1980s Coastworker 180 transom core replacement questions/advice sought

[CW180]

Hi all

I have discovered that having just sold my previous boat due to the amount of structural work needed and the limited amounts of free time I have available, that I'm now sadly facing a similar but slightly smaller scale problem on my 'new' boat.

The boat I just got is an 18' Coastworker console boat:

I found damp in the transom to varying degrees, and am fairly sure now after investigation that this will need to be treated with a re-core rather than some attempt to treat the damp and then rebond the slightly delaminated layers of the transom.

Now I have never tackled a job like this before. I am savvy in matters of a mechanical nature, but not very experienced in glassing layup etc so this is daunting but doable for me.

This is the transom in question:

And inside (where you see the sealed, self draining deck of the boat):

The core still seems strong, and is dry in some areas but I don't entirely trust that it could be dried and treated successfully and last a long time, much as I would like to believe that's the case.

I already have some sheets of marine ply (12mm) that I can make new panels from, and about 1.5 gal (UK) of West Epoxy (105/206).

What I would like some input on to begin with is the matter of doing this by removing inside or outside skin?

I have seen lots of accounts of boats repaired either way during my last week or so of investigating this kind of job). It seems that many people see it as perfectly acceptable to cut the outer skin, whereas some people begin to foam at the mouth at the though of doing this!

Going from the inside would be difficult for me due to the bonded in sealed deck that I REALLY am reluctant to start hacking up. I have grave fears for just how well I might be capable of tidying all that back up if I did attack the transom from inside.

Now I started thinking about the physics of a hull/transom/outboard, and which parts of the transom would suffer the most stresses and have the most forces acting on them.

Presumably the biggest stress from an outboard is in a clockwise torque action (ie viewing the boat side on, bow at the left, stern at the right).

My rationale for this is twofold -

• First that the weight of the engine would presumably exert force in this way constantly by virtue of its weight and the way it hangs (ie mostly behind the pivot tilt tube point and bracket), and
• Second, when accelerating/or when underway, the outboard is exerting both the force of its weight AND the thrust of the prop/leg pushing forward towards the hull.

So from what I can gather the forces against the transom are predominantly going to be working to twist like so:

Now if that's the case, then surely a recore from outside is preferable in terms of strength?
I.e. you would want the best and least molested surface of the transom on the inside, since that is where the forces are 'pulling' at (towards the rear at the top), whereas on the outside face it's a compressive force against the transom (low down) that shouldn't matter as much if it's been subject to repair. The reason for this is that the torque against the transom would be low down where there is a very strong bond against the bottom of the hull/stringers etc.

Cosmetically/aesthetically I can see the inside being a much better option but I don't care about that, and in terms of strength, while I'm no physicist, the outside seems the better option.

Yet with all that said I know some people start to foam at the mouth at the prospect of someone cutting the outer skin like this. So why is that? Or do I have this figured out all wrong?

I'm not stating I will do it either way yet, but the outside seems more logical both from ease of access, and from strength points of view, but this is not based on experience!

I have got some supply of carbon cloth that I was going to use for other projects, so regardless of whether I recore from inside or outside, would it be prudent to utilise this strong material along joins etc, and where an overlap/fillet will take place - that sort of thing?

Appreciate tips on this sort of thing thanks.
Jim

 

[Woodonglass]

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

Welcome to the iBoats Drydock!

I'm very pleased that you took my advice and posted your rebuild here on the World's best Boat Restoration Forum.
You will be pleasantly surprised with the help you will soon be receiving from some of the best boat restoration professionals in the world.

This link will bring up a custom search I formatted for you on Center console threads here on the forum.


http://forums.iboats.com/search.php?searchid=2383781


Start browsing through them and you will see what some of the others here on the forum have done with their boats. Some of the pros will be along in no time to give you their advice on how to handle your issues.

Welcome Aboard

 

[oops!]

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

hi....welcome to iboats.

you mentioned that you sold your other boat due to major work involved.

sorry to say my friend, this one is more work if you do the transom replacement traditionally.

to cut the outer skin is not a good idea at al.....in fact....imho it is out of the question.
the problem with outer transom preplacements is that to structuraly secure the transom. you need to glass it from the out side....this will mean layer after layer of fiberglass wrapping ourond the outside corner of the hull and underneath the hull....

this wrap around causes a bump that only feet of fairing can do away with.
on the bottom of the hull, it will inevitably cause what is known as a hook, this hook in the hull will cause performance issues with the hull. possibly serious.

to do the transom properly.....you will need to either seperate the cap from the boat.....and pull the entier upper liner.

this will be increasingly difficult due to the fact the hull is foamed after the liner is installed from the factory. so the seperation will be of major difficulty.

the other way you could do it is to cut the skin on the interior. a slice across the gunwhale to the deck and back up the gunwhale.
thus exposing the inside foam, stringers and transom which then could be ground out, and a simple transom replacement made possible.

after the transom is replaced...the interior skin placed back into position, glassed in then the foam replaced filling the void from the repair....the skin then faired,,and re gellcoated

the above mentioned repair is a fair amount of work. especially for a novice boat repairer.

there is another method that could be considered.
it is called the seacast method, and in your condition, the method I recommend,

seacast is a permanant transom that is water proof and will last the life of the boat or longer.

the work involved is minimal.
you remove the top edging off the boat.....using a chain saw,,,,cut away the transom wood....pour in your new transom...let cure...replace the trim.....and go boating !

here is a link to the review

http://forums.iboats.com/showthread.php?t=206019

reguardless of what method you chose......we will be here to guide you to th4 best possible repair

 

[Woodonglass]

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

This is a link to another site that shows a transom similar to yours that is being repaired with a chainsaw and the seacast the both OOPS and I have suggested. By the way OOPS is one of the best PRO's on the iBoats forum. You just can't get much better advice than his.

http://www.tidalfish.com/forums/showthread.php/212806-Seacast-Transom-Replacement-w-Pics

 

[CW180]

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

Thanks for the replies, welcomes, and suggestions. I appreciate the comments thus far.

I was upset yesterday to watch my old boat be towed away from my own house having wanted one of those since being a youngster, but had to face reality as a dad to two young kids needing lots of attention (and also in the middle of a bike rebuild, car rebuild, and house jobs needing doing!).

My few hours per evening spare time wouldn't go far on the old tub, so after that getting the new boat you can imagine my dismay to find this needs doing!

It's still way less work than the old boat required though.

Oddly enough I was reading last night about Oops' stretch job on his boat - an impressive and ballsy undertaking indeed! Didn't get through reading all of it though as it was getting very late.

I had thought the core was still good in mine since I had taken several core samples which showed as dry and sound, but having now removed the transom cap I can see that these unfortunately were lucky draws. Yes I did want/intend to treat it until this point, but having seen what it really is like I know full well that would not be sensible.

Points received & understood in regard of cutting the outside face. I've seen lots of cases where people have done that and done an impressive looking job, but only time will tell for them in respect of strength I guess.

Cutting the inside away horrifies me in respect of hacking into the deck because while I'm sure I could rebuild it strongly enough, finishing is definitely not my fort?, and I don't want a mess of a job to look at each time I then use the boat!

Seacast would be ideal, although the weight it would inevitably end up does concern me somewhat, and it ain't cheap (but we all know boats are not cheap things to own!).

I believe I have a strong and easily achievable solution though. One that will reduce both the cost and weight in question, and still doesn't involve cutting out either transom face.
I already have a supply of 12mm marine ply sheeting in my shed (core is approx 36mm with 7mm or so skin on either side), so my plan is as follows:

1) Excavate the old core via the chainsaw method etc. Bar on my chainsaw isn't that long so this will be fun removing the rest via whatever means!
2) Measure and cut out 2 new ply transom panels at 24mm thickness (2/3rds of original core thickness). Screw and bond together (using stainless screws and away from areas needing holes through transom). This will need lots of trial & error in terms of fitment to get them just right.
3) Once satisfied that the new core panel is the correct size and shape and can be positioned correctly with relative ease, I will progress to Seacast (or equivalent). Some will go in the bottom of the transom void as a bed to fit the new panel into. The panel will have a notched surface at the bottom to help it sit & bond very securely with the seacast layer beneath. The seacast will need to be poured deeper than is needed for the panel to bed into, to ensure the panel is evenly encapsulated with the stuff to seal and secure fully in place.
4) Remaining seacast will be poured in place either side of the panel, to fill to the top of transom. I'll have to work it into position (depending just how thick the substance is) to ensure it's not full of air pockets etc. I saw reference on one thread yesterday to using a thin flat metal bar or suchlike, worked up and down to be sure of this.
5) Optional but probable - add & bond/clamp an additional ply panel across the inside of transom face (after suitable prepping), and glass in place. This will mean I have the same total thickness of ply core material as original transom, but with the addition of seacast. This should give an additional benefit of giving a transom laminated with several different layers of ply/fibreglass/seacast, which should give it a huge amount of strength, but less weight and cost than simply filling the original core void with seacast alone.
6) Glass a cap in place over the top of the transom
7) Build a splashwell for the outboard

Should be very very strong, and comparatively cheap. Here's a no expense spared "artist's impression" as it were:

A friend of mine has done a lot of fibreglass and carbon construction previously and he will help with this, plus a marine engineer friend of said friend has said what I'm planning should be more than adequate, and overkill with the extra panel, but no harm in doing so.

In a one liner to summarise, new ply plus seacast in original core space, plus additional ply layer glassed & bonded on the inside face of transom. Will be stronger than original, and with the new ply in the core space fully enclosed in seacast it will be rot/wet proof.

 

[oops!]

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

basicaly what you are doing is using plywood to help fill the transom to keep the cost of the seacast down.

the only problem i would have is the seacast material might need a certain thickness to achieve the stregnth needed for transom torque.

it is possible that the lack of thickness could cause the material to go brittle. i would contact he manufacturers of seacast and ask about the stregnth of using the material in thinner layers.

one thing about the seacast method.
once poured, its done. so there is no cost of other materials like glassing the interior of the transom. so while the product cost may be higher, the overall cost of the job gets closer to the traditional route.

one question...
will the glass pro you have as a friend not help with fairing and re gellcoating the inside skin if you did the cut out method?
and how come he didnt correctly advise you to skip the outer skin removal process?

 

[CW180]

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

basicaly what you are doing is using plywood to help fill the transom to keep the cost of the seacast down.

the only problem i would have is the seacast material might need a certain thickness to achieve the stregnth needed for transom torque.

Cost reduction and weight reduction at the same time yes.
It's a valid question about the thickness and I think I will contact them to ask about this, but at the same time don't forget the layers involved here and how the differing layers will complement each other in terms of strength.

I would be very surprised if the thickness matters beyond a certain amount and it's almost going to be doing the job of a strong filler rather than being the main part of the core itself since two thirds of the void will be ply, and this of course will provide most of the original strength. The seacast will be completely enclosed too obviously. All that said of course, it's still worth checking.

Another thing to consider I suppose is that I've shown it above as the ply going in the middle of the core void, but that needn't be the case necessarily, and on reflection may not be the best idea. The ply could actually go directly against either skin (personally I think against the outer skin would be preferable but that's not based on anything scientific admittedly), then the remaining core space to be filled would be one single thicker layer of seacast rather than two thinner layers.

In hindsight that would be a better idea I suppose. It's more effort in terms of making sure the skin in question is cleaned up properly for the ply to bond neatly against but worth doing. I would bond this in place and clamp first before adding the bulk of the seacast (I keep wanting to type seaquest for some reason!). This would have the additional benefit that I'm not trying to pour seacast into a narrow gap too, so now you've mentioned the thickness thing, I think this would be more effort but better all round.

Another option to reduce chances of something like thickness becoming a factor would be to increase the length of the strands mixed in (don't know at present how long those bits are). I also have a modest but useful supply of carbon cloth/roving and was considering chopping that to mix in for extra strength. It's ages since I've used it to make anything, and may as well use it where it counts. Why not eh since it's there!

Further, if I do go ahead and add the extra ply panel inside the transom and include that beneath the transom cap, then the seacast layer is not only sandwiched very solidly between all the ply which will enhance resistance to forces that might make the thickness an issue, but it means I have the full amount of original ply, but with a very strong extra bonded layer of the seacast inbetween. Done like this it should be immensely strong for my needs, specially considering the boat is rated for 125hp and I'll be using just 75hp.

one thing about the seacast method.
once poured, its done. so there is no cost of other materials like glassing the interior of the transom. so while the product cost may be higher, the overall cost of the job gets closer to the traditional route.

I do appreciate what you're saying there, and if I wasn't scratching for money currently I would take the easy option and just pour it full up since I am a lazy person!
For me at the moment though, at $200 a tub plus shipping (which will be a lot for me) the cost of the extra compared with a bit of fibreglass (which I already have some, albeit not quite enough) is significant to me having just bought the boat, various other parts for it, trailer parts, needing a new tank to go with the engines I've also just secured for myself (not to mention I need to do the headgasket and turbo on my car too now and need money for parts for that).

I also have about 1.5 gallons of west 105/206, and some poly resin in my garage, so cost wise a bit of extra glassing is pretty much nothing except a bit of time (not that I'm suggesting using both kinds of resin of course!! ). I understand the point you're making though and it would be a very valid one for a lot of people, but for me the little extra work isn't something I mind, especially when money is a bit tight at the moment and I have for the most part the materials available that can help reduce the cost, with hopefully no real downside other than a bit more effort & time.

one question...
will the glass pro you have as a friend not help with fairing and re gellcoating the inside skin if you did the cut out method?
and how come he didnt correctly advise you to skip the outer skin removal process?

Yes he would do - he's already offered to. He's not actually a pro as it were, but he has got a lot of experience of making car panels out of carbon & FG, and also doing structural stuff since his car has a FG body.

How come he didn't advise on the latter is simply that I hadn't asked him specifically about it since he's not a boat person, just a friend that's done lots of glassing over the years (and done it very nicely too as he's a bit of a perfectionist compared with me when it comes to tidiness and attention to detail etc!).

Gelcoat isn't his thing admittedly, so that will be a learning curve for me. I'd already bought some of that last week and pigment, ready for little tidy up bits around the hull where necessary.

Sorry if that's a bit of a waffly reply - I'm bad for that!!!


You know after all that - I did have a question I wanted to ask, and now I've written all that out it completely escapes me! :facepalm:

Cheers
Jim

 

[oops!]

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

i think that bonding the transom wood to one side of the skin or the other is out of the question....

the reason being, that it will be inpossible to get a proper bond to the old glass.

in bonding.....the glass must be propperly prepped,,,this means grinding the outer layer to the glass, cleaning with acetone, glassing, rolling out the air, then, in the case of a transom. clamping.
this will be impossible to do in the case of a thin channel of glass to work on......air will be every where, and you will have a bad bond.

this leaves the core surrounded by seacast. as mentioned, im not sure of the needed thickness of seacast to insure stregnth.
however, in most cases of plastics, the thinner, the weaker.
if seacast says its ok,....go for it.....however, transom wood core placement will be crucial to make sure the wood is evenly encased by seacast.

keep in mind, if you do the wood core method, seacast will void the warranty. as well....if any thru transom holes are not properly sealed. the core could rot over time. leaving a void in the centre of the transom.

but regardless of what you decide, this is your boat....you can do anything to it you want. we will guide you to the best way we can while keeping it safe.

cheers
oops

 

[CW180]

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

Ahh, yes - point taken, good thinking.

Thanks for the supportive comments on this anyway - it's encouraging.
Obviously I don't want to do anything daft or dangerous with it but just trying to ascertain at present the options available to keep costs as low as I reasonably can without cutting corners that could cause it to be a dangerous bodge. I'm getting a bit old for that sort of hassle and I'm not even old!

 

[Woodonglass]

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

Nida-Core is basically the same product as Seacast but significantly less expensive.
http://nida-core.com/french/nordprod_nidabond_transom.htm
Several of the guys here on iBoats have done their transoms using this product. You can use Drill bit extensions on your drill to remove the wood from the areas that the chainsaw will not reach. These extensions are made up to 3 ft long and a modified spade bit will get the job done. There are several threads on the forum showing how to pour the product. I realize your desire to repair your boat within the limitations of your budget, however there is only so much you can do within the limitations of reality. The reality is with a self bailing deck such as yours you only have certain ways of doing it and all of those have been covered. It's been determined, IMHO, that the Poured composite transom offers the best solution when you consider that "Time is Money" and all the other options. As OOPS stated it's your boat so you can and will do as you see fit. We'll be here to assist as best we can given the conditions you present us with. Most of us have "Been there and done that" many times over and hopefully you will appreciate the "Experienced Advice" that you receive here on the forum. Our #1 concern is the safety of you and your passengers.

 

[CW180]

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

Appreciate all that, thanks.

The time is money thing doesn't really factor in for me, except in terms of being able to use the boat ideally this summer, and if not then certainly by next summer. Like I said when my previous one was sitting neglected outside - I'd like to get it sorted but the sea is not going anywhere and will be there waiting for me whether it's this year or next. The difference is that with this boat I'd be upset if this caused a delay beyond next year.

Re' drill bits - I've never seen extensions quite like that though they must be around from what you've said. I was going to just buy some threaded bar (or dig some out more likely!) and weld to a spade type bit, and try that. My chainsaw isn't massively long but am trying to see if I can borrow one with a longer bar.

I can't see that really even with the amount of stuff I give myself to do!

Thanks for the nida-core reminder though. I'd seen mention of it but not actually investigated yet so I will do thanks.

 

[CW180]

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

Well, some very minor progress but not a great deal unfortunately.

I've started to chop out the transom now. Unfortunate and disappointing for sure but at least I'll be confident it's solid once done.
Contrary to other peoples' comments that this is an easy job with a chainsaw, it's proving to be quite the opposite.

Chainsaws apparently don't seem to like cutting through plywood end on - maybe fine when it's rotten but this isn't. It's wet yes, but not rotten and it's proving to be very slow going indeed! All the glue I suppose is bad for the teeth on the saw. I know it had good edges on when I began but I should check to see if they're suffering as a result of this. I think there are 2 thin layers of glass or resin between the ply layers and this is making it worse.

Gonna take some time getting the old wood out that's for sure. I dread to think what it will be like once the saw has got as deep as it can do.

On the plus side, instead of a yamaha F50, I now have a pair of Honda BF75 four strokes, and it didn't cost me a penny to change. So one good one, and one complete running engine for spares when I need them.

The hull is rated for 125hp so 75 will be fine, and nice to know I'll have a load of spares on tap.
The review article I had for this boat was 22knots with 40hp and two people, so with 75 it should be rapid, specially given the hull weight is somewhere around 350-400kg!

I can look forward to it being done I guess, but wood removal is gonna be a real pig to do.

Seacast did not bother even replying to my enquiry about shipping to the UK and they have no UK dealer that I'm aware of. Consequently I will not be buying their product.

Nidacore pointed me to the 3m website and I'm still waiting for a reply from them about a UK supplier. Would be nice to know someone will get back to me in due course hopefully....

 

[Woodonglass]

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

Use a 1" Spade bit and an extension to drill holes down into the transom. Will make the sawing a LOT easier. YOu can use a flat file to resharpen the bit.

 

[CW180]

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

Thanks - was planning on using these once I'd finished sawing as I've got loads of them, but it hadn't actually occurred to me to drill down through anyway to ease the job of the chainsaw. Kinda obvious really now you mention it!


The plus side is I can get away with drilling later in the day as it makes so much less noise and isn't going to upset the neighbours.

 

[CW180]

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

On another note related to renovating this boat, I'd ideally like to turn the boat over so I can do a nice job of sorting out all the gouges, scrapes and the scruffiness underneath and get it back to a glossy smooth, clean hull again that looks pretty and doesn't drag.

The engine is off so it's the ideal time I'd have thought. So she's 18 foot long, weighs approx 400kg and no cuddy/cabin to worry about, just a centre console (stainless rail is removed as I've been straightening it). Currently sitting on a trailer.

What is the easiest way of turning over a boat like this (bearing in mind I don't have a forklift/winches/any sort of hoist etc)?
Would be really good to do this so I can spend some time properly doing the underneath but having googled it people seem to use various techniques.

The boat is sat outside on my drive so no ceiling to bolt anything to. I'd prefer not to have to build some huge timber frame if I can avoid it as well, but I'm assuming there's a good possibility I may have to.

Thanks!

 

[CW180]

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

Ok, never mind advice on turning it then!

Well, this is getting interesting now folks.

Getting the plywood out is proving to be a real ballache because there was only one very small bit of rot, and apart from that, it's pretty much rock solid despite being damp. The chainsaw is REALLY having a hard time going through it despite new bar & chain etc. Drilling is more successful, albeit very slow & tedious, with regular stops to sharpen the 25mm paddle bit I'm using.
Once the holes are drilled across the transom, the chainsaw has no bother ripping through the bits left between holes.

It's gonna take some time this, although to be fair, I only tend to get 10 minutes or so attacking it each weekend as it's too noisy to do in the evenings, and I get bugger all time at weekends when I can do this stuff.

But there's a new problem I face. Well, a couple actually.
First, Nidacore cannot supply their product (emails went via a chap at 3M interestingly) to the UK unless I buy a full pallet! Not an option.
Seacast might be able to, but I wouldn't know as I have emailed them to ask this on two occasions and do not appear to have received a reply to say whether or not they have a uk supplier or can send it here economically. I'm guessing the answer is no.

Problem #2 is what I've found while excavating the transom core.

Difficult to describe but behind (rearward) of the inner transom skin (ie as viewed looking backwards while stood in the boat), there is a second fibreglass layer bonded to the back of the inside skin (ie effectively inside the transom void) - shown in red in this diagram:

This runs across the full width of the boat and is what makes the transom void a sealed enclosure that you would normally be able to pour these repair products into.

This is delaminating in places from the inside transom skin however. Difficult to show this in the diagram, but basically it means even if I can get a pourable transom compound, it will escape down into the sides of the hull due to the condition of this 'partition wall' as you might call it, which would otherwise contain the stuff.

This partition ideally needs removing as the fact it's delaminated in places means the rest won't be far behind, and this means that the new transom core (whether ply or pourable stuff) would then not be bonded to the inner transom skin. It would be bonded to the partition, but that is no use if the partition has delaminated from the inside skin, as is happening now.

I can excavate this I think, but it will open up the transom void to the sides of the boat between outer hull and inner skin, making the use of a pourable compound impossible.

There's no way to realistically repair/rebuild that partition without removing the outer transom skin for access, and I'd really rather not do that. So it seems the only real option is a new ply transom fed in from above with a thick layer of epoxy either side, then clamped very firmly on both sides of the transom to bond well. The bond should be good assuming the inside of the skins are cleaned up sufficiently well.

What I would likely then do, is add additional means of securing the inner & outer skins to the new ply core by use of a lot of stainless screws which would be slightly countersunk then sealed over. This would assist the bond of the new core.
Either that or bolts running through both sides with plates on them.

As originally planned, I am still likely to add an additional layer of ply to the inside of the transom for complete peace of mind, so it will be thicker & stronger than factory build anyway.

But I thought I'd post this to see if anyone has brainwaves about how else this could be dealt with as an alternative?

 

[Woodonglass]

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

Based on your previous pics, The Transom cap covers the outer skin of the hull and the inner skin of the boat. It appears from your drawing that if your inneer skin has deteriorated to the point that it will allow the pour in transom material to flow into the interior of the hull you will need to fabricate a new inner skin. Easy enough to do. Plenty of examples of that here on the forum.

As to flipping the hull, if your yard is big enuf and you have 4-5 mates and some beer, you can get some blankets and roll her over in the yard. thats what I did and then build a cradle to put her on....

 

[CW180]

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

Ok cheers - will search for threads about inner skins then.

Doesn't sound too bad to roll then. Not going to be doing that until the transom is dealt with though as there's no point really doing anything else until that's done.

 

[CW180]

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

Will start a different thread for that to get the best exposure for advice.

Slightly disastrous development, but even though this has depressed me a bit, I suppose ultimately it has to be for the best in the long run.

Have discovered various bad things that has made me reach the conclusion that I've got to remove the cap.

I've removed the rub strip, drilled out the rivets to remove the ally rub rail that holds it, drilled out the rivets behind that which hold the cap on.

Something else is keeping the cap help on though.

Any suggestions from you experienced people what else I have to do for the cap to come free?
E.g. the console and seat, & fuel tank pod are riveted to the floor.

Is it likely that these all also need drilling out and removing to facilitate the removal of the cap? I have already drilled out the rivets for the centre console and seat, but they appear to also be stuck down with resin or something as they remain rock solid in place. I've begun working round the edges of them with a bolster and hammer to try and separate from the deck but this is not really making progress and I'm a bit worried now that they're not going to come off without some utterly horrific savagery.

I have a horrible fear that the cap is bonded onto the stringers or framework beneath the deck by resin. No idea if that's the norm, but it would make sense that it's held down one way or another. If that's the case, how on earth do I separate it???

This is the boat, in case you guys know of these things, or at least similar ones. I'm told they're similar to boston whalers?

I'm now at the stage where I'm in unknown territory, and past the point of no return, so I really appreciate the assistance of any of you who have done such jobs, especially if on craft of similar construction.

Not a very happy bunny right now and I can't see how I'll have the boat in the water this year at this rate.
Have to say though, at least if sh1t has to happen, a nice day softens the blow a bit.

Thanks guys.
Jim

It's gone 8pm now so time to stop hitting things with a hammer. I'm going to sit on the boat with a cold beer, and discuss with her about my plans to sort her out, and how it would be nice to get a bit of co-operation if she wants to be made to look her best again and be looked after properly etc....

 

[BillP]

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

These are tough ones and you are right, the liner is probably glued down to the stingers and hull. A typical 20'-24'r will use 20-40 gals of epoxy paste to set a liner. I gleened that info from calling boat factories for past projects. It's not realistic to think one can be removed if done that way...and many are. Also, many have stingers that are actually boxes with a wide (12"+) footprint to give a generous bonding surface.

Everybody has their own ways to fix boats. In Florida anyway, and at yards who make a living doing transom rebuilds, it's very normal to cut the outer skin off, insert the new transom from the back and glass the skin back on...without wrapping glass around the corners. Cosmetically it looks no different than before cutting. The exterior transom skin typically add very little structural value to the transom core anyway...sure there are exceptions, but cut 50 boats up and you will find 49 of them have nothing more than a skin that gives weather and ding protection. Regardless, it has to be glassed from the inside and requires cutting access holes in the deck and liner. Which poses other problems. The key in cutting access holes is to cut with a bevel so the "plug" can be epoxied back flush with only a glue line showing. If you don't bevel it you have to add "cleats" to hold the plug flush for gluing. Bigger boats are easier than smal ones like yours but this how the pro boatyards do it.

The method I use (learned from a boat mfg) to glass though access cut outs is: cut approx 15" x 10" x 18 oz woven roven squares and lay out on a board. Thicken the resin with cabosil and work the thickened resin into the patches (while they are on the board)...it WILL wet out. Peel up form the board and glass away. This holds the resin in the cloth and prevents major draining and dry laminations on vertical surefaces. The smallest access hole I've done this is through is a 4" dia, one handed and by feel. It's tedious but is doable and labor intensive. Some folks size the cut outs to fit one of the standard off the shelf hatches available everywhere.

Good luck.

bp