New SJ21 Owner in New Hampshire

[Sea Major]

Greeting to all in this marvelous forum! I have just purchased, at auction, an SJ21 MarkII, 1979. I have a couple ( well a LOT) of questions, but just a few to start:
1. She doesn't have a Keel gasket. Can one sail without a Keel Gasket, or is that not advised? I have purchased one from Gene, and will install it if needed.
2. I will have to recore part of the deck. I have the deck fitting removed. It seems all have used End grain Balsa. Is a laminate not a good replacment ( such as Marine grade plywood?( I am certian I am asking a question here that has an obvious answer, since Balsa appears to be the material of choice)
3. I need a set of cushions. What are my options here?

Those are good for a start. Also, how do i find other SJ21 owners in my area ( New Hampshire, USA.?)

Thank you so much!

Bill Grant

[cguthrie]

You can sail without a keel gasket but be prepared for the cockpit drain to be more like a geiser (Old Faithful)
Balsa is relatively cheap, light and strong. Good exterior plywood will work. I've used rigid PU foam - no rot, no water absorption. If it's a small area you can fill it in solid with epoxy which is actually a good thing to do with bolt holes anyway.
Finding boats in your area can be difficult. Participate in the local racing scene, check marina's and boat yards.
Enjoy,

Cal Guthrie

[Diarmuid]

Welcome, Bill. Recoring the deck is an inevitable SJ21 project; it's not bad at all, once you get in the swing of it. Have you determined how much core you will need to replace, and where the soggy bits are? That's always the first step.

We recored from a foot before the mast step to the bulkhead on our Mark 1. We worked from below, which is somewhat of a pain because you are fighting gravity; OTOH, the inner skin is dangerously thin as a reference surface, and keeping the original outer skin intact saves a lot of tedious cosmetic blending. Possibly the best solution is flipping the boat (only half kidding. )

We chose CoreCell foam; it's not quite as strong as balsa in pure compression, but its flexural properties are better. And compression isn't so important because we put solid phenolic cores under the winches, mast step, and the controls bridge that spans our hatchway. Plywood is the worst core material: it wicks and rots like balsa, but without any of foam's or balsa's weight advantage.

You can buy balsa in 2x4' (and possibly 2x2') sheets, with blocks glued to a fabric scrim. This is easier then bedding individual blocks, but you have to work fast. Jamestown Distributors and Defender both sell it. Core on our boat was 3/8"t. I think the Contour Core balsa (on the scrim) comes pre-sealed and ready to use; raw balsa blocks may need substantial 'buttering' before you bed them, lest they drink all the bedding resin and leave a dry joint. (Foam also needs buttering.) Definitely use marine epoxy, rather than polyester or vinylester resin. Cab-O-Sil is a handy, inexpensive thickener.



Once the solid cores and the foam were glued in, we applied three layers of fabric plus a fairing coat, sanded, and painted the interior. I could have spent more time smoothing it out and hiding the weave, but frankly ... it's a hell of a lot neater than the factory finish! 'Better than Clark, less good than Hinkley' is our guiding principle.



Finally, do yourself and posterity a favor & isolate all thru-deck fasteners from whatever core material you choose by drilling, overboring, filling, and re-drilling the penetrations. It's tedious and there's all kinds of arguments over the best way to do it, but it really is worth the time. Even the best bedding compounds can fail; having a solid epoxy 'bushing' around every thru-deck fastener means it's no big deal if things start to seep.

My approach (not the only one) is to drill down from above with a 3/16" or 1/4" bit, according to the bolt size. Then I cautiously drill up from below with a 1/2" or 5/8" bit, deliberately ground to a shallow angle and not overly sharp. This prevents self-feeding. You may want to arrange a stop collar; I just did it by feel (but I spend all day with a drill in my hand.) You now have a small hole in the top skin and a larger hole thru the bottom skin & core, with all core material removed. Tape over the lower holes and inject epoxy from above -- neat first, then as thick as you can squirt it. Vibrate the deck around the holes, then go back around & top off any that settle. When it cures, redrill with the correct diameter drill (some people will drill a funnel-shaped hole) and bed your hardware.

Sounds awful, but the whole thing took under a week and cost a couple hundred bux. BTW, since we had the hardware off anyhow, we took the opportunity to upgrade winches, jib cars, put a plate under the mast, and we painted the decks with KiwiGrip non-skid. That rather added to the cost. And of course, it helps to have sailed the boat for a few years, so you know what changes you want.



You can sail with a wet core for awhile, too. Our was wet for probably a decade under the PO, and we sailed it wet for a couple more years.

Welcome again, & keep us apprised of your progress!

Bob McGovern
Laramie, WY

[Sea Major]

Thanks Cal and Bob. OK, so I will be using Balsa as a core and installing my Keel gasket before I go out. I haven't yet determined the extent of the rot, but I know one area that is soft for certain. Thanks for the Pictures Bob, actually, it helps alot!
I will definitely send updates. Now onto exploring this website........


Bill

[Diarmuid]

Here's an SJ21 web site from Tim Thorpe Allen, a really nice fellow who lives up your way (Boothbay, ME):

http://sailing.thorpeallen.net/Quasar/

It includes info on recoring with balsa. Like him, I was *this* close to sawing off the whole coachroof & bringing it into the the shop; glad I didn't, tho. Tim hasn't been doing much with the SJ21 lately, as he's been fixing and racing their Peterson 34.

As the Quasar site shows, you also should check your transom for water intrusion. The port 2/3rds is balsa cored, and leaks around the rudder gudgeons and motor mount are endemic. I fixed those areas before worrying about the deck, because having your transom tear off could ruin your whole day.

It seems there are some bulkhead/chainplate rot issues on Mk2s and 3s. And you'll want to get some sense how solid the keel pivot bolt is. Clarke bedded the thing in polyester resin, or some kind of putty. It's fairly common for years of thinking back and forth to pulverize that material. Our keel pivot had over 1/2" of play in it, and the plywood cheek plates surrounding it were totally soaked. Another tedious but not-too-difficult repair. Finally, have a good look at your keel cable. Those need monitoring and occasional replacement. We've swapped over to a Technora-cored winch line & are very happy with it.

That's most of the big issues with this boat. They are pretty simple animals. Sail a little, fix a little, and you'll soon have it better than new.

[cklamp]

http://www.pbase.com/mainecruising/sealing_the_deck

go over this article... it will show you the importance of chamfering the hardware attachment holes better than I could... I've done the drill, chuck out balsa, and then fill the hole things in a few different groups. If I didn't chamfer the hole the first time I did the job, it was done later as the sealant is just too "thin" at that area to last, so they've all been gone over again.

If you have a harbor freight near you, they have 1/2" chamfer bits for about 2-3$, so it's a no brainer really.

Also, if you want to minimize diarmuid's point about the balsa sucking up all the epoxy, read the link above again:) they go over that as well. Basically fill the "void" with straight up epoxy mix, let it soak a few minutes, drain it back out, bulk it up with the "cab o sill" or whatever your brand of epoxy calls it, then refill those voids. The "runny" straight epoxy mix will soak into the balsa better and avoid some of the "slumping" diarmuid is talking about.

I've read Don Casey's articles many times... they're great, but the pictures and demonstrations this guy has done are fantastic.

And welcome to the group!

later
C

[Sea Major]

Thanks Bob for the points to check. I think I will check the transom tomorrow. At least remove the motor mount and Gudgeons and make sure I drill/seal/backplate them securely. I am currently replacing the bulkhead just forward of the transom ( it was shot). I have got it ripped out and the joint just about preped for a new one. I most likely will build it and fit it into place premade, but I am still considering how I want to do it.

How do I check the pivot bolt? It looks like it is ebedded in the glass. ( I am afraid of what you are going to say..I have a feeling its going to involve a grinder)

Bill

[cklamp]

Bill, a grinder's definitely one way to check it as you're correct that it is embedded into the glass... but you could also "lift" the boat up off the trailer, lower the keel and see if it "wobbles" back and forth. If it does, you have some slop in the pivot bolt.

I think most of these boats will have some slop being 30+ years old, it just depends on to what degree and whether you really want to tackle that fix right now or not. Mizu has some slop and it's on my to do list, but she's still a fast boat. She didn't seem able to point as high as other's in the seattle NOOD recently with the same speed, but did ok with a 3rd in the spinnaker class overall. Point being that it may, or may not, be something to worry about.

As I said, it's on my to do list for Mizu, but that list is also quite long, and in terms of priorities it hasn't moved to the top yet, but it's actually getting very close to the top now.

Later
C