Reinforcing Transom Question

[jbgoalie1]

1983 Bass Tracker Tournament Tx w/ 1983 50hp Merc
I have some cracks in my transom between the upper and lower motor mounting bolts. The wood feels solid and dry but I'm sure there is some wet/rot some where as it is the original. I plan on having it checked ASAP, is there anyway to reinforce the transom to get through about another year? I was thinking a square of heavy aluminum to more evenly distribute the weight?

The wood on the outside of the transom is really soft so it doesn't appear to be providing support. Replacing the exterior wood and adding an aluminum brace both seem doable and cost efficient for now. Will this be safe or should I keep the boat off the water until i can have the whole thing replaced?

I know the best thing to do is to replace the transom but as a college student, that isn't an option until after graduation.

 

[sublauxation]

Re: Reinforcing Transom Question

Can you post pics? Are there actual cracks in the aluminum part of the transom? Can you see the bottom braces from the hull to the transom, and if so are they also cracked?

 

[ezmobee]

Re: Reinforcing Transom Question

Replacing the transom on an aluminum boat is not that big a deal. Once you've got the motor off, you may as well do it right. It's not even expensive.

 

[jbgoalie1]

Re: Reinforcing Transom Question

I will post pictures this afternoon. All the aluminum is solid not cracks not stress points that I can find.

I have read some of the other threads and replacing the transom does not seem difficult but living in an apartment everything is a little more difficult than it should be. I just found these cracks yesterday and am going to be trying to find a price for the local repair shop to do it if they well.

 

[Cadwelder]

Re: Reinforcing Transom Question

I've been where you are (years ago, but been there). It's hard to do repairs in an apartment parking lot. But as ezmobee said replacing a transom on a tinny isn't a major deal. Can you find a friend willing to let you use his garage for a weekend or two? Or even someones driveway? This will not be a long process, but will be pricey to hire it done.

 

[sublauxation]

Re: Reinforcing Transom Question

Is it just the outside plywood that's cracked or the inside too? Lots of people, myself included, don't replace that outside piece when they do the transom. As others have said, replacing the transom is pretty easy if you can find a place to do it. The hardest part of doing it at an apartment is probably finding somewhere safe to put the motor. Make sure to check the bottom aluminum transom braces where they attach to the hull, mine were cracked and had to be rewelded. If you do it yourself be careful when taking off the transom cap, it's hard to find a replacement for the original.

 

[ljc1957]

Re: Reinforcing Transom Question

See if you can post some pics. I'll bet fixing it the right way would be almost the same as the temporary repair. Once you have the engine off, you might as well do a permanent fix. It's a lot easier than you think. I feel your pain. I've done most of my work in parking lots. Once the engine is off, find a place to secure it. Get yourself a good tarp to cover the boat with at night and get a long extension cord. Good luck.

 

[jbgoalie1]

Re: Reinforcing Transom Question



Here is a picture of the cracking, its actually below the lower motor bolts on the inside. I cleaned around the aluminum brackets and couldn't find any cracks in them. As far as I can find this is the only cracking.

 

[ezmobee]

Re: Reinforcing Transom Question

Yeah that's shot. Another problem I've had with rotted transoms on aluminum boats is they leak. The fasteners lose their seal and it leaks through them.

 

[jbgoalie1]

Re: Reinforcing Transom Question

So I think I'm going to do the right thing to replace the entire transom, sadly its going to keep me off the water while I finish finals but its better than a motor falling off. Just bummed the weather has been perfect here in Central Florida

I've been reading some threads and I'm pretty handy but want to make sure I understand and get things right.

1. The new transom should be marine plywood. I think it is 1.5 inches thick.
2. Do I need to seal the wood before installation? if so what is the best way to seal it? Best products to use? It doesn't appear that the original wood was ever sealed with anything and its 25+ years old
3. When should rivets be replaced with identical rivets or should stainless hardware be used?
4. When reinstalling the motor I've read to drill oversized holes and fill with epoxy, let it harden and then drill the mounting holes in the epoxy to mount the motor bolts through? I guess the theory here is to seal the wood and only have holes in the epoxy?

 

[ezmobee]

Re: Reinforcing Transom Question

Two pieces of 3/4" ply is typical. Marine is optimal, exterior is acceptable. Arauco plywood from Lowes is particularly nice exterior grade. Best waterproofing is fiberglass. Epoxy resin without glass is second best. Marine spar varnish or porch and floor paint are other methods. All depends on how much you want to spend and how long you want it to last. Oversized holes filled with epoxy or 5200 is a good idea. I don't know much about the fasteners because there weren't any rivets involved with a Starcraft transom replacement. I was just able to reuse all the factory stainless bolts.

 

[Av8nBill]

Re: Reinforcing Transom Question

I just finished replacing the transom on my old Monark jon and did the two 3/4" pieces, glassed and epoxied the oversized holes like suggested. I also had a sheet of aircraft alumimum (.040") laying around so I sandwiched the glassed wood with that for a little nicer look. It makes the rest of the boat look like, well, you know. :redface:

I replaced all the transom bolts with stainless and sealed with 5200. I had to remove the hull-to-transom brace by drilling out the rivets and used closed head blind rivets and 5200 to get me on the water for this season. Next fall when I tear everything down to re-paint I plan to replace them with solid aluminum rivets and replace any others that may need it.

It went pretty smoothly, hope yours does as well.

 

[ljc1957]

Re: Reinforcing Transom Question

JB, From what I can see in your picture, it looks like it would be real easy to fix that. I would sandwich 2 resin coated pieces of exterior grade 3/4 plywood, then fill the oversized holes with 5200. Should be able to do it in a weekend.

 

[jbgoalie1]

Re: Reinforcing Transom Question

I have decided that I may tackle the transom replacement this weekend. What would be the best thing to use to replace the rivets that come out? I was thinking stainless steel nut and bolt? I was worried about a galvanic reaction, would using an aluminum washer between the bolt head and the boat, as well as under the nut help prevent this? Is it better to attempt to replace the rivets with aluminum rivets? Do they make aluminum nuts?

Also what is the best adhesive to use to put the two plywood pieces together?

I know its been mentioned that replacing the outside piece of wood is not necessary, I would like to have something there, would replacing it with a piece of heavy aluminum sheet be ok?

Sorry for all of the questions and thank you for everyone for the advice and encouragement, Im excited to give this a try and hopefully be out on the water soon.

 

[ezmobee]

Re: Reinforcing Transom Question

Stainless is fine. No worries. PL Premium adhesive (kinda like Liquid Nails but better and sold in the same section) to glue the two pieces together. Put whatever you want on the outside as it's not necessary.

 

[jbgoalie1]

Re: Reinforcing Transom Question

I have seen multiple threads talking about using aluminum rectangle tubing and fabricating a transom out of that. What are the cons of that. Its been talked about on iboats but I have not seen any comments about it being done and it its worked out?

 

[Bob_VT]

Re: Reinforcing Transom Question

I have seen multiple threads talking about using aluminum rectangle tubing and fabricating a transom out of that. What are the cons of that. Its been talked about on iboats but I have not seen any comments about it being done and it its worked out?

Where?

 

[mark1961]

Re: Reinforcing Transom Question

I have seen multiple threads talking about using aluminum rectangle tubing and fabricating a transom out of that. What are the cons of that. Its been talked about on iboats but I have not seen any comments about it being done and it its worked out?

My transom was built from the factory with thick aluminium plate and bracing inside where the motor mounts, its a wood free zone.....it would be simpler/cheaper for you to replicate what you already have though, if you seal the wood up well it will last another 20+ years.

 

[jbgoalie1]

Re: Reinforcing Transom Question

In this restore thread there are a couple different examples on page 2-3

http://www.tinboats.net/forum/viewt...=all+aluminum+transom+welded+aluminum+transom

I was thinking of getting tubing the same width of the original transom wood, and same shape, I would think i could just slide it in and reattach everything the way it was, no need for replacement ever

Mark do you have a picture of how the factory did it?

 

[mark1961]

Re: Reinforcing Transom Question

I dont think the design of mine would suit your needs as the braces are welded to the keel extrusion on the horizontal plane, from what i can tell yours doesnt have an extrusion like that to brace off.....i will post pics for reference though just as soon as photobucket is up again.