1987 S2 7.9 Starboard Bulkhead Rot

[glennmul]

Hi,

I have a question. I just bought a 1987 S2 7.9 and the starboard bulkhead has some rot on the lower left corner. My first question is do I have lower the mast to remove the chainplates or can I relase the tension and then remove them? Also, how hard is it to remove the bulkhead. Is there a ton of fiberglass holding it or is it relatively easy. I am good with wood, but don't know too much about fiberglass.

Thanks for the help.
gmulhare@nwsc.com
Glenn

[Quinn McCarthy]

Hi Glenn

This seams to be a common problem with 7.9's. When I did mine there was not a whole lot of glass that needed to be cut out. I did most of it with a Dremel tool. I was careful taking the old one out so that I would have a pattern to copy for the new piece of plywood. When I got the old one out I used Bondo to fill in the rotten sections. Bondo is quick drying and easy to work. Once I had my new template I used it to make a new one out of a new piece of plywood. I upgraded from 1/2" to 5/8. It seamed like it was quite a bit tougher. I used a router with a pattern bit to cut out an exact copy of the template. Then I refitted it back in and epoxied it back into place. You can buy teak veneer for the plywood or use teak plywood. I used veneer on the v berth side and a piece of white Formica on the head side. That really lightened things up in there. When I did it the boat was on the trailer so I didn't have to worry about the tension in the rig. I can't imagine wanting to remove that much structural material with the mast up. As long as I at it I cleanned all of the rotten and wet core material out from around where the chain plate comes through. Once I had it all grubbed out and dried out i filled the whole thing with epoxy. We haven't had any problems since. Let me know if you have any more questions.

[Sam Buschell]

I would take the rig down first.
If you need to take it down for any reason before the job is done it would be more risky.

[Roger Kuebel]

I've found rot at the top of the bulkhead. It is most pronounced about 5 inches outboard of the inboard edge. I'd like to make sure I deal with the source of the moisture, but so far haven't found it. Any suggestions as to what the culprit might be?

[grandillusion]

the chainplate is probably the leak, it's common

[Tom Elsen]

No need to take the mast down. Just secure it to the toe rail with the jib and spinnaker halyards.
Check and re-seal (minimum) or repair the thru-deck at the chainplates. If the deck rot isn't too bad you can do it from the top sides. There are lots of postings here about how to do that. Check both the port and starboard chainplates.
If the problem below is 5" from the inboard edge of the bulkhead, it's possible that the fittings for the board tackle bridge are leaky. Check that as well.
Finally, see the posts about reinforcing that starboard bulkhead. Very very important. If you've got rot there, it will need to be replaced and reinforced.

[dave]

It's not necessary to drop the stick if you loosen the shrouds first and then connect the halyards to the toe rail on the side on which you want to disconnect. Using all three halyards gives you two backups just in case something happens to one, as in some dillhole releasing one!

[dave]

Sorry Tom, I guess I missed the first sentence of your post. I wasn't trying to redundant.
No problem Dave. Better to be right twice )

[Doug Frye]

Attached shows what happened after we pulled the bulkhead on Robyn (177) and started to survey the extent of bad balsa.

Under winches
Under Spinlocs
Under Mast Step
Around Shrouds, both sides

I had a great time with roto-zip from top...decided I would rather be the dripper rather than the dripped-on.

[Bob Kirsten]

Doug,

Thanks a ton for the pictures you attached, but, man does it ever scare me. I know I have some Genny track water leaks and chainplate, but not sure about the mast step. From all the advise on this site, I figure on pulling all fittings to do the bent nail and epoxy trick, but I am afraid I could run into your kind of "full monty". Am I correct, that you started with the bent nail, but found dark, punky balsa all over the deck area? Did you have access to a moisture meter? Then It sounds like you used the Zip tool to cut the exposed deck (top only, not cutting thru the ceiling) and proceeded to scrape the balsa off the deck and off the ceiling. Where did you source the balsa, and what thickness? I assume you dry fitted the balsa pieces before epoxying them onto the ceiling, and sealing the top surface. Did you put any marine ply in at hardware mounting points; or bent nail and epoxy them later? I can see that you used screws and wood blocks to hold down the deck replacement after the epoxy was applied. What did you use for filler after that? Then, did you Awlgrip the cabin top; or whole deck and cabin? Did you add any non-skid?

Thanks Doug,

Bob Kirsten
DD Mau

[Doug Frye]

Didn't need moisture meter....drilled holes where deck was a little springy and squeezed wood chips and fingers were wet...kept working my way out til balsa was light tan and no water on fingers.
Got the free balsa scraps from S2, they still use it. Not sure what thickness although I will try to find and measure some. Used cut out upper deck skin and traced on balsa and cutout with band saw.
Wetted the balsa down well before placing it in hole with pure west epoxy (making sure to get between every block) Then troweled slurry of west and 460 colloidal adhesive silica filler on, Wetted out hole, then slurried hole. Can't say enough good stuff about West 406 (only sand it down if you have to before fully cured, it gets real hard.)

Then neatly (yeah right) placed balsa in hole and screwed it down everywhere making sure the slurry erupted from every hole.

THIS IS THE IMPORTANT PART

Waited until epoxy had set up kinda rubbery hard and shaved off all the little blobs with sharp wide chisels (worth their weight in not having to sand later)
Then kind of tapered edges around hole back with small disc sander and layed in some precut strips of cloth about 1/2 wide to reinforce the seam. Used colloidal silica adhesive filler there too.

Sanded and used built up adhesive tape dams to put some of details back in deck. Didn't worry about little non-skid diamonds. Mixed non skid balloons in with some of Algrip
Sanded and rolled on Algrip to everything white topsides. (very hallucinatory)

Didn't re-inforce anything but did overdrill holes and line with epoxy then re-drill for screw size.

Do check your mast step....mine was a steel plate (very rusty) over marine plywood (I think but it was somewhat decomposed). I replaced it with hi-strength aircraft aluminum plate (McMaster Carr Catalog) and marine plywood (I made sure)

[dave]

"Sanded and rolled on Algrip to everything white topsides. (very hallucinatory)"

You're lucky that's as far as it went. Awlgrip, Imron and many other 2 part paints contain isocyanates, along with many other nasty chemicals. Given enough exposure over a short period, you can become DEAD , and "enough" ain't much!!!

Hope the job holds up for you. Fun, ain't it?.................................................

http://www.osha.gov/SLTC/isocyanates/index.html

[Doug Frye]

Yep...next time I will use outside fresh air pumped into full facemask....I think the stuff even went through my skin.

[dave]

Just be glad that you still have a "next time" in you!