A soft deck

[normbue]

Another 7.9 in the fleet has serious deck problems. The mast step, centerboard turning block and a couple of stanchions are all caving in. Can anyone forward me information on repairing this? Or do we have to cut it all out?

[AJ Oliver]

Hey Norm -
Many 7.9's have had those issues, and those repairs made.
There should be lots of advice here on how to go about it. On # 445, we did the mast step from above; but the deck around the winches, stanchions & turning blocks from below - it's a lot cheaper if you can avoid the professional help needed to re-do the top of the deck.
Good Luck !! AJ Oliver, # 445, Class Struggle, Sandusky Sailing Club

[AJ Oliver]

And yes, all the wet core needs to be cut out. It's not hard - just get down below with a dremel tool, peel back the carpet/liner and have at it. You'll find that the outer skin in really worth saving. On my boat the dagger board turning block was OK, but the core around the chain plates was bad (even though there were no visible signs), as were both stanchions near the cockpit, both cockpit winches, both cockpit turning blocks (which I removed - works just as well and has a cleaner look), and both genoa tracks (which I shortened by about a foot).

When I put it back together, I used solid epoxy plugs for all the through bolts, winch bolts, genoa track bolts, etc. so that even it it leaks again, water will not get into the core. You can now also buy non-balsa core material that is closed cell (does not let water in).

I did almost all this job myself, but had invaluable advice from one of my crew guys who is a very talented machinist & all around handy peep. He had an ingenious solution to the poorly designed mast step that has stainless steel bolts going down into an aluminum plate (there is almost always major corrosion down there. I also did it just after I retired from teaching, and had a lot of time. I went REAL slow and asked lots of questions. Hey if a Political Scientist can do it, ANYBODY can do it.

I'm not sure if it is a good idea to miss a sailing season to do all this work. One thing you might consider is doing the mast step & chain plates now, sail the boat this season, and do the rest of the work next winter. That's kinda what I did.

Hope this helps! OK, now when can I sail on your boat? Kidding, sort of . . (See my obnoxious post under "crew". I stand by what I wrote; most of the hot shots who sail 7.9's are NEVER on this board helping people out. In economic theory we call this a "free rider problem". I know you won't be like that, will you?)

PAX & Fair Winds, Skip Oliver, #445 Class Struggle, Sandusky Sailing Club

[normbue]

Skip, Anytime you want to come to Lake of the Ozarks in Missouri, there will be room!!!

[AJ Oliver]

Hey Norm -
If you do a search for "Hull #153 getting full overhaul" you'll see a discussion of the repairs you are contemplating with some photos of shortened genoa track, etc. The archives have a lot of good information on those topics. I am by no means an authority, but have been able to get by asking for and heeding advice.
AJ

[normbue]

OK, Now I've discovered a leak in the hull, right behind the center board trunk. It looks like board may have hit it, but I don't see marks on the board itself and the water comes all the way into the bilge. Any one else ever see this before? Could the brace that hold up the cabin floor have rubbed a hole in the base of the trunk?
This boat need a lot of work, But it rally sails fast.

[Mark Rode]

I had similar damage just aft of the board. I cut out the skin from the outside, cleaned out the soft balsa, install new balsa and glass on new skin. Fair, fair, fair...then seal and paint. No issues 5 years later. I think it had been bumped and cracked while loading on a trailer in the past.

[wkwtucson]

I too am replacing the plate in the deck below the tabernacle (mast step plate on top of the deck).
My boat is a few hundred miles away and I do not have the old plate out yet but I have the tabernacle.
QUESTION: Does anyone have the dimensions in plan for the plate.
Seems like it must be around 12" long and 10" wide from other photos on this forum.
It appears to be metal (chucks of the corroded plate stuck to a magnet).
I also would like to know how thick the plate was originally??
I drilled some holes thru the deck below the tabernacle to inspect the old plate.
It is corroded in the front but not bad in the aft end.
This is hull number 29 from 1982 and the plate does not appear to be aluminum.

I was going to weld the stainless (SS) bolts to the plate and use nuts from above per this forum.
Seems like some have used 3/16' thick SS plate. I am thinking of going with 1/4" even though I understand the SS is stronger than what I am replacing.
Kevin
Hull-29

[AJ Oliver]

Hey 7.9er's -

A member asked for photos of mast step repair. Here it the answer . .

I had an email and computer crash not long ago and lost those photos. I see that the Class website has lost them too . . Darn !!

But I think you are on the right track. We made the repair described below three years ago, and it has worked out very well. We epoxied the stainless steel plate right onto the wood framework. We also took out the problematic spin pole downhaul block (just forward of the mast step), and replaced it with a welded tang on the front of the mast step. My genius machinist crew also noted that the mast step had signs of depression (not the psych kind) from the pressure of the mast boot. He welded an additional 3/16 stainless plate on the boot (where the mast boot rests) to reinforce it.

Hmmmm. Hey my mast it up now, but I could send you a picture of what it looks like at this time. Shall I do that?

Good luck - very sorry I cannot be of more help.

I'm thinking of moving this thread to the Non-PM part of the class site. Someone else might benefit.

Quoting myself . .

For the mast step repair, we decided to replace the aluminum base plate with 3/16 inch stainless steel, and to weld studs to it that would protrude upward through solid glass layers to the mast step. The mast step will then be attached to the studs with nuts. Using this method, we will no longer have to screw bolts down through the core material into the aluminum base plate.

Hopefully, this will solve the problem of water intrusion below the mast step, as well as corrosion problems due to the aluminum/stainless interface. Let me know if you want more photos or information. (soliver@heidelberg.edu)

It sure helps to have talented machinists on the crew!!!

Unquote . . PAX, AJ Oliver # 445

A few more points - Take careful measurements of the position of the tabernackle (sp?) before you take it out. Dist. from stem of boat to tab.; centered from side to side; thinkness from wooden support post (in cabin) to deck surface where tabernackle rests.

Here is a photo of the finished product. I think it was a good idea to weld a tang on the front of that tabernackle for the spin downhaul block. Note also the added (3/16 ss) plate under the mast boot. My crew guy noticed that there was a depression developing in the tabernackle where the boot rests.

In conclusion, the trick was to remove the plate that rests on the wooden support post at the front of the dagger board trunk. Replace with 3/16 ss plate (yes, I think it's about 10 by 12) with four studs welded to it. Add about 1& 1/8 " solid glass of something that will NOT compress. Don't think ti will ever leak again - will probably outlast me.

What is San Carlos, Mexico like? On line photos look beautiful !

[wkwtucson]

thanks for that and your earlier responses.
I was thinking of buying coosa bluewater 26 to put over the new plate internal to the deck.
Maybe hardened west system is better.
I think I down loaded some of those older jpeg files from your previous posts.
I could send them back.
San Carlos Sonora Mexico is paradise.
Tell no one.
we race two regattas there every year in late May and late Oct thru the Tucson Sailing Club.
it is all phrf and we like to fly the chute.
kevin

[Rolf]

I re-worked my mast step last year and I am finishing up my transom this spring. I rebuilt the step from the base up removing the top layer of fiberglass and working my way down. I used west system epoxy, balsa core from Jamestown distributors and glass from US Composites. I took pictures for reference. Bottom Line I peeled the deck back until I hit dry core then worked it back. You can see pictures here. I don't have the finals yet since I still have to drill the deck for electrical wiring. My email is rolfham@yahoo.com for things I would do differently.

https://www.flickr.com/photos/rham/sets ... 016724725/

Rolf

[normbue]

Thanks, They are good pictures, and shows the scope of the project. Might be a good job for the Marina, not an Old man.