heard transom crack

marvin the minnow

Petty Officer 3rd Class
Joined
Jun 16, 2010
Messages
85
I was tightening down my motor mount bolts today and made a newbie mistake of over tightening and heard a crack. not sure if the wood cracked inside or if it was just the gelcoat cracking. all the old timers out at the boat launch have told me i have a solid transom for a 33 year old boat. i hope i didnt cause structural damage.
 

Monterey10

Petty Officer 2nd Class
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Apr 13, 2007
Messages
194
Re: heard transom crack

There is some flex to transoms. However, the gel coat wont flex. Look for cracks in the gel coat.
 

marvin the minnow

Petty Officer 3rd Class
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Jun 16, 2010
Messages
85
Re: heard transom crack

I backed the nuts off a little bit but there is a little bit of bow at the motor mounts on the outside of the transom.
 

Bob_VT

Moderator & Unofficial iBoats Historian
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May 19, 2001
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26,019
Re: heard transom crack

I backed the nuts off a little bit but there is a little bit of bow at the motor mounts on the outside of the transom.

Explain?

Did you also use large ss fender washer's and sealant?
 

seabob4

Lieutenant Commander
Joined
Jun 10, 2008
Messages
1,603
Re: heard transom crack

You cracked the gelcoat at the mounting holes. As long as you used a good polyurethane adhesive/sealant, you'll be fine.

But there will be others that say...
1lg021thumbsdown.gif
 

marvin the minnow

Petty Officer 3rd Class
Joined
Jun 16, 2010
Messages
85
Re: heard transom crack

You cracked the gelcoat at the mounting holes. As long as you used a good polyurethane adhesive/sealant, you'll be fine.

But there will be others that say...
1lg021thumbsdown.gif

I used big SS fender washers and sealed the area with silicone. Im planning on having a guy replace the transom in the winter before i do any cosmetic restore work.
 

marvin the minnow

Petty Officer 3rd Class
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Jun 16, 2010
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85
Re: heard transom crack

I take that back... i didnt use fender washers on the outside because the motor mount uses a carriage bolt which does not allow for a fender washer...
 

Bob_VT

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Re: heard transom crack

No.... fender washer's just on the inside ;)

Carriage bolts ?? You really should use a good SS 1/2" bolt.....
and in the future....never use silicone on a boat ;) Seabob mentioned it you should have use polyurethane sealant and yes you heard the surface cracking.
 

marvin the minnow

Petty Officer 3rd Class
Joined
Jun 16, 2010
Messages
85
Re: heard transom crack

No.... fender washer's just on the inside ;)

Carriage bolts ?? You really should use a good SS 1/2" bolt.....
and in the future....never use silicone on a boat ;) Seabob mentioned it you should have use polyurethane sealant and yes you heard the surface cracking.
I was using a SS 1/2" bolt but it didnt seem like it was correct. the SS carriage bolts allow the head to stay in place while inside the boat tightening the nut... I guess ill have to pull everything and strt over with the correct hardware and sealant...
 

smokeonthewater

Fleet Admiral
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Dec 3, 2009
Messages
9,838
Re: heard transom crack

the 1/2" carriage bolts will be fine for a season if they fit properly and if you are replacing the transom after this season don't sweat the silicone either.... just use 5200 in the future I would also switch to hex bolts then too as they are MUCH easier to work with if the threads seize than carriage bolts
 

seabob4

Lieutenant Commander
Joined
Jun 10, 2008
Messages
1,603
Re: heard transom crack

Install the top bolts (hex heads) with the head on the outside of the transom. You can reach both the bolt and the nut from there. Install the bottom bolts, hex heads also, with the bolt heads on the inside of the transom. That way, if you have to move the motor up or down, it's a lot easier to put a pair of vise-grips on the the lower bolt heads, back them off a little bit, and re-position the motor.

BTW, that's exactly how I have installed thousands of O/Bs. Vise grips on the bolt heads on the lower mounts, impact on the nuts...for the last 16 years...by myself.
 

5150abf

Vice Admiral
Joined
Aug 12, 2007
Messages
5,808
Re: heard transom crack

You should be able to stand on the motor without the transom moving more than 1/8'' if it moves more than that it is on its way out.

Unless you weigh 300lbs it should take your weight without moving.
 
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