Hello, cat sailors. It’s good to have the forum up and functional again.
I am taking apart the project Nacra inter 17 I just got. I need to separate hulls and beams. I can not remove one bolt, aft inside one. It wouldn’t bulge. Any tricks I need to know?
Does anyone know how the threaded part in the hull is made? Is there a metal plate fiberglassed? I just worry that I will snap the bolt eventually and I want to foresee repairs in the future. If there is the plate, is it one for both bolts or two plates for each bolts? Inters 17 are rare but Nacra inters 20 probably have had same problems before and I’m pretty sure that the structure is the same. So what to do and what to expect if I break the bolt?
Thanks.
Vladimir.
Hopefully out NACRA experts will share info soon. Probably if you do get the bolts out it would be a good idea to replace them if possible with good stainless steel ones.
Welcome back to the forums, last post in 2022!
@damon-linkous thank you, Damon.
I pulled the bolt out, after two days of careful tries and liberal application of PB blaster which was blasted in every hole possible in hope of reaching the bolt.
bolts will be replaced. I am installing wings.
I am installing wings.
Cool, don't think I've seen wings on a Nacra 17. I know Nacra has wings now for the new boats, are you using those or a home brew?
Be sure and take and share pictures as you do the work. I'm a wing fan from way back to the Hobie 18 Magnum.
The new Nacra designed set of wings which can be adopted to any Nacra. Cool concept.
anyway I’m not yet to put wings on the boat. Still fixing holes and gluing the mast together. I am on my fourth Nacra F17. One I sold many years ago. Three more I bought after retirement one after another. I made Nacra powercat out of one. It was beyond of resurrection as a sailboat. Another one becomes my racing cat. I love the “Atomic Bumblebee” and right now I am in process of making Nacra F17 Sports Cruiser. With reefs, storage compartments, oars and pedal drive. That’s the plan at least.
Hello, cat sailors. It’s good to have the forum up and functional again.
I am taking apart the project Nacra inter 17 I just got. I need to separate hulls and beams. I can not remove one bolt, aft inside one. It wouldn’t bulge. Any tricks I need to know?
Does anyone know how the threaded part in the hull is made? Is there a metal plate fiberglassed? I just worry that I will snap the bolt eventually and I want to foresee repairs in the future. If there is the plate, is it one for both bolts or two plates for each bolts? Inters 17 are rare but Nacra inters 20 probably have had same problems before and I’m pretty sure that the structure is the same. So what to do and what to expect if I break the bolt?Thanks.
Vladimir.
That bolt is likely stuck in an aluminum plate glassed into the hull. Each bolt usually has its own plate. They corrode over time, which makes the bolt freeze.Penetrating oil,Heat (heat gun),Gentle tapping,Loosen a little, tighten a little, then loosen again
If it snaps or the plate breaks free, you’ll need to cut a small access port and replace the insert — very common on older Nacras.
@maryscott Thank you. That aluminum plate worries me. I got the bolt out but new bolts screwed in are a bit wobbly. Just one corner of the boat. Rest are ok.
I can tight them up and the crossbeam went in fine and feels secure but…
how do I make the access port? Go in from a side? Or just dig the plate out from the top and fiberglass a new one from the top?
I probably will not do it right away, but it would be nice to know how to address the problem if it becomes serious.
After reading this, I was a little concerned about my 2010 C2 F18 (Hull/Sail # 215) that I recently purchased. The ratty-natty tramp is to be replaced when the new super-duper-custom tramp arrives from Goodall Aus, by way of Jill from Red Gear Racing. That means the beams should be detached and re-bedded with the new tramp installation.
So I tried wrenching the eight beam/hull bolts loose. Thanks to the cat gods, they all were reasonably easy to extract with merely a short 3/8" socket-wrench, even though she spent at least 13 of her 15 years sailing the Chesapeake.
Kinda interesting to me that the dolphin striker compression post was not creating even one short little millimeter of upward deflection of the front beam, not even close to what it's supposed to be (~10mm deflection as per the manual).
@crazyru - I would recommend an access port (quality of port matters) on the deck. I had to add ports on my modified 18-2 to beef-up the rudder gudgeons. They tap into an aluminum plate that stripped out. I ended up thru bolting them. With these bots getting older, I would recommend pulling the beam bolts and thru bolting them. Years ago, I had pulled all 4 of the beam bolts out of the aluminum plates on the forward beams. I ended up using a Time-Sert thread repair but haven't tried pulling the bolts out since - which I may tackle this winter. I would recommend thru bolting and merely using the glassed in aluminum plate as a backing plate.
@texastuma yep, that’s exactly my plan.
just for the future references, if someone will run into the same problem.
the bolts and fiberglassed plates on rear crossbeam are accessible from aft (and the only) hutch on Nacra Inter 17. It is 4 inches in diameter and if anyone need to do any work here it pays to remove the hutch completely, it gives way better access.. it is possible to put big washers and nuts on new bolts on inside while leaving the plate still fiberglasses.
I haven’t gotten to underneath of front beam yet, planning to do access hatches in front of the beam. Will report.
anyway progress on developing Nacra F17 Sports Cruiser 🙂 is steady.
i spliced the mast from two broken ones successfully, installed wings from new Nacra 570, and actually sailed the boat a few times already. More things to do, like storage, oars, etc…
@texastuma yep, that’s exactly my plan.
just for the future references, if someone will run into the same problem.
the bolts and fiberglassed plates on rear crossbeam are accessible from aft (and the only) hutch on Nacra Inter 17. It is 4 inches in diameter and if anyone need to do any work here it pays to remove the hutch completely, it gives way better access.. it is possible to put big washers and nuts on new bolts on inside while leaving the plate still fiberglasses.
I haven’t gotten to underneath of front beam yet, planning to do access hatches in front of the beam. Will report.
If it were me, I would not put a port hatch in front of the front beam. That is a recipe for a catastrophic hull failure . . . seen it many time through the years. A port hatch aft of the front beam is not an issue.
You should remove the deck cover to access in front of the front beam. There are several threads here on how to do it.
You should also have knowledge of the bulkhead positions. I have the bulkhead layout template for the I20/N20, and I can dig it up and share here. I would guess that the I17 would be similar to scale.
@pm thank you Philip. Integrity of a bow with a hatch in front of a beam is a concern for me. However I am modifying the boat for long distance adventure cruising. (I have completed a dozen of Everglades Challenges (300 miles) Couple of Ultimate Florida Challenge (1200 miles) and I had an attempt at R2AK although crashed my boat before reaching Alaska.
so, I would like to have an access to the front. I was actually thinking to create three independent waterproof chambers in each hull. Anyway, my thinking so far is to laminate longitude stringer on both sides of the hatch. It should take care of the weakening of the hull due to the hatch. I don’t know. I am just throwing ideas around. Any thoughts?
CrazyRu
@crazyru If you are wanting to build bulkhead zones, it may be worth pulling the decks off and do it right... much easier access.
Here are some pics a member posted showing how the forward deck comes off.
https://archive.thebeachcats.com/pictures/index.php?/category/1168
@texastuma removing the deck will not solve the problem of accessing the area later. So I will need an access port anyway,
to store things and inspect bolts. Bolts penetrate hulls in front of main solid bulkhead. Also if I decide to divide a hull into three separate watertight compartments, I will need a port in each compartment to inspect and pump water out. All of this makes removing the deck unnecessary. The bulkhead under the front beam is solid except the lower channel for water. I can put a plug there with ease from the port behind of the main beam, I already put the port in. And I can reinforce the area around the port in front of the beam, which isn’t going in until weather gets warmer to work with epoxy.
my main concern right now is how to increase survivability of the boat. Existing flotation (there are big plastic jags inside) is enough to keep the boat afloat but not enough to get out of major leak on my own.
So it is either putting more flotation (and in this case removing decks will help) or dividing hulls into separate chambers. I am still in decision stage.
@crazyru Sounds like you have a plan. Only note I have is, when thinking about increasing floatation...
don't make the mistake I've seen done a few times and fill the hulls with foam, which is much heavier than the air it replaces. 😉 Floatation bags or a few blocks of foam like factory is one thing but...
You may laugh, (You are very experienced, this note is for others reading along.) but quite a few times someone has had the idea that filling their entire mast up with expanding foam would help keep it from sinking. Ending up with a mast that weighted a ton.
@damon-linkous The foam is a big no-no in boat building. It will absorb water, besides being heavy. That I know:) . That’s one part of the problem. The hulls are divided by bulkheads, so adding flotation isn’t as easy as sliding in Opti’s flotation bags.
Also I choose Nacra Inter 17 as my platform because it is biggest boat I can handle alone. Not just sailing, sailing is easy, but also moving around, stepping mast, righting after capsize etc. Adding anything to the platform makes it heavier. At some point I could just start with Nacra 20 (which I also have), since it is the ultimate long distance boat. So I’m still trying to keep weight down. This is another argument toward making solid bulkheads and dividing hulls into waterproof compartments. Anyway, I will think about it a bit longer.
Here is another question.
what to do with chain plates? Apparently they are just fiberglassed in on sides of the hulls. 25 years of stainless steel without air in wet environment is a possible trouble.
Cut them out preventably and replace with new? Or Drill holes through them and bolt a new chain plates on outside using old ones as backing plates? Or just laminate dyneema loops on outside as back ups?
I actually like this solution since I have laminated soft dyneema on my last homemade boat and it worked perfectly. But it may be too radical to discuss here 🙂
@crazyru Now you're talkin'!!! I would not drill and externally bolt. If the stainless is going to fail, it will be most likely just below the deck - as where the water will sit. If you have the decks off and can get access, replace the existing chainplates... If you have experience with glassing in the loops - go for it and post the videos... What's the worst that can happen?