Leaky boat!!

[Sean]

My boat (16 ft aluminium) has a small leak in it somewhere, so small i cant find it ???. Is the only way to find it to fill it with water, and is this ok structurally for the boat (and the enviroment in this dry time!). also with an underfloor fuel tank will this pose a prob when welding it? :o :o thanks guys.

[Kerry]

That is one way that can find leaks BUT be very careful with how much water you put in it and also consider just what else might get affected with water that normally should be on the outside not the inside.

What do you define as a "small leak"?

First I would check the bungs (both the fitting and the bung itself) as these can have a habit of developing a leak.

Cheers, Kerry.

[Lucky_Phill]

Kerry is right, and let's not forget the mounting bracket for a transducer. check all areas that have external attachments to the hull.

Then slowly fill with water.

Cheers Phill

[stilltryin]

makes it easier if you use a food colouring dye in the water, but don't leave it in, some will stain

[Sean]

Thanks for all the tips guys i will see to it, any ideas on the welding with fuel??

[adrian]

pending on where the leak is will have a say on the matter . i've had some welding done with 1/2 a tank of fuel on board and the boat and myself are still here to be safe drain the fuel out first.

anzac

[harrya64]

Hi
If you do drain the fuel out ! What about the fuel vapores just as bad as fuel it self, maybe more so
Be very carefull

[harrya64]

Can someone tell me
The under floor fuel tank in a Ally Boat are they a seperate Tank from the boat skin it self?
Just Interested
Harry

[Jewmaster]

If you drain the tank fill it with co2, pump the exhuast from your car into the fuel tank before welding and it will choke the oxygen out of the tank so it can't explode. Make sure you worry about your electrical equipment while they are wleding, It may get fried if it is still connected.

[Graham_N_Roberts]

Hi Sean,

As Kerry said, check the bungs first. As for filling her up with water, I reckon that would put a hell of a strain on the hull, apart from needing a heck of a lot of water. They're designed to keep water out, not in.

As a welder, I've welded quite a few tinnies (let's forget the brands), and I'd say with confidence that if the bungs are intact, check the keel for cracks. Use a spray on stain available from engineering supplies. The only other likely area would be the stern.

You don't say if you will weld it yourself. ::) Unless you have a TIG welder and aluminium rods, or can realy handle an aluminium wire fed MIG, get a workshop to do the job. I've had to repair a hull that a well meaning owner tried to weld with a stainless steel electrode. :'( Instead of a small crack to weld, we had to cut and shut a patch.

But wich ever way you decide to have it welded .... :o remove the fuel tank please. I have seen the results of a professionally cleaned (and certified clean) fuel tank expolde. ;) So, the shot time it would take to remove it, will ensue you still have a boat.

Hope you get back on the water ... cheers. :D

[aido]

my old 5.3 mtr savage was always leaking, the bottom sheets would crack
right next to the keel beam extrusion weld. i always thought welding aluminium required carefull heat treating to avoid fatigue cracking. typically cracks right next to the weld bead.
when i got more than a few bucketloads after a trip, i'd get worried. pounding
hulls in the ruff stuff is the culpret i reacon.
i shopped around for a welder, some wanted the boat stripped and inverted to do a good job. impractical for a half cab tinny.
i doubt the bottom/keel forms part of the tank structure on any of our boats.

give john dexter engineering a call when you need to weld.
he used to do my crack repairs (boat on trailer) and i was more than happy with the price/quality. he's over at cleveland boating services if thats your area.

[Sean]

Thanks for all the help guys, good news is, ive found the split, i'm still not sure about how to go about the welding. How hard is it to remove the tank and how much can i expect to be charged for the weld. Also a welder I know recommended 'marine sikaflex' or liquid alluminium, any thoughts?

[freddo]

hey i'm fred i have a leak in my aluminium boat and we just use kneadit aluminium opoxy $12 that u can get from your hardware or go to a plumming place and get some ferropre epoxy $30