1980s Coastworker 180 transom core replacement questions/advice sought

[CW180]

Re: 1980s Coastworker 180 transom core replacement questions/advice sought

Just got a load more gelcoat (since I'm determined to do things the hard way!).

On closer inspection under the boat there's much more extensive scraping and gouging that's gone on, with one or two of the scrapes maybe an inch wide or so and running 1/2 to 3/4 the length of the hull! So I'm still giving thought to flipping the hull before I fit the engine so it's easier to sort all that damage. Not sure if I can easily do that with lack of space etc, so I might build a timber cradle above the boat where I can suspend it and pull out the trailer.

Would make sense as I can then do work on the trailer too since I've no idea how well the rollers work etc.
Not wanting to work on an overhead surface like this but I'm not sure I'd easily be able to get the boat on its side or upside down really.

Here's how it is as of last night:

 

[Woodonglass]

Re: 1980s Coastworker 180 transom core replacement questions/advice sought

CW180, Not being a Nere d' well but... your tabbing, IMHO is a bit suspect. I think you should have ground it back further and tabbed it all the way to the outer edges of the stern. The 3-4" tabbing might not be sufficient. There is a LOT of torque and stress placed on a transom. More than you can imagine. The composite IS Very Strong AND you did leave a large outer lip, I just hope it's all tied together with sufficient strength. Maybe I'm just being a Worry Wart!!!

 

[CW180]

Re: 1980s Coastworker 180 transom core replacement questions/advice sought

Thanks for the comment Wood. At this stage, I can only hope that this isnt the case.

I've spoken to a fair number of people prior to and after doing this from boat builders, repairers, and marine engineers, (ie outside of forums where in fairness it's can sometimes be hard to gauge peoples knowledge/expertise/credentials etc).

The general consensus has been that I've added far more strength through the whole build than is actually necessary, but of course the only way to ever know is for me to end my days with the boat still intact! Or looking at it another more ominous way, if disaster strikes then I know of course it wasn't up to scratch.

Appreciate the input either way but I'm confident it's fine for a number of reasons, including:

1) According to posts on this topic (and others I've spoken to outside of forums) The strength is allegedly not so much the outer skin where I have cut, but primarily in the tabbing on the inside edge, which I have made massively stronger than it originally was. From the factory the inner tabbing was a single layer of CSM, and it now has a very thick fillet with several layers of biax & epoxy on top, and additional encased marine ply framework that I fabricated.

2) Even if the outer skin is still a very serious structural component in this respect (others on this topic have stated that it's not), the fact that I've used epoxy instead of polyester, along with biax, carbon fibre, and tape, should mean it's actually stronger around the join than was originally the case, not to mention better protected against water ingress into the core over time.

3) The engine is a 75 and the boat was originally rated for 125hp. So it's well below it's max rating, and is built from superior quality materials and with more strength features now.


I've yet to find details of a repair like this that ripped apart from this bit being done the way I have.
That doesn't mean it hasn't happened of course, but I haven't found any cases to compare to a problem case, when researching the job.


Last night I collected some gel from a local marine engineer/boat builder who is currently building a 46 foot composite cat, and describing/showing him the photos of the repair. He assured me that what I've done with the project is likely well above what would ever be required on something like this given the materials used and the reinforcement added in the crucial areas etc.

He even had knowledge of my actual boat prior to me owning it, some of its history, and knowledge about the build of these models in general.

I can't say that I 'know' it's right since I'm a novice of course and it's the first time I've done this, but from all the comments I've received from people first hand in the boat build/repair community I'm confident it's more than enough.

I just hope sincerely that they're all correct and that your worry is unfounded. Nothing personal of course!!

If any of what I've posted in these points above is completely flawed and I've overlooked something critical etc, then nuisance value aside I would of course far rather know and deal with it appropriately now, than find out to my cost/peril that I've done something disastrous.

 

[Woodonglass]

Re: 1980s Coastworker 180 transom core replacement questions/advice sought

You are absolutely correct about the inner tabbing and I did not mean she would be dangerous, I just meant she might be suspect to flex and cracking at the joint. Sorry I did not make myself clear. You did a great job in making her structurally sound.

 

[CW180]

Re: 1980s Coastworker 180 transom core replacement questions/advice sought

Ahhhh, sorry - my bad for assuming that's what you meant!!
The peril of internet conversations rears it's head

I see you point but I'm hoping still that'll not be an issue due to the build up of the lamination that I've done around the join. Especially with carbon in it, and the numerous layers of glass which have their strength in opposing directions from one layer to the next etc. Hopefully it'll still be very very stiff and strong.

I hope my reply didn't sound at all 'over defensive'!

The only bit I'm curious/wary about really at the moment is the gel where it covers the scar, since it's sitting on a layer of filler that is epoxy based, albeit also with cabosil & microfibres. It will be interesting to see how this lasts over the years, given the poor reputation for polyester on anything epoxy.

Time will tell for that I guess.

 

[Woodonglass]

Re: 1980s Coastworker 180 transom core replacement questions/advice sought

Yeah, epoxy and Gelcoat are not good friends on most occasions. Maybe yours will be different. We can only hope.

 

[CW180]

Re: 1980s Coastworker 180 transom core replacement questions/advice sought

Indeed! I hope obviously that it stays put but if not then I'll sort it out. It's a matter of cosmetics and to a certain extent I won't lose sleep over it, although of course if it stays good I'll be happier.

Well tonight I got a timber frame together above the stern of the boat and the stern is now suspended above the trailer by a few inches.
Front/mid of the boat are still touching the trailer (since the trailer has tipped a little to accommodate the angle of the lift) but on Thursday when I collect my new engine crane from the courier, I can lift the front clear of the trailer then remove the trailer.

Once that's done I'll add support beneath the boat, and it'll be clear for me to get underneath and sort out the damage, and do a few bits on the trailer as well.

This came today as well:
http://www.ebay.co.uk/itm/261054081...NX:IT&_trksid=p3984.m1439.l2649#ht_1947wt_924

And fits perfectly in my honda even though it's a mercury part. This should make it loads easier manhandling the engine into place compared with ropes/chains to try and keep it straight.

 

[CW180]

Re: 1980s Coastworker 180 transom core replacement questions/advice sought

Update:

Scrapes beneath the hull are repaired and gelcoated now, except for a couple of very small bits I can finish with the boat on the trailer.
Trailer has been repaired too, with some new rollers where needed, bolts replaced with stainless ones etc.

So she's back on the trailer, and yesterday I got a good thick layer of flowcoat on the back.
Sanded that tonight, and while there are a few small bubbles to fill I'm pleased with the outcome.

Used my new DA orbital sander tonight for the first time in anger. Not finished yet but it's doing a great job of giving a nice smooth finish to the topcoat with pretty low effort!

So here it is at present:

I have my engine crane ready, so once the smoothing is done tomorrow night its time to start dangling the engine and panicking over drilling the bolt holes in the perfect spot!

Hopefully just a few weeks away from a test run but we'll see.

Also bought a hybrid "Wetline" battery today, which is 105ah rated, so more than ample power for my needs as the main starting battery.

 

[Woodonglass]

Re: 1980s Coastworker 180 transom core replacement questions/advice sought

She's really starting to Look Nice! Won't be long now!!!!! Keep on Keepin ON!!!!

 

[CW180]

Re: 1980s Coastworker 180 transom core replacement questions/advice sought

Thanks Wood. So excited about getting near to testing it, but I've got all the rigging to do and electrical wiring and so on, so it will still take a while.

The good side about that work though is I can do it late at night without making noise that would upset my neighbours etc, so hopefully progress can get faster now...

 

[CW180]

Re: 1980s Coastworker 180 transom core replacement questions/advice sought

Well yesterday I had a bit of an irritating setback re the surface of the transom.

After sanding the gelcoat and sticking a 1m metal ruler across at various angles I found it wasn't flat where the engine bracket will be going.
Bugger.

So I still had about 500ml of flowcoat left and added this and spread it accordingly. Hey presto I went from a nice smooth (but not flat) transom to a messy one again.

Tonight it was back to sanding again, but carefully planned and checked regularly for high/low points. Used a marker to keep marking all the bits needing smoothing down and finally had it nice and flat.

I wasn't going to take a risk after all the work so far, since tightening the heavy engine bracket against a slightly concave surface could have caused something to crack, or dare I suggest it even to eventually cause some delamination in the transom? No chance!!!

Also yesterday I got a dodgy pair of rollers (non original ones) replaced on the trailer with original spec ones.

Picking up a piece of 8mm smoked acrylic tomorrow for a windscreen. I'm not going to attempt to bend it to find round the edges of the console as it'll prove a costly disaster I think, so I need to come up with a means of clamping it at the top edge to the hand rail that runs above it.

Lastly (for the minute) I need to start figuring out the wiring setup for the whole boat. Not quite sure how this will work yet but will post up more details in due course.

 

[CW180]

Re: 1980s Coastworker 180 transom core replacement questions/advice sought

Aaaaannd, once again I've had to add more gelcoat.

Found a patch under where the engine bracket will be and it had a slightly concave bit on the surface so that's had more gel added to it, and is really good now it's smoothed down.

It seems that my skill in mixing pigment into the gelcoat is awful as the colour of the transom is patchy due to uneven pigmentation where different batches of gel are showing. It's mostly sort of offwhite though, and is both flat and smooth, so it;s better than I expected to be and I'm really pleased.

So it really is now ready for the engine to be test fitted and the holes drilled etc.

Now the transom cap is only sitting in place currently and is not yet bonded on.
My plan is to leave it off when test hanging the engine to locate the correct positioning of the engine (as it hangs from the crane).
I'll mark the holes, then remove the engine.
Drill the holes oversize by a minimum of 2mm (1mm all round resin barrier once redrilled),
Fill with epoxy mixed with microfibres
Drill to the correct 12mm size.
Then mix up peanut butter and put a thick layer inside the transom cap and place it on the transom.
Lower the engine to its position, and in doing so this will push the transom cap to its perfect alignment beneath the bracket.
Remove excess peanut butter that has squeezed out, then remove engine again once the PB has set. Tidy up any bits left over, then bolt engine up.

Does this sound like a sensible plan of attack?

One other question is that I was wondering about putting a thin layer of rubber mat between the engine bracket and transom to cushion it against the new gelcoat. I know some people put a thick bead of silicone or marine sealant on the face of the bracket, but as a wet layer when added this will do nothing for cushioning, hence the thought of a layer of rubber a couple of mm thick.

Is this a sensible thing to do, or could it cause issues in future if the rubber perishes etc?
I'm just slightly paranoid about tightening up the engine bracket/bolts against my lovingly crafted new transom!!

 

[Woodonglass]

Re: 1980s Coastworker 180 transom core replacement questions/advice sought

Some people use Aluminum. The rest of your plan sounds fine.

 

[CW180]

Re: 1980s Coastworker 180 transom core replacement questions/advice sought

That's true yes. I have some ally pieces but probably not quite big enough. Will have a look.

Another question I have is in relation to wiring and batteries etc.
I know more or less the circuit/wiring I need to do for the equipment going on the boat, but I'm unsure about the positioning of part of it.

The two batteries will fit in the stbd rear locker and it's apparent the previous owner had the battery in there as there's an isolator and earth strap.

Here's where I mean:

I have to make brackets for the two batteries.
But I need to position the rotary battery selector and ideally I want it so that I can more or less turn round and reach it to turn it from both batteries to the house battery after I stop the engine.

You can see I've just sat the selector on something in the photo to show where it would be practical for me to have it, but I need to know if there's any sort of compelling safety reason why it would be a bad idea to position it there, or anything like that. The primary isolator will be inside the battery locker as it previously was.

Thanks!

 

[CW180]

Re: 1980s Coastworker 180 transom core replacement questions/advice sought

Here's the moment I've been excited about but also worrying about (one of the moments like that anyway).

Now the bit I kind of need to be as sure as I can be about here is the placement of the engine, heightwise.

Here's how it is positioned when it is resting full on the top of the transom. The front tip of the anticav plate is 0.5 inches below the general line of the keel (engine is tilted down as far as it can go):

I suspect it's just ok at this height since most info I've read suggests anywhere from an inch under the keel to an inch above it. Higher up giving slightly better performance as a rule of thumb. I wish there was a way for me to know in advance of getting it all bolted up.

Here's the positioning of the bracket against the (lovely new) transom:

Now since this engine cannot sit any lower that it is in this pic (and you wouldn't want it to I suspect), I presume that the upper bolt holes should be using either the top
bracket holes or second down, and the lower bolts at the top end of the slots for them? This means there is plenty of adjustment available for the engine to go higher if needed but not lower (since it cannot do that anyway).

Sound correct? I think I'd use the second holes from the top rather than the very top ones, as I think the top ones are a touch too close to the top of the transom in respect of retaining maximum strength and resistance to breaking. Sure it shouldn't matter, but I prefer the bigger gap from the top by using the second holes down.

Last question for now - in respect of getting the engine perfectly straight to the keel, should I basically be underneath the hull, looking down the keel to make sure it is straight, or is there a better way? This is after measuring for where I 'think' it should be of course!

Many thanks. All being well, I may have an engine attached within the next 24-48 hours.....

Oh, and please don't worry about the cosmetics of the hull around the edges at the back - will be tidied up shortly!

 

[CW180]

Re: 1980s Coastworker 180 transom core replacement questions/advice sought

Just been out for a look then round the nearby boat park to compare the setup on all the outboard boats there and figure out the 'norm' or most common setup, and in about 8 boats out of 10 the anticav plate is either level with or higher than the keel. I only saw a few with the plate actually below the keel and they tended to be pretty old boats or flaky looking engines.

So while not wanting to speak badly of others' vessels or what have you, I suspect it might be the case that they've been bolted in place however they happen to easily fit, and are a case of "the prop is in the water and we're going forward so that's fine" with the owners.

So my conclusion from this is that the engine currently sits too low as it is. I need to raise it.

What I may therefore be tempted to do is to simply raise it so the plate is level with the keel, then prep the holes with mucho upwards adjustment, slather the cap with peanut butter then mount & bolt up the engine and secure the cap to suit this.

With that done, the default for the engine to be sat 'on' the transom - as well as bolted to it - will be what I use for test run.
If it's unsatisfactory, then I can raise it up, and make a block of profiled hardwood or suchlike to sit between bracket and top of transom where other people would be happy with a gap. Maybe not needed but would give me peace of mind and I think look better.

So this is the plan.

 

[Willyclay]

Re: 1980s Coastworker 180 transom core replacement questions/advice sought

Sound correct? I think I'd use the second holes from the top rather than the very top ones, as I think the top ones are a touch too close to the top of the transom in respect of retaining maximum strength and resistance to breaking. Sure it shouldn't matter, but I prefer the bigger gap from the top by using the second holes down.

IMHO you should use the top holes in order to provide yourself the maximum adjustment capability in the future. The link below will get you to the mounting height recommendations from Mercury in diagram form. Good luck!

http://continuouswave.com/whaler/reference/engineMountingHeight.html

 

[CW180]

Re: 1980s Coastworker 180 transom core replacement questions/advice sought

Thanks.

The engine is on now at last after a minor problem with the lower bolt holes.
I did use the top hole positions for drilling after a monumental amount of measuring and head scratching etc.
Tricky with no good verified reference surface to get it all spot on.

The engine was a bit low directly on the transom, so it's on the second set of holes, and the anticav plate sits approx 0.5 inches above the keel line. In theory it ought to be pretty good here.

So now I need to do the engine rigging and wiring etc then it's not that far off from testing time.
Also need to mount the aux engine.

As predicted with the engine attached the trailer balance is bad. I can't really move the boat any further forward than it is, so I have to hope that the axle U bolts feel like being adjusted, or else it's angle grinder time. Don't want the boat doing wheelies on the trailer now do I!!

I happened to see another coastworker a week or two back and noticed it had a sort of splashwell type thing going on that was really basic and wondered if this would do for mine:

Just a piece of ply locked in place to stop water getting far. Better than nothing but I'd rather have something that stops it actually getting on to the deck in the first place. Tricky to know what's best really.

Getting there though!

 

[Woodonglass]

Re: 1980s Coastworker 180 transom core replacement questions/advice sought

Nice job on the Motor Mount!!!!!

 

[Willyclay]

Re: 1980s Coastworker 180 transom core replacement questions/advice sought

I did use the top hole positions for drilling after a monumental amount of measuring and head scratching etc.........The engine was a bit low directly on the transom, so it's on the second set of holes, and the anticav plate sits approx 0.5 inches above the keel line. In theory it ought to be pretty good here.

Looks good for a starting point in the testing/verification process. Good luck!