1988 Enticer restoration. Advice welcomed.

[OFFSHORE GINGER]

Hey guy's , just a quick mention and that is ............i personally do not care what people use for materials , and how they do it .because 9 times out of 10 they are going to to a repair of this nature the way they want to regardless of the information that is avalilable .

 

[DropTop5.0]

I love reading all these posts and I'll say that I don't know crap about fixing a wood boat but I can hold my own inside a Submarine. By the way, Submariners go deeper!!!

My 2 cents from a newbie; I know if I paid 40k for my Enticer I would expect that it was Engineered to the max. It should last nearly a lifetime. But I also understand that a company has to stay profitable which means that maybe sometimes they could have spent more money and made it a little bit better. They don't because they have to make the ends meet just as we do in our own lives. With that said, OG are you building a transom to last 'till 2040? Is it okay to build a twenty year transom?

I'm not throwing stones. I just had my third Crown and coke and I'm just trying to ask questions for my own understanding... Is one method a two year transom and the other is a 30 year transom depending if you put glass between the layers?

Thanks for the discussion.

 

[OFFSHORE GINGER]

Hey guy, to tell you the truth the bottom line is i practice what i have done in the past working at Skater building Fountains , Cigs , Platinum's , and boats for the Navy Seals along with working at PowerQuest , S-2 Yachts , and not to mention Thompson Boats where quality was really not a factor , and thank you also for the discussion.

 

[Rob B]

Glass in between the pieces of plywood does nothing to add strength, it's just added weight and expense (I certainly didn't find any glass in the middle of either of the two transoms I've repaired). All that's needed there is good adhesion. I'm saying this from an engineering background - composite structures get their strength mostly from glass being in tension. The center of a composite structure is at zero stress, so there's no strength to be gained by adding structure there. As you go further and further out from the centerline the strength of a material contributes more and more.

I know this might not make sense, it didn't to me at first either, but I've been given the exact same explanation from a two different structural engineers. In fact I've been kind of bored lately so I may do some layups and test them to failure on one of our Instrons at work. I'll post the results sometime in a week or two.

I'm not sure I get the "composite structures get their strength mostly from glass being in tension" part. How do you put fiberglass in tension? I understand that comment when it's applied in the concrete/steel world. So tomorrow I'll ask that question to our Structural Engineers.

 

[Rob B]

So I asked the Structural Engineers today about whether or not adding fiberglass fabric between two pieces of plywood increase the strength. I also asked about fiberglass in tension. Keep in mind that they aren't Marine Engineers but deal with wood, concrete, steel, etc. The answer I got was the same as what groundloop said in the above post. However where the strength comes from is multiple layers of wood, similar to building a box beam.

For the second question in the horizontal position, you can put fiberglass in tension by compressing the topside while the bottom layer is bowing, hence the glass is in tension. As a side note the forces from the motor torque puts stress in a downward position and if the transom wasn't glassed in place the bottom would give causing it to fail. I'll draw up a diagram showing what was explained to me. If anyone knows a Marine Engineer ask him the same questions. I'm curious to hear their answer.

 

[OFFSHORE GINGER]

Hey guys , i guess i stand corrected ,and to tell you the truth .one can only hope that C-M 's new 43 wave crushing boat ( punshier ) with twin 700's has a little more beef in the transom them just putty sandwiched between two layers of ply but then again i am not a structural engineer, and Robbie i do know Marine engineer's ,and having been in this business for over forty plus years now doing fiberglass repair building boats that do triple digits with number 6's hanging off the back i personally feel that the transom area structurally needs more beef then normal just because of load conditions and the pounding it takes and when i re-do a transom it basically is the same way i have done it in the past building high performance boats . Robbie , just remember you were the one who asked me to throw out a layup schedule ,and why do i always feel i always have to defend myself on this forum after everything is said and done .

 

[paulsboats]

why?

 

[OFFSHORE GINGER]

Paul , not to be rude.........but Why.................. what ?

 

[atc250r]

I don't think you should feel that way OG. Its discussions like this that end up in better/more durable boats in the long run. I also agree that what works on paper in the engineers' office doesn't always translate into the best way in the real world. They spend millions designing the new subway cars that we run here in NYC and there are many cases where the ones we have been running since the 60's are proving more reliable than the new stuff. Not trying to knock anyone or there profession but that's the experience I have had.

 

[Ramifications]

OG- you shouldn't feel as though you need to defend yourself or your build methods. First off, it isn't always the easiest to read people on a forum like this. You loose every part of conversation, but the words. With no mannerisms, tone and body language, it is very difficult to know who is joking, genuinely curious etc... I think 99% of the guys on here are only asking questions to better understand you method, without trying to sound like they are second guessing you. Again, if you read it the wrong way it could easily sound like someone is questioning your knowledge when they aren't. A lot of times diagrams, like the ones Cmpulse puts up, are a major help. I know I have never done any type of fiberglass until I did the work on my Mate, so I came from knowing nothing about it. I did a lot of reading and picture viewing before asking any questions, for fear that my basic and borderline stupid questions would come off the wrong way.

I know I truly appreciate all of the advice you, and others, put up on the board

 

[Madtown]

I understand were some may say that glass in between the transom ply's may be overkill. Heck just solid wood is going to be better than what was in my boat. I think if you build it a little stronger than what it originally was when new & create proper drains that should work just fine for another 15 years yes?

 

[Rob B]

OG there's no need to defend yourself. A close friend and mentor told me along time ago "you'll learn more on the job than in a classroom", that statement is so true in the real world. I learn something new everyday on here. I'm glad you posted the layup schedule and for the record I've seen a similar one on other boating forums. Thanks for the advice you've given us so far.

A side note: Remember I'm asking a question from a technical standpoint, not real world applications. The guys I asked has never worked with fiberglass before, so keep that in mind. They're only going by what is taught in a classroom and in a book.

 

[paulsboats]

why do you feel you have to defend yourself? is what i meant..

 

[paulsboats]

So I asked the Structural Engineers today about whether or not adding fiberglass fabric between two pieces of plywood increase the strength. I also asked about fiberglass in tension. Keep in mind that they aren't Marine Engineers but deal with wood, concrete, steel, etc. The answer I got was the same as what groundloop said in the above post. However where the strength comes from is multiple layers of wood, similar to building a box beam.

For the second question in the horizontal position, you can put fiberglass in tension by compressing the topside while the bottom layer is bowing, hence the glass is in tension. As a side note the forces from the motor torque puts stress in a downward position and if the transom wasn't glassed in place the bottom would give causing it to fail. I'll draw up a diagram showing what was explained to me. If anyone knows a Marine Engineer ask him the same questions. I'm curious to hear their answer.

i talked with a retired marine engineer /professor from mass maritime acadamy what he said was pretty much what your engineers said word for word!

 

[Rob B]

i talked with a retired marine engineer /professor from mass maritime acadamy what he said was pretty much what your engineers said word for word!

Paul do you think the reason for the extra fabric between the plywood is to keep the plywood from flexing/bending?

 

[paulsboats]

im sure it helps prevent it but most factory stuff ive seen has been only put together with bonding putty.i always use glass in between the layers of plywood with a cobosil mixture also.dont want any air voids at all.he said the tabbing to the sides and bottom are most important! ive seen some boat with none at all right from the factory must of been a push to get er done! i have always over built the transoms on any resto ive done.there is alot of strain back there! even on my little boat i made the transom as thick as possible.if it was any thicker i would have to mount the engine on a jack plate. no such thing as over kill i believe. i think the flexing and poor sealing is part of the problem that causes these boats to rot out.

 

[paulsboats]

I understand were some may say that glass in between the transom ply's may be overkill. Heck just solid wood is going to be better than what was in my boat. I think if you build it a little stronger than what it originally was when new & create proper drains that should work just fine for another 15 years yes?

Yes sir!

 

[Lawson'sLanding]

I picked up my marine plywood the other day and sanded for about 2 hours after work today. There is a pic of my old transom on top of the piece of marine plywood. I'm hoping to not have to buy another piece. I plan on making my knees and horizontal brace out of this piece as well. I guess I have a couple more questions. Where the hull meets the transom glass is not a right angle. Should I angle cut the transom wood to compensate for that or just count on the resin/cabosil to fill that void? Also, how thick should I expect the cabosil/resin layer between the new transom and the hull be(the glass/resin on the transom skin is not straight)? Anyways here is a couple pics. I am using the cardboard attached to my marine plywood to make a template for the transom. I wasn't happy with the fit of the factory transom wood.

 

[Ramifications]

I picked up my marine plywood the other day and sanded for about 2 hours after work today. There is a pic of my old transom on top of the piece of marine plywood. I'm hoping to not have to buy another piece. I plan on making my knees and horizontal brace out of this piece as well. I guess I have a couple more questions. Where the hull meets the transom glass is not a right angle. Should I angle cut the transom wood to compensate for that or just count on the resin/cabosil to fill that void? Also, how thick should I expect the cabosil/resin layer between the new transom and the hull be(the glass/resin on the transom skin is not straight)? Anyways here is a couple pics. I am using the cardboard attached to my marine plywood to make a template for the transom. I wasn't happy wi the fit of the factory transom wood.

To make sure you get the most out of the ply, use your templates and lay it all out first to make sure it fits and you're not wasting any space.

I don't know enough about the cabosil etc to make any suggestions, but if you want to get a good fit on the transom wood, cut it a little bit bigger then needed. Put a small angle and fit it, trim if needed and refit.... you get the idea. I'm not sure you want a perfect fit, because you may need space for the cabosil to do its job.

Hopefully someone else will be along shortly to help with the cabosil.

 

[Rob B]

Once you're done with testing fitting, apply a nice thick layer of cabosil and resin to the inner skin, then clamp the transom in place. You want the cabosil to ooze from around the transom as you tighten the clamps, leave those on overnight or a day or two. Once that's cured use the cabosil to fill in all the voids flush with the transom all around. You're good to go!!