# Transom in Aluminum boats



## stockrex

Greetings!

Can someone pls educate me:

Do all the aluminum boats have plywood under the aluminum skin on aluminum fishing boats like lund, crestliner etc?

How often will the transom need to be repaired?


----------



## Captain of the 4-C's

If you go to replace it - do not use treated plywood but a marine plywood that is sealed. Treated Plywood will corrode exposed aluminum metal.


----------



## SWMbruiser

Not all, but most do. Some have an area exposed and that is the easiest way to tell if it is soft and spongy. Sometimes they are not exposed and the only way I can imagine telling if there is no resistance to tying the motor down. I looked over one of our boats and I am pretty convinced it can't be replaced except by the manufacturer.


----------



## DM1962

I have found the floor and transom to last roughly 10 years. Less if you don't cover it or fish in monsoons. The problem is the manufacturers use cdx plywood on the transom and not marine plywood. If you replace it use 3 sheets of marine grade, screw them together and seal it with West systems epoxy. Good for many years. Replacing the transom is a bitch. I did this on my Crestliner.
I bought an Aluminum Triton which has composite floors and no wood in the transom or boat at all
Good luck


----------



## idylmoments

It's a lot of work. Good advice above. I did an 18 Crestliner last summer. Laminate together and completely seal marine ply. Menards has marine ply in stock and the cheapest. Any hole you drill, back fastener out and seal hole. It will last much longer.

Easiest way to tell if yours is rotted is somehow examine the wood at the bottom of the transom. Either by removing fasteners etc. See if it's wet or you can poke a screwdriver thru it.


----------



## ChasinSprints

You didn't specify what type of alum boat you are referring to. If you have to replace a transom be sure to measure the original thickness. Original thickness is critical in I/O application to make sure the drive shaft is fit to the proper depth in the engine coupler. Yes indeed use CCA aluminum safe marine plywood. This past summer I completed a complete resto on a 1972 Starcraft Chieftain. The transom consisted of 2 sheets 3/4" plus a 1/2" plate where the inner gimble mounted. Bond the plywood together with waterproof adhesive which can be screwed together or weighted heavily until cured. This pic is of the new transom I put in the boat while doing the initial fit. It was then removed and sealed with 3 coats of 2 part epoxy. It will certainly outlive me before it ever rots. All bolts that went through the alum and the transom wood were liberally coated with 3M 5200 to prevent water intrusion. 



This pic is the transom and deck after the epoxy and mounted.


----------



## Far Beyond Driven

10 years? I fish from a 1971 holiday that is rock solid. Also a 1994 sea nymph that is as well. Both have had the privilege of garage storage or on a covered shore station. Both also have over 2000-3000 hours on them.


----------



## stockrex

idylmoments said:


> It's a lot of work. Good advice above. I did an 18 Crestliner last summer. Laminate together and completely seal marine ply. Menards has marine ply in stock and the cheapest. Any hole you drill, back fastener out and seal hole. It will last much longer.
> 
> Easiest way to tell if yours is rotted is somehow examine the wood at the bottom of the transom. Either by removing fasteners etc. See if it's wet or you can poke a screwdriver thru it.


yes, any screw will cause water intrusion due to wicking effect.


----------



## Far Beyond Driven

Good idea on any transom is to drill a hole larger than needed, fill with epoxy, then drill a smaller hole in that for the screw.


----------



## stockrex

ChasinSprints said:


> You didn't specify what type of alum boat you are referring to. If you have to replace a transom be sure to measure the original thickness. Original thickness is critical in I/O application to make sure the drive shaft is fit to the proper depth in the engine coupler. Yes indeed use CCA aluminum safe marine plywood. This past summer I completed a complete resto on a 1972 Starcraft Chieftain. The transom consisted of 2 sheets 3/4" plus a 1/2" plate where the inner gimble mounted. Bond the plywood together with waterproof adhesive which can be screwed together or weighted heavily until cured. This pic is of the new transom I put in the boat while doing the initial fit. It was then removed and sealed with 3 coats of 2 part epoxy. It will certainly outlive me before it ever rots. All bolts that went through the alum and the transom wood were liberally coated with 3M 5200 to prevent water intrusion.
> 
> 
> 
> This pic is the transom and deck after the epoxy and mounted.


reposting my response from last night, looks like it did not go through

Chasin,
Nice resto, thanks for sharing the pics,

1. I do not have a boat or one in mind yet, I want to upgrade from my 13ft folding dingy. Definitely have to go used but my knowledge is lacking on their construction

2. So most boats are made with indoor grade plywood, wow, that is alarming. Which makers use synthetic/composites for their transom? 

DM1962, 
did you go with this maker?
http://www.tritonboats.com/boat/432.aspx

When I was at the boat show last year, I tried to peek at the transoms via the hatches next to the outboards fuel/steer lines but I could not see bleep.


----------



## stockrex

Far Beyond Driven said:


> Good idea on any transom is to drill a hole larger than needed, fill with epoxy, then drill a smaller hole in that for the screw.


that makes sense, thanks


----------



## stockrex

Far Beyond Driven said:


> 10 years? I fish from a 1971 holiday that is rock solid. Also a 1994 sea nymph that is as well. Both have had the privilege of garage storage or on a covered shore station. Both also have over 2000-3000 hours on them.


unfortunately, mine will be stored outside with a cover. but it is good to see if taken care of they do last longer,
I think shore stations rock


----------



## here2

It's not horrible to do if you have some resources and mechanical knowledge. I have a 76 start raft super sport that's dry and solid , but I got it from original owner and always stored indoors. 

You usually have a handful of through bolts along the side and along the top. The corners are where most issues happen it seems, especially on crestliners or at least my buddies was welded down. We just cut them w a welder and repaired as best as possible w the new install. Also hVe done small 16 row boat and that was simple and a sylvan super snapper? I think and that was a mix between the crestliner and row boat. Marine ply , epoxy lamination and all edges sealed w 2-3 coats of epoxy and I'm w far beyond if you can drill larger holes and fill w epoxy around and screws or through bolts 

Tony


Posted using Outdoor Hub Campfire


----------



## Supersport18

DM1962 said:


> I have found the floor and transom to last roughly 10 years. Less if you don't cover it or fish in monsoons. The problem is the manufacturers use cdx plywood on the transom and not marine plywood. If you replace it use 3 sheets of marine grade, screw them together and seal it with West systems epoxy. Good for many years. Replacing the transom is a bitch. I did this on my Crestliner.
> I bought an Aluminum Triton which has composite floors and no wood in the transom or boat at all
> Good luck


 I have a 1977 Starcraft Supersport that has a solid ORIGINAL transom and floor. Keeping the boat covered or inside makes a huge difference. I have replaced a transom in a 1975 Mariner 21 and it wasn't too terrible of a job. Use the original transom as a template. Screw marine plywood together with Gorilla glue and stainless screws. Coat with west marine epoxy 2 coats. Good to go. Good advise to seal holes with epoxy to stop water intrusion.


----------

