Sealing up the transome after mounting jack plate?

[ndaniels]

Allright, I'm installing a 8" detwiller jack plate (the on the water model) and am wondering about the proper way to seal the transom. I have my 3m 4200 sealant and was wondering about where to apply? Around the washers, bolts and backside of the plate? Any placed in the transom bolt holes themselves? This is my first time removing and resealing anything on the transome. Hope everything is dry!!

 

[groucho]

Everybody has their own technique and opinion. I have always made sure to liberally coat any bolt and washer that goes through the transom with sealer/silicone. You are basically trying to keep any water from getting into the core. Putting it on the backside of the plate won't hurt anything but you really aren't sealing much either. Same with the nuts. Just creates a mess.

I've never had a bad transom as a result of this method. At least in the first 15-20 years of the boat's life.. Didn't keep them all that long. Mortality for other reasons. After that well maybe it was the boat that might have went to seed??

 

[wizard8575]

the instructions for my plate say to put a circle of sealant around each bolts hole.

 

[boatman4021]

You should always put some on the transom around each hole so that when the bolts pull it together, it will squeeze in around the bolts. It is much easier to clean off some excess before it dries than to pull it back apart and redo the job. Too much is good, not enough is bad.lol boatman

 

[ndaniels]

Good deal: I pulled the bolts out and everything looks dry and in good shape. I'll have to wait on bolts to show up, but got the top two in transome and motor so I could move it to pack wheel bearings. Everything looks like it'll work out real good- I had to grind a little on the top corners of my top washer plate and backside of jackplate to clear screws for the aluminum transom plates. Tommorow- wheel bearings, seals, wp gauge, and the scoops for the lower unit. Thanks for the help!!

 

[175checkmate]

I would not recommend using the 4200. I took a plate off a boat that used this. Pulled the jell coat off when we had to pry the plate off. Simple bath and tub caulk works great. A bit in the bolts holes, followed by a 360 deg circle around the bolt hole and install the plate.

 

[ndaniels]

I would not recommend using the 4200. I took a plate off a boat that used this. Pulled the jell coat off when we had to pry the plate off. Simple bath and tub caulk works great. A bit in the bolts holes, followed by a 360 deg circle around the bolt hole and install the plate.

I was rethinking the 4200, because it was sealed with clear caulk and that seemed to work fine. I think I'll try the tub caulk.

 

[groucho]

I don't know why 4200 would have done that? It's designed as a sealant FOR marine applications. It's a non-hardenening sealer that cures and allows for dis-assembly so I doubt that was 4200 was really on there in the first place. Some other brand??

I've seen it used on virtually everything around boats as a good all-around, almost all purpose sealant since it was introduced by 3M ( no I'm not getting paid by them either) and I've never heard of or seen a problem w/it.

I certainly wouldn't use a bath sealant in a marine application if I had a choice. Better to then use a marine grade silicone then instead. It's designed for the stress and give that this sealant will need.

 

[LAAllison]

Sealant

Ditto to what groucho said. 4200 is the right stuff. It's not a silicone and doesn't harden. Your Mate isn't a bathtub.


Art


Roll Tide

 

[daren34]

if the 4200 or 5200 won't release hit it with a heat gun or bad a$$ hair dryer and it will soften right up

daren

 

[jallen355]

It was more likely 5200 than 4200. 4200 is suppose to allow dis-assembly as groucho said. I have heard of 5200 defacing transoms before, however. I'll let ya know how 4200 comes apart in the coming weeks as I will be removing my jack plate that I installed this past fall using a good bit of 4200.

 

[ndaniels]

Well 4200 it is, then. I already have a tube of it sitting here, might as well use it!

 

[175checkmate]

Now that i have thought about it, I believe it was the 5200. Learned my lesson on that stuff.