'79 H30 Keel Stub

[jwitczak]

Hi all,

Sometimes its better not to look ...

In a 'below-the-waterline' overhaul project I found a dark spot in the fibreglass just above the keel joint, aft. Since the grinder was having a busy day elsewhere anyway, I took a bit off to see if it was superficial or ??? The small black spot opened up to reveal unsound fibreglass/resin at the spot with lots of embedded air pockets. Same running forward on the keel joint a bit. The black spot turned out to be wet dark brownish 'gunk'. The resin that was there was hard, albeit filled with air pockets, I did not recognize any actual glass at the location - but I'm not so experienced I can really tell what I'm looking at.

I had assumed that the construction in the bilge would be solid or at least built up on something, but looking into the hole there are pockets that extend easily 4" or more in some directions. The black 'gunk' was in a small pocket at the opening (maybe a 3/4" cube in total) - it in no way filled the spaces inside that I could tell.

Does anybody know how the construction 'should' look? At the very least, I want to fill in the unsound glasswork - either by grinding and re-glassing or filling and fairing. Maybe try to clean and dry out the void areas and fill? Or would you drop the keel and dig deeper (I really don't want to consider that!)? Keel bolts are torqued and look in good condition (in the bilge anyway). To the best of my knowledge, the keel seems soundly attached at this point. Any thoughts, opinions, help appreciated.

Jeff
'79 H30

 

[whatfiero]

keel stub

yea dry it out and fill with glass then seal with e paint it's expensive but where you grind-ed down to the glass (past the gelcoat ) ya need to get sealed back up if that keel is steel ya need to seal with e-paint as well

 

[H33CRich]

not sure what e paint really means, but I think you mean Interlux Interprotect 2000 E; 2 part epoxy barrier coat. Good stuff...

 

[jrowan]

Wow that's a big hole. I would use West Systems epoxy that can be applied via a caulk gun to apply epoxy into the rear of that void first and build it up with several layers of epoxy. You will need to insert some type of fiberglass roving / webbing into the repair area to give the epoxy something to bond to, otherwise it may oose out of the hole before it sets up, and the roving will increase the strength of the repair. I have also used the Interlux barrier coating with good results, but it is only a paint & very thin. Applying a full layer of epoxy over all areas where the fiberglass is ground down is needed. Good luck.

 

[ggrizzard]

Hunter built the stub that way to allow the owner to
smuggle their gold out of the country!

 

[jwitczak]

Thank you for the reply's. Looks like I'll be cleaning out, rough filling and reglassing. Maybe I'm just desensitized by this point, but it makes perfect sense that the voids were for 'extra storage' ;-) -- thx for the laugh.

The plan all along was to put a couple layers of IP 2000E to reseal the gelcoat after fairing out the keel joint, just figured I'd get the entire hull cleaned up so hopefully just have to do it once - that's when I found this defect. I've already cleaned up a bunch of blisters, a crack, and some superficial gelcoat scratches, scrapes, etc.

Thanks again for the feedback.

Jeff

 

[kloudie1]

No experience here, but it surely does look like a hollow "fairing cap" that was glassed to the aft of the keel stub for streamlining.. doesn't look like it has a structural purpose.. Ya might want to think about filling with some closed cell foam or epoxy fluffed up with microbaloons, then shaping and glassing over the outside to make symmetrical and fair.. If ya decide to epoxy fill, you'll have to do it in 4-5 pours to keep from having a temperature problem as the stuff kicks off.

 

[DianaOfBurlington]

Repair of damp-glass spots

Whoa.

Jeff, that needs to be stuffed with 'glass, not just filler. Start by cutting a few smallish ovoid pieces to fill it up; then grind them fair and 'glass over with lighter stuff, like plain mat. Anything thick like ProMat or biax will work to fill it. Roll it out to the utmost of your ability and do not allow any air bubbles.

The best filler to add to this layup (not used alone) would be milled fibers. It doesn't sand well, but it's the closest easy-to-apply filler that is structurally and chemically similar to what the boat's already made of. For this, avoid any filler without fiber to it.

For this, also avoid Smith's or any wood-saturation epoxy. I might consider Gougeons' for its adhering and holding properties; but matching the repair material to the boat's material as closely as possible is really the best course here.

Consider using vinylester resin as it will not soak up water in future (it costs about 150% or more of what regular resin costs. You may use a quart of it here). The more you replace old material with vinylester, the less water-saturation breakdown will be a problem. This is one way to essentially 'save' an old boat and assure it years to come with hassle-free maintenance.

Whatever you do, don't use 'boatyard'-grade resin (the purple stuff like at WM). Get the real production (green) stuff from a builder; or invest in vinylester. Needless to say it should not have added wax. Also use the correct MEKP hardener at an honest 2%, maybe more like 3%. Never skimp on underwater repairs.

Of course this all starts after you dry it out. Once you have ground it all clear, don't worry about filling it at all till it's had the season to dry. Leave it open for this winter so it has plenty of time to weep free. Applying heat or air from a fan will help accelerate this-- whenever you are at the boat or able to ensure it's being looked-after, have a fan hooked up and running. Use the prevailing weather as well. And keep rain/snow/ice out of it by taping a shroud over (but not sealing) it.

Also-- don't touch it with bare fingers! This uncured/broken-down gook can be a hotbed of bacteria that does weird and very damaging things to your skin and beyond. We had a guy get nearly deathly ill from scratching an elbow on raw 'glass inside a saturated boat from the tropics. (I am not exaggerating.) Use gloves and eye gear.

I agree with Rich about using Interprotect; it's essentially a 'replacement gelcoat' and will do the trick permanently. Consider also Pettit Protect, which goes on thicker so it requires fewer coats. Both need at least 10-12 mils' thickness to work; and, if you can't apply bottom paint within 3 days of that, apply 2-3 extra sacrificial coats that can be lost when you have to sand it prior to painting. Without assuring yourself 10-12 mils of finished under-the-paint barrier coating, don't waste the money on the stuff & go with gelcoat instead.

Above all, don't sweat this, Jeff. It only looks terrible. It's actually a quite common problem for boats of this vintage (a client, Jerry, is stripping the whole bottom of his C44 right next to my boat; I just did mine myself) and all it takes is the work itself. You'll probably find this is a very easy fix (2 weekends) if you delay till late spring (whenever 'glass and resin will kick off in your area, when it's over 60-65 degrees all day). You'll be sailing by April or May, no worries.

Keep us apprised of your progress!