Fixing leaks....

Thread starter #1
I found some leaks on my boat, The first is at the tip of the bow under the aluminum edging. Can I bust broadly apply some gloop or do I need the take the edging off? What sort of gloop is recommended. The second leak is from under the splash guard. How do i get that thing off or can I just apply some gloop to the entire guard edges? How do you get the rivets off? Once off what do you replace them with? Also,,I have a small 1 inch ding in the guard edge. Will marine tex work for that? Also,,, Also....on the very bottom of the boat the white is rubbed off at the centerline. Is that anything to worry about?Thank you.Thank you. :confused:


Member Emeritus
Hi Damien,

(Assuming older aluminum edge, not newer rolled edge w/rubber edge guard) Take the edging off and do the leak test again. Find the exact point of the seam leak.

Assuming the seam is delaminated where the leak is, tip the boat on it's side and prop it up in a manner that will allow resin to run into the seam, spread the seam open _slightly_ with a putty knife or small screwdriver, mix some polyester resin according to the instructions and run it into the edge seam. Wrap waxed paper over the repair area and clamp the seam with several spring clamps while the resin sets up.
Leak test again - all ok?
Reinstall the edging. For a "How To" on the trim see:

Splash Guard - install an inspection port - See:
Drill out the rivets, remove the guard, check for a cracked deck - fix if needed.
Reinstalling guard - lay down a bead of marine silicone calk - run the calk in a small circle around each rivet hole, attach guard while the calk is still wet. Fasten with new "Pop rivets"** and use aluminum backing washers on the inside of the hull. Do another leak test - all ok?

** Pop Rivets or Blind Rivets and the tool to install them can be found at most marine supply stores and hardware stores like ACE. Take an old rivet for size comparison. Get new rivets long enough to go through the guard, hull and backing washer + 1/4".

Riveit Tool $25,
Rivets $5,
Washers $2,
Silicone $6

I don't know about dings in the aluminum - epoxy such as Marine Tex as a filler - sure? (again, assuming older aluminum edge, not newer rubber edge guard)

Gelcoat rubbed off the bottom - see:
or give the area a coat of marine bottom paint
Go to the various paint manufacturer web sites for instructions on how to apply their specific brand of paint - they are all a little different.
If the fiberglass isn't scratched to the point where water can get into the glass cloth - just smooth green - no worries. Fibers exposed - fill deep gouges with resin+milled fibers and then gelcoat or paint.

This is just a quick outline of the repairs. Before you start you need to do your homework about the materials you are going to work with. Whole books have been written on fiberglass repair and there isn't enough space nor do I have the time to write another here. If you aren't familiar with the materials and methods, I strongly advise you make your first trip one to the book store. Plan out your repair steps and have all the necessary tools on hand before you embark. Do one repair at a time.


One thing to add to Waynes ecellent advise. West Marine has several cheap books on fiberglass and boat repair. Well worth the money even for someone that's used fiberglass and epoxy before.
Thread starter #4
Thank you all for all the info. FREE FLORIDA VACATION WITH USE OF SUNFISH TO ANYONE THAT COMES TO HELP ME WITH THIS!. I hope I did not bite off more than I can chew. I am not terribly handy. Any input on the frozen gooseneck? Also, the bottom of the hull "bounces" off the bottom off the cockpit on one side only. Could one shoot some foam in there? From where? Regards. Damien in Estero, Fl.


Member Emeritus

> Any input on the frozen gooseneck?

Hmmm..., where's it frozen?

If it won't swivel try "WD-40" or "Break Free". Add a few drops to the pivot and let it sit for a day then add a couple of more and let it sit again. On day 3 try working the two rings a little at a time - mild pressure in one direction and then the other. It will eventually free up. Thereafter apply a lubricant like BullShot bicycle chain lube once a month. I suggest BullShot because it has the unique property of going on as a liquid, but it dries to a waxy film that is less greasy/runny than oil or grease lubricants. One or two drops is all you need - any more makes a mess.... and keep all lubes (except sailkote) away from your sail !
You could also use dry lubes like silicone, teflon, or that secret stuff called Mc Lube SAILKOTE.

Read the warnings on anything you buy - be sure they are compatable with the materials your boat is made of - fiberglass, nylon, and polyester (Dacron)

If, on the other hand, you are attempting to _remove_ the pivot bolt that holds the gooseneck rings together, be aware that the end of the threads has been intentionally squashed out-of-round. This was done at the factory as a way to prevent the bolt from coming out should it ever loosen while you are sailing. Removing this bolt usually requires loosening it enough to get room to hacksaw off the head -or- unscrewing it using Vise-grips. Either way the bolt is trash when you are done.

Most people usually only do the latter if they are installing one of the new adjustable goosenecks.

> Could one shoot some foam in there? From where?

One could. I've tried this and it works - sorta. I have used "Great Stuff" insulation foam in this application. The problem is it doesn't have good structural properties. After a year or so it breaks down from flexing and the cockpit floor looses adhesion again. I know there is a two part foam that is mixed and poured. I've only used this variety in big spaces where getting it in wasn't an issue. Maybe that type of foam has better strength.

To get Great Stuff foam into the hull space -

The cockpit "tub" was originally attached to the hull by four 6" diameter spots of fiberglass resin (aprox.) I'm assuming two things have happened, (1) an attachment spot has broken free, and (2) the hull has softened from use and is now flexing at this spot. The gap between cockpit bottom and hull is almost nill so all that's really needed is to reattach the tub. Great Stuff has good adhesive properties as anyone who's worked with it will attest to.

To get the "Stuff" into the hull, flip the boat over and press on the hull to determine where the loose spot is.

Return the boat to its full upright position and very very carefully drill three 1/8" diameter holes in a 6" triangle in the cockpit floor above where the hull is flexing. Drill only through the cockpit floor (about 3/16") - NOT clean through the hull. Now drill a hole in the center of the triangle that fits the nozzle tube of the Great Stuff can snuggly.

Put masking tape over each of the 4 holes and punch through the tape at each hole - clean back the tape in the holes. Tape pieces of waxed paper to these tape strips covering the cockpit floor and side(s) within a foot of your triangle.

Following the preparation instructions on the Great Stuff can, insert the nozzle tube into the center triangle hole and slowly squirt in foam until it pushes out the other three holes. STOP squirting.

Remove the tube and leave it all alone until the foam is set up.

Once the foam is set (24 hrs as I recall) remove the waxed paper and tape and excess foam blobs. Using your drill bits (but not in the drill) clean out the 4 holes to the depth of the cockpit tub. Plug each hole with gelcoat putty to match the color -or- marine tex or other epoxy putty. Let set then sand lightly to match the cockpit surface.

Go Sailing

One word of caution on using any expandable foam in a marine application. Make sure it is CLOSED CELL foam. Open cell foam that is commonly use in household insulation products like it's name says has openings all through it like a sponge. It can and will suck up any moisture that gets into the hull just like a sponge.
The moisture that gets in it is just as hard to remove as any that gets in the blocks built into the hull.


Member Emeritus
Fortunately "Great Stuff" is a closed cell foam as is the two part mix-and-pour stuff sold by West Marine.

I'm not aware of an open cell foam. Mike, what brands have you run into so I can watch out for them?

Wayne, most of the insulating foams sold at big box hardware stores designed to plug holes and around cracks in houses are of the open celled variety. Good choice on using the marine version. Most folks just go to the "hardware store" to get it.
the rim i would judge on its condition. if its in good condition keep it, if its broken ext i would replace it. also it depends on your budget. the trim comes in 5 ft sections ($20) at and the rivets ($5 a pack 13 to a pack) you need are there too
hope that helps