How to fix stripped threads in deck for genoa track?

Apr 19, 2020
64
Catalina 310 Kenosha, WI
On my C310, I noticed that one of the screws for the genoa track was sitting a little high and blocking movement of the car past that point. I tried tightening it, but it seems the threads in the deck are stripped. Any suggestions on how to repair it? Fill with marine epoxy maybe and then re-drill a pilot hole?

IMG_20200725_194354019_HDR.jpg


thanks
 

HMT2

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Mar 20, 2014
899
Hunter 31 828 Shoreacres, TX
I had to do something similar on a screw hole that held a bimini bracket. I drilled it out, used West System Epoxy thickened and put a wood plug in the drilled out hole, then added a little more thickened epoxy to level it out, then waited two days. Then drilled a pilot hole and put a new screw in. It’s held for four years.
 

RitSim

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Jan 29, 2018
406
Beneteau 411 Branford
On my C30 the screws went thru the deck and had cap nuts on the interior ceiling.
 
Feb 17, 2006
5,274
Lancer 27PS MCB Camp Pendleton KF6BL
That is what I would do. First expand the hole the next screw size, then fill with some type of material that will not expand when drying, and then re-drill. I would make sure that what ever fill I use, it is packed in there tightly.
 
Feb 26, 2004
22,760
Catalina 34 224 Maple Bay, BC, Canada
They are not screws, they are bolts with countersunk heads and are held down below by washers, nuts and cap (acorn) nuts. You should remove the protruding bolt, determine why it loosened, and rebed the hole to avoid water intrusion.
 
Last edited:
Apr 19, 2020
64
Catalina 310 Kenosha, WI
They are not screws, they are bolts and are held down below by washers, nuts and cap (acorn) nuts. You should remove the protruding bolt, determine why it loosened, and rebed the hole to avoid water intrusion.
Thanks for the heads up... I will look closer at this on the weekend. Those nuts must be on the back side of the ceiling mounted hand rail.
 
Jan 17, 2013
439
Catalina 310 St. Simons Island, GA
And what I learned recently is when you rebed those bolts, do not turn them from the top. Just hold them and turn the bolts underneath because you want your seal to be waterproof. We rebed about 7 of them last week and used polysulfide for this. Do not tighten all the way until your bedding material has a chance to cure, maybe overnight.
 
Apr 19, 2020
64
Catalina 310 Kenosha, WI
It turns out that there are no nuts under the deck holding the track down. My guess is that there is an embedded metal plate in that area of the deck that was threaded to receive the bolts and the one I'm having trouble with is stripped. I could drill through the deck completely, but the galley cabinet face with doors looks like it's right where the hole would come through. Can anyone confirm this?
IMG_20200821_105733496_HDR.jpg
 

rukidn

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Apr 23, 2012
160
Catalina 310 258 Sandusky, OH
There is indeed a tapped plate as Catalina placed in many areas. It would be best to remove the rail, repair the stripped hole (you may find more) and rebed. Timesert inserts would be a very robust thread repair. Timeserts are much stronger than helicoil.
 
Nov 18, 2010
2,441
Catalina 310 Hingham, MA
As Rukidn said there is a plate embedded in the deck. It's an aluminium plate. So likely someone tried to tighten it down and stripped the aluminum threads.

This is a somewhat difficult and labor intensive repair. Remove the rail, which may prove difficult as many of the machine screws may be seized and there is no good way to get penetrating oil on them. Look into a hammer actuated impact drive. This looks like a beefy screw driver that is made to rotate slightly when you hit it. Impact driver - Wikipedia

Once you get the track removed and cleaned up you will have to asses the damage to embedded plate. As Rukidn said look at the Timeshert inserts. Basically you would drill the plate out to a larger hole, tap it and then screw in the threaded insert. This will leave you with good, new threads that you can use to put the track back down. You may find you need to repair several of the spots.

Then bed the track with Butyl Tape following Mainesail's article. Because of the threaded plate this is not a perfect use of Butyl. You will need to use a Qtip with mineral spirits to soften the buytl at each machine screw. I find in this application it's easier to apply the butyl to the deck than the hardware. And then do a very small cone on the bottom of the track on each screw. You have to be very careful not to get the butyl on the threads or in the holes for the machine screws. The butyl will jam in the threads and seize the screw.

Make sure you put a little Tef-Gel in each hole first so you can remove the track in the future if needed.

Good luck. If you take some pictures during this it would make a great tech article for Mainsheet.

Jesse