Metal plate instead of plywood core for transom? Not the bandaid thing..

[Woodonglass]

Re: Metal plate instead of plywood core for transom? Not the bandaid thing..

You have a 1986 Venture Stallion Bass boat listed as a boat in your post. Is this the boat that's needing a transom replacement? For most people a $3,000 transom would/could not be considered for their boat restoration. That would be more than the total cost of most full stringer, deck, transom restorations here on the forum. Most people consider a 40 year boat a good investment and most don't keep the boat that long. You might be very disappointed with the re-sale value of a High-Tech boat restoration. Re-couping the money you put into a boat restoration is a coin flip at best.

Just out of curiosity, are you an engineer by profession?

 

[Watermann]

Re: Metal plate instead of plywood core for transom? Not the bandaid thing..

I sure hope Kung doesn't find out his house has structural elements in it made from wood as they have been for 1000's of years. He will be beside himself with desire to change out the roof beams and sheeting to carbon fiber and maybe even some titanium!

I can't wait to see what you come up with on your boat when you get to the rebuild stage.

 

[kungpaoshizi]

Re: Metal plate instead of plywood core for transom? Not the bandaid thing..

I sure hope Kung doesn't find out his house has structural elements in it made from wood as they have been for 1000's of years. He will be beside himself with desire to change out the roof beams and sheeting to carbon fiber and maybe even some titanium!

I can't wait to see what you come up with on your boat when you get to the rebuild stage.

I rent!

And yes, I am an engineer now that you ask.
Otherwise I was just spitting out a figure at random. I know the aramid/cf fiber I have found is about 40$ avg per yard, by 50". This would allow me 2 layers and about a foot remaining.
Depending upon my calculations that I've yet to pinpoint, that's going to add up.
I'm thinking I'll do a 1708 layer followed by the ACF, 3 total of 1708 and 2 sandwiched ACF's.
I have yet to sit down and do the math though, so this is again, a generality.
Also the ACF will not be touching the Coosa. (2nd and 4th layer)

I do realize that if I do it economically, I can do it for much, much less. But as I'm single, don't have kids, don't have debt, I'm in the market for something fun and unique. I don't expect the boat, if I ever sold it, to fly off the shelf so to speak. I do however expect that it will (with the use of higher quality materials) be easier to sell, and hopefully with a better premium.

I merely mentioned it because it's the direction I'm going to take. Whether or not people want to offer suggestions in the area I'm venturing.. (ha, pun)

I really do like the constructive criticism though, makes ya think, and it's always a better way to refine things.

 

[Woodonglass]

Re: Metal plate instead of plywood core for transom? Not the bandaid thing..

You still haven't told us what boat you're building this High Tech transom for. Pics are always welcome and almost a necessity here on the forum.

 

[fishrdan]

Re: Metal plate instead of plywood core for transom? Not the bandaid thing..

I overbuild things at times and call myself "Captain Overkill"...

But wholly smokes! Epoxy, kevlar and carbon fiber for rebuilding the transom of an ol' 86 bass boat is going to earn the title of "Admiral Overkill"... Probably going to need some soild gold cleats and a titanium prop to go along with the transom...

 

[jbcurt00]

Re: Metal plate instead of plywood core for transom? Not the bandaid thing..

I suspect the high tech materials won't have the same impact (or attraction) for a buyer that they hold for you, KungPao.

I work in a challenging market for many of the products I am charged w/ selling. I often refer to the challenge in the following way when speaking w/ my direct report boss:

It's a Ferrari, I know it's a Ferrari, I'll concede that a Ferrari is a 'good', 'well built' car that may even be worth what they ask for 1. HOWEVER (a BUT isn't quite stern enough a word), 95% of the people in the position I call on, wouldn't even buy a Ferrari 'if' they could easily afford it. BTW: I fully believe in our Ferrari-esque product being worth what we charge for it...

For me, as a buyer, the inclusion of the materials being discussed would be off-putting. Perhaps it's inaccurate, but to me it'd be like putting a carbon fiber hood on a Yugo. I'd ask myself Why? Of course I'm not a typical buyer. A look thru my boathouse would easily suggest that. Put another way, it'd also seem similar to what some guys do to mod their motorcycles. To me it screams I abuse & run the ever-loving HECK outta my bike, and pushes that particular motorcycle off my list of considering purchase.

It might be extremely beneficial to find a few people to bounce the high tech materials idea off of, unless you just want to treat it as a test of what you're capable of. It should be a group of people that would be your target market, not a few of your buddies that are high tech~engineering junkies too. They likely support the idea on theory alone.

Good luck w/ your project, however you proceed

 

[jones01m]

Re: Metal plate instead of plywood core for transom? Not the bandaid thing..

My dear engineer friend, I believe you are talking out your wazoo!!!
Even mediocre calculation methodologies on composites rely on reams of test data from laminate samples produced by repeatable manufacturing processes.
Your calculations are going to amount to exactly jack when it comes to practical application in your garage.
But, I wish you luck, and I hope when the construction is complete there is a way you can convince yourself your theories are correct.

 

[glenn property of pam]

Re: Metal plate instead of plywood core for transom? Not the bandaid thing..

always a interesting read. Wooden mentioned that you have a venture 1986 if that is the case then I would check inside to see if the glass was hand layed or chop gunned to start with. My venture was a chop gunned boat and the transom did not span the width of the rear so most of the force was being taken to the stringers by knee braces. I like the venture brand as it was well designed just built a little cheap.

 

[GaJeff]

Re: Metal plate instead of plywood core for transom? Not the bandaid thing..

I think you need to tear it apart BEFORE you buy anything. I'm sure that you WILL find that your stringers will need to be done. Nothing on a boat ever rots by itself. By the time you see the rot or notice something, it's already to late. That statement of 3k will be true except it will be for a restoration not a transom.

If your going to use CF for the restoration your going to have an originally cheap both worth 10k (to you only) with fabric you can't prove you used.

People are just jumping around to buy an old bass boat that has been fixed by someone who isn't a professional for the amount that your going to to think is fair.

JUST USE VE OR POLY

There are generations of boat builders here that will tell you over and over what you've been told already. I'm going to PM you my address.... Send me some of that cash you got just sitting around. I'm going to use it for more poly resin.

 

[kungpaoshizi]

Re: Metal plate instead of plywood core for transom? Not the bandaid thing..

Wood, the only reason I'm doing this is because I never, ever, under any circumstances, want to have to do any of this again.
Also I plan on going with 6-10" setback most likely with a jackplate, so any extra strength will be welcome.
I wouldn't call it high tech though, even Kevlar has been around for awhile.
The biggest concern will be which epoxy to use (leaning towards marine grade, medium cure, from tap) because depending upon how I schedule, I will probably have to account for adhesion properties of the aramid and the lack of poly for the CSM bonding agents.
This is a concern, but I believe I can address it with a few simple test panels. I suspect though with a weight upwards of 50 oz. I wont' have to worry about much strength wise, just delamination long term, so accuracy will be key.

Fishrdan, ya, that about sums it up lol. I do what I can, little bit of extra cash I'll put into functionality, but not cosmetics For the hull topcoat I've going with a frogskin layer specifically engineered for a lower drag coefficient, I kinda consider that cosmetic...

JB, I agree on the Ferrari, I would never pay for it. But it doesn't mean I wouldn't take it if it was reduced price or free!
As far as bouncing the ideas off others, I have found a consultancy service in composites, but ultimately the tech isn't new. I've already found a good deal of resources on the net so far, and of course a good deal of conversations like this thread on other sites. (skeptics everywhere! lol) Me myself, I'm a man of science, so I do greatly heed caution from words of wisdom, but just because they were wise yesterday, doesn't necessarily make it true today, to think otherwise would be a regression in learning. Let alone, every piece of tech has a proper place and time. I'm not blindly ignorant on this subject, so I'm definitely not considering any of this on a 'wow! cool!' factor.

Jones, I have no doubt tests are carried out, but reams? Are you talking about that thin stuff that tears, people used to write with those graphite devices... and it was made from uhh trees? Oh yes, paper....
I agree there's a margin of variance in multiple directions when comparing a finished product, but as any true test will show you, the test is only as good as the preparation and care taken. This is also the same consideration that must be made and prepared for when moving anything to production. Will I be doing hundreds of tests? No. I believe the only true test, will be how well I follow manufacturer instructions and replicate certain conditions. If reams and reams of test data from a professional environment was the only safe way to do anything, this website would not exist for one, and there would be many more people dying from bad fiberglass jobs in boats. Also, some of the most amazing people in history never went to college or were instructed on how to do anything in the areas of science they dabbled in, so if you're limiting yourself because of your uncertainty about doing it correctly, you're missing out!
As far as talking out my wazoo, ok, if I am, prove me wrong that adding aramid and carbon fiber twill is a BAD idea, and does not strengthen anything. Not unnecessary, not expensive, but legitimate test data, or even a nice little story on a random forum, showing a combination of the 3 (G,CF,A) leads to a premature failure, or a test that shows plain glass is better. (I'm sure you have an example in your reams and reams of test data)

GlennPropertyOfPam, from what I've seen it looks to be chopped, but I only have a limited view. I do know it's built fairly tough, I've beaten the hell out of it so far.. lol.. I do recall someone else saying that, "Venture hulls were always heavy." I guess I really haven't compared too many 16' boats and their weights. Did yours have the 2 humps in the back filled with foam? I can see where I think the transom just goes straight down, but I've yet to pop the top.

GaJeff, ya, I'll make my shopping list and final measurements and decisions on material AFTER I gut the sucker.. I'm planning on cleaning up the rest of the hull and restoring 100%. As far as the cost and what it's worth, I'm not too concerned. I'm doing this mainly for my own use and fun of experience. Like someone else said, "I wouldn't be interested in it if it had those materials!" But well, you're just one kind of buyer. There are many people in this world who would appreciate and see, no it wasn't restored by a professional, but it WAS restored, and it looks to have been by someone who's taken attention to detail. While you might think "professionals" in commercial environments are the way to go for superior quality work, I know A LOT of car guys that would say taking their car to the shop for a "professional" to work on is about the worst mistake you can make.
I mean really, they have no personal attachment to what they're working on, it's just another boat in a long line of boats, from some random Joe Schmoe.

Why is it you say use VE or Poly though? I've seen, "better quality works come from epoxy as it does not shrink as much as the others."

 

[jb93]

Re: Metal plate instead of plywood core for transom? Not the bandaid thing..

I say this with humor..........I had no idea that I was being an enabler. :facepalm:
Engineers....gotta love them. Honestly though KungPao....the point really is why build a $3000 transom when a $300 transom will last 40 years and will be unperceptively different in performance.

Since you love technology, I can help you better spend the savings you will have by skipping all the high tech materials.

You are going to want a nice graph/fishfinder ($1000) that Links to your Minn Kota Ipilot Link trolling motor (they are awesome) for $1800. That will leave you just enough to go ahead and put the second fishfinder on the bow tied into the transducer on your Ipilot troll motor..$300. All of that will catch you a lot more fish than a transom built out of UNOBTAINIUM....which I know that is what you are really looking for.

I get that it is a process and you have to explore. I'm just trying to be a voice of reason here, and I know engineers speak LOGICAL extremely well. I am interested to see how you proceed...bring on the pics!

 

[glenn property of pam]

Re: Metal plate instead of plywood core for transom? Not the bandaid thing..

GlennPropertyOfPam, from what I've seen it looks to be chopped, but I only have a limited view. I do know it's built fairly tough, I've beaten the hell out of it so far.. lol.. I do recall someone else saying that, "Venture hulls were always heavy." I guess I really haven't compared too many 16' boats and their weights. Did yours have the 2 humps in the back filled with foam? I can see where I think the transom just goes straight down, but I've yet to pop the top.

The 2 humps are the extra flotation needed to off set the weight of the motor in case it sinks. As a engineer you have to understand that your plan to increase strength in the transom area is correct but as a engineer you need to step back and decide how you are going to increase strength with minimum weight with out causing a material-edge. Bonding a very stiff item to a flexible item takes a lot more skill as all the motor vibration will transfer from the stiff material into the flexible and the joint will have to take the brunt of it. If your transom is not bonded to the sides of the hull then I would be more into engineering knee braces and shifting weight to the front of the boat to off set the change to the center of gravity that the jack plate is going to make. Most bass boats are back heavy and once loaded they are real back heavy which is not a problem at speed when they are running on the pad but is terrible when sitting still fishing as you are always having to lean forward and it makes the seats uncomfortable as they are tilted forwards 15 degrees. I like the fancy materials and I wish the bottom mid section of my outer hull had layers of Kevlar built in so if In case I hit something in the water.
If you really want to go nuts then go nuts and reverse mold the hull of the boat and get rid of the chop/wood/heavy resin and make a bullet proof ultra light hull I will come along for the ride as its interesting and its always nice to spend other people's money. (you have to understand we like to spend other peoples money so don't think for a moment that we are suggesting anything based purely on cost)

 

[ondarvr]

Re: Metal plate instead of plywood core for transom? Not the bandaid thing..

You seem to think that with “better” materials your boat will last much longer, these so called better materials don’t necessarily equate to a longer life of the structure, they are mainly designed to make a lighter laminate for the same strength. Remember structures are engineered for specific properties, not just randomly over built to an inexperienced guess. I gave you a method of making a no rot transom that will still be around when your kids are tired of it, it would be relatively low cost and easy to do, but because it doesn’t contain carbon, Kevlar and epoxy you seem to think it may not last.

The stresses you seem to think that are beyond the limits of glass, poly and VE are used every day to build countless bass boats that handle stresses far greater than your 115 is putting on your hull. When they do add other fibers a composites engineer designs the laminate schedule so the fibers work together for better properties, not against each other and limit their value.
Your rebuild won’t fail if you use the products you desire, it won’t fail if you use the more common and less costly product either though, and there will be no difference in lifespan.


Again, if the entire hull was being custom built with these products then there may be some value, but for the situation you’ve laid out I see none. An old boat bass boat with an even older low HP motor, where the goal has been expressed as a longer life span. Nowhere in that objective is there a requirement, or even a remote need for the products you desire to use.

By the way, I stay at Holiday Inn Expresses several times per week, so this helps with my understanding of these things

Or maybe it’s because I travel frequently with the Vectorply rep as we go to different boat builders (and other markets, like aerospace) helping them design laminate schedules for their boats. I supply the resins and he supplies the fiber, yes he supplies carbon and Kevlar, rarely are these fibers used in boats though.

Don’t get me wrong, these products can be used, many people do because they love doing it, but the actual need isn’t really there. Some boat builders like to advertise they use carbon and/or Kevlar in their hulls, this is mainly a marketing ploy to grab the attention of those that get excited about high-tech buzz words than for actual function.

 

[kungpaoshizi]

Re: Metal plate instead of plywood core for transom? Not the bandaid thing..

jb, I do plan on the 1198 and most likely the 101# terrova/ilink.. that's been in the pipe for a couple months

glenn, ya, if the design you're describing is there (I think it might be, but it seems like there is a section across the entire back I'm tempted to say, won't know for sure til cap is off) it does change the design for reinforcement, but ultimately there's a limited number of directions and pressure to each that will be had, what I mean to say is the possibilities are few for the interaction of the stress points and their various parameters.. Thanks for the heads up though, now I've got 2 different plans in progress jumbling around for ideas.

ondarvr, honestly, I don't doubt an all glass situation would do the job AND do it WELL. I have no doubt that a plywood core even, would do the job just fine. The key in this case though is care after implementation. As wood rots, by putting wood in, you've already started a "clock" so to speak, and you've engaged in that care to prevent things from happening. But of course, as everything in life always goes the way we want it to, I'm not sure why I'm even doubting the age old practice.
One question I would have for you, perhaps others might chime in...

If we break down the fibers, all 3, into generalized anonymous categories of use(for ease of hypotheticals), I might tend to say that aramid is on top, glass in the center, and then carbon fiber below. Now given that each of the outside materials (cf/a) preform to unique strengths, and unique weaknesses, and glass itself has AVERAGE strengths of the other 2, but a serious weakness in the case of a couple weaknesses, we're basically looking at the 3 materials as good for separate purposes IF they are used ALONE and by themselves. Glass would win in more tests.

But now the question remains, when COMBINING the 3, or even 2 (G+CF or G+A), which numbers would come out on top for generalized use in multiple tests. You could say it's the average of the 3 plus bringing up the low numbers(weaknesses) in the direction and specialization of the composite being added to the glass. Basically each material compliments each other. I think we can all agree on that fairly easily.
The question remains, not what happens to the strengths, but what happens to the WEAKNESSES?

So you have to realize, that though each material has it's negatives, when you bring these 3 together, it raises the average minimum.
So in turn, if using a combination of the 3 fibers, and building a ratio of the inclusion of the 3 fibers(I'm sure it would depend more upon fiber orientation than ratios), to come to the same weight as a similar part is ALL glass, the hybrid would win every time. The range of variables is smaller with the hybrid material because you have "brought up" the average minimum and average maximum because of the base material being glass, and then ADDING in reinforcement in the form of "specialized" fibers.
You can see these characteristics in other products where a company has a base product, develops something better, but not quite as 'uniform' in tests across the board, as the original design.
(this is in reply ondarvr to your touching on, 'just because you use the materials, doesn't make it last longer')
Because if you're looking at a board of statistics of tests, in the center you'll have your glass as the median for 90% of the tests as it's characteristics represent that, and it usually sits in the middle of the other 2 fibers.
Thus longevity and resistance to fatigue, would be a smaller margin of error and smaller margin of premature failure as when compared plainly to glass, or either of the 2 specialized fibers when used plainly by themselves.

One might say, when speaking on properties of materials and 'years old best practices', if I'm looking to maximize integrity across the board, and there's of course never any shortcoming when talking about taking care of an object over a 40 year period as long as you 'keep it well maintained', the course of action I'm looking into is completely wrong. I should be looking to copy the design of the boat, and do what a real boat designer or any good engineer would do, and build the transom wholly out of wood, and then instead of fiberglass, build the hull and internal structures out of solid wood too.

 

[ondarvr]

Re: Metal plate instead of plywood core for transom? Not the bandaid thing..

I have never recommended wood to you because you didn't want it to rot.


The rest of what you said has hints of fact but much more rambling and proves you need to do more reading and study the fibers in greater detail before jumping in and creating your perfect laminate.

 

[kungpaoshizi]

Re: Metal plate instead of plywood core for transom? Not the bandaid thing..

I have never recommended wood to you because you didn't want it to rot.


The rest of what you said has hints of fact but much more rambling and proves you need to do more reading and study the fibers in greater detail before jumping in and creating your perfect laminate.

Please let me know what area you would suggest. I do need to work out my numbers, but the science is rather simple. The actual application will be the tougher part.

Though you might consider it rambling, I'm very specific in what I'm talking about.

 

[GaJeff]

Re: Metal plate instead of plywood core for transom? Not the bandaid thing..

OMG your severely over thinking this whole deal. If you use that CF set up more than likely it will break in due time. I say this because for one your adding something that is way more stiff than the rest of the hull. DO NOT confuse stiffness with strength. Just because its crazy stiff does not mean its stronger, the strength is the same. Now you have something that is just as strong but way more stiff, which means will break instead of crack. You need this to remain flexible to absorb the loads. Just like spacing stringer above the hull and not on top. If you lay them on top you will create a stiff point on the hull with no room to flex and ultimately crack the hull. And second as I mentioned your not a professional. It takes a long time and a lot of experience to lay glass right. Not saying you won't do a good job but your lack of experience can lead to lams that look good but aren't sound... Trust me it takes time to learn the tips and tricks to get this stuff to do what it needs to do.

When it's all said and done your going to have a transom that will flex at a different rate than the hull which will cause it to fail. Maybe your transom maybe your hull but over all it will come back up and you will be at the beginning again. If you want strength use 24roving for your transom and tab it in with 2408 instead of 1708. It will be stronger but still flex with the rest of your poly hull.

Jeff

 

[GaJeff]

Re: Metal plate instead of plywood core for transom? Not the bandaid thing..

And just another note.... I'm not an expert by no means but I have built a lot of stuff from glass. Mainly semi-truck hoods so I know the importance of making sure to do the job right with the right materials. If I were to "repair" a hood with carbon fiber in a certain spot the vibration from daily abuse will cause it to crack somewhere else. I know this because I have had the same thought as you. Think of the cause and effect of combining materials.

There is nothing HI-TECH about carbon fiber or Kevlar. It has its place in certain applications. But for yours it's not suitable. Even if you were to do the entire boat it would still be a bad idea as the hull is still a different composite and it will eventually fail.

Jeff

 

[pyrotek]

Re: Metal plate instead of plywood core for transom? Not the bandaid thing..

- In your case, these fancy materials is not about saving weight. I think you agree with this.
- The wood core won't rot unless you drill through it and yours sealant caulk starts to leak. Often times you won't know it is leaking until it has started rotting. This imo is the only advantage of using the composite cores. If you can guarantee any of your holes you need to drill are properly sealed then I see little advantage. Sure maybe you miss one and your composite core will save you. I think the likelyhood of this is low (10%). If that 10% risk is too high for you - use composite. However, if you know where your holes are needed, you can add glass in to the whole section so there is no wood.
- Use epoxy. Most people don't use it here since poly is good enough, but its true epoxy is technically a better sealant. You want to do some things overkill - this is your best bet. And its easier to work with due to lack of vapors/smell, imo. Biggest downside is you shouldn't use gelcoat on top of it.
- just as boats are marketed with some carbon fiber, kevlar, kungpao wants to be able to say his boat also has carbon fiber. If that's what you want to say - use it!

 

[Woodonglass]

Re: Metal plate instead of plywood core for transom? Not the bandaid thing..

Hmmm, 60 post's, 3 pages and still not one picture of this boat! That must be a forum record. An all about a speculative transom for a bass boat. Usually in this amount of time a transom has been ripped out, a new one built and installed. One more question, why are you going to put a Motor POD on this boat? What is your reasoning for this. Have you researched and studied the handling and performance issues than can arise from this? Most who have done this are NOT happy with the results.:05.18-flustered: