Deflated tube (Valiant Rib)

[Toothy]

Hello all

Im new to this forum but would appreciate some advice.

I have a Valiant 4.9DR which i have owned for about seven years, it was a year old when i bought it.

It has always given me good service and i have always looked after it well.

A few weeks ago the starboard side rear tube deflated without warning whilst the rib was stored on my drive. I pumped it back up and looked for a leak with soapy water. There were several areas where small bubbles were coming from.

The bubbles were all arising from out of the black rubbing strip down the side of the rib. As i am no expert in this field i took the boat down to the Valiant agents where i origionally purchsed it from.

Having de-glued and pulled back a section of rubbing strip about 12 inches long what they have found is that a section of the tube seam under the rubbing strip, which was supposed to be "hot welded", is completely clean and has obviously never been stuck together.

It appears that the only thing holding the tube together in that particular area has been the glued on rubbing strip on the outside.

The Valiant agent has stopped the investigating at that point whilst we consider the options.

Has anyone heard of this before.

The agent has sumised that as the seam is hot welded under rollers that perhaps the rollers werent hot enough or perhaps at the time of welding the tube was contaminated with something that prevented a succesful weld.

As we havent done any further investigation we dont know wether there are any further affected areas so far undetected.

Any advice greatly received

Toothy

[GRAHAM SOMERS]

Originally Posted by Toothy

Hello all

Im new to this forum but would appreciate some advice.

I have a Valiant 4.9DR which i have owned for about seven years, it was a year old when i bought it.

It has always given me good service and i have always looked after it well.

A few weeks ago the starboard side rear tube deflated without warning whilst the rib was stored on my drive. I pumped it back up and looked for a leak with soapy water. There were several areas where small bubbles were coming from.

The bubbles were all arising from out of the black rubbing strip down the side of the rib. As i am no expert in this field i took the boat down to the Valiant agents where i origionally purchsed it from.

Having de-glued and pulled back a section of rubbing strip about 12 inches long what they have found is that a section of the tube seam under the rubbing strip, which was supposed to be "hot welded", is completely clean and has obviously never been stuck together.

It appears that the only thing holding the tube together in that particular area has been the glued on rubbing strip on the outside.

The Valiant agent has stopped the investigating at that point whilst we consider the options.

Has anyone heard of this before.

The agent has sumised that as the seam is hot welded under rollers that perhaps the rollers werent hot enough or perhaps at the time of welding the tube was contaminated with something that prevented a succesful weld.

As we havent done any further investigation we dont know wether there are any further affected areas so far undetected.

Any advice greatly received

Toothy

The seams are not high frequency welded but thermo welded and all the pressure testing is carried out for 24-48 hours before the rubbing strake is applied. As well as this the tube will never have been able to hold pressure over 7 years with just the strake keeping the air in. I would suggest that you send the boat to an approved Service Centre for testing

[Toothy]

Hello Graham,

Thanks for you reply.

I understand that the tubes are thermo welded and then pressure tested, but the affected area of tube so far uncovered is totally virgin material. If the weld was succesful at manufacture how would it have come apart so cleanly? If i tried to pull apart an unaffected area of seam it would surely rip and tear and leave residue of the opposing piece of material.
The boat is currently with my local Valiant dealership and they are at a loss for an explaination other than a manufacturing defect.
I could understand it if the tube had burst, there would be evidence of that, however the seam is as clean as a whistle.

Any other ideas?

Toothy

[Locozodiac]

Don't know if this is true, but somebody that's been at Zodiac factory states that for thermo welding procedures a bonding tape (some sort of glue) is placed between both fabrics seams and then machine thermo welded, it's not that you weld both fabrics one on top of the other, but who really knows for sure ? If so, that could explain your tech problem.

Happy Boating

[GRAHAM SOMERS]

Originally Posted by Toothy

Hello Graham,

Thanks for you reply.

I understand that the tubes are thermo welded and then pressure tested, but the affected area of tube so far uncovered is totally virgin material. If the weld was succesful at manufacture how would it have come apart so cleanly? If i tried to pull apart an unaffected area of seam it would surely rip and tear and leave residue of the opposing piece of material.
The boat is currently with my local Valiant dealership and they are at a loss for an explaination other than a manufacturing defect.
I could understand it if the tube had burst, there would be evidence of that, however the seam is as clean as a whistle.

Any other ideas?

Toothy

It is rare for this to happen. What Valiant Dealership is lookin into this for you ?

[beamishken]

is it possible that during welding of the tube they use a roller on the inside & the outside but there will become a point where they cant physically get the inner roller inside the tube as the tube becomes a completely sealed chamber. then they close up the last part of the tube with the overlaid rubbing strip?

this would account for the tube appearing to have never been welded

only a guess but would explain the situation

[Toothy]

Originally Posted by GRAHAM SOMERS

It is rare for this to happen. What Valiant Dealership is lookin into this for you ?

Samspeed Marine in Falfield, Gloucestershire.

They have spoken to Barrus for me but they are not interested because of the age of the boat.

[thomas]

I had a few seams fail on my Valiant, one had been repaired early in the boats life, took it to JCraft and had it fixed like new - they're also prone to coming away from the hull on the under side.

[RIBFIXER]

The initial problem could have been a manufacturing weakness, in my experience welded seams usually only produce small leaks. The seam should be repairable if the material is in good order.The repair should be carried out by experienced pro's as it will entail an internal repair and external strengthening.
Hope this helps.