Bottom hull filling with water

norgold

Member
I was given an old laser and now found out that it's made in two parts - the top (cockpit) and bottom (hull). How was the cockpit edge sealed into the hull? There is nothing there now (I can actually move the cockpit out of the hull a little). Water is obviously going in through this gap, coming into the cockpit through the bailer. After 30 minutes of sailing there's enough water in the hull to take 10 minutes to empty through the back plug.
Will using a silicone caulk (like for bathtub edge) seal the joint?
 
I don't know what they used to seal that joint originally. I'd suggest either 3M 5200 sealant, or even an epoxy, to seal it up. Bathtub caulk would probably work for a while, but you also want + need real structural adhesion - - sticking it together. The hull and the deck will flex as the boat moves thru the water + carries big loads from the mast, daggerboard, rudder, hiking straps. You want those 2 pieces well + truly stuck together, rather than just sealing the water out. Also all that flexing will rip the bathtub caulk out again in short order.

Whatever you use, you'll do well to put some time into really cleaning out old sealant, loose debris, + etc from the joint and the joining surfaces, so that whatever you use, really sticks well to the real solid fiberglass, instead of some surface junk that'll come right off.

Another thing worth checking on old Lasers is the mast tube. On many or most old boats it's a weak point, and has
1) already broken + was repaired,
2) was reinforced before it broke + is now OK, or
3) has NOT been reinforced yet and hasn't broken yet either.

If your boat is #3, you DEFINITELY will save a whole lot of time to do the reinforcement before it breaks, rather than the repair after it breaks. There's a whole bunch of threads on this forum about how to go about that.

Good luck + have fun.
 
I don't know what they used to seal that joint originally. I'd suggest either 3M 5200 sealant, or even an epoxy, to seal it up. Bathtub caulk would probably work for a while, but you also want + need real structural adhesion - - sticking it together. The hull and the deck will flex as the boat moves thru the water + carries big loads from the mast, daggerboard, rudder, hiking straps. You want those 2 pieces well + truly stuck together, rather than just sealing the water out. Also all that flexing will rip the bathtub caulk out again in short order.

Whatever you use, you'll do well to put some time into really cleaning out old sealant, loose debris, + etc from the joint and the joining surfaces, so that whatever you use, really sticks well to the real solid fiberglass, instead of some surface junk that'll come right off.

Another thing worth checking on old Lasers is the mast tube. On many or most old boats it's a weak point, and has
1) already broken + was repaired,
2) was reinforced before it broke + is now OK, or
3) has NOT been reinforced yet and hasn't broken yet either.

If your boat is #3, you DEFINITELY will save a whole lot of time to do the reinforcement before it breaks, rather than the repair after it breaks. There's a whole bunch of threads on this forum about how to go about that.

Good luck + have fun.
Thanks for the reply. Two questions: When doing this work what's better or easier: boat right-side up or upside-down?
2nd: What is the mast tube? My mast is sitting on a steel plate.
 
1) right-side up or upside-down for working on the rail:
I have not done this with my boat so I'm guessing, but my guess is that I'd probably start with the boat on it's side to clean the joint out - scrape a little, blow a little with compressed air if you have it, or maybe bellows or a blow in a tube yourself. I'd surely wear eye protection for the blowing part. Then I think it's turn it upside down before applying the epoxy / sealant, so gravity works it deeper in there.

2) the mast tube is that tube that goes down into the deck where you stick the mast. The steel plate you're talking about is at the bottom of the mast tube, if it's what I'm thinking. The usual way it breaks, is that the bottom of the tube breaks free from the bottom of the hull, inside of the hull. Then of course the mast falls over, while it's still stuck thru the deck. Here's a picture of the mast tube INSIDE my hull, after I fixed mine after it broke -
fixed- inside bottom.JPG

Here's the bottom of the mast tube, where it broke away from the bottom inside of the hull -
04 mast step, bottom of tube.JPG

and here's what the mast did to the deck, after the tube detached from the bottom and the mast fell over:
03 deck closer.JPG

So it's probably / hopefully pretty clear why it's a whole lot easier to cut a hole in the deck + reinforce that joint down at the bottom of the tube, than to "see if it breaks" and then have to fix the deck and all that other stuff WHEN it breaks.

I don't know how old your boat is. Mine's early 70's and I've heard that the tube-to-hull joint is weak in boats older than early 90's ... maybe some others with more accurate info will chime in here. One thing that helps to test it, is to pour water into the mast tube, and see if the water level stays or if it drains down. If it drains down, that's a very strong indication that the joint at the bottom is compromised. Honestly if it were me (but it's not), if I bought another old boat, even if the mast tube held water, I'd open her up + reinforce that joint - - just cuz so many of them have broke, and it was such a hard job to fix the deck, and reinforcing before it breaks is SO much easier.

If you search on this forum you'll find tons of posts about this - where to cut an inspection hole, how to reinforce it, sealing the hole back up with an inspection port or just closing up the deck with glass, etc etc etc.
 
Norgold, I second cskudder's advice about pre-failure reinforcing of the mast tube!

One of my old Lasers had extensive separation between hull and deck. I found it easy to do this repair with the boat upside down. Use a Dremel or Rotozip type of tool to thoroughly clean all loose or damaged old adhesive out. A shop vac will hep to remove the debris. I used polyester resin to make the repair, mostly because I had lots of it on hand and that has worked fine. Many people will say it that epoxy is better and that may be. I'm sure that one of the West System products will be ideal for this. The nice thing is that this repair is easy to do.
 
Here's what I mean by steel plate:
And the sail number 3466. What year is this?
IMG_3357.JPG
IMG_3356.JPG
 

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Norgold, now that we know your boat is a Laser 2 you can disregard the advice about the mast tube! (Some Lasers have a metal disk in the bottom of the mast tube - that's what I thought you meant.)

In fact, I have no idea if the advice about re-attaching the deck to the hull is applicable to your boat either.
 
The hull is filling with water, but now I know that it's RAINWATER. How and where is it getting in when the boat is not even in the water? Through the bailer? Last time I checked it was a lot of water. How can so much water get into the hull when the boat is on dry land, rightside up?
 

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