My Macgregor 26D has a shoebox deck hull joint. It was never bonded or sealed from the factory. Simply through bolted and a small bead of sealant run on the outside of the overlap joint. I want to add a sealant to bond the two, or even use an adhesive. The problem is I do not know how clean I can get the joint to get a proper adhesion. At the bow there is no gap between the two but a couple feet back from the bow to the steam its easily able to separate the two to get a sealant in-between. I have seen threads on using 5200 or the like, but I know prep work is key. And they is the issue as i don't know how clean I can get it or how clean it needs to be. I have a oscillation tool with a "finger sander" attachment that should help. I am certain i can get it 75-80% clean. I doubt this will be clean enough. So is there a better sealant/adhesive to use on a dirty joint?
Sealant for a dirty deck hull joint
- Thread starter kendyoozed
- Start date
In my research I found that Methyl Methacrylate (MMA) may be just what I am looking for BUT, they are expensive!
When I did mine I used an oscillating tool with a rasp to clean out the old sealant. The old sealant was mostly very dry and brittle so it came out fairly easily. I then blew it out the best I could and sealed it back up with 3M 5200 and bolted it down. This is one of the rare places on a boat I would use 5200.
I’m thinking since there was no sealant that I should use 5200. But leave a 3/16 gap then once the sealant sets I can crank down the through bolts to provide a better seal.
That's pretty much what I did. I used UHMW spacers to keep the gap, mostly around 1/4" ~ 3/8". I posted the details here:
Resealing the Hull to Deck Joint
I've had this boat for a year now. I knew there were some rain leaks but I didn't know where. The previous owner thought the large saloon windows leaked and he had this crack seal stuff he would apply now and then. I've never seen that stuff work so I started removing and rebedding the windows...
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