Stem/Keel Repair - Update

[withintheruins14]

I am redoing this boat stem here. The stem already has old repairs, but I plan to grind/sand them out. I have 3 questions;

1. Based on what you've seen in the video. Is this mostly a cosmetic reshaping of the pointy/tip part of the stem? Or, is it that I should sand and taper back each side from the center line and lay new glass that covers a larger area from left to right than just "reshaping the pointy tip of the stem"?

2. Would you lay the glass in long vertical strips down the stem or short patches across the stem from port and starboard? Is a one-sided repair even acceptable for the keel? I mean, it's the area of the boat most battered up by the water

3. What exactly is shown in the cut? Is it a left and a right side + a "third" in the middle (possibly different type of glass) interior side?

Thanks, looking for some good ideas

 

[PaulK]

You might want to grind back a little bit of a taper (perhaps 3"?) and then lay a fiberglass strip up the whole length of the damaged stem and forward end. You can buy a roll of fiberglass "tape" that is perhaps 4" wide that would work very well in this situation. I used it along the stems of cedar-strip kayaks for extra reinforcement there. Lay the first strip centered on the stem. Follow that up with another layer offset to one side, which will go out to the full 3" you ground back. Then a last layer offset on the other side, going out to the 3" you ground back on that side. That will give you three layers of fiberglass over the stem, and two over each side. You sand it all down after it's set, and apply gelcoat to match the rest of the hull and topsides. (Matching the gelcoat color is the hard part of this repair. It's not required for structural integrity, but the boat would look funny if the repair wasn't hidden under gelcoat.) Good luck!

 

[dLj]

I've no idea how this boat was built. In fact, I don't even know what boat it is by looking at it. So this is a preface to let you understand I haven't much of a clue as to what I'm talking about...

That being said, a number of boats are built in what's call clamshell type construction. That means each side of the hull is laid up and then joined down the centerline. Maybe your boat was built this way, I've no idea. But if that were the case, then the three different structures you are seeing may in fact be three different structures - each side as you've pointed out, and that center line. It may also easily be simply the two sides were originally one, and that center piece is a structural reinforcement.

Does this even matter? Well, only from the standpoint that the centerline is likely structural no matter how the boat was built...

I'd suggest you take that into consideration as you figure out how to rebuilt it.

dj

 

[dlochner]

The hull was likely laid up in one piece. It is a small enough boat to do that.

The thickness of the hull (the scantlings) will taper from ¾" to 1" at the bottom and near the keel to something thinner near the gunwale.

The hull will need to be ground back to find solid undamaged fiberglass. Once the damaged glass has been removed, the area should be ground back to form a 12:1 taper.

Multiple layers of glass will then need to be laid up with epoxy. There are many types and weaves of glass, 1708 seems to be a popular option. Which ever glass you use, you will want to lay the glass up so that the yarns run at 45° (on the bias) to the centerline of the boat. This will yield the strongest repair.

With this information, I suggest you give Jamestown Distributors Tech support a call. They will guide you on the fabric choices.

There will be a lot of sanding and grinding. Thinking about dust collection would be a good idea. No one wants to be breathing the dust.

Good Luck.