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CharlieCobra · 30-08-2011, 08:21

As you know, we just finished the Hunter 54. On inspection,found about six feet of the the 300+ Lbs owner side deck flexing under his weight, not good. Faced with the mess and expense of core replacement on a boat with no money left in it, I decided to try a trick this same owner suggested for sopt wet core repairs. I mean, why the hell not right?

The fix is something he used some 20 years ago and the boat's still good. So, I went out and bought a manual greasegun, System 3 "Silvertip" Laminating Epoxy (which I really like after using it) and some grease zerts.

Arianna or Arie as she likes to be called, (my new assistant), and I, loaded up the cart and went on deck to puzzle this out. I started with two rows of holes drilled to the bottom of the core, which was wet, and inserted the zerts (grease nipples). This was problematic as the damned things didn't wanna go in so with judicious use of a hammer and a socket, we got them in. Drilling the holes 3" apart turned out to be way too close as the epoxy started pouring out of adjacent holes immediately on pumping.

After doing those first holes, I settled on a square pattern with holes in the corners, about 6-8" apart and one in the center. This worked well and each hole took 10-15 pumps before epoxy started flowing out of adjacent holes. Another problem with the zerts is that they pull out of the holes 99% of the time when you attempt to pull the gun off. If you don't leave the gun on for at least 30 seconds for the pressure to dissipate, you're rewarded with an instant backflow of most of the epoxy you just injected.

You can tell that it's working as you move to new holes when epoxy starts flowing from the holes you left again and also from holes you haven't yet injected.

Word to the wise, do not open the gun to check it because it's getting hot. The 200F catalyzing epoxy under pressure will burn the piss out of your hands no matter the thickness of your gloves. Thankfully, Arie was quick to yank them off of me before I got scalded. Very sharp and observant Lass that Arie.

So, we continued to drill holes and inject epoxy along that 18"X72" section. BTW, if you have a break in the bottom skin, you WILL find it or at least the epoxy will. This is a very messy procedure so make sure you have an entire box of good, thick gloves, a large bag of rags and a gallon or two of DeNatured Alcohol.

It took about three hours to finish the job and we left it to cure. he next day, we sent our own 300 pounder up to walk the decks. wow! It actually works! Just a bit of fairing and deck paint and it's DONE! Sweet!

Apparently the key here is hydraulic pressure which gets the epoxy into and through the wet core. You can see water being displaced as you pump epoxy in. The System 3 Laminating apparently cures just fine in wet core.

**knottybuoyz** · 30-08-2011, 08:42

Interesting technique Charlie. I once saw a fella using a vacuum pump to dry the core before he basically infused epoxy into a soft core. It worked but a few spots caved in a bit from the vacuum. I've done a few small spot infusions myself and it works well if you have the right equipment.

webejammin · 30-08-2011, 08:44

Seams like you would want to get rid of the water that is in the deck before you put the epoxy in otherwise you will always have water in the deck. I wonder is acatone injected into the deck would evaporate the moisture before adding the epoxy?

Jetexas · 30-08-2011, 08:54

Any chance you have photos of this procedure?

CharlieCobra · 30-08-2011, 08:55

Dunno, might make a nice bomb...

CharlieCobra · 30-08-2011, 08:55

Quote:

Originally Posted by Jetexas

Any chance you have photos of this procedure?

Nope, didn't have a cam with me.

Cheechako · 30-08-2011, 09:12

Interesting. I guess as a low cost fix , even with the moisture in there it works. It's a typical way to fix delaminated cored hulls. Saw a 44 footer with about 300 3/8 holes drilled in the topsides once. The boat was only cored to the waterline. The core wasnt wet but the glass was separated from the core in a lot of places. (Built prior to vacuum bagging came about) The yard injected resin with a pump on the lower holes until it came out a couple of feet up. Big job but fixed it well I guess after a good paint job.

**minaret** · 30-08-2011, 09:19

I've done it this way quite a few times when clients insisted because there was no cash left for a proper repair. Usually we dry it out with the hotvac first, or inject acetone and then vacuum. The big problem is that you usually find a route to the inside of the boat, and it's easy to ruin a headliner this way. I drill the holes far apart first and put vacuum on them. If I suck air through the deck with the vacuum I know that the resin is going to find it's way in, and I start looking for stuff to tape up inside. I like WEST slightly thickened and injected with a very large syringe, less mess than the grease gun, disposable, and still plenty of pressure. Often I find a void in the core that would take many gallons to fill, usually running along the outboard edge of the side deck where the core hits solid glass. If this happens you generally have to drill a hole where the void is and fill with thickened, letting it kick before continuing to make a dam. Otherwise you end up pumping five gallons of epoxy into it and its not so cheap anymore. Generally we refuse to do this anymore, and certainly won't warranty it like we do a proper core repair.

**Jim Cate** · 30-08-2011, 09:24

Nice job, CC.

Once did a sorta similar thing with a deck that had separated from its dry balsa core, but used a caulking gun for pressure (not nearly as much pressure). Worked fairly well, but had a bad side effect: Apparently I had drilled a bit deep on at least one hole, for shortly afterwards I discovered an overhead light fixture in the galley (below the repair area) that was full of cured epoxy. This lead to the discovery that a wiring conduit was similarly full... not easily dealt with!

So, if you try such a technique, be careful when you drill the holes!

Cheers,

Jim

David_Old_Jersey · 30-08-2011, 09:36

Always a fine line between innovative solution and a bodge.

For me the decider is usually whether I did it

, or someone else

Nateman · 30-08-2011, 09:38

Man! I hope the next owner of that boat never see's this thread!!! LOL

Great temp fix, but holy hell will it be hard to fix properly down the road!

Gotta do whatcha gotta do sometimes I suppose...

Charlie · 30-08-2011, 09:39

I have a similar problem on my boat but it does not have a cored deck. There are slight bubbles where the deck lifted. This is very helpful but I have a question: 1)Is there any need to place something heavy on top of the repair?