88 Bayliner Trophy 1710 - wet foam and ...?

[Woodonglass]

Absolutely nothing to be concerned about. Typical construction in many boats. I'd recommend putting back exactly like you found her

 

[DeepBlue2010]

Not everything Bayliner - or factories in general - did was because it was the best to be done. Far from it. Cost savings and simplifying the assembly process weighted more on their mind so they stopped at the good enough level and rectified the decision by making assumptions. A big assumption in this specific installation is that the bulkhead will maintain its integrity forever and as a result the stringers would be always connected as if they were one straight long piece. But in reality when the bulkhead fails as it did in this situation, the stringers function will be compromised.

I agree that it is typical installation; if I remember correctly, Frisco’s boat had the same configuration and it was longer than 17 foot. It will also hold fine as long as no joint is compromised. But, if you are going to replace stringers - and you might need to because of the cuts you need to make to extract this rotten bulkhead - you might as well do it the way it should have been done from the outset. Also, if I were in your shoes and I decided to yank the stringers, would not use a foam core. Plywood would be my choice. My 2c

 

[Woodonglass]

I'd like to see a "Close Up" pic of the intersection of the Bulkhead and Stringer. From looking at the pic again it appears the bulkhead is secondary to the stringers and that they in fact are full length in relation to the hull. It's hard to tell from the pic posted. Post up some more pics so we can get a better look. Am I to understand that your existing stringers are foam cored stringers???

 

[Arawak]

Will get some photos tonight. Stringers are definitely secondary to that bulkhead. Also definitely foam cored. I was told by a boat designer that BL experimented briefly with foam filled around this time but had delamination issues and went back.

Although I'm not comfortable with this design of stringer, it has been good enough for 26 years.

However, I was planning to move that bulkhead 7" forward, along with the tank. The bilge is tiny and does not have room to install a decent sized bilge pump properly. This complicates that plan.

I have the time.... 6 long months of Canadian winter ahead of me. And I had already budgeted for putting in new plywood stringers.

But will continue to think on it. Don't have to decide today.

Photos forthcoming.

 

[DeepBlue2010]

Ok, I'll have a look this afternoon to see how that would work.



When it's not under way, yes.

Have a look at the third photo in the very first post. That compartment with the hatch open has a drain with a hose down to the through hull in question. The through hull is below the waterline, except when boat os on plane. The drain it runs up to is well above the waterline... probably 12" at least. Plus, it's a watertight compartment, and its lip is another 6" above that. So the only risk is the hose giving out. I'll make sure I have good quality Trident hose for that, and marine hose clamps.

I don’t understand, how can the hatch drain to an underwater fitting?! Nothing can drain to an underwater fitting without a mechanical/electrical aid to overcome the force of water. Is this the filling fitting and you just had a typo? If so, how you turn on and off the water to start filling. I did not see any valve on the bronze through hull!

Also, what makes you think that this compartment is water tight?! I did not see any gasket or lock on the hatch. I think you are refereeing to the fact that it doesn’t leak as a container of water to the underside of the boat. Be that as it may, I was more concern about the situation of over filling and flooding the deck.

Sorry, I don't have any good photos from before it was all apart. Have a look in post #2 where you are looking towards the stern. There are two drains at the floor. Each of these has a hose going down to a scupper through hull. These are just below the waterline. The flappers have in fact failed long ago, and if I load it up enough and sit on the transom I can get the back end of the cockpit just below the waterline and some water to come into the cockpit.


I'm actually considering using regular 1.5" through hulls instead of flappers, and keeping a set of drainplugs on hand in case I ever had a need to plug them.

Depends on how high you deck is from the water line, these flappers could be your only choice. I don’t recommend using regular through hull in this place. IMHO, a good quality bronze through hull with flappers is better choice. They also come with the flapper recessed so you have enough space to install a plug if you have to.

 

[Arawak]

No Title

I don'€™t understand, how can the hatch drain to an underwater fitting?! Nothing can drain to an underwater fitting without a mechanical/electrical aid to overcome the force of water. Is this the filling fitting and you just had a typo? If so, how you turn on and off the water to start filling. I did not see any valve on the bronze through hull!

Also, what makes you think that this compartment is water tight?! I did not see any gasket or lock on the hatch. I think you are refereeing to the fact that it doesn’t leak as a container of water to the underside of the boat. Be that as it may, I was more concern about the situation of over filling and flooding the deck.

I'm not really sure how to clarify. I guess all i can say is the the fitting circled below had tubing running to that bronze hull fitting. there's no pump or valve as far as i can see.

 

[Arawak]

As promised, here is the photo of the two sections of string butting against the bulkhead in the middle. You can see that they don't even really line up.

 

[Arawak]

Dad and I have discussed this at length, and taking into consideration the advice given here, plus some reading, plus what feels right, we decided that we'll replace the primary (inner) two stringers. The junior ones closer to the chines will remain, with maybe a little cleanup and support around the joints.

I should mention that my daughter has joined the team... here she is removing part of a frame. She's always into my epoxy doing stuff anyway, so she may as well learn to use it on a boat.

 

[Woodonglass]

Alrighty Then!!! Wood Bulkheads and FoamCored Stringers. Leave it to Bayliner to do build things with whatever was Laying around the shop that day!!! Here's the deal, on boats under 20ft, it's not all that critical to be "Perfect". If it was, Bayliner would have been out of business a long time ago. You can put additional Bulkheads in if you want but they are not necessary IMHO. Running the Stringers Full length and in one piece would be ideal and then the bulkheads secondary to them. The Glass and tabbings will distribute a lot of the stress across the hull but the wood will also carry some of the load. The new 1708 biax is much stronger than the old woven roving and much stronger than the blow in glass that was used in some of the builds. When you're done she'll be a TANK compared to what she was.

 

[jc55]

Exactly. I have peeled woven roving off by hand quite easily but anything you do is going to be far, far above factory.

If I had to add anything, I would say that since your cap is an insert, your biggest challenge will be making sure it drops back into the boat at the exact same height so that the cap screws will line up perfectly. Parts grow, and points of references can get lost. Sometimes the thicknesses of the plywood and additional layers will be different. No shame in mid project cap reinstalls. I put the cap in and out 3 times on my Sport Craft build and glad I did. Cool boat!

 

[DeepBlue2010]

The crew - that is us - is welcoming the addition of your daughter to the team Welcome aboard, very impressive.

I noticed you mentioned "Epoxy"; maybe I missed it earlier in the thread but are you planning to use epoxy resin for this project?

 

[Arawak]

Leave it to Bayliner to do build things with whatever was Laying around the shop that day!!! Here's the deal, on boats under 20ft, it's not all that critical to be "Perfect". If it was, Bayliner would have been out of business a long time ago. You can put additional Bulkheads in if you want but they are not necessary IMHO.

Yeah, I know where you're coming from, and I know you're right. It's just a piece of mind thing. This is pretty much exactly what I want in a boat for up here, so I will likely have her for years to come, and if I ever get caught by the weather out on Lake Huron or Erie, it will give me piece of mind.

And it's FUN

 

[Arawak]

Exactly. I have peeled woven roving off by hand quite easily but anything you do is going to be far, far above factory.

The hull itself, as it came out of the mould, is quite good. Plenty of thickness and no flexing.

The strings are shoddy, sloppy work, although they are actually quite well tabbed in. The fact that much of the plywood in the bulkheads wasn't covered by anything, and what was covered was just gelcoat, is also shoddy.

The cap is bulletproof. I wonder if Bayliner made it or subcontracted them.

If I had to add anything, I would say that since your cap is an insert, your biggest challenge will be making sure it drops back into the boat at the exact same height so that the cap screws will line up perfectly. Parts grow, and points of references can get lost. Sometimes the thicknesses of the plywood and additional layers will be different. No shame in mid project cap reinstalls. I put the cap in and out 3 times on my Sport Craft build and glad I did. Cool boat!

I would love to be able to do that, but the boat is in place until spring. The garage door is closed, and an insulated wall screwed in place over it. The cap is quite heavy, so it's on sawhorses under a tarp in the backyard. The one advantage I have is that dad's support structure is bolted in place to the concrete pad, and I'll be able to lower it down and even hold it in place inches above.

It only bears weight on the structure below in two places, and I would guess not much at that. The cap supports the weight of the sole itself for the most part.

 

[Arawak]

The crew - that is us - is welcoming the addition of your daughter to the team Welcome aboard, very impressive.

Can you say it like this? (Sorry, computer geek.... :lol: )

I noticed you mentioned "Epoxy"; maybe I missed it earlier in the thread but are you planning to use epoxy resin for this project?

Yes. I have used it for all my boat projects over the past 10 years. It's costlier, but not outrageously so. Much nicer to work with IMO. No VOCs, lots of working time. Get the mix ratio right and it's almost foolproof.

I do have some polyester resin I need to use up, so that might get used to put a layer of 4oz cloth on the top of the foam compartments.

 

[jc55]

Oh, that's great news then Arawak.

 

[DeepBlue2010]

I get it (Computer geek here as well and x-Microsofty)

In this case, make sure you don't use 1708 or any fabric with CSM in it. There is a Bi axial 17oz for epoxy. You probably know that already but a reminder will not hurt.

 

[Arawak]

Computer geek here as well and x-Microsofty

x-IBMer

In this case, make sure you don't use 1708 or any fabric with CSM in it. There is a Bi axial 17oz for epoxy. You probably know that already but a reminder will not hurt.

Yeah, I wasted a lot of epoxy filling out CSM for no good reason in the past. :blue:

1708 is still useful for building thickness, like i'll have to do on the transom. Also, if I'm not working wet on wet I'll start with 1708 mat side down to make a good bond to the cured lightly sanded weave. Sometimes it's handy to even out an imperfect surface too.

I'll be primarily using 12oz biaxial (aka double bias) 8" tape (no mat) for the stringers and transom tabs. Wets out more easily than 17oz which makes it easier to do the entire schedule in one go. Two or possibly 3 three staggered tabs, and then cover the whole thing with a single strip.

I still have a fair bit of 1708 kicking around, so that might get used for the first layer in some of the odd corners around the transom and for the transom inner skin, to build back the original thickness.

The transom in these things kind of bizarre. It only covers the inner two stringers, about a third of the width of the stern. Since I'm replacing those stringers, I think I'll extend its width out to the junior stringers. This will only be a 6" - 8" strip along the bottom, but it won't hurt.

Tomorrow Dad and I will go plywood shopping. Last year we found some nice ACX fir at our local Home Depot, with plenty of plies and few voids. Hoping to luck out again. Will also get daughter to mix epoxy, make PB with woodflour, and laminate some small scraps for practice. After that, we'll pretend it's a stringer and bed it to another scrap (pretend hull), make fillets, and tab it in as a practice run. Last, we'll bash it with hammers and stuff after it's cured for a few days to see how string it is. In my experience, the wood breaks first.

 

[DeepBlue2010]

1708 should not be used with epoxy resin, they are not compatible. It has an 0.08 layer of CSM in the back of it. CSM binder as dissolved by the styrene in the polyester resin. Epoxy has no styrene in it so the binder of the CSM will not dissolve. If you are going with epoxy resin, no CSM should be used.

 

[Corjen1]

Dont know if it will help, but her is what my 68 glaston looked like after rebuild.....(agree with Wog, under 20 ft, not as big of an issue.....) We all know GLASTON was the king of design..

 

[Arawak]

1708 should not be used with epoxy resin, they are not compatible. It has an 0.08 layer of CSM in the back of it. CSM binder as dissolved by the styrene in the polyester resin. Epoxy has no styrene in it so the binder of the CSM will not dissolve. If you are going with epoxy resin, no CSM should be used.

WEST has a good article on this topic.

But it's not hard to find epoxy-compatible 1708. The mat is stitched, not attached with a binder. US Composites and many others sell 1708 that they advertise as epoxy-compatible. The 1708 I get from Noah's in Toronto wets out fine with E.A.S.T. system, with no milky haze.

In fact, the guys (Joel Shine and Jacques Mertens) at Bateau.com are epoxy nazis (not to mention Bayliner haters :lol and they use it in some places. And those guys know their stuff.