Gel coat damage on transom

[markhodges78]

So I pull my 200hp motor off to replace the mounts and trim pump on a 91 wellcraft boat I just purchased I reinstalled the motor on sunday ( using 3m 4200 ) just to find out that the trim wont go alway down so I had to remove motor again to remove the trim assembly but I only removed 1 of the transom mount brackets. well when I removed the bracket the 4200 pulled chunks of gel coat off all way to the glass in both bolt locations... My thoughts on repair is to just build the area up with some resin and sand smooth since it will be hidden by the mounts what are you guys thoughts...


Thanks Mark

 

[Scott Danforth]

Stand back and take pics of the whole transom. It may be a simple fix, however gel should not separate like that.

 

[dingbat]

In normal installation, only the bolt holes are sealed, typically with a silicon sealer

You effectively “glued” the motor to the transom with a medium strength (#300 per square inch) adhesive.

Obviously the 4200 has better adhesion than the gel coat.

Sand it down and apply gel coat.
Use silicon sealer only on the bolts and holes

 

[markhodges78]

Stand back and take pics of the whole transom. It may be a simple fix, however gel should not separate like that.

Ok I will get my son to send me a picture

 

[markhodges78]

In normal installation, only the bolt holes are sealed, typically with a silicon sealer

You effectively “glued” the motor to the transom with a medium strength (#300 per square inch) adhesive.

Obviously the 4200 has better adhesion than the gel coat.

Sand it down and apply gel coat.
Use silicon sealer only on the bolts and holes

Every thing I have read says no silicone ... use 3m 4200 I thought I was doing the right thing

 

[markhodges78]

 

[dingbat]

Every thing I have read says no silicone ...

On the internet I take it?....lol
Lots of people out there parroting w/o fully understanding the situation.

Not all silicons are equal. You have to use a silicon designed for use below the water line.

BoatLife's Life-Seal or Life-Caulk are a few

https://www.boatlife.com/wp-content/uploads/sites/2/2019/05/Sealant-Chart.pdf

 

[markhodges78]

Any Ideas for a repair

 

[Scott Danforth]

Any Ideas for a repair

The fiberglass has dark spots, so that needs to be checked for rot

If the transom is dry and rot free.....then sand the entire skin of the transom with 80 grit to clean off the dirt, grime and bottom paint.

Then, where the scars are, clean the area with 40 grit or coarser. mix up some thickened gell paste with a bit of waxand fill the scars.

Sand with 80 grit to smooth

Then spray your whole transom with gel.

Buff as needed

 

[markhodges78]

yeah the transom is solid and dry I even sealed from the inside and pulled a vacuum for days on each hole just to see if I could pull any moisture out and got nothing. now the boat spent its life in the water at a dock so I'm sure some moisture got in but the holes was dry....

 

[Scott Danforth]

yeah the transom is solid and dry I even sealed from the inside and pulled a vacuum for days on each hole just to see if I could pull any moisture out and got nothing. now the boat spent its life in the water at a dock so I'm sure some moisture got in but the holes was dry....

only way to test a transom is to test drill and look at shavings. light colored and dry is good, dark and damp is bad