Installing an outboard motor

[climb29028]

Hi everyone. I have a question regarding mounting an outboard motor. Would it be a good idea to coat the inside of the holes that have been drilled into the transom to mount the motor with Marine Tex before the bolts go through the holes? It just worries me that the Sikafex (or whatever sealer they use) is not enough to keep all water out from seeping into your transom. At least if you have Marine Tex sealing the wood inside the holes it will prevent rot from happening if water get's through the Sikaflex? What are your thoughts on this? Thanks.

 

[dozerII]

I always coat the inside of the holes completely with either the Sikaflex or 3M 4200 to seal the wood then install the bolt.

 

[smokeonthewater]

I always remove any silicone and seal with 5200 inside outside etc.

 

[gm280]

I have a little different idea I'm going to try. I am presently rebuilding my boat project and installed a tough and new transom. And my plan is to drill the engine mounting bolt holes a good size bigger then the bolt size and then fill in the holes with Peanut Butter (which is made with polyester resin, Cabisol, and 1/4" milled glass mixture) to seal those holes back up again. Then after they cures and is hard as a rock, I redrill to the correct size again and install the bolts with a good sealer and install the OB. So any water that could possibly seep in would never ever get to the actual wood in the transom ever. And that will keep that new transom from rotting again... A little extra work, but will allow years more of a rot free transom wear. And I plan to do that same thing with ever screw, bolt or fastener that will go into the transom. So while that takes more effort, it will hopefully keep the new transom rot free.... JMHO!

 

[ondarvr]

I have a little different idea I'm going to try. I am presently rebuilding my boat project and installed a tough and new transom. And my plan is to drill the engine mounting bolt holes a good size bigger then the bolt size and then fill in the holes with Peanut Butter (which is made with polyester resin, Cabisol, and 1/4" milled glass mixture) to seal those holes back up again. Then after they cures and is hard as a rock, I redrill to the correct size again and install the bolts with a good sealer and install the OB. So any water that could possibly seep in would never ever get to the actual wood in the transom ever. And that will keep that new transom from rotting again... A little extra work, but will allow years more of a rot free transom wear. And I plan to do that same thing with ever screw, bolt or fastener that will go into the transom. So while that takes more effort, it will hopefully keep the new transom rot free.... JMHO!

This method is used with epoxy, polyester isn't as strong and doesn't hold well in this type of application.