old stuff and adhere well. Used jack-stand and 1/8 plywood to crank it all together and hold it up.

Step 10 - Left mast step bolts IN but wiped with wax. Completely rebuilt the step out of solid glass (3/4 inch think, it's not going to rot or break again. Rolled outside to let cure so it didn't get too hot (30 degrees will keep it from burning up) - left the whole step 1/16 inch short on purpose.

Step 11 - Sanded the new step, laid one final layer of glass then a layer of high-strength vinylester filler. Removed the bolts then put a layer of saran wrap on top of this mess then bolted down the mast step to exactly the right height, and let cure this way so the deck portion matched the metal step shape perfectly to help prevent point loading. After fixing them for 2 months I hate spiderweb cracks. Little ********'s.

Step 12 - Sanded the sides and curve smooth, then painted the whole thing. Game, set match.

[AJ Oliver]

Dear 7.9er's -

Do any of you have some leftover "Coosa board" from your mast step repair? I intend to use it if possible when I put my step back together. (I checked the Coosa company web site, and as best I can tell, they only sell eight foot sheets.) I'll be glad to pay what you think it's worth plus shipping.

You can email me at <soliver@heidelberg.edu>, or phone 419-625-8654

Fair Winds, AJ (Skip) Oliver
Sandusky Sailing Club

[Tom Elsen]

Tom & Dave
Many thanks for posting such a complete, detailed and well-informed thread here.
All of us benefit from what you've done. That you've taken the time to document and share it is better still.
Thanks again.