# Transom rebuild -- What would you use?



## Brett (Jul 16, 2008)

Plywood is still the least expensive, durable, effective transom material I know of.
Just make sure it's sealed and 'glassed over completely.


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## firecat1981 (Nov 27, 2007)

Brett is right, the whole "no wood no rot" thing is kind of a sales gimmick praying on peoples fear after some crappy builders tried to get away cheap. Decent plywood and epoxy resin is your best bet. If you shop locally you can find some exterior grade (not pressure treated) ply with minimal voids. 1/2" or 3/4" transom, with a extra clamping board on the inside top to make it 1.5" will be all you need. 

From what I gather you are just replacing the inside? Personally I would cut the whole transom out and make sure it was done right.


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## Frank_Sebastian (Oct 15, 2007)

It seems like I am always replacing transoms here in Sebastian. I will share what I know from doing many transom repairs. I use epoxy only and I like 12oz biaxial glass of two layers min. It is very strong and fairly easy, but you need to read the how to do it from several sources. (easy to find by using search feature)

First clean the area of the transom , floor and sides of the hull for the last 12'. I use acetone liberally and wipe it off with handfuls of paper towels as it can dry and redeposit oil and grease. Find some good plywood. You will have to go to a real lumberyard as the big box places sell only ply that can be used in weather protected areas. Expect to pay >$30 for a sheet of good exterior pine of 1/2" AC grade. You will be gluing two layers together. You may find a half sheet, but it will cost nearly what a full one does. Follow the directions for transom repair with epoxy using a schedule for a small boat. If the resulting 1 1/4" transom is too narrow you can add a clamping board. Two to three coats of epoxy will waterproof the transom and it will last for many years. Any holes drilled in it will have to be sealed. 

Best regards,
Frank_S


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## Frank_Sebastian (Oct 15, 2007)

Clean with acetone for about twelve inches, not 12'.

Frank_S


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## cwalden (Jun 24, 2011)

Thanks guys. I will do that. 
I dont want to replace outside, as it is still in very good shape. Replacing it would create a seam and therefore a weak spot.
I have been working with fiberglass/Carbon Fiber/Kevlar for about 25 years, so I know the drill there and have everything on hand. I was just wondering if there was a better material for the core. Looks like wood it is... Thanks again.


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## cutrunner (Jun 8, 2010)

Pvc board. Just like starboard, but adheres to fiberglass very very well.


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## DuckNut (Apr 3, 2009)

There is a better material.

http://www.transomrepair.net/index.php
http://nida-core.com/english/nordprod_nidabond_transom.htm

I have used both. Used Seacast for roughly 15-20 years, Nida for about 3. Far superior to wood in all aspects.


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## paint it black (Nov 3, 2007)

I use SpaceAge and mantex.....


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## firecat1981 (Nov 27, 2007)

I love the advertisements of some of those products when you go to the website. Like one says it has copressive stregnth many times greater then plywood, but lists it as only 3500psi :

I'm not saying there aren't better alternatives to wood out there, but everyone who suggests them in these topics always seem to leave out how much a sheet, or pour in kit, costs. Some of those products cost almost half of what a brand new gheenoe would cost.

PS, those kits you pour in over the rotted wood....well lets just say I know from recent experience they aren't worth much if you want it done right


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## cutrunner (Jun 8, 2010)

^^ agreed, i like composites and wood, and feel they both have their uses and needs in different areas. If wood is done right its really hard to beat, price and strengthwise. Big name top builders still use wood.Pursuits stringers and transoms are wood, Yellowfin cores their hulls with balsa. Like Firecat said , its kinda a gimmick. By the way, foam breaks down also.


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## paint it black (Nov 3, 2007)

1.5" spaceage would run you around $900 to $1000 a sheet.

Not worth going out and buying it for a gheenoe. But when you have some laying around, there's nothing else I would use. 
I had some mantex laying around so I used it on my classic. I used SpaceAge on my Trihull...


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## cwalden (Jun 24, 2011)

Thanks guys. I think I will just use wood. I did some checking today and noe of the other recommendations are available here. I already have the wood.

Pour in fillers are not really an option here. There is only the outside of the transom, a replaced wood core and then the whole thing was painted with grey goo... not sure what it was but it looks like it was about the consistenmcy of warm peanut butter. When I remove it all, there will only be the outside layer of the transom. it will be much easier to build a Plywood/Glass/Plywood sandwich and then cut it to fit and glass the whole thing over.

Right now, the drain tube is about a 1inch piece of aluminum tube that is flared on both ends to fit the hull. Looks manyfactured that way. It will obviously not fit anymore when I do this. What would you guy use? I would like to keep the diameter outside the tube to a minimum, so that I can keep it as close to the bottom as posible to drain as much water as possible...

Academy Sports has several drain tubes, but the flare on them is really large and will not sit close to the bottom at all. I'm thinking 1/8 or 1/4 flange...


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## firecat1981 (Nov 27, 2007)

I make my own drane tubes by wrapping some glass around an apprpriate sized dowel rod. No flaring needed.










1. get a dowel the same size as the plug you will use. sand the dowel a bit to take away about a 1/32" of the diameter.

2. Use wax paper, or plastic sheeting (drop cloth) and wrap the dowel 2-3 times. make the piece atleast 4-6 inches bigger then the intended tube. smooth it and tape it in place

3. wrap fiberglass cloth around the tube wetting it out as you go, make sure only to brush resin in the direction of the wrap. wrap it 3 times or so

4. when it is dry slide it off and test it to see if the plug fits it right.

5. Set it in place with thickened epoxy, when it dries trim off the extra length of the tube and you are done.


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## cwalden (Jun 24, 2011)

EXCELLENT idea!!! I knew there was a reason that I asked you guys questions...


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## Alaninga (Jul 28, 2011)

plywood...check around, there are some plys that are much better than others. A custom furniture builder who was a 'wood fanatic' showed me some plywood one time that he scrounged from a shipping crate. It was 12 ply and only about 5/8" thick! The more plys the stronger in most cases because the glue is stronger than the wood, and thinner wood plys leaves less room for air gaps. You might find some excellent [strength wise] plywood if you shop and ask around!
I've owned 8 boats myself not including my Dad's boats. When I look at a used boat for sale, I always get some odd looks when I start knocking on the transom with my knuckles. I've had one 'logged' transom and don't care to buy another! 
My Triton has no wood in the transom.


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## cwalden (Jun 24, 2011)

This one is solid, just ugly and it messes with my OCD...


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## firecat1981 (Nov 27, 2007)

> The more plys the stronger in most cases because the glue is stronger than the wood, and thinner wood plys leaves less room for air gaps.


Actually the more layers doesn't have to do with the strength that much, it has to do with the stability. More layers means it is less likely to warp and curl. The more plys the more stable it will be, also good plywood always has an odd number of layers. The glue is a very minor part of the equation, but it is important to make sure it is water-proof/water-resistant, especially if you cheap out and don't use epoxy.

The strength and voids(gaps) are different. The strenght comes from the species of wood and the thickness of the plywood. The voids, or lack there of, come from the grade, better the grade the less voids. That being said even though most guys perfer using the BS1088 and BS6566 standard plywoods, it doesn't mean you can't use others. The most important part of the equation is using good resin, epoxy if you can swing it.

Read this, it's from one of the best boat building resources.
http://www.bateau2.com/howto/marine_ply.php


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