Project Cobra

[jakew009]

Originally Posted by willk

Great thread. I've used Hudson a couple of times and I've found them to be exceptional!

I should also give mention to Coastal Rides, they have loads of random Raymarine stuff at huge discount especially cables and the like. Also very quick to deliver.

[jakew009]

Originally Posted by Maximus

Could do...but a longer and nicer run along the wild North Devon Coast is from Watchet...??? 60ish nm if memory serves.
Should be able to get some accommodation if you fancy a Two dayer and stop over?
..Not that I'm being over forward you understand!!
Either or route suits me.

Drop me a PM and we can swap details

Ahh but Appledore is just a few miles from me, Watchet is a different county

Will drop you a pm

[jakew009]

Think that’s the wiring harness just about complete, all the stuff that isn’t fitted to the console (lights, bilge pumps, radar etc) will connect to the terminal block so it could be easily disconnected in the future.

Wired the backlights for the switches so they come on in the first position of the deck / interior light switch.

Nav and anchor on another switch.

The boat will have two bilge pumps, one big one small. Wired them both to an dpdt on / off / on switch so they are fused separately but controlled together.

The bilge will bypass the battery isolator so it can be left on.

[Maximus]

Originally Posted by jakew009

Ahh but Appledore is just a few miles from me, Watchet is a different county

Will drop you a pm

If you won't /can't/don't fancy Crossing the County line (I know It is a Big Step (up) for "Debeners"!)... I can always meet you over the Sandbar .... for the crossing.
Look forward to hearing from you.
...Re-furb is looking Good

[jakew009]

Realised I needed even more wires to make all the backlights work. Finally complete...



Then time to make some battery wires. Angle grinder is the easiest way to cut 50mm plus cables







Then time to break out the beast



Which makes perfect crimps every time



Cur one in half to check



But of adhesive heat shrink to finish off



Got it mostly wired up. The wires will all be tidied up later once it’s all tested.
I put a 300a megafuse on the battery cables (50mm2). I didn’t fancy having them unprotected given the length.
I also put a 100a on the 16mm2 house battery cable, but now I’m thinking I should have done that in a bigger cable (more on that next post).



All the negatives come back to this post so only 1 cable to each battery terminal

[jakew009]

So my original thought was the 50mm2 cable has a rating of about 350a, so I fused it with a 300a mega which will blow at about 600a which should be more than enough to start the engine but still blow if somehow the cable shorted out.

I then thought there’s no need to use massive cables for the house load.. so used 16mm and an 100a midi fuse to protect it.
But...... it never occurred to me that I could end up starting the engine with the house battery if somehow the engine battery went flat and they were paralleled together.

So I’m thinking I will swap the midi fuse for another 300a mega and up the cable to 50mm2 to the isolators.
The 16mm from the isolators to the fuse box will be under protected but I can’t really comprehend a situation where that’s a problem given most battery cables aren’t protected at all.

I know I could do away with the fuses completely, but I really don’t fancy an unprotected 50mm2 cable running most of the length of the boat below deck where I can’t check it


Anyway... I think it all works

[Pikey Dave]

Originally Posted by jakew009

So my original thought was the 50mm2 cable has a rating of about 350a, so I fused it with a 300a mega which will blow at about 600a which should be more than enough to start the engine but still blow if somehow the cable shorted out.

I then thought there’s no need to use massive cables for the house load.. so used 16mm and an 100a midi fuse to protect it.
But...... it never occurred to me that I could end up starting the engine with the house battery if somehow the engine battery went flat and they were paralleled together.

So I’m thinking I will swap the midi fuse for another 300a mega and up the cable to 50mm2 to the isolators.
The 16mm from the isolators to the fuse box will be under protected but I can’t really comprehend a situation where that’s a problem given most battery cables aren’t protected at all.

I know I could do away with the fuses completely, but I really don’t fancy an unprotected 50mm2 cable running most of the length of the boat below deck where I can’t check it


Anyway... I think it all works

I use these at my battery terminals

https://kojaycat.co.uk/fuse-boxes/-h...amic-cube-fuse

[jakew009]

Finally a bit more progress

Had to make some bus bars for joining the fuse box sides together. Decided to use some copper bar, I figured by the time it has corroded sufficiently to cause a problem the bot will no longer be my problem. Everything exposed and electrical will eventually get covered in liquid electrical tape once I know it all works.



Bars fitted



Covers on



All of the wires that go ‘out’ of the console (to things like radar, lights, bilge pumps etc) will originate from these terminal strips. Makes it easy to disconnect in the future and troubleshooting is easy.



I’ve still got a bit of tidying to do with the wiring. I’m not overly proud of it but there is a colossal amount of stuff in a very small space and it’s the first boat I’ve ever wired trying to use a lot of what was previously installed.

If I did it again I would do it differently and make a power distribution panel on the bench in an enclosure and then just mount it inside the console with terminals for the battery cables etc to connect to.

Secondly I’d use Czone or similar digital switching rather than the Carling switches. Doing the fuses and backlights was a pain in the ass and creates loads of extra wiring.
I was going to do Czone on this boat but wasn’t sure how to do the bilge pumps and anchor light that may need to be left on with the network off. However, in hindsight a bypass switch for those wouldn’t be very difficult.






The console is just about complete now bar the autopilot / steering connections and putting the hand rails etc back on.

This is how the console looked when I got the boat:



And how it looks now:

[pilotwillie]

Glad I’ve only got a plotter and vhf [emoji844]
You need to swap out that wheel to complete the look.

[jakew009]

Almost ready to marry the console back up with the boat again.

Plumbed in the autopilot pump:



I think that’s the console just about done inside. Just waiting on some new batteries and speakers. I spent ages cleaning the old speakers up and painting the grills, only to find that one didn’t work at all and the other sounded like crap. Just about every system on this boat was crap and broken.

My advice to any doing a similar project is just to consider everything junk and replace the lot rather trying to salvage stuff. It’s just not worth it if you put any value on your own time.



Got the holes for the front locker drilled.



Mounted the screws



Test fit with lid on, will silicon it in tomorrow.



Front of the console basically finished:



I really want to try and finish it this week... we shall see.

[Barraaaa]

Fair play .. Very tidy work so far

[jakew009]

Forgot to take many pics today

Finally the console is back in:




Cleaned the boat inside




Decided the advantage of lithium batteries weren’t worth it for now, so ordered a 120ah AGM leisure battery. Also found some nifty aluminium hold down trays I think will work well.

Wiring A frame and servicing engine tomorrow. Need to change the coils and see if that lets it rev up.

[jakew009]

I think when this boat was built there was a shortage of sikaflex in Bridgend as basically none of the fitting and screws were sealed in (even the below waterline ones in the transom for stepladder).
Luckily it’s been on dry stack most of it’s life so it’s not affected it.
It’s weird because the hull seems really well built it’s just the fit out and rigging that was complete pants. Are newer Cobras any better? What year did they get their act together electrically?

Anyway, these (almost) captive nuts are now sealed in as best I can:



The console bolts on top of these. I’m not going to sikaflex the console down in case I want to take it off again. I can’t properly seal it anyway as the cable duct comes in and I can’t seal that.



Working in the console is a nightmare. I haven’t tidied all the hydraulic lines yet. Connecting the fuel filler was a pig but a bit of Vaseline made it much easier to slide on. Ordered wrong size vent pipe so waiting on that to come.



Had to recruit a friend to get inside the console to connect the hydraulic pipes as I had had enough of standing on my head



The Cobra ribs didn’t really have a traditional conduit (drain pipe) that went from transom to console. There is just a big void beneath the hull with a hole at either end lined with a 4 inch bit of drain pipe. It’s quite a good idea as it makes it easy to pull lots of stuff through.
However it gives very little abrasion protection, and not knowing how roughly finished the underside of the deck was, I put everything in individual conduits to protect it. Since I moved the batteries to the helm, I had long leads going back to the engine.
The baler twine is used to yank the assemblies through. I left some spare drawstrings and conduit for future use...



Cables replaced all the way up to the engine. What’s the best thing to protect the engine with. Some sort of spray on grease / sealant? Is saw crc656 mentioned?



Some new pencil coils. I don’t know if they were all knackered but for 15 quid each I just replaced the lot. Was going to swap the plugs but they looked like new so didn’t bother...



All swapped over, Mercury sealer wanted 1200 quid for that little job alone...



When I was poking around inside the engine I noticed one of the pins in the multi pin connector had clearly been problematic before as it was very corroded / bodged and would not stay in the multi connector. It was cable tied to another cable in the plug but that wasn’t really working. I don’t know exactly what the wire did but I imagine it could have caused some interesting error codes when it became flakey



I didn’t have any pins for the connector so I just bypassed that pin with a bit of wire. It’ll do for now and at least won’t cause any problems...

[jakew009]

Took the step ladder off the back and cleaned the wood up / oiled it with some linseed.



Found some really nice battery holders on Etsy of all places. I was going to make some myself but for 30 quid I just ordered these...



Figured out how to get the fuel sender out of the tank. Wanted to check it works and calibrate it. Figured it would be nice to know that it works as it is supposed to as without any motion potion we’re not going to be going far.



I think the sender is a bit dodgy as it seems to jump a bit between 60-80%. I assume it’s just a series of reed switches connecting resistors and one has died. Ordered a new one as I’ve replaced everything else.



The original Mercury multi connector was all corroded and their wiring is crap (Mercury why you no use tinned wires?) and I had binned the silly paddle wheel thing that was on the transom, so just decided to chop the multi connector off and connected the wires with nothing to corrode.
I haven’t used any bullet connectors or anything, I figured for the few times I’d want to disconnect something I’d just chop the wires and redo them with a new crimp.



Got the fuel gauge showing up on the plotters after some fiddling and calibrating.



Flow coated inside the lockers. Before they were just bare nasty fibreglass with lots of rough edges. Cobra why you no do this at the factory?



And inside the rear locker. Still need to fill the holes where the battery switches used to be.



Straightened out all the hinges and polished them. They had bent really badly as the silly little screws came lose. Going to replace them with bolts with nuts behind which is what should have been done originally.

[jakew009]

Continuing on the theme of crappy welsh boat design...

Spent some time figuring out how to get this piece of crap:



Back inside here:



The Cobra design is a bit unusual because the hull of the boat isn’t sealed at all from the deck. Any water that lands on the deck flows into the big hole at the back into the bilge area here. It seemed a massive area that was completely inaccessible. On the basis that the bilge pump is the only way that water gets into the boat, gets out again, I though the silly little bilge pump that was completely inaccessible seemed a bit crap.
Anyone who has ever had the misfortune of working in this area will know exactly what I mean...
This is looking back towards the fuel tank. I think there is enough space here for a fresh water tank in the future...



Anyway, after thinking about it for a few days, I decided to make some modifications. I present a much bigger bilge access hatch:



So, so much better. The underneath of the deck was remarkably clean given no one had been down here for 15 years. Found plenty of nuts and bolts that had been dropped..



The deck seemed well built with no signs of water damage.



I’m now putting two bilge pumps down here. One 700gph auto pump and a 2000gph emergency pump that will clear it very quickly. They are both wired individually on separate fuses so hopefully we will never be without a Working bilge pump. Reading stories of boats stuffing and not being able to pump out the water quickly worried me.

I could also now clear the crap out of the drain bung that kept blocking it that previously was inaccessible.



The silly Cobra diamond plate bracket can now go in the bin and the pumps secured to the bilge floor with easy access by leaning over the rear seat if they get blocked. What’s the best way of fixing them down? I’m thinking of sikaflexing in some foamex and screwing the pumps to that?

[GuyC]

That looks a good modification.

My boat has a piece of ply that the cage is screwed to so I guess Formex would achieve the same thing. I've looped my pipework round so I can pull the pump out of the space and the wiring junction box is as high as possible so it doesn't suffer water ingress until as late as possible. It's theoretically waterproof but better safe than sorry.

The bilge pump won't significantly change the amount of water in the boat following a stuffing. Even with 2700 GPH, it only equates to about 3.5 litres per second (if my maths is right). Getting rid of stuffing water is primarily driven by your transom height and the size of your elephant's trunks / freeing ports.

It is a very interesting thread and you've done some very good work.

[jakew009]

Originally Posted by GuyC

That looks a good modification.

My boat has a piece of ply that the cage is screwed to so I guess Formex would achieve the same thing. I've looped my pipework round so I can pull the pump out of the space and the wiring junction box is as high as possible so it doesn't suffer water ingress until as late as possible. It's theoretically waterproof but better safe than sorry.

The bilge pump won't significantly change the amount of water in the boat following a stuffing. Even with 2700 GPH, it only equates to about 3.5 litres per second (if my maths is right). Getting rid of stuffing water is primarily driven by your transom height and the size of your elephant's trunks / freeing ports.

It is a very interesting thread and you've done some very good work.

I'm planning something similar but decided to use a chopping board to mount it on rather than the foamex as it'll be a bit stronger (chopping boards are cheaper than HDPE sheet).

With regard to stuffing, I hope I never stuff it. Cobra's don't have any elephant trunks or any way of getting the water out other than the bilge pumps and the transom is effectively higher than the tubes. That's why I thought putting a decent bilge pump in would help. Maybe I should put in a couple of 2000gph pumps

[jakew009]

Sorted out the heap of boxes that all the stuff came in



Flow coated the bilge



Fitted the new speakers

[jakew009]

Replaced the bilge pumps. Turned out the original one was knackered like everything else on this boat, I did think it was a bit anaemic. One is a 2000gph the other 750gph. They are both eBay cheapies but seem better built than the expensive Rule pumps, I bought a spare of each.

Moved the outlet so it now fires out over the transom even with the cover on. Before the full canvas cover covered the outlet which I thought was a bit silly.



Mounted pumps to a cut down chopping board and then used some stainless bolts glued to the bilge floor. Just needs some nuts to hold it down.

[Nos4r2]

This really is reminding me of my Ballistic rebuild
You're getting as obsessed on certain points as I did. Fun isn't it