• Welcome to the Checkmate Community Forums forums.

    You are currently viewing our boards as a guest which gives you limited access to view most discussions, articles and access to our other FREE features.
    By joining our free community you will be able to:

    » Interact with over 10,000 Checkmate Fanatics from around the world!
    » Post topics and messages
    » Post and view photos
    » Communicate privately with other members
    » Access our extensive gallery of old Checkmate brochures located in our Media Gallery
    » Browse the various pictures in our Checkmate photo gallery

    Registration is fast, simple and absolutely free so please, join our community today!

    If you have any problems with the registration process or your account login, please contact support by clicking here or by using the"contact us" link at the bottom of the page.

transom bolt sealant

1979checkmate

1979checkmate

Member
i'm about to put the motor back on to my trimate but i just have a question or two. What kind of sealant should i buy to seal around the mounting bolts? Also, there is a metal plate that goes on the transom between the motor and transom as well that the bolts pass through. SHould i apply sealant to the back of this plate as well? or would it be better to leave the plate unsealed so that in the event that water can get behind it through a gap in the sealant, it can at least still drain out the bottom?
 
remove the plate and clean any old sealant off the back and runs a large round bead of silicone around the bolt holes on both sides of the plate. u can use something like 4200 or boatlife marine silicone caulking.
 
Thanks!,
I have also heard of some people driling own the transome holes slightly larger and placing a pvc sleve inside with epoxy to seal the ends that way water cannot get to the wood in the transom? Anybody here try this?
 
5200

Most guys are afraid to use 5200 because of its strength, but if you absolutely want to seal and protect something its the way to go. Its advertised as a adhesive sealant and it works very well as such. I have been using 5200 since 1994 and you won't find a better product.
FYI: There is now a product to soften 5200 when you do want to remove it.
 
how about the 4200? I would go with the 5200 but i may experiment with using different bolt holes on the motor to lift it up some to find a sweet spot for the boat. While i'm on the subject how many holes up do you guys suggest to run a 115 tower on a trimate II?

EDIT: would the 3 oz tube be sufficient or would i need a cartridge? Sorry, first time putting a motor back on, lol/
 
This post should start a HUGE debate, the last motor I mounted I used two tubes of 100% silicone caulk. I had no leakes, but lots of dirty rags. With sillycone, you will be able to remove the motor in the future with out issue.

Soon I will be mounting a new Jackplate and regardless of what is posted here I will use silicone. But what do I know?? Most posters here have only read about it.
 
thanks for the input, i'm anxous to see other's reaction. For all i know there is no difference between regular 100 percent silicone as opposed to marine silicone. ANybody have any insight?
 
I used life-caulk on both of my boats now. Its made to go under the water line without problems. Silicone is not designed to go under water even tho its water proof:confused:. I think maybe after 25 years the silicone might fail but then again, not many people have their boats rigged the same for over 25+ years. All my boats when bought, had silicone on them and there was no problems with it failing. Then again all my boats did not sit in the water year round.

When I mounted the motor on the playmate, I drilled a 11/16" bevel on both sides of the hole. Just enough that I started the bolt into the 1/2" hole and caulked around it. This allowed a small "V" of caulk to seal the holes and bolts. I then caulked the inside and installed the fender washers and tightened the nuts down. I feel this is real well sealed, hopefully:thumb:
 
I used 3M 5200 adhesive sealant for the transom bolts on my Enforcer. I probably went overboard on the type sealant used, but I didn't want water ever getting in thru the bolt holes again. One transom resto is enough.:D
 
There are a lot of good sealants out there, but none better than 3M 5200.
 
I would suggest using a sealer that is FUEL PROOF! Sooner or later your outboard motor could leak some gas when it is tilted in the up position. Or you usually find out about a sticky carb float after gasoline has leaked all over your splashwell and transom. Gasoline quickly dissolves standard silicone, leaving your transom bolt holes vulnerable to water. I don't know if any of the 3M products are fuel resistant but some of the Permatex sealers are. Good luck with your project.
 
My current Eluder project is the second boat I've had to replace the transom in. From what I can tell both transoms got wet (and rotted) because silicone sealer failed for whatever reason. It appeared that it adhered better in some spots than others, maybe the surfaces weren't cleaned well enough before applying the sealer (that's just a guess though).

In any case why not use the best products available when you're sealing holes in your transom below the water line? Anything that won't get removed - 3M 5200. If you plan on removing a fastener at some point in the future - 3M 4200.
 
You must log in or register to reply here.
Back
Top