Transom/Stringer Replacement 78' Chrysler Sport Satellite

[Kanobrega]

Hello all, first time poster -
Much thanks to everyone on this forum - since finding some problem last weekend with this 15' boat, I've learned lots if useful things here, great info - I've gotten a pretty goid idea of what needs to be done. However, since I've never done this kind of repair before, or even owned a boat for that matter, I'm sure I'll need some pointers on the "how" part.
Bought this boat last weekend - looked great, garaged for 16 years by the previous owner, so it appeared to be in great shape. After getting it home I was hooking up a battery to check the electrical system, and noticed a crack in the transom just above the bilge. This boat had a 75hp Chrysler hanging on it, I think the bouncing on the ride home cracked it open and exposed the rot.
Removed motor, cut the upper hull/splash well off to get a better look. Transom is basically 1/2" plywood, with a 1" ply T shaped just kind of stapled to the top, not laminated together in any way. My plan is to replace this with two 3/4" laminated pieces, full thickness all the way across unlike the original.
Yesterday, while preparing to cut the transom out, I found the rot extending up the stringers (3/4" plywood), so looks like I'll be replacing that as well, about 9' towards the bow, where the solid wood is.
So my first question is - is it a bad idea to replace the stringers from the side, in general? Not concerned about easy, just about maintaining hull shape during the General?
(Was trying to post pics, apparently I need to make a few posts before doing that?)
Thanks for any input!

 

[Kanobrega]

Adding pics...

 

[Chaser 32]

Looks like you've got your work cut out for you. If it were me, I would tear it all up and redo it. That way I knew it was good throughout. JMO

 

[Kanobrega]

No Title

Yeah, I think you're right, I've talked myself into it. Seems like it would be easier to replace all of it instead of trying to scab things together.
I managed to get the remaining 1/2" transom out yesterday. I would up using a router to make vertical strips 4-6" wide cutting down to the outer resin layer, then using a thin stiff scraper about 8" long I found at HD to peel it off starting at the top. The bottom of the transom was mulch, but above the bilge certainly wasn't... I'll work on grinding and sanding tonight to prepare for the new transom.
I want to have that tabbed in good to maintain some stiffness before I start on the stringers.
Thanks!

 

[Kanobrega]

No Title

Progress update - spent the 4th grinding the transom area. Been tied up with domestic duties the past few days, and will continue this weekend working on the new transom and some detail sanding.
Been doing a lot of study the past few days, and will be placing an order today for the resin and a few other things - I decided to go with VE for this overall, and use PL adhesive for bedding, West Six10 for filleting, marine plywood for the transom, and ACX for the stringers and deck, along with 4lb urethane foam for filling after the deck is down.
Couple of questions-
- Would the Six10 be compatible with a VE layup over it? I'm ordering fill8ng material to make PB if needed, but wanted to simplify this for my first try.
- The original transom stopped about 1/2" short of the corner along each side. Should I cut and radius the new one to fit flush, or leave a gap like the original and PB it, or keep it like the original? The original was snug against the hull bottom.

 

[Kanobrega]

No Title

This is the as-purchased boat. I really like the looks...

 

[Slager]

VE resin is an polyester based resin and won't stick to the Six10 epoxy putty. Making peanut butter out of your resin is easy and cheap and if you use polyester even cheaper.

Also, there's no need for the 4lb foam unless your boat doesn't have stringers etc. 2lb foam is half the price and works just as well.

On the transom, and generally with anything you do, you can always put it back like the original. The best practice is to not let the wood edge of the transom or stringers touch the hull. You should leave approx 1/4" gap around the edges and fill with pb. This ensures you have even contact and no "hard spots" that could eventually lead to cracking as the boat flexes. The transom isn't a particularly flexible part of the boat, so it probably doesn't matter.

 

[Slager]

Also, using PL to bed the stringers isn't recommend here anymore. It requires at least 72 hrs to offgas for a thin bead, longer for thicker. If not fully cured it will create bubbles in you filets, fiberglass etc. Thickened resin is the go to bedding material now.

 

[gm280]

Kanobrega, I read over you boat refurbishing thread and you have done some nice work with removing the transom wood and grinding for new materials to go in.

A few things come to mind, First, take tons of pictures AND measurements now so you will have them to go by when you finish up the rework. Then plot those measurements on some drawing of the boat for reference. That becomes especially true if you de-cap the top. The sides have a tendency to splay out and then the cap doesn't fit anymore. So you have to make side supports to keep that from happening.

Second, I would stay with polyester resins and skip any epoxies. They are not compatible and polyester will do the job way better then you would ever think. Most on these forums use a laminating polyester. I use 435 laminating polyester from US Composites out of Florida. But depending where you live, you could use another vendor for your supplies.

Don't use the PL. A lot of iboaters on here use TiteBond III glue to assemble the plywood together. It is totally water proof after it dries and works great. Do use exterior grade plywood for everything.

Also read a few boat refurbishing threads on here to get a base line what what you will be doing. And also post questions and post pictures of your progress. We can offer the better ideas as you move along. JMHO

Nice having you aboard!