Transom cracking

[reveregrady]

Hi all,

I have a 81 Grady white seafarer 24. I’ve owned the boat 3 years. Last season I noticed transom cracking, gradually it got worse. I’ve inspected by tapping around transom with hammer, all sounds came back hard and dense. Also, I’ve had a 200lb friend jump on outboard with it trimmed up. Very little flex. Since then I’ve removed my etec 200 o/b and have removed all items like transducers, no water leakage. Transom was “supposedly” replaced 3 years before my ownership, making it a 6 year old transom. I’ll take the previous owners word as he was an older gentlemen and the original owner from 1981. In areas where cracking occurred, “new” glass was sticking out as if not enough resin was used. I’d like to grind back cracks and re-glass with 1 layer of Matt, 1 layer of 1708 biaxial, then 2 more layers of Matt. I’d like recommendations/ advice from somebody with experience. Thanks in advance.

 

[SkunkBoat]

definitely looks like the transom was done and its cracking along the repair seam.

You can't run like that. You have nothing to lose to strip the paint FIRST, then grind with 60 grit to get a look at it.
(Point is, don't grind the paint deep into the glass)

Maybe the new transom wood is good and they didn't finish the job well....maybe they didn't know what they were doing.

Check the inside also... for glass coming away from the wood.

If you redo it, use EPOXY.

 

[reveregrady]

definitely looks like the transom was done and its cracking along the repair seam.

You can't run like that. You have nothing to lose to strip the paint FIRST, then grind with 60 grit to get a look at it.
(Point is, don't grind the paint deep into the glass)

Maybe the new transom wood is good and they didn't finish the job well....maybe they didn't know what they were doing.

Check the inside also... for glass coming away from the wood.

If you redo it, use EPOXY.

Thanks for your response. I intend on stripping it down. Hopefully everything underneath is in good condition and I can reglass.

 

[DennisG01]

When they glued the transom skin back on, they didn't grind the seam a few inches on eash side and lay in glass to bridge the repair gap. In other words, the repair seam was a weak point. I think you'd be fine (assuming no core damage, of course) with doing just that - grind, lay in new glass and fair.

 

[seasick]

I agree that there probably was a repair and it has failed. What worries me is that if the outside skin delaminated, it shouldn't sound 'solid' as you said. Of course that depends on your skill at tapping the transom. Assuming you tapped correctly and it sounds solid, it looks like the repair may have delaminated from the inside skin. In any case, you probably will need to recore and glass. It is possible also that the core is not delaminated but moisture got into the surrounding areas of the repair and froze in the winter.

 

[Fishtales]

Investigate the core. If there are cracks likely water got in and your core is wet. I agree with the glass overlap. I’d want 3 inches if possible. Your prob looking at a complete rebuild.

 

[reveregrady]

I agree that there probably was a repair and it has failed. What worries me is that if the outside skin delaminated, it shouldn't sound 'solid' as you said. Of course that depends on your skill at tapping the transom. Assuming you tapped correctly and it sounds solid, it looks like the repair may have delaminated from the inside skin. In any case, you probably will need to recore and glass. It is possible also that the core is not delaminated but moisture got into the surrounding areas of the repair and froze in the winter.

Thanks for your input. I uploaded a video of the tapping to YouTube, please let me know what you think. https://youtube.com/shorts/O40yUmhjeoA?feature=share

 

[seasick]

A large metal faced hammer like that is not the optimal tool but can be used . Best is a leather faced small hammer ( may be hard to find) or a small plastic faced hammer. You are also hammering harder than you need to. The method is tapping, not hammering..
In your video, the bottom edge you tested is the edge of the hull and that is solid fiberglass layup. It should sound solid. The tapping you did above the crack sounds different to me as does one spot along the edge. Try tapping again, a little less forceful and go up the transom from the bottom up and see if the sounds are more like thuds or are hollow sounding. Try tapping one tap at a time as you move about 2 or 3 inches away from the spot. Try some vertical lines and some horizontal lines.With the age of that hull, I would expect some changes in the sounds. If possible try some tapping on the inside too.

 

[reveregrady]

A large metal faced hammer like that is not the optimal tool but can be used . Best is a leather faced small hammer ( may be hard to find) or a small plastic faced hammer. You are also hammering harder than you need to. The method is tapping, not hammering..
In your video, the bottom edge you tested is the edge of the hull and that is solid fiberglass layup. It should sound solid. The tapping you did above the crack sounds different to me as does one spot along the edge. Try tapping again, a little less forceful and go up the transom from the bottom up and see if the sounds are more like thuds or are hollow sounding. Try tapping one tap at a time as you move about 2 or 3 inches away from the spot. Try some vertical lines and some horizontal lines.With the age of that hull, I would expect some changes in the sounds. If possible try some tapping on the inside too.

Thank you for your time and your response. I will facilitate your recommendations and recheck. Hopefully when I grind it back the core is in good condition and transom can be repaired. Thanks again.

 

[reveregrady]

Just wanted to update everyone… sanded all paint and fairing compound off. Ground area of crack down with grinder, tapering area on both sides. Core seems to be dry and in good shape. Seems the tech that replaced the transom did a poor job tapering the glass work existing to new. Thanks everyone.

 

[SkunkBoat]

Fairing compound was the weak point.
If you aren't worried about asthetics, just glass another large overlapping layer of 1708 over the seam with epoxy and DON"T use fairing.
Paint it and go fishing.

transom looks low. Is that a 20" transom?

 

[reveregrady]

Fairing compound was the weak point.
If you aren't worried about asthetics, just glass another large overlapping layer of 1708 over the seam with epoxy and DON"T use fairing.
Paint it and go fishing.

transom looks low. Is that a 20" transom?

Yes, I’m happy. Thanks for your help. 25 in transom.

 

[reveregrady]

Crack ground down

 

[reveregrady]

Upper crack. Ground down, found 3 pieces of plywood in core. One piece was separated from the rest at top of transom. Cleaned out, filled with west system epoxy. Clamped end to end.

 

[gw204]

Hate to tell you this but there is no way I would trust any part of that transom.

• The seam at the bottom wasn't glassed properly. Assume all the other seams are inadequate as well.
• With a crack that severe, there's no way the core isn't wet.
• Whomever did that just bonded the original skin back on. This is fine if it's in good shape. Your's is not. It looks to me like there's cracking along the bottom edge where the engine mounts.

Rip all that out and start over.

 

[HookUp]

Are there any tubes in those motor well drains? Looks like the brass ones are gone.

 

[seasick]

A plywood to plywood piece should not rely on a resin glue up only. The better approach is to use a layer or multiple layers of fiberglass between the plywood. That does two main things; It allows small pockets to be better sealed and more importantly it adds strength and rigidity to the connection. Plain epoxy is very brittle and can crack if stressed. fiberglass cloth is not strong until it is wetted with epoxy and cures.
The strength of the layup is dependent om layering of fiberglass cloth across surfaces that you want to act as one strong piece.
Just opening the cracks and injecting adhesive or epoxy will not produce as strong a structure as overlapping layers of glass cloth and resin will.
Your approach may hold up for a while but the bottom line is that the original repair seems to have been poor quality