Transom Repair 1979 Century 3000

8

84EdH

Chief Petty Officer
Joined
Apr 30, 2011
Messages
575
My stringers were showing rot when I tried mounting engine mounts, so we cut into the fiberglass and found really rotted stringers. Checking the lower transom shows some rot also. A repair guy says we should replace the transom wood. He proposes to cut the last few inches of the beams and replace the the whole transom wood, then fiberglass it all over.

Questions: Any special plywood type? Any certain thickness? Does cutting into the main beams sound like the route to go?

Any help appreciated...

Ed
 
Woodonglass

Woodonglass

Supreme Mariner
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Dec 29, 2009
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25,924
Re: Transom Repair 1979 Century 3000

Welcome to iBoats Ed!!

We really need some PICS so we can SEE what you are seeing. It is almost impossible to help you diagnose the problem without being able to at least see pictures of the issue. My signature has a link on how to post the pics. Lots of help here on the Forum so getting this done WON'T be an issue if you have the willingness, time, and money to get the job done.


WelcomeAboard.JPG
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Cadwelder

Cadwelder

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Re: Transom Repair 1979 Century 3000

Well 84Ed,

Woody just said the most important part..we need to see what you got. As far as the plywood, my choice is marine grade, but that is a really heated debate somtimes...so basically whatever exterior grade plywood you want to use is fine.

Your plan sounds okay, but I bet you have a lot more rot than just the area your looking at...I'd be willing to bet your deck and stringers are gone all the way up. Be sure and check them out good.

Post the pictures and let see what we're dealing with.
 
8

84EdH

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Messages
575
Re: Transom Repair 1979 Century 3000

Hey thanks for the feedback. I have no pictures of the rot yet. I have posted pictures of the closed in bilge area in another post.....but they dont show whats hiding. I will post pics as soon as she is opened up.....

thanks!
 
F

florida boat 53

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Aug 2, 2011
Messages
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Re: Transom Repair 1979 Century 3000

Yeah, post pictures - sounds like it might be a perfect candidate for Seacast, if it's really all that rotten :confused:
 
F

florida boat 53

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Re: Transom Repair 1979 Century 3000

Oh & I just realized I've posted the "seacast" name twice...but I've got seacast on the brain right now 'cause I've been reading up on Florida's new recycling requirements and it keeps coming up because it's made with recycled material...don't mean to sound like a broken record
 
8

84EdH

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575
Do I really need to tear all this out?

Do I really need to tear all this out?

I found some rotted stringers in the motor mount part of the stern. We tore out the fiberglass around the wood stringers to replace. On the port side of the transom, where the stringer ran into the transom wood, the transom wood is rotted. I took the transom plate off and found the wood around the transom plate where it is tripled up seems firm. The transom seems solid. The coupler was perfect, implying there was no transom movement. If i must tear out the whole transom, I will. I would just hate to do it unnecessarily.

I have posted some photos, which I know dont tell the story.

Can test drill holes determine how bad the transom is?

You can see from the photos, there is still a "box" of fiberglass covering the lower part of the transom. Any way to test this area without tearing out the fiberglass box? Can you test drill from the outside? or is that just not good sense?

the one photo shows the only area obviously bad, just beside the transom mount where the rotted stringer came up against the transom....

another photo shows where the stringers were tore out and cleaned down to the boat bottom, with the fiberglass box (covering other stringers) still sits. No movement or soft spots anywhere.

I weigh about 200lbs. I hung on the swim platform and pushed my feet up against the transom from the outside and got no deflection. does this imply a still decent transom?

all help really appreciated.
 

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8

84EdH

Chief Petty Officer
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Messages
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Re: Transom Repair 1979 Century 3000

I just posted pictures that continue the story of my bad stringers and transom in another post titled "do I really need to tear all this out".

I realize I should have just added on to this thread......
 
Woodonglass

Woodonglass

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Re: Do I really need to tear all this out?

Re: Do I really need to tear all this out?

84,

I believe that this is your 4th thread on the SAME subject. The Forum recommends that you keep ALL posts in ONE THREAD to make it easier for ALL of the members to follow along with the project. You are making it very difficult for ANYONE to help you by bouncing all over the place. Not everyone is like me and reads almost every post everyday.

Now to answer your question your pics indicate that you need to take core samples of the transom, stringers and motor mounts to determine their condition. That will tell you how to proceed. Do a search for Core Samples to find out the proper way for doing it.
 
Marada92

Marada92

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Re: Do I really need to tear all this out?

Re: Do I really need to tear all this out?

If the transom wood is rotten down low and you seal it back up it'll eventually spread further up. How long that takes who knows but it'll happen. Along with spreading to any other exposed wood that comes in contact with it. You can cut out the rotted part of the transom and just replace that and hope you got it all out. Seen a few people plan on this fix only to tear into it and realize it's worse than they thought. Good luck to ya man!
 
zopperman

zopperman

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Re: Do I really need to tear all this out?

Re: Do I really need to tear all this out?

No. All the rotted wood needs to go. It isn't safe. even 200 pounds of you can't apply the force of a motor and a hull flexing in rough water or trailering and hitting bumps.

Drill out core samples and look at the wood shavings... dark and wet means it needs to go.

The transom is sturcturally incorporated into the hull and stringers for a reason.. it makes it much stronger. I would start drilling some core samples out of your deck too... it might be rotting. Generally rotted stringer is indicative of a rotted transom and deck. Drill the holes in various locations so you get a good sampling. Good luck!
 
8

84EdH

Chief Petty Officer
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Apr 30, 2011
Messages
575
Re: Transom Repair 1979 Century 3000

thanks for the feedback. I will read up on the core sample procedures and see what I find. Maranda, your right, I dont want to cut corners and do this again...
 
island mike

island mike

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Jul 31, 2011
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440
Re: Transom Repair 1979 Century 3000

Trans rot:Stringers rot :deck rot, Had the same did not like it and ripped everything out,(gotta be a little bit crazy)Even the balsa wood encased in glass inside hull,Replaced everything with honeycomb(nidacore)exept the transom that got 2 marine grade sheets of ply encased in fiberglass..Its a hell of a job even for me (boatyard worker) But hey, keep focused,You will get there,And uh.. by yourself a good mask!
Good luck.
 
island mike

island mike

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Re: Transom Repair 1979 Century 3000

Forget the samples man,If your stringers are rotten,More than likely your deck and transom are too..Start ripping!!
 
8

84EdH

Chief Petty Officer
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Apr 30, 2011
Messages
575
Re: Transom Repair 1979 Century 3000

Well it sounds like its time to start cutting! My plan of attack is to cut the deck at the rear of the boat and expose the bottom of the transom end to end, and to see what the stringers look like.

I will put some photos up when I get this done.

thanks for the advice fellows!
 
zopperman

zopperman

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Re: Transom Repair 1979 Century 3000

island mike said:
Forget the samples man,If your stringers are rotten,More than likely your deck and transom are too..Start ripping!!
Click to expand...

More thank likely, yes, HOWEVER, I wouldn't nix the samples... I had a rotten deck, but fine stringers and a SOLID AND DRY transom.
 
8

84EdH

Chief Petty Officer
Joined
Apr 30, 2011
Messages
575
Re: Transom Repair 1979 Century 3000

Well I have removed the deck and foam exposing the rear wall of the transom all the way to the fiberglass floor of the boat. I have a photo showing the transom area and then a diagram (sorry it looks like homework!) trying to explain what I found. I totally expected to find one large piece of ply covering the transom area end to end. I did not. You can see from the diagram, there is a large center piece, then a smaller piece where it is doubled up (with the cutout for the transom mount), then two wings that go to the port and starboard corners. there is no wood, as shown in the outside lower corners.

Is this normal? I mean Century made good boats....its held strong for 32 years so I guess it works!

Now, the port side down by the floor is where the large single piece is rotted. This is the spot the stringer for the motor support ran into the transom. Can this be patched? or do I still need to rip out the 37x32" piece?
If the center piece is ripped out and replaced, It seems I could leave the intact "wings" alone.....agreement?

The other side of transom is dry and solid. Both the upper "wings" of the transom pieces are dry and solid.



you can see the verticle
line where the center piece
of the transom is separate
from the 12x22" piece .
these pieces were all
glassed over.
DSCN1892.jpg DSCN1902.jpg

starboard DSCN1893.jpg port DSCN1894.jpg


all advice appreciated....obviously this is all new to me...
 

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Woodonglass

Woodonglass

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Re: Transom Repair 1979 Century 3000

Here's my 2? worth...

(Click the Pic to Enlarge)

OutdriveTransom.jpg
 
8

84EdH

Chief Petty Officer
Joined
Apr 30, 2011
Messages
575
Re: Transom Repair 1979 Century 3000

I would love to know how to draw and print on the photos as you have......very clear!

The thickness should not be a problem as their is the fiberglass wall of the transom about 5/16" then one piece of 3/4" ply (the X area), then a smaller 3/4" plywood layer doubled around the transom cut out.

It would be pretty easy to cut a piece of plywood that would inclued the X area and the two lower wings. do you think that would add rigidity?


I am turning my attention to the stringers now. I drilled some test holes and the wood in the exposed area (cased in fiberglass, shown in the two photos) seems solid. There was an 8" piece of 2x4 out at the extreme sides of the boat that was not enclosed in fiberglass. I presume these were there to have a place for the plywood deck to anchor on the outsides. Have you seen construction like that before? I thought there would be one continues piece of 2x4 running the whole outside of the floor of the boat, but I guess not. Any thoughts on this?

I would love to see a schematic of the framing from Century on this boat.

thanks for your expertise, I appreciate it!
 
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