Project Cobra

[jakew009]

Hello all

Hoping for some help and advice as I go along. I know next to nothing about ribs, but am learning fast

I recently bought a 2005 Cobra 7.5 with a Verado 250. I really wanted a newer boat, but the budget wouldn’t stretch to the ~40k required to buy what I wanted. Therefore I settled on this boat, which had just had new tubes, and I will completely refit it to bring it up to 2020 standards.

I have a pretty well equipped workshop and can tackle most stuff (set up for spraying etc), so hoping it won’t be too bad.

At the moment my tentative plan is as follows:

- rip all the existing electric wiring off the boat and replace with new
- take out the existing gauges and replace with 2 x chart plotters and one Mercury Vessel View
- install simple shore power for easily charging the batteries
- move the batteries and power steering pump under the console rather than having them in the bilge. Swap leisure battery to LiFePO4 to save some weight.
- install fake teak deck through the boat
- replace anaemic bilge pump with 2x larger ones
- repair / respray console and seating gelcoat if they need it
- remove anti foul / respray bottom of hull.
- sort a few bits of upholstery

I picked the boat up on Tuesday and towed it back, uneventful once I found a garage I could pump up the trailer tyres with!





My original plan was to get it on the estuary this weekend for a shakedown trip, but after more thought and investigation I decided to crack straight on with the refurb. Whoever originally wired these ribs up should have been taken out the back of the factory and shot! It might have all just about worked but I didn’t trust it enough to take it on the water.

This was after I remembered to start taking photos and removed the rear seat. Is it normal for the furniture just to be screwed down with a couple of screws and no sealant or anything? Certainly made removal very easy.



The 2 batteries and power steering pump used to live at rear of the boat. I think my plan is to move these under the console instead. It seems pretty stupid to have batteries in what is effectively the bilge with water sloshing around if you take on any water before the bilge pump can evacuate it? The previous owner already had to replace the power steering pump last season at great cost so don’t want a repeat of that.


I gradually untangled the rats nest of wiring and ripped out the crap leaving just the original Mercury loom. Notice the original lovely bit of diy store flex with an earth that was powering the bilge pump? That is what triggered me to rip everything out - it went into the under deck conduit as a 2 core auto cable at 12v, came out as 3 core flex at 9v that barely spun the pump.



Most of the connections looked like this instead and snapped as soon as you touched them.



Eventually got everything out



And then attacked it with the steam cleaner



Next it was on to removing the rest of the furniture and emptying the console...

[jakew009]

Next job was to finish ripping out some more of the furniture. Stuck it in the workshop for now as it needs some modifications.



Then started ripping out the wiring under the dash. It was all very knackered but maybe that’s normal with a 15 year old boat.



The original fuse box was completely knackered



Cobra was obviously under budgetary constraints making their own bussing posts rather than just buying some bus bars ��



Got everything disconnected, just need to remove the last few things from the console today as ram out of time yesterday as had other stuff to do. So far time taken is about 6 hours, will try to keep a tally



The Mercury looms and other crap laid out on the deck. Anyone want a relatively new Boss radio or Garmin 2006c? It’s pretty crap



Next job is to finish removing the console then pull everything through the conduit before another deep cleaning.

[boristhebold]

Sounds like a fun project, would agree with you on the wiring set-up, I had a 2004/5 7.5m cobra and ended up re-wiring everything.

Perhaps add to your list carbon effect dash panel.

Look for a stockist of decent marine wiring, buy proper cabling and those solder connectors you just heat up with a heat gun. New batt switches with the auto monitoring and charging component that charges which ever battery needs it.

Yep rear seat comes off just buy undoing about 8 self tappers. Not sure about helm seat mine had about 6 bolts.

On mine I removed every self tapper that was practicle to remove and replaced with ss nuts and bolts, all of them around the locker panels and seats as far as possible.

Use decent vhf cable and gold type connectors, might be an idea like I did is wire up a connector in the rear then feed vhf cable to that from console and to that from a frame mount, that way if aerial is ever damaged you only need replace to the back and not the entire length.

Install positive fused or breaker unit and negative bus bars. Make a decent wiring diagram after.

Fit a always on source switch for bilge pumps so can be seperate from battery switches so that everything can be left off and you have a choice to leave bilge on in auto mode if you want to leave on amooring overnight.

Fit a horn and switch on console, always useful.

[boristhebold]

And if your fitting new electronics, consider going nmea0183 or nmea2000 or if raymarine etc its own network.

[spartacus]

Interesting project. You haven't even got it wet in anger, which I completely agree with after seeing that wiring.

Use tinned cable and check out Blue Sea systems for battery isolators, fuse boxes and switch panels. Quality stuff.

if you're using stainless self tappers, then bead of Sikaflex 291 too. Can't comment on seat pods, but does sound dangerous if that's all it's held on with.

Good luck with refurb.

[Orwell boy]

Enjoy your project ,looks good ..............Discover the beuty of a scrubbing brush and some bleach ,washing powder ,hyperchlorite or oxalic acid ,all dirt cheap chems ,but will be amazed at the results on the deck areas ,i too have a massive karcher but it doesnt touch the results gained with above .
keep us posted ,thankyou

[Nasher]

Jealous of that project, that will be fun getting it back up to scratch.

Nasher.

[GuyC]

Originally Posted by jakew009

Hello all

- rip all the existing electric wiring off the boat and replace with new
- take out the existing gauges and replace with 2 x chart plotters and one Mercury Vessel View
- install simple shore power for easily charging the batteries
- move the batteries and power steering pump under the console rather than having them in the bilge. Swap leisure battery to LiFePO4 to save some weight.
- install fake teak deck through the boat
- replace anaemic bilge pump with 2x larger ones
- repair / respray console and seating gelcoat if they need it
- remove anti foul / respray bottom of hull.
- sort a few bits of upholstery

Very good project.

Kojaycat and 12V Planet are good for marine wiring and bits. Blue Sea Systems is good kit and it's worth checking on Ebay for deals.

Having shore power on the boat introduces another layer of complexity. You could incorporate a fag lighter connection and then it is relatively easy to connect a CTEK or Optimate or similar. That keeps the 240V off the boat.

Can't comment on the batteries. I've gone with Optima Blue Top but a lot of people seem to be going down the lighter weight route.

Fake Teak - lots of choice and a few on here have gone down that route. Ribtecer has gone for real teak.

Bilge Pump - I've got two - one large and one small. The smaller one is auto which I can leave on auto all the time. This is in addition to a manual pump.

Lots of advice on here on gelcoat and spraying, particularly Nugent, although you say you have a well equipped workshop for spraying so maybe you are already in that line of work.

Just on Sikaflex - 291i is a sealant / adhesive and 292i is a structural adhesive. If you need to remove something in the future without wrecking it, use 291i. Neither Sika's like long term exposure to UV. 295 is UV resistant so you can use that if you are putting beads in.

A few people on here seem to have woes with underdeck tanks on older boats. I'm not sure how the Cobra ones fair and whether it is practical to inspect it with all the deck furniture removed. Someone will know.

Good luck with it and keep the pictures coming.

[Ribtecer]

Great thread, looking forward to the progress.

And you have a Defender - fantastic.

[GuyC]

Originally Posted by Ribtecer

And you have a Defender - fantastic.

Hence the well equipped workshop.

[jakew009]

Originally Posted by boristhebold

Sounds like a fun project, would agree with you on the wiring set-up, I had a 2004/5 7.5m cobra and ended up re-wiring everything.

Perhaps add to your list carbon effect dash panel.

Look for a stockist of decent marine wiring, buy proper cabling and those solder connectors you just heat up with a heat gun. New batt switches with the auto monitoring and charging component that charges which ever battery needs it.

Yep rear seat comes off just buy undoing about 8 self tappers. Not sure about helm seat mine had about 6 bolts.

On mine I removed every self tapper that was practicle to remove and replaced with ss nuts and bolts, all of them around the locker panels and seats as far as possible.

Use decent vhf cable and gold type connectors, might be an idea like I did is wire up a connector in the rear then feed vhf cable to that from console and to that from a frame mount, that way if aerial is ever damaged you only need replace to the back and not the entire length.

Install positive fused or breaker unit and negative bus bars. Make a decent wiring diagram after.

Fit a always on source switch for bilge pumps so can be seperate from battery switches so that everything can be left off and you have a choice to leave bilge on in auto mode if you want to leave on amooring overnight.

Fit a horn and switch on console, always useful.

Thanks, all good ideas.

Is a ‘dash overlay’ a better option than glassing in the holes and starting again? It would certainly be a lot easier just to put a panel on top and maybe give more of a ‘glass bridge’ look?

Still got to decide on fuses vs circuit breakers but I’m veering towards fuses.

It’s going to be all Raymarine gear going in so will be their Ethernet stuff, but also NMEA2000 for the engine gauges on the plotters and maybe the VHF / AIS? Haven’t looked into it much yet, just know I’m fitting two 9’’ Axioms on the top and a Mercury Vesselview next to the throttles. Don’t want any other guages.

[jakew009]

Originally Posted by spartacus

Interesting project. You haven't even got it wet in anger, which I completely agree with after seeing that wiring.

Use tinned cable and check out Blue Sea systems for battery isolators, fuse boxes and switch panels. Quality stuff.

if you're using stainless self tappers, then bead of Sikaflex 291 too. Can't comment on seat pods, but does sound dangerous if that's all it's held on with.

Good luck with refurb.

To be fair my entire boating experience so far can be summed up with a few years worth of dinghy sailing 15 years ago when I was about 12, and a PB Level 2 course last summer so I decided if I’ve waited this long, I can wait another few weeks.
I’ve wanted a boat for ages, but other projects kept coming up and I knew I would turn whatever I brought into a full on refurb. The original plan was a cabin cruiser of some sort, but I decided a rib was a much easier first boat.

Tinned cable and decent crimps will be ordered shortly.. just got to decide which ones.

Thanks for the sikaflex advice

[jakew009]

Originally Posted by Orwell boy

Enjoy your project ,looks good ..............Discover the beuty of a scrubbing brush and some bleach ,washing powder ,hyperchlorite or oxalic acid ,all dirt cheap chems ,but will be amazed at the results on the deck areas ,i too have a massive karcher but it doesnt touch the results gained with above .
keep us posted ,thankyou

Thanks, yes I have a lot of scrubbing to do. The steam cleaner has quickly shifted the bulk of the grime but now I need to properly scrub it.
The deck I’m not too worried about as it’s having fake teak over the top of it but everything else needs shining up. I’m hoping the GRP furniture inside the boat will clean up so I don’t have to spray it all as I’ll end up having to do the whole boat to match the colour up.

[jakew009]

Originally Posted by GuyC

Very good project.

Kojaycat and 12V Planet are good for marine wiring and bits. Blue Sea Systems is good kit and it's worth checking on Ebay for deals.

Having shore power on the boat introduces another layer of complexity. You could incorporate a fag lighter connection and then it is relatively easy to connect a CTEK or Optimate or similar. That keeps the 240V off the boat.

Can't comment on the batteries. I've gone with Optima Blue Top but a lot of people seem to be going down the lighter weight route.

Fake Teak - lots of choice and a few on here have gone down that route. Ribtecer has gone for real teak.

Bilge Pump - I've got two - one large and one small. The smaller one is auto which I can leave on auto all the time. This is in addition to a manual pump.

Lots of advice on here on gelcoat and spraying, particularly Nugent, although you say you have a well equipped workshop for spraying so maybe you are already in that line of work.

Just on Sikaflex - 291i is a sealant / adhesive and 292i is a structural adhesive. If you need to remove something in the future without wrecking it, use 291i. Neither Sika's like long term exposure to UV. 295 is UV resistant so you can use that if you are putting beads in.

A few people on here seem to have woes with underdeck tanks on older boats. I'm not sure how the Cobra ones fair and whether it is practical to inspect it with all the deck furniture removed. Someone will know.

Good luck with it and keep the pictures coming.

Thanks for the pointers. I’m certainly no painting expert but have all the stuff and have repainted various things in the past... most recently an artic lorry tractor unit

Interesting you mention the tanks.. I was looking at that today. I haven’t had a chance to check yet but I assume it’s aluminium. I was thinking of draining them right down away to remove any crap that may be in there, and I can easily pressure test it at the same time.
I could replace the tank but I really don’t want to do that if I don’t have to... ripping you the deck and glassing it all back in etc is going to be a lot of extra work.

[jakew009]

Originally Posted by GuyC

Hence the well equipped workshop.

Very good

The workshop was for keeping a fleet of tractors going all summer... doing less of that this year as focussed on my other business but boat engineering seems positively simple in comparison!

[jakew009]

Today’s instalment

One of the most disgusting jobs I have ever done - pulling all the cables through the hull.
There was some sort of weird black gunk that was kind of like grease but was water soluble (eventually). It stuck like shit to a blanket.

For some reason the Cobra doesn’t actually seem to have a conduit as such, the cables must just sit in the bilge underneath the deck?

Anyway eventually pulled them all through and got absolutely covered in this black shite.



I would love to wash this shite out but not sure how I’d do it without ripping the decks up?
Started sorting the cables out



What a disgusting job, washing the tubes off afterwards took an age.



Got the console free as well, the fuel pipes looked knackered and the jubilee clips were rusted out so I just chopped them and will replace with new.

I’m planning on draining the tank right down and cleaning it out so I know I’ve got a good fuel supply - any suggestions on best way of doing that? Need to get a camera in there and pressure test first I suppose.



The console is completely stripped now



Unless someone can tell me it’s a bad idea I’m going to move the batteries and the power steering pump into the console and have the bilge area behind the seats completely empty. It’s going to be a bit of a squeeze getting everything in but it will at least be dry and clean. I can’t imagine I’ll be making many modifications once it’s fitted and if I connect everything to a terminal block type thing it could be removed quite easily anyway.

The new plan for the console is two 9’’ Axiom screens on the top level, and a third screen where the stereo / vhf used to be (for engine data mainly). The VHF will be replaces with a Ray90 black box type unit and stereo will be controlled by the plotters.

The current Smartcraft gauges have dodgy LCDs and were only replaced a few years ago, so not wasting any money on them. I was going to get a Vesselview type screen, but now I’m thinking of a third Axiom screen and a Mercury NMEA gateway which will give me most of the engine data. The money I save I could buy the diagnostic software that will give me much more info than the Vesselview would...

[charliee]

The batteries are hardy in the bilge area, you have 2feet of space below the deck, that’s what I call the bilge. I have a twin battery setup and each are housed in battery boxes - port and starboard. It’s a very neat installation, with isolation switches all housed behind the rear seat, mounted up high.
What is the steering pump you refer to, is it not attached to the back of the steering wheel, something like a seastar unit?

[Maximus]

Plenty of fettleing to do but nothing structural by the looks of things...for me the Consul is defiantly the place for batteries ect (more protection ..less wiring...better weight distribution...more deck room) access my have to be improved but remote charger plug on the consul works well...eases charging (and testing) considerably.
No ...not all manufactures RIBs have seats and consuls are just screwed down,and seeing as you're doing a total strip down I'd give some serious thought to glassing them in....stronger.. neater..and dry storage!
The rest is step by step stuff...although that Consul is pretty "Swiss Cheesie" and it may well pay (depending how you want the new layout) to simply Bond and bolt in (with small SS dome heads ..looks good if done properly and very strong!) completely new piece of Decent Guage F.G in white over the whole Consul face and start again with new cut outs ect.
Either way enjoy the Build and the very Best of British with Her

[Maximus]

Double post

[_monkey]

Adding to the console opinions; I found it easy to blend in gelcoat when I changed out the stereo and switch panel (narrower and different heights than previous units), but I found the colour matching a problem - the answer from ECF was to send them a piece of the existing gelcoat for them to colour match.

I thought this was a good approach and provides a more contemporary look.