What's the best way to identify leaks?

Swell · 16 September 2011, 10:48

I have a Hypalon inflatable boat from the 80’s, so it’s getting on a bit, but the Hypalon is generally in good shape. I’ve fixed a couple of obvious leaks but both tubes are still losing air, albeit very slowly. I’m struggling to identify where from though, and I suspect it might be seams.

What are the most likely areas for leaks?

Is there an easier way to identify leaks other than by listening for air escaping, which is what I’ve been able to do so far?

It’s a Metzeler Juca by the way.

willk · 16 September 2011, 10:56

Use a liquid detergent (e.g. hand dishwashing detergent or similar) mixed about 25/75 with water and carefully paint it over the whole boat, section by section, paying particular attention to seams, floor joins and valves. Small leaks may only become apparent some time after you have passed over them when the micro bubbles begin to build up. Doing this on a "soft" day can help as it keeps the boat wet for longer.

If you have a lot of small leaks, then an internal tube sealant may be the best option for you.

Swell · 16 September 2011, 11:05

That sounds like an effective method. I’ll give it a go.

I’ve read mixed opinions about internal sealants e.g. using ‘green slime’ which is sold as a tyre internal sealant, but it sounds like a great solution for the whole boat if there are quite a few very small leaks.

Is there a particular product which is known to work well?

willk · 16 September 2011, 11:18

Quote:

Originally Posted by Swell

Is there a particular product which is known to work well?

You should try a search on here - I dunno.

The detergent works very well - but you need to be thorough, obviously...

Nasher · 16 September 2011, 11:39

I use a washing up liquid/water solution in a hand spray to cover the tubes.

large leaks will show up with just the spray, but small leaks will need a wipe over with a sponge or cloth whilst carefully looking for bubbles.

Which sealant to use, if you go down that route, will depend on whether you keep the boat inflated or rolled up.

Nasher.

Swell · 16 September 2011, 12:33

It is a big if as it depends on how 'sieve-like' the boat is after the leak checks. The boat would definitely be kept deflated - does an internal sealant need the boat to be kept inflated of vice versa?

S4Simon · 16 September 2011, 13:13

Cheap hand pressure sprayer is the way to go as mentioned Fill with a generous squirt of detergent and then water. Pump and go. Easiest and surefire way.

tinker · 16 September 2011, 15:56

Think Slime is water soluble, so a not a good idea for a boat. I used the Polymarine stuff and it worked a treat on my air deck, just kept it inflated and rotated every now and again.

On the leaks, have you checked the valves? They nearly always leak in my experience, washing up liquid and water does the trick to test for the leaks.

Swell · 16 September 2011, 17:41

Quote:

Originally Posted by tinker

Think Slime is water soluble, so a not a good idea for a boat. I used the Polymarine stuff and it worked a treat on my air deck, just kept it inflated and rotated every now and again.

On the leaks, have you checked the valves? They nearly always leak in my experience, washing up liquid and water does the trick to test for the leaks.

Do you need to keep the boat inflated if you use an internal sealant?

Nasher · 16 September 2011, 18:15

Quote:

Originally Posted by Swell

Do you need to keep the boat inflated if you use an internal sealant?

Sorry, to clarify my earlier post which was hastly put together whilst 'taking a break' from preparing a report at work

Some internal sealants are not really meant for deflated boats as the coated insides of the tube will stick to each other.
Some are however OK, so you just need to be careful which one you choose. I believe the one sold at Ribshop is OK but you'd need to ask them to be sure.

Nasher.

Swell · 16 September 2011, 19:00

Quote:

Originally Posted by Nasher

Sorry, to clarify my earlier post which was hastly put together whilst 'taking a break' from preparing a report at work

Some internal sealants are not really meant for deflated boats as the coated insides of the tube will stick to each other.
Some are however OK, so you just need to be careful which one you choose. I believe the one sold at Ribshop is OK but you'd need to ask them to be sure.

Nasher.

Cheers for that, will do.

Swell · 19 September 2011, 12:50

Just to say that I did the leak check yesterday and the technique works a treat! I used very dilute washing up liquid and applied it using a small wash bottle, the sort where you squeeze it and a thin jet comes out of a tube in the top.

Thankfully there were very few leaks, and the seams are generally in good shape which I'm relieved about. Those that I found were from a couple of areas repaired by previous owners and from a particular area on Metzelers right at the very front where the Hypalon is permanently folded in a bit of an awkward shape and is obviously prone to wear and leaks. In that area both the seams and the material itself had leaks and I'm going to have to use a big patch to repair and reinforce the material. Should be good or a few more years once done though.