Burst Seam

bas695 · 04 November 2007, 04:23

G'day All
Well just made the jump into rib land with a secondhand gemini 505.
Took it for a spin yesterday and loved it.....but next day after a few hours sat on the trailer in the hot Australian sun the tube burst on the cone......see attached

I guess lots of new things for me to learn but was wondering if anyone can help with a few questions
1. how easy is this to repair...should I get a pro to do it?
2. this particular seam doesnt have any internal reinforcement tape (but looking inside the other seams do). is this just a manufacturing defect or is this how the make the final closure of the tube?
3. should i be worried - is this indicative on state/quality of rest of tubes - they all look visually fine and it is only 4 years old.
4. the valves do not appear to have safety release on them...should I get them installed?

Thanks for any guidance you can give.....

Nos4r2 · 04 November 2007, 07:04

Deflate the rest of the boat before you burst the baffles too.

I won't comment on how to repair as the tube builders here are far more competent than I'll ever be but if your tubes get hot enough to burst I'd definitely get some pressure release valves.

Leafield A6 (google it) pressure release valves will do the job.

keelhauled · 04 November 2007, 07:09

That looks like quite an easy fix but you will need compatible glue. Before you do anything fit overpressure release valves for safety. Also this time of year in Australia you should try to protect your rib from the sun while its on the trailer and manually deflate tubes to prevent this happening again. You could consider fitting wear patches to reinforce seams.

bas695 · 04 November 2007, 08:32

Quote:

Originally Posted by Nos4r2

Deflate the rest of the boat before you burst the baffles too.

I won't comment on how to repair as the tube builders here are far more competent than I'll ever be but if your tubes get hot enough to burst I'd definitely get some pressure release valves.

Leafield A6 (google it) pressure release valves will do the job.

thanks have deflated the other tubes and will get the release valves fitted. there arent many ribs in australia (mostly aluminium runabouts) maybe the sun and heat is one reason

bas695 · 04 November 2007, 08:36

Quote:

Originally Posted by keelhauled

That looks like quite an easy fix but you will need compatible glue. Before you do anything fit overpressure release valves for safety. Also this time of year in Australia you should try to protect your rib from the sun while its on the trailer and manually deflate tubes to prevent this happening again. You could consider fitting wear patches to reinforce seams.

the rib was actually under its cover but was still baked silly....will need to find a garage for it.

regarding the repair are there any tricks to ensuring a good seal..seems a bit tricky getting the last bit together of the cone.

good idea ref the wear patches will look into it. thanks for your reply

Ian M · 04 November 2007, 08:43

This looks like a job for Falklands Man

Biggles · 04 November 2007, 09:55

Quote:

Originally Posted by Ian M

This looks like a job for Falklands Man

Nah,

He's only experienced in deep freeze work. This job sounds too easy.

Tomas · 04 November 2007, 10:27

Quote:

Originally Posted by bas695

thanks have deflated the other tubes and will get the release valves fitted. there arent many ribs in australia (mostly aluminium runabouts) maybe the sun and heat is one reason

I'm at 17 degrees N of the equater and have a ten year old Avon SeaRider. I'd like to say I always keep the boat covered and out of the sun but it just ain't so. My tubes are slack in the early morning and tight in the afternoon with the sun expanding the air. I don't have pressure release valves and don't have a gauge to measure bars of pressure in the tubes. What I do have is ten year old tubes that have seen more UV and heat in two weeks than a tube would see at 40 N. in a year and they are nothing if not perfect!

Properly constructed Hypalon tubes will provide a completely acceptable duty cycle in the tropics, period. Possibly you were too diligent in pumping your tubes or possibly you had a poorly glued joint. Hopefully you'll get some good advice on the re-glue job and not experience another blow-out.

Biggles · 04 November 2007, 10:31

Quote:

Originally Posted by Ian M

This looks like a job for Falklands Man

He has't been on here for a while. But their again it is the summer in his part of the world. He's probably out in bermuda shorts having a few barbies

Locozodiac · 04 November 2007, 16:38

Sorry to say, Leafield A6 pressure relief valves will not do the job quite well because this valve opens at only 2.4 PSI and the recommended working presure of any PVC & Hypalon inflatable boat tube is 3.5 PSI or 0.25 Bar.

With 2.4 PSI your dinghy boat type, not a rib type will perform not as it's intended best working presure performance. See if there is a 3.0 or 3.5 PSI automatic presure relief valve or use your normal air valve and buy a presure manometer. (This option will cost far less than to change all valves) Most inflatable manometers available on the market reads from 0 to 14 PSI or 1.0 Bar.

If you have a Rib type, will be Ok as only small portion of the tubes touches the water and having less presure won't have any direct benefit in performance as traditional inflatables would.

Locozodiac

Richard Selman · 04 November 2007, 18:40

Just need the right spring....... 0.5 up to 13 psi

http://www.leafieldmarine.co.uk/Docs...ON%20CHART.pdf

prairie tuber · 07 November 2007, 01:10

I believe all 5.05m Geminis are RIBS, not SIBS.

http://www.gemini-inflatables.com/in...es/default.asp

Locozodiac · 07 November 2007, 22:40

This is the best way to avoid under or over inflation tubes: Mostly for traditional PVC & Hypalon dinghies, but the overall idea can be applied to Ribs: A lot cheaper option than to change costly valves and avoid hand labour fees to fit automatic pressure valves.

Under inflation: Poorly performance on water, excesive stress on seams and transom holder, premature wear to inside compartments internal cone.

Overinflation: Damage, bursted tubes, seams,

Tube Ribs: Inflate to 3.0 PSI in winter, same for summer, but recheck once on water and deflate to 3.0 if cruising in excesive sun.

Dinghy Tubes : Infalte to 3.5 PSI in winter, 3.0 PSI in summer, in shadow or early morning, check after 15 minutes once on water and deflate to 3.5 PSI if the reading is higher because of the excesive sun.

The general idea is to maintain all tubes working at the same pressure, this will give years of enjoyment and long life to your loved boat.

A photo, is better than one thousand words...

Locozodiac

jyasaki · 08 November 2007, 15:30

Loco; Good operational advice, but you're missing the point, I think: The OP had a problem with tubes overpressurizing while sitting in the sun on the trailer.

Inflating accurately to 3 psi and allowing the boat to sit in the sun is a sure recipe for burst seams. My boat will, like Tomas's go from sagging to extremely firm in the span of morning shade to noonday sun.

To that end, my practice is to firm up tubes once the boat is splashed; and soften the tubes as immediately as possible when recovering onto the trailer.

When storing the boat (on the side of my house) tubes are deflated enough so they literally hang. During the summer, I still take a glance and make sure they stay deformed. (Summer temps where I am range from mid-60's at night to near- or just-over- hundred degree F.)

jky

bas695 · 08 November 2007, 20:24

Thanks JKY will make sure I keep it semi deflated in future and wack it up when it goes on the water.

We have pretty similar temperature variance as So Cal here in Sydney so will have to keep my eye on it.

Will the boat have been damaged being over pressurised like that or does it generally just go on the justed seam?

Locozodiac · 08 November 2007, 20:56

Zodiac. Avon, Quicksilver, Sea Rider just to name some boat builders recommends working presures of 3 to 3.5 PSI with the boat on the water, if you are leaving it outside on a trailer in plain summer heat you should deflate the tubes accordingly to match your local heat and not to pass these readings; deflate & use a cover. When not in use, you should shade you boat, under a roof, garage, etc.

There are boaters all over the world with different city temperatures, our summer heat parameters cannot be applied to other countries and vice verse as a perfect universal rule. If you have daily extreme temperatures changes, then you have a real problem. Remember, sun is the worst enemy for tubes.

Anyway, the posted thread was to promote the use of presure gauges and their correct usage, seems nobody is using them or cares about.

jyasaki · 09 November 2007, 15:42

Quote:

Originally Posted by bas695

We have pretty similar temperature variance as So Cal here in Sydney so will have to keep my eye on it.

Will the boat have been damaged being over pressurised like that or does it generally just go on the justed seam?

Well, I'm in Northern California. Little cooler overall than SoCal. Usually.

Overpressurizing the tubes is generally not a good thing. It sort of depends on exact circumstances, but assuming all the pressures in all the chambers are relatively even, blowing one seam transfers the strain to the next chamber. You can sort of postulate what might happen then.

Loco; Didn't mean to criticize. As I said, your advice was good; just a tad off the mark. I use a Bravo 12 electric pump with a built-in adjustable shutoff. No idea how accurate it is, but it works well for me.

jky