Leaking motor mount bolt

H

haliman

New member
Hello all,
I was out on my 19’ Angler yesterday and noticed one of the bottom motor mount bolts is leaking. It is a very fine leak, the sun was hitting it just right and I saw a shine. Wiped it dry and a few minutes later it was there again. My thought is I will take the nut off and bolt out, clean everything up really good and then reseal. I will first look for any damage and hopefully there will be none. Should I reseal with 3M 4200 or 5200. I thought 5200 is what I should use but after reading some posts about resealing some people said 4200 would be good. I will do each bolt one by one just in case. Is this the right way to do it and if anybody has done this before, are there any unforeseen issues I should know about.

Thanks everybody!!!
 
Who rigged your boat? I'd check with them and make sure that, if you have a cored transom (and surely there's a core in there :roll: ) that they undercut and sealed those holes properly or you're in danger of soaking that core. If they did not, I'd spend the time and/or $ to remove the engine and do the job properly. If you don't know, you MIGHT be able to see when the offending bolt is removed but I'm not sure. For sure, use something other than 5200 when you reseal it or you may never get the bolt out again!
 
I am not sure who rigged it as I bought it used. Just talked to the factory and they recommended either boatlife ot sikaflex for sealant. Thanks for the reply!!
 
I doubt any (maybe a very few) dealers actually undercut the bolt holes and fill them with epoxy and then re-drill them out.

Too time-consuming!

Most probably use a flexible compound like the suggested Sikaflex or Boatlife to get it done quickly.

Time is money! :wink

Joe. :teeth :thup
 
A 2008 boat should have a foam core. But if it is leaking, I would seal it properly. If the factory says that they use Silkeflex or Boatlife, that must be what they use currently (not necessarily what was used in 2007 or 2008 when the boat was built)

Sikaflex 292 is a urethane similar to 5200. But there are a number of Sikaflex products--and they should have been specific as to which one they use.

Boatlife is a company name--and also have several products. Life Caulk is a polysulfide, and comes in several different forms (two part, pourable etc)

Boatlife also makes Boatlife Life Seal, which is a combination polyurethane and silicone--which is often used for plastics, like the hatches on the Lazarette.

Boat life also makes a silicone--which I would not consider using.

The best thing to do is as Charlie suggests--but most likely this was not done at the factory. I would do that--but your choice. I have not tested the amount of moisture this core will absorb. I would use one of the urethanes--probably 4200 after examining the core and repair.
 
I would remove the engine and then overdrill/undercut all of the mounting holes, fill them with thickened epoxy, and then re-drill the actual motor mount holes. Then when mounting the engine, I would use a good marine sealant (polyurethane, polyether, polysulfide, etc.).

So far I have re-done (or "done" anew) all the holes in my transom except the main engine mount holes. None were over-drilled/filled; all were filled with sealant only, many with just a bare trace of it at that. My boat had virtually no water time and was stored indoors, so I had dry core to start with -- but even at that, there was some damp core around the lower transom drain (which I removed). I shudder to think what it would have looked like if the boat had sat in the water. As soon as I have a chance to hoist the main engine, I'll do those holes as described above.

I'm especially particular with holes that are below the waterline.

Sunbeam
 
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