Inspecting for hull leaks

Matt Miller has suggested the best way to check for leaks is with air and soapy water. This shows how quick and easy it is and where to look.

Equipment:
--vacuum with hose
--soapy water with brush
--cardboard cut-out
--tape

Procedure:
1. Cut a cardboard large enough to cover one of your hatches with a hole to accommodate your vacuum hose. Precision is not critical.

2. Open a convenient hatch and tape your cardboard over the opening. No need for it to be air tight -- this requires very little pressurization.

3. Insert one end of your hose into the outlet side of the vacuum to provide a source of air and the other through the cardboard. Tape over any large gaps. Don't worry about blowing your hull up.

4. With your vacuum exhaust blowing air into the hull, liberally paint soapy water over any suspected leak area.

Here is what the set-up may look like:


Areas that will normally leak are rudder lines, rudder handles, large hatch and non-gasketed hatches (ex: 5" screw-in hatch)

Areas that should not leak but are easy to correct (or live with) are gasketed hatches (ex: Twist and Stow) and their mounting surfaces.

Stressed areas to check as a precaution:
-- front nose of drivewell
-- cam lock areas on either side of drivewell
-- scupper cart holes
-- seat peg recesses
-- rudder mount area
-- any place that looks seriously cut, scraped, or abraded

Any leak should be easy to spot!




It's pretty hard for leaks to hide using this technique. The idea of filling your hull with water, by comparison, is slow, inefficient, poor at pinpointing leaks near the top surface and potentially stressful to the hull.

Hobie has made several improvements to minimize water entry in '07 and '08 with redesigned cable routing, cable entry points, cable tube seals and rudder controls. Still, my wife no longer stores her paperback books in the hold without some sort of bag (especially in active water).

With your left over soapy water you can finish cleaning your boat!

See also checkika' post on KFS at:

http://kfs.infopop.cc/eve/forums?a=tpc& ... 5331077794

I'd rather discuss leaks here then on KFS.

Let's see if we can find the most frequent causes, particularly for heavy water.

Roadrunner.

My dealer used the drain plug. Easier setup.

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I use the kayak drain hole and a piece of drip irrigation hose stuffed in the vacuum hose with a rag around it and a piece of duct tape. With the Adventure, the front hatch acts as a release for any excess exhaust. Soapy water and a sponge makes quick work of finding any leaks.

Kayaking Bob

I've been getting too much water in.

Ran the bubble test.

Found three places I would not have considered. Probably part of the "many holes" theory.

First is the plug for the old up down handle. Even though I had gooped the hole when I put the plug in, it leaked. The little molded pocket*** for the handle collects any water coming in. Pulled it and cleaned off all the old goop. Re-inserted. This time made sure there was enough goop to even fill the hollow side channels.

One screw on a pocket net was leaking. Removed and gooped. It appeared that during initial inserting the hole had been stripped, maybe tightening of screw during assembly?

A hole I had filled in when I misdrilled stbd outside pulley hole was leaking as was one of the bolts holding the pulley. Gooped.

While doing the test the fwd hatch was bubbling. It should have as that's where the pressure is released. But holding it down with slight pressure stopped it.

After test figured it wouldn't hurt to tighten up bungie cord which does get slack overtime. If you think your fwd hatch is leaking you might try this. Here's a pic of how I did it very quickly using two plastic ties.



although no bubbles, I again removed twist and close center and rear hatch gaskets, wiped everything clean, sprayed with silicone and replaced. I have this dwn to about two minutes per hatch. Goes into regular maintenacne procedure.

Yak still leaks at least a pint or two under rough water conditions.

The dealer thinks the main culprit is the rudder lines. SO for the second time :

ATTN HOBIE ENGINEERS!! MATT PLEASE RELAY!

Use a OC-1 method for the rudder lines. Lead the tubes OUT at the rudder hand location. This means the line fitting is outside the hull.

The only reason for being inside is to protect it. Mount it outside and just cover it with a small cover that has a half circle or less exposed rearward where the lines can be attached (call me if you don't understand). This stops any leakage!!

Also the upper portion of the cover can be ridged so the handle can now be locked in at specific angles . Another subject I've discussed on KFS. But kill two birds with one stone!


[***That pocket and the rear cup holder are where the rod holders should be relocated IMHO. At least Hobie could sacrifice a leaking hull that's turned in to test such the geometry of these locations with a rigged mainsheet..][/u]

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Reconlon's irrigation tube in the drain hole is a great way to do this. Here's a modified version that needs no taping and virtually plugs in. It also uses baffles and a sliding tube to regulate air pressure for those boats without lift-off front hatches (like the Classic and Sport):



The 1/2" low pressure drip irrigation tube (black) twists directly into the boat's drain (with plug removed), or with a 1/2" drip connector (shown below) you can even leave the plug in but unscrewed.


The other end of this tube slips into 1/2" class 315 (thin wall) PVC pipe (white). I drilled about 16 - 1/4" holes to vent excess pressure at this point. By sliding the black tube in and out, pressure can be regulated by covering some of the vent holes.

The PVC fits snugly into an adapter (1/2" x 3/4" in this case) to fit loosely into the vacuum hose. The Duct tape shown bulks it up for a snug friction fit.

You can keep your Hobie Leak Testing Trombone with your vacuum accessories. For someone who has multiple hulls or does periodic testing like reconlon, this should save some time.

All parts are commonly available and can be found at hardware stores like Home Depot. There are alternate ways to rig this set-up also without having to buy large quantities of material -- I just had this on hand.