Coronado15 Rebuild

Epoxy is very easy. What is the mixing ratio for it? Is it 2:1 or 3:1 or 5:1? You will want some chip brushes and a bunch of paper towels and some denatured alcohol. The alcohol works great for cleaning up. I used to use acetone but gave the alcohol a try, and it won me over. You will want a box of those disposable vinyl gloves. Mixing sticks and mixing containers. You will be a pro in maybe 15 minutes.

I think that stringer was moved aside when you sent a kid in there to pull out the soggy flotation block. No big deal, it's job now is to act as a form for the new fiberglass. It will be stronger than new.

 

It's 2:1.. I think I've picked up or already had everything I needed. Which is why I have no further excuses.. I even messed about with fiberglass on my old car back in the 80's, so I really have nothing to fear.. except the fear of running out of epoxy.

 

I got started. At first I was just going to mix 1 pump and try it out on the backing plate for the mast partner(does that hunk of wood have another name?). Once I did that piece I felt compelled to keep going. I coated the base plate, and the cap, then I decided to glue up the CP layers. I added a heavy coat of epoxy to each (inside) face and clamped it all together. I hope it bonds :-0. I didn't do the fin part of the assembly yet because I want to do some more shaping on that before I seal it up. I didn't take any pictures yet, but I figured you'd be glad to hear I'm off to the races.

 

Well take a picture at some point. I picked up a quart of non-skid paint and I'm working in the cockpit. Have to head to West Marine right now. Exchanging the shackle I bought yesterday and I want to see if they have a paint can shaker.

 

It doesn't look like much, but it took lots of sanding. I mixed 2 ounces of polyester filler and tried to fill some low spots. The filler never kicked so I scraped it all off with a putty knife. Time wise, it was a setback. It probably would have cured if left over night but I just don't have the time. Working all day today and planning to go sailing Saturday morning. It looks very fare even without the filler.

 

This is the non-skid I used. I was looking for something that provides some traction under foot, but also won't take skin off the knees.

 

Hey that looks like it came out great, are you happy with the properties, as in traction but not skin removal?

 

Had a good day sailing yesterday. The paint needs more than 2 days to dry. It was very soft and I'll have to paint it again. No big deal, painting is the easy part. The abrasiveness of the stuff is pretty good, just about perfect.

 

That's a good looking part. What's the plan for installation?

 

Loose plan at this point, there is a cap that I still have to attach to that whole assembly, that should all fit in to within an 1/8th of an inch. I'll test fit it again before gluing it up.. I think the boat needs to be flipped so I can fill in around the old mast step backing plate..(if that's what it's called).




you can see the voids all around that.. so I want to fill that in

and then I'll slide the new piece in place, hopefully it will be snug, but not need to be forced and thus cause the boat to change shape. If I need to build up a little more with some cloth to close that 1/8 of an inch.. then fine.

I tried to add some silica to my mix to build up the fillets, but I guess I didn't add enough because it still kind of self leveled out along the whole base... It still seems strong but I would probably add quite a bit more to the mix for filling in those voids and for future fillets.

 

Lots of good work can happen after the hull is flipped. That mast step backing plate could be completely filled in with epoxy and then glassed over with a few layers of cloth out to the edge of those stringers. That whole area of the cockpit sole will be one solid piece. I left an original sheet of fiberglass in place, and that acting like a dam to prevent the liquid epoxy from flowing out from around the backing plate. I remember seeing that you removed that sheet (from right below the hatch) so you will probably need to rig up something else as a dam. Even that ridge along the top edge of the trunk can be flooded with epoxy and built up with cloth. Pull out all loose and brittle glass, chip away those blobs of cement, and sand everything down. Build it up with fresh glass to the point where you would feel comfortable standing on it.

 

All good points hopefully that will all be easily accessible once boat is flipped. I have plenty of through holes below the hatch so a small dam can be patched in. Probably a good idea to back plate that area anyhow. If I were building this beast again.. which I hope I don't ever have to, I might have made the two outer layers of my post longer at the cb end so they could overlap the cb trunk, as it is now my CP is considerably wider than the CB trunk, might make glassing them together a little more tricky.. either way it's a hearty piece and should be considerably more solid than original. Certainly more so than what I took possession of last July. I'll post a picture of her once I get her flipped and can get myself in there without trapeze.

 

I considered the same set up. That point of the hull , right in front on the centerboard trunk is the boats natural pivot point. It wants to literally fold, right at that spot.

The bow wants to fold up and so does the stern. Add the weight of the crew just above this point and also the compression of the mast, and you can imagine. The trick is to tie together both sides of the hull, so that it can't fold (flex.) Extending the outside plies of your compression post aft to along each side of the CB trunk is exactly the type thing that would work.

My hull did fail at that "pivot point." My Father and I were sailing down wind and we bumped into a sand bar. I had the centerboard control lines tied down so that the board could not retract (I now use a bungy cord only.) If you can imagine, the sand bar was pushing the leading edge of the board aft and the whole hull wanted to swing, bow down (because the board acts like a lever.) Well,,,the bow would really rather float so the hull cracked right at that pivot point, just in front of the trunk.

I posted a couple pictures of that repair, let me know if you'd like to see them again. So I guess what I'm saying is that everything should be reinforced and also tied together so that the stresses that focus onto one part of the hull, can be distributed to the other adjacent parts.

 

I wish I had thought to extend it forward like that before I made the post. Or at least before I had glued it all up.