Cracked Fiberglass Near Transom

[Mack_attack28]

So, I think it was a bad idea to google this before asking on this forum. I also read a few threads on here, and none had the same issue as me. But, now i'm pretty freaked out. I guess it's similar to doing an internet search for your health problems... Anyway, I have some deep cracks to the gel coat that are fairly recent. They are about an inch long and are right where the engine bracket part of the transom meet the deck/ladder platform. This is on a 1996 272 Sailfish. My first thought is that the engines bouncing around on the trailer caused the stress on the transom. The four stroke engines are heavier than the two strokes that came with the boat. I have two cracked drain holes for the engine well that made me nervous that the whole transom was rotting out. I removed the brass (i think?) drains and probed the wood with a sharp pick and it was not mushy. I also tapped the entire transom and didn't notice and change in sound.

So, obviously these cracks are not good. But two questions: 1.) should I be concerned the whole transom is going to rip out of the boat due to the engine weight? 2.) would a transom saver that supports the lower unit on the engines and connects to the trailer prevent the bouncing and subsequent damage?

Some sort of flex happened, that cracked the outer fiberglass and I am trying to determine if this is a sure sign of a severe problem, or whether I can prevent it from getting worse by using a transom saver, and storing the boat with engines trimmed down. If anyone has experience with these cracks please give me your advise. Thanks for the help!

P. S. I removed the rub rail and caulking in the pictures so that I could see the actual fiberglass that was covered up.

 

[Harpoon]

So, what happens if a 200 lb guy stands on the cav plate of the motor an bounces his weight up & down? If you have a transom problem, you'll likely see/hear it when bouncing. Those 4 Strokes are a little heaver than the 2 strokes of the 90's. They may be stressing (even over the road) some areas where the gel coat is very thick, like inside corners etc. If you don't end up replacing the transom, those cracks will need chased and properly sealed up with 5200 to prevent water intrusion.

 

[Mack_attack28]

So I should put some weight on one of the engines and see if there are any noises or obvious movement?

 

[SmokyMtnGrady]

As I read Harpoons suggestion is you need to take a big dude or Amazon like lady and have them stand on the motor and bounce . You need dynamic forces to see if there is flexing going on. As I understand your reply it seems if you are suggesting just adding static weight.

I am not a mechanical engineer but you could have had an one time event where your trailer went over a large bump causing the motors to bounce severly and thus a crack. I am trying to be optimistic.

You could get a marine surveyor to run a moisture meter to rule out the wet transom. You could randomly drill tiny holes to spot test the wood. I think you need to make sure the the transom is set to rule it out completely. If it is dry and you have no flex after getting somebody to stand and bounce on the motor , chalk it up to age and maybe rough trailering. If it is the case repair the crack with gel coat and seal it up well.

 

[Harpoon]

Yes, give it some good bounces, watch and listen. Just because you have cracked gel coat doesn't necessarily mean your layup is delaminating from the core. However, if water gets in there and freezes/thaws things will get ugly. You can also pop an engine bolt out and see if the core is moist.

 

[Mack_attack28]

Ok, Ill stand on the cavitation plate (is that the correct word?) and bounce up and down. The thought kind of scares me, but i guess this shouldn't be too much since the engine weighs a lot already. Should i have the engine trimmed down or a little bit of an angle?

 

[family affair]

The thrust from the engines create load far higher than the engines could every create from bouncing down the road. Sorry to say, but if you have any movement back there, you have a problem that will need $$ thrown at it. Been there, done that.

 

[Tucker]

Those pics made be break out in a cold sweat. Please keep us posted with developments.

 

[Mack_attack28]

Sorry for the cold sweat! So, I used a leather mallet and thumped the entire transom. There are no hollow spots. I used a camera on the inside of the hull and all appears normal. I tilted the motors about 50% and had a friend put his full 220 pound on the lower unit and bounce it up and down. The transom has a very small (1/8 inch or less?) movement backwards. The cause for the crack is this: the cracking is on the deck/cap right where it meets the hull. Obviously they build the hull, then drop the deck onto it. Since fiberglass does not have any flexibility, when the transom flexes back an 1/8 inch it cracked the thin piece for fiberglass on the deck cap under the rub rail. So it seems that indeed under a lot of pressure torturing down on the motors, it flexes the top of the transom very slightly. Obviously no movement is good, but it doesn't seem like I have a rotten transom. Is there anyway to brace up the transom to prevent the movement? The easy answer is to say "have the transom rebuilt." That's my last resort as I do not see any real consequences yet, and the wood sounds ok.

 

[DennisG01]

What I see there worries me. From the pictures it appears to be more than just gelcoat that is cracked - it appears that it is the fiberglass, too. To answer your question about "band-aiding" this, as opposed to a full fix... I'll mention an idea and then you look to see if it will work for your boat. You could... Fiberglass a piece of wood/layers of ply/maybe even Coosa across the inside of the transom. It doesn't have to span the whole distance, but make it as long as you can. Glass it in as high up on the inside of the transom as you can. Then, run two aluminum angles from that new piece, forward to your stringers. Maybe 3' to 4' forward of the transom. In other words... "triangulation". With this, the stress of the engines is now transferred down to the stringers. This is a general concept that works - you may have to alter it to fit your bilge area.

 

[Mack_attack28]

I was kind of thinking something like that. Currently the engines sit on the transom which doesn't have any triangular joints. It doesn't take an engineer to know that right angles aren't the strongest, and this is right where the cracks have appeared.

 

[DennisG01]

I might even be inclined to add a "hypotenuse" :mrgreen: at each corner of the aft motor well... just left of where the port engine sits on the transom to the port side of the motor well (and starboard side as well). You'd want to reinforce the back side of the motor well sides, but that shouldn't be too hard.

 

[Mack_attack28]

That got geometric really quickly. I'm thinking like you said, run a support downward and forward at a 45 degree angle, through the thin fiberglass of the motorwell and tie it into the stringer on each side.this would basically help take the weight off of those pressure points.

Or just shore the transom with 45 degree angles under the engine well. Transom connected to stringers with glassed over wood. Aluminum brace may be easier. Only down side is that I'd have access ability issues under the deck.

Or maybe just get a transom saver for towing. Mark the cracks and see if they get bigger before getting extreme. I was hoping someone had experienced this or similar on their boat.

 

[Mack_attack28]

Actually the aluminum like Dennis said in your first post is basically the same idea.

 

[L.R.]

There should be No movement at all in the Transom,even with a 400 lb. Guy jumping on the Engines..

 

[DennisG01]

Or maybe just get a transom saver for towing. Mark the cracks and see if they get bigger before getting extreme. I was hoping someone had experienced this or similar on their boat.

Mack, I don't think this is something you want to try and take a chance on or wait to address. There is a real possibility that this can go from minor to major very quickly. The transom takes a real beating out of the water, too. And you don't want to find out what Mr. Murphy "legally" has to say about that when you're 30 miles off... if you know what I mean!

How much heavier are your F225's than what would have been on there in '98 (OX66's?)?

 

[Mack_attack28]

OX66 is about 540 pounds and the F225 is about 600 pounds. The boat is rated for a maximum of twin 225 HP so it's already at the limit and that was before grady knew that the four strokes would come out. I'm not sure an extra 120 pounds makes a difference, but technically it's more weight than the grady intended for the transom.

Since the engines are 2002s I assume they've been on there for 15 years now. Perhaps the largest engines plus 120 pounds over 15 years bouncing around on a trailer have finally started to crack the fiberglass right inside the notch on the transom. I just really do not think I'm dealing with a rotten transom. When I bought the boat I had ano inspection done (didn't want to pay for a full survey, but the guy is a surveyor) and he tapped the entire transom and deck and didn't hear anything alarming.

Let's assume there isn't any rotting, and the transom is solid. There shouldn't be any reason I can brace the transom with aluminum supports right? Maybe I'm missing something. Should I call grady white?

 

[gw204]

Get a second opinion from a well known surveyor in your area. Grady will most likely recommend that it be inspected/surveyed by a pro anyway.

If your first surveyor used a rubber/leather mallet to sound the transom, take his report with a grain of salt. That's not the right tool for the job. It needs to be tapped with the handle end of a big screw driver, the wooden handle of a hammer, a solid plastic mallet, etc. Something hard that won't muffle the sound. It should also be checked with a moisture meter.

 

[Harpoon]

If you can see the transom flexing 1/8" that is some considerable deflection. Visualize those engines lifting that boat out of the whole again and again, I'd suspect that the deflection will get worse. Eventually, the transom will likely crack all the way though and water will seep in. Slowly, then quickly (I've lived this).

I'd have this looked at by a good glass repair person. Perhaps some reinforcement will remedy the situation, or not. It's not the end of the world.

 

[DennisG01]

If you call Grady... think about it, what do you think a company is going to say? The only thing they can say is "get it checked out". Save the call. It would be better to take it to a reputable repair shop to get it checked thoroughly. Even rot aside (which, honestly, I haven't even been worrying about), it doesn't look good. Like I started to mention, this can go from minor to a MAJOR catastrophe in a real hurry. Shoring it up could be just what it needs - but you really need to get it checked by a pro IN PERSON. I can't speak for anyone else, but there's only so much that can be done via a forum.