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

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kungpaoshizi

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I've tried searching, but there's a ton of people asking, "Can I put a metal plate on my transom?"

What I mean, is, if I'm going to take the time to properly restore my boat to what I consider satisfactory condition for long term~

If I pop the boat open, and replace the transom, has anyone ever just skipped putting wood back in and gone with a light aluminum plate? Or a combination of HPDE and aluminum layers all epoxied together or such? I'm talking about a fiberglass boat, so steel would be out of the question since it's at max motor hp for the model, and the weight on the back already IS noticeable.
So I wouldn't want to add any weight with a steel plate of some sort...

I'm just curious because if we're replacing rotten wood, is the wood core one would put back in just going to rot in the end as well? /shrug (the odds I'm sure are against us even 30 years later)

What alternates are there to a wooden cored transom for a fiberglass boat?
 

jbcurt00

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

Poly resin based alternative:

Nida-Core

SeaCast

expensive, but won't rot. Cast in place.
 

kungpaoshizi

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

Anyone ever tried acrylic sheets?
 

Woodonglass

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

I totally understand your anxt about this but... I have a 52 year old boat with the original wood transom. Reason why...Proper care and maintenance. If you do the same there is no reason not to replace the transom with wood. This will tell you how to do it.

"Fabricating Decks, Stringers, and Transoms"

Once the transom is in place and the boat is back in the water anytime a hole is drilled into the transom it should be filled with a marine sealant and the hardware also coated with the sealant. the transom should be regularly inspected and any cracks or breeches immediately repaired in the correct manner. If this is done. A wood/glass transom will last indefinitely. Wood only rots due to bad care and maintenance.:)
 
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GT1000000

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

Anyone ever tried acrylic sheets?

Depending on the size of your transom...
a 2' x 4' piece of 1.5" thick acrylic sheet would cost in the neighborhood of 3-400 dollars...
I don't think it could take the stresses imparted on it by and outboard engine pushing on a 1-2000 lb boat...
I don't think many materials would stick to it except more acrylic, so I think it would be difficult at best to adhere it to a fiberglass hull...
It weighs almost 3 times more than the equivalent sized plywood...
And, why would you want to reinvent the wheel...when there are already tried and true materials that have been successfully used to build transoms for decades...:noidea:

Do you have a stash of acrylic on hand and are just jonesing to find a use for it...:confused:

But hey, but I would love to see something new...
 

jigngrub

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

Look for Kiln Dried CCA Pressure Treated Plywood, it comes with a lifetime warranty and won't rot if it gets wet... about $100 for a 4'x8'x3/4" sheet. It isn't the stuff you buy at Home Depot or Lowes and it's hard to find, you can usually find it at boat dealers that have a service shop or they can tell you where to get it.

It's light, it's strong, it's wood... and it'll never rot.
 

GaJeff

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

Aluminum would be a good idea but then you have to glass it up to keep it in place... Plus aluminum is mad expensive. It would be a lot of work to shape and a lot of money to source. I started out with a deck and transom replacement and of course no one item rots alone so now it's deck transom and stringers. My boat is only a 19.5 I/O and I'm already up to $3200 just in material. That means wood, resin, glass, and all the sandpaper and disks. Protective equip. like gloves, tyveks, gloves, tyveks, earplugs, gloves, tyveks... Oh and a third shop vac. The wood is by far the CHEAPEST material yet.

Go with what is a solid method, unless you got the coin to spend on your creation.

Jeff
 

Yacht Dr.

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

I've tried searching, but there's a ton of people asking, "Can I put a metal plate on my transom?"

What I mean, is, if I'm going to take the time to properly restore my boat to what I consider satisfactory condition for long term~

What alternates are there to a wooden cored transom for a fiberglass boat?

For an OB you can build your trans any way you like without too many problems. You just have to make it strong enough for your application. The glass tabbings are going to be your Main issue when installing any transom.

I see no reason not to use ply personally .. its cheap and can be cut and placed with minimal effort.

Up to you though ..

YD.
 

73Chrysler105

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

Depending on the size of your transom...
a 2' x 4' piece of 1.5" thick acrylic sheet would cost in the neighborhood of 3-400 dollars...
I don't think it could take the stresses imparted on it by and outboard engine pushing on a 1-2000 lb boat...
I don't think many materials would stick to it except more acrylic, so I think it would be difficult at best to adhere it to a fiberglass hull...
It weighs almost 3 times more than the equivalent sized plywood...
And, why would you want to reinvent the wheel...when there are already tried and true materials that have been successfully used to build transoms for decades...:noidea:

Do you have a stash of acrylic on hand and are just jonesing to find a use for it...:confused:

But hey, but I would love to see something new...

Maybe they want to replace the transom with acrylic so they can have more visibility behind them.
 

bakerjw

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

Good plywood is the tried and true method. If you want to go with something other than wood, the composites like SeaCast are good, but you have to get the inside sanded down very thoroughly and get it all cleaned out. Personally I'm from the same school as WOG. Do it in wood and take care of it.
 

kungpaoshizi

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

Lol yes Chrysler, I want a good view of my motor without having to leave the console! :p

The only reason I ask is I don't know :)
But it makes sense that if wood rots, why put it back in /shrug...

I've yet to verify if the transom is ok or not since the PO mounted the motor in a horrible manner..
I even found whirly bird seeds from a tree in the gas tank when I cleaned it out, so I imagine it wasn't stored properly....
There's also a dent in the transom cap from the motor being trimmed up too far, I'm sure water has made it's way in under that tiny dent.

What makes the kiln dried CCA wood rot resistant? I'm always a skeptic when it comes to 100% anything, so when they say 100% rot resistant, is it really? Is 100% rot resistant wood what they used when the boat was first built? :|
 

73Chrysler105

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

Notice its resistant not Rot proof. Just like all watches are water resistant but no watches are water proof. At some depth all watches will break. With the right amount of neglect any wood will rot. Even Diamonds the hardest substance known will crack and break in the right circumstances so is anything ever absolute NO.

And the Acrylic was just an attempt at humor but they do make glass bottom boats for tours so why not try it. I would just thing that Acrylic is too brittle to hold a 300lb motor on the back of it flexing back and forth and not crack even surrounded by fiberglass.
 

kungpaoshizi

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

Right, I don't doubt under certain circumstances anything is possible...
I thought about acrylic only because it's used for larger fish tanks that contain hundreds of pounds of pressure, it would be just as ludicrous financially as a thick aluminum sheet..

The thought crossed my mind though, of taking one of the rot resistant specially treated plywood and then just encasing that in something like Goop Coat it (epoxy with Kevlar fibers), or a carbon fiberglass, and then of course covering in the normal fiberglass like the transom repairs I've seen..

I might be trying to strengthen it too much :)
 

jb93

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

I think the best answer to address your concern is using the Nida-Core board mentioned in one of the first responses. It was tied to Seacast, so maybe you thought it was also a pour in place...which is not the case. Coosa Bluewater board is similar. These are the composite type panels many of the new boats that are "Wood Free" are using for transom. A sheet of 4x8 that is 1-1/2" thick will probably set you back $500-600. Two sheets of 3/4 marine grade plywood, glue and sealers (various options) will run you $200 and some time to glue them up to make 1-1/2" thick. If you go with Arauco plywood, that cuts your cost down to $150. I have no problem using plywood, as done right it will last a few decades at least. However....$300-400 for some sleep insurance and a composite transom is not a bad investment either. If the extra $ is not a big deal to you, then do whatever you are more confident with. Just don't make a mistake cutting a Coosa Board....ouch!! Make a template out of something cheap first, test fit and fine tune before you cut a $600 panel.
 

kungpaoshizi

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

Ahh awesome! That coosa board looks like a solution!

Definitely note to self before cutting a 600$ piece of material! lol

Thanks very much!
 

jbcurt00

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

Poly resin based alternative:

Nida-Core

SeaCast

expensive, but won't rot. Cast in place.

I think the best answer to address your concern is using the Nida-Core board mentioned in one of the first responses. It was tied to Seacast, so maybe you thought it was also a pour in place...which is not the case.

Yeah, I was thinking Nida-Bond which is a pour in place product, but posted Nide-Core.:facepalm:

SeaCast & Nida-Bond are a pour in/cast in place product, neither is inexpensive.

Nida-Core is one of several composite sheet goods that is also not inexpensive as jb93 mentioned.
 

Watermann

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

You should keep your transom posts to one thread in the same forum category. It's just easier for everyone that way.
http://forums.iboats.com/boat-topic...ate-condition-wood-inside-transom-624969.html

Your boats transom will need 1 4x8 sheet of ply (I prefer marine grade), glue and finishing materials you decide on whether it will be epxoy resin or paint and spar urethane. Definitely will cost under $150. if you go with spar rather than the 80 - 90 a gallon resin which would need painted anyway if exposed to sunlight.
 

jb93

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

Your boats transom will need 1 4x8 sheet of ply (I prefer marine grade), glue and finishing materials you decide on whether it will be epxoy resin or paint and spar urethane. Definitely will cost under $150. if you go with spar rather than the 80 - 90 a gallon resin which would need painted anyway if exposed to sunlight.


Since I believe the OP is talking about a fiberglass boat in his initial post, I upped the cost of making a transom out of plywood as it would take poly or epoxy and fiberglass over using just spar coating - which I think is more often used on aluminum boat transoms. I may have overshot the cost of plywood a little though as I was figuring the possibility of having to buy 2 sheets of plywood to laminate up to a 1-1/2" 4 x 8 panel, which would be = to the same size as a Coosa or equal type panel. Depending on transom size, 1 sheet may be all that is needed. Also..maybe composite panels are available in less than a full panel size. Perhaps OP could find a less than full sheet of composite at a discount?

I am sorry about not clarifying that a little better KungPao. As noted already, most feel plywood properly done is AOK. I tend to agree, but I can see the merit in composite too. Done right, you will end up better than factory new either way. Whatever floats your boat. :)
 
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Re: Metal plate instead of plywood core for transom? Not the bandaid thing..

interesting. I would have looked more into the composite panel for the transom as $600 doesn't sound all that bad as I could have got 2 transoms out of a sheet (bass boats). Postage might be a deal breaker as well as what type of resin you would have to use to tab the transom to the hull
 
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kungpaoshizi

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

Ya, I'm thinking longevity and I'm willing to pay the price.
Not sure on the resin yet, but might mix it with perhaps a carbon fiberglass or aramid/carbon mix with the Coosa. I'm hoping to shed a few pounds but the strength will be ridiculous.
 
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