I did a pressure test on my Nacra 5.2 today because one of my hulls was taking on more water than usual. I found leaks around the inspection ports and a small crack in the dagger board slot at the bottom front seam. Could I just put some resin over that crack or should I use a small patch. The crack is about 1/2 to 3/4 inch and small bubbles where coming out. Also some tiny bubbles where coming out from
the port inspection cover ring base. what is the best sealent to use there?
-- 2016 Hobie Getaway
1978 Nacra 5.2
1978 Hobie 16 (back in the day) --
pictures would help us BUT... i just did the exact same repair to my mystere (leak at the base/seam of centerboard well) - fairly common
I dried the boat out very well, roughed up the corner/seam and 12" all around the area with 80 grit
mixed up some west systems epoxy, added a ton of fumed silica to the mix ans smeared it all around the crack and area.
then i laid wax paper over all the epoxy and worked it into my "wound"
smoothed it out with my hand and let it cure
Passed the "on the water" test
regular silicone should be fine here
if you can get it from the inside as well as the topside . it will be even better
You might get lucky & seal it via running a bead of any good quality silicone sealant around the ring base. Wipe everything clean with acetone to get decent adhesion. If it still leaks, bite the bullet, & do it right. remove the base, run a bead underneath & re-rivet...or if you are lucky, just re do the machine screws.
Here is one of the cheapest, & simplest ways.
Put ome soap in a wash bucket, & use a small mop. You cover a lot of area in a few minutes. Sparaying with a spritzer bottle can take quite a while. https://www.thebeachcats.…ictures?g2_itemId=118697
Grind out a bit of the crack, If you can access from inside, try to gring just without touching the gel cote. Make your grind "shallow", fair it outwards. Wipe it down with acetone to remove any grunge or grease. Then wipe some unthickened epoxy on, it will penetrate the crack. If you ground a little to far, tape some plastic sheet on the outside. That will make your patch conform. Cut a couple small pieces of cloth, tap the resin,
( thickened with micofibre to about ketchup consistency) into the cloth so it it totally wetted, & place it over the crack. If resin is dripping off, you have to much-tap another layer of cloth into the patch.
If you can, tilt the hull so gravity keeps the patch in place. Once it cures it will be stronger than the original.
Resin alone is not that strong. It's much like concrete, the strength is in the steel, the concrete is filler. With fibreglass, the strength is the cloth/additive. The resin makes it stiff & binds everything.
Coloidal silica is strong, but it's a bitch to sand/fair. For 90% of my fixes, I use microfibre additive,(West System 403).
Look here for advice. https://www.westsystem.com/the-105-system/
-- Hobie 18 Magnum
Dart 15
Mystere 6.0XL Sold Was a handful solo
Nacra 5.7
Nacra 5.0
Bombardier Invitation (Now officially DEAD)
Various other Dock cluttering WaterCrap --
Ed knows your boat better than I - his method may work better
my repair was on the very thin fiberglass "sheet"that fastens to the hull (centerboard well side bulkhead)
there is nothing but air behind this to grind into or glass on
my crack was probably from a rock that broke through ... i was making a hole patch more than a structural part
I didn't want to add glass for a few reasons:
i didn't want to change the profile of the base of my board well
I didn't want to place wet glass above my face while lying on the ground (no way i was taking my cat aprart and flipping the hulls to do this repair
I used heavily thickened epoxy so it wouldn't sag, and would be strong
I used wax paper to flatten it out and make it smooth so no sanding would be needed
(Wax paper is your friend to reduce sanding and fairing)
Yes, I remember my Mystere 6.0. I assume they were trying to save weight, & because it is not structural it can be very thin.
You made a good choice by thickening to the point where it wouldn't sag.
Wanderoo- as MN3 said, the straight epoxy has little strength, flex it a bit & you get a crack. The additives act like tiny strands, they get interwoven in a complex form, then the epoxy binds them together.
It's sort of like mixing pure cement powder. It's not that strong, but adding sand gives you grout, or mortar. add some aggregates, & you get concrete.
-- Hobie 18 Magnum
Dart 15
Mystere 6.0XL Sold Was a handful solo
Nacra 5.7
Nacra 5.0
Bombardier Invitation (Now officially DEAD)
Various other Dock cluttering WaterCrap --
What I found to repair a small leak in the dagger well of one of my 18's was to put thickened epoxy over the crack and then using a shop vac over the drain hole pulled a small vacuum on the hull. This helps to draw the epoxy into the crack. Not my idea just something that I read and tried with success.
-- Pete Knapp
Schodack landing,NY
Goodall Viper,AHPC Viper,Nacra I20 --
Do you have access to the crack from inside the hull? If you can get in there and put some glass on the crack, it will be 100 times stronger than trying to repair with thickened resin alone.