My daysailer has a screw loose and I don't want to lose the centerboard

[rcairflyer]

New sailboat owner here!
On a Hunter 170, there are four screws securing the centerboard retaining bracket. This bracket is on the bottom of the hull. One is missing its head. [See attached.]
Considering the function, I want another screw there. It's below water and I really don't want water infiltration. I don't think removing the bad screw is a viable idea, so I'd add another alongside. My plan would be to drill a pilot hole through the bracket and into the hull, then drill a clearance hole in the bracket. What would you do next? Force marine sealant in, then drive the screw? I was thinking to use 3M 4200. Any other suggestions? Have you got any tricks for forcing goop into a hole?

Added thoughts:
The centerboard is in a pocket, and if there's wood, or any reinforcement behind this bracket, I expect that it is all around. So driving another screw along side should be a pretty reasonable thing to do, and certainly beat trying to replace the busted screw.

I thought about backing the other screws out to determine their size, but I don't want them to break either. OTOH, a little test might be a great idea. And if they break, break and replace them one at a time. Don't break the remaining 3 in one go and have the counterweighted centerboard drop on my face.

 

[rgranger]

I think I’d try to remove the other three bolts so I could get a good look at what the condition of the substrate under that bracket. Like you said.... you don’t know if there is a wood core or if it is solid fiberglass. I doubt there is a wood core but if there is you might have more repairs to make that just a screw .

With the bracket out, there might be enough of the broken bolt’s shank exposed for you to grab it with some vice-grips and back it out. Some PB Blaster and time may be required... Make any necessary repairs and then put it all back together.

 

[shemandr]

If you're going to try to remove the three screws you probably should remove as much of the paint on them as possible. Use heat, paint remover, scrapping and incantations. Then the PB, time, and the exact right screwdriver. My guess is that at least one other will break.
I liked plan A, myself.

 

[jssailem]

Welcome to the SBO Forum. Congrats on acquiring your new to you boat.

Looking at the image, I concur you need to get a 4th screw into that bracket.

I survive by fixing things right the first time and avoid taking shortcut steps. Then I tend to hold on to my toys for longer than most others.

Is this boat going to be sitting in the water all the time? Sitting in the water it is likely that the screw corroded enough to break off. Water, being water, likely invaded the hole and further into the boat's hull substrata than is normal. The screws used may have been of a cheaper metal.

SHORT CUT: Perhaps you can squirt "goo" into the holes and hope for the best. It might last for 6months ... a year... til you sell the boat to some other unsuspecting new owner.

Or you can take the other 3 screws out. Drill or fish out the remaining screw end. Fix any damage under the plate. Put epoxy into the screw holes and then redrill holes to fresh seat the new screws you will use to fix the platte to the bottom. Then go sailing knowing that you have properly secured the centerboard and that your boat is sound. It will take you places and bring you safely home.

Plan that the center board may fall out. Use a block or line to hold the center board in place so it does not fall out on your head.

 

[rcairflyer]

Welcome to the SBO Forum. Congrats on acquiring your new to you boat.

Looking at the image, I concur you need to get a 4th screw into that bracket.

I survive by fixing things right the first time and avoid taking shortcut steps. Then I tend to hold on to my toys for longer than most others.

Is this boat going to be sitting in the water all the time? Sitting in the water it is likely that the screw corroded enough to break off. Water, being water, likely invaded the hole and further into the boat's hull substrata than is normal. The screws used may have been of a cheaper metal.

SHORT CUT: Perhaps you can squirt "goo" into the holes and hope for the best. It might last for 6months ... a year... til you sell the boat to some other unsuspecting new owner.

Or you can take the other 3 screws out. Drill or fish out the remaining screw end. Fix any damage under the plate. Put epoxy into the screw holes and then redrill holes to fresh seat the new screws you will use to fix the platte to the bottom. Then go sailing knowing that you have properly secured the centerboard and that your boat is sound. It will take you places and bring you safely home.

Plan that the center board may fall out. Use a block or line to hold the center board in place so it does not fall out on your head.

Thanks. 2 screw heads look beat up. I'll have to clean off the paint pretty well before trying to remove them. I'm thinking about additional screws alongside 3 others.

 

[rcairflyer]

If you're going to try to remove the three screws you probably should remove as much of the paint on them as possible. Use heat, paint remover, scrapping and incantations. Then the PB, time, and the exact right screwdriver. My guess is that at least one other will break.
I liked plan A, myself.

Thanks. I like the cleanup advice. I went with plan A. I'm confident the sealant is in place.
The bracket lifted nicely in the one corner, so I'm really happy to have added that screw.

 

[rcairflyer]

I think I’d try to remove the other three bolts so I could get a good look at what the condition of the substrate under that bracket. Like you said.... you don’t know if there is a wood core or if it is solid fiberglass. I doubt there is a wood core but if there is you might have more repairs to make that just a screw .

With the bracket out, there might be enough of the broken bolt’s shank exposed for you to grab it with some vice-grips and back it out. Some PB Blaster and time may be required... Make any necessary repairs and then put it all back together.

Thanks for the thoughts, but after a closer look, I see the bracket is thin... about as thick as a joist hanger. There won't be much to grab.
When I installed a new screw, I added sealant to the vacant hole, and forced sealant into the new hole.

 

[rgranger]

Okay
If you decide to ever back those screws out another trick I’ve had to use in the past is to take a dremel and cut a new slot in the screw head for a wide (larger) screw driver head