Sealing bolt holes in transom

[MRichardson]

How do you guys go about sealing the thru-hull holes for the transom? I just re-installed a transom, squirted 5200 into the holes, screwed the bolt thru the hole and put on the washers/nuts.. Still have some leaks. Should I have gone around each hole with a bead of 5200 first? Is there a trick that works better than that?

 

[krawler]

Put some into the hole and around the top of the bolt/screw and on the threads, so when you tighten it down there is goop squishing out from under the bolt/screw head. Then just use a paper towel to wipe off the excess and make it look clean. I do this on both the inside and out to make sure that it is sealed but most important on the outside.

One other note, if the hole is a lot bigger than the screw, then make sure to use washers on both sides.

 

[cva34]

You talking motor mount holes..If so most use 4200 its like silicone..Or Marine Goop.or Quality Silicone ....5200 is considered Permanant..Something that is not to be removed..Hope i'm on right track....cva34

 

[Iverson_4x4]

I haven't seen it done yet, I'm not sure why either. I am going to us the 3M 5200 to fill the bolt hole first, and on the outside washer I am going to use a rubber washer. This will allow the rubber washer to expand and create an air tight bond as you tighten the bolt. I picked my rubber washers up at Lowes.

 

[nomowork]

Did you let it cure properly. I let my 5200 and even my fast dry 4200 sit for almost a week before it even touches water.

 

[sr71]

Did you let it cure properly. I let my 5200 and even my fast dry 4200 sit for almost a week before it even touches water.

x2....also, I used nylon washers which would expand slightly to seal and eliminate contact between ss bolt and aluminum to prevent corrosion (if the rubber "breaks" or ages it might separate and you will have a loose connection leak). Just my 2cents.....

 

[Iverson_4x4]

x2....also, I used nylon washers which would expand slightly to seal and eliminate contact between ss bolt and aluminum to prevent corrosion (if the rubber "breaks" or ages it might separate and you will have a loose connection leak). Just my 2cents.....[/quote]

To be honest... I didn't think about that! Rubber usually doesn't fair too well with gas either... Thanks for the tip on the nylon washers! Luckily I am just at the stage where I am putting the bolts back into the transom... Going to go pick up some nylon washers this afternoon!

 

[MRichardson]

Thanks everyone. I will be taking it apart this weekend and employing the techniques mentioned, including nylon washers and generally being a lot more liberal with the goop this time around. Then I'll let it sit for a week.

 

[MRichardson]

Wow, thanks for the advice guys.

I used copious 5200, coupled w/nylon washers and let it cure for a week and a half. When I put it in the H20, not one single drop came in after fishing and running it for 4 hrs or so. It's never been this dry.