Tube overinflation

51ROB20 · 28 March 2012, 20:46

Has anyone else had a problem with the tubes on their RIB overinflating with this hot weather ? I ended up having to let some of the air out as they became "rock solid" but then in the evening they became soft and re-inflated again the next morning. Is it safe to allow the tubes to become over inflated due to the sort of temperatures we have been getting or is there a risk of them bursting ?

SPR · 28 March 2012, 21:41

lol in Scotland , we can only but dream ....

51ROB20 · 28 March 2012, 22:41

What I forgot to mention is that my rib is sat on its trailer in the garden while I am doing a re-furb. On monday I put a thermomiter on top of the tube and got a surface reading of 83 deg farenheit.

SPR · 28 March 2012, 23:00

I have black tubes and it's on drying mooring I always deflate slightly before leaving if on cold day...

regards

Nos4r2 · 29 March 2012, 00:33

I always semi-deflate the Searider when leaving it too.

Peter_C · 29 March 2012, 02:44

I too deflate my tubes before leaving the boat in the sun. If I owned a worthy boat, I would install OPV's (Over Pressure Valves) into each chamber. Much cheaper than a blown tube.

jyasaki · 29 March 2012, 09:11

I blew a seam and a baffle leaving the boat on the trailer in the sun.

If it is at all warm, I soften the tubes as soon as it comes out of the water.

jky

51ROB20 · 29 March 2012, 21:16

Quote:

Originally Posted by Peter_C

I too deflate my tubes before leaving the boat in the sun. If I owned a worthy boat, I would install OPV's (Over Pressure Valves) into each chamber. Much cheaper than a blown tube.

Hi Peter, what do OVPs cost and where can you get them? I am not sure if it would be cost effective fitting them on an early SR M4 ?

jezza2011 · 29 March 2012, 21:23

I used to let them down a fair bit in the summer when it was on the trailer.
But since I had it retubed I have got pressure relife valves fitted, but saying that it was very hard in the sun today.

BogMonster · 30 March 2012, 00:16

I got pressure relief valves in my new one because the Humber tubes used to get rock solid in direct sunlight with black wear patches on them. The PRV's blow off on a sunny day, even in our temps here, so they are well worth having. I've never heard them go, but if you get hot weather > cold weather the tubes are usually soft.

jyasaki · 30 March 2012, 03:13

Quote:

Originally Posted by 51ROB20

Hi Peter, what do OVPs cost and where can you get them? I am not sure if it would be cost effective fitting them on an early SR M4 ?

Do a search for "Leafield A6" and it should turn up sources near you. They're about $20 US here, but they were also shipped from England.

jky

rokar · 31 March 2012, 00:53

jyasaki, obtained a set of Halkey-Roberts pressure valves to put in during my refurbish. But I could not find a sight with enough info on how to reliably install them. Would you happen to have any info where to look? I've also been thinking about seeing if Wing could install them for me since they are only about 70 mi away. Thanks. Rokar

jyasaki · 31 March 2012, 18:43

Hi Rokar;

The inflatable shop nearby (Sal's Inflatable Service) recommended cutting a fairly large (3-4") hole, and double gluing (inside and out) the patches containg the OPV's. Said the double fabric and double glue bond would make for a stronger installation.

That said, the design of the Leafield valves says specifically that it's meant to seal on a single ply of fabric. It would, I think, be tough to get the locking nut in through a just-large-enough hole though.

So, bottom line is, I have no idea. Pete Chandler have info on how his were installed.

jky

51ROB20 · 31 March 2012, 23:08

Quote:

Originally Posted by jyasaki

Do a search for "Leafield A6" and it should turn up sources near you. They're about $20 US here, but they were also shipped from England.

jky

Many thanks for the info, I will have a look on line over the week-end.

rokar · 01 April 2012, 18:53

Hi 51rob20,

I'm sorry that I forgot to mention that the HR valves were obtained from an outfit called NRS @ nrsweb.com. We have had very good experiences with them but they are a little on the high side. The pressure relief valves are rated at 2.5lbs so I hope that that would help give you an idea of tube pressures.

Thanks jyasaki for getting back to me with your info. The PR boots for the inside of the tube have flanges that are only 3in. in dia. The side of the flange that faces out has been prepped from the factory (roughed up). So, I think I can go with a smaller hole, fold it like a taco and then layover another piece with a smaller dia. on the outside.

rokar

Chris Caton · 01 April 2012, 19:03

Quote:

Originally Posted by 51ROB20

Hi Peter, what do OVPs cost and where can you get them? I am not sure if it would be cost effective fitting them on an early SR M4 ?

try henshaws, they fit tubes to lots of ribs and have a good online shop for bits, they sell the glue etc as well, i got a spare inflation & PR valves from them a while ago

the PRV do work, on a cool day after it's been hot the tubes are always soft and need a bit of air, but much better than getting them repaired, been there, got the t-shirt

Peter_C · 01 April 2012, 19:36

Not being in Europe I would just buy from a local USA supplier like NRS web. I am including the NRS website that then shows there are different pressure ratings. For instance my boat has a 3 psi fill pressure would I want the 3.25 psi OPV? Or is the higher pressure one at 4 psi the correct one to get?

Raft & Inflatable Boat A6 Pressure Relief Valve by Leafield - Man of Rubber, Inc.

http://www.nrsweb.com/shop/product.a....9&deptid=1030

A long time ago when I was researching them, I found a higher cost of around $50 US valve that had an adjustable pressure set point.

I have never deemed my boat worthy, but starting to rethink one in the bow would protect my three main tubes. Hmmm...damn you RIB.net you are costing me more money! Rather my complaint should be another dang project into the list, which is a long one. Off to spray for poison oak again.

headdamage · 01 April 2012, 19:53

I wonder what pressure it takes for the intercommunicating zodiac valves to pop and release some air? I've never seen/heard them do it on my MkI or MkII but I've read that they are designed to self release if there is too much pressure in the tubes. I've always chickened out and manually released the air when the tubes seemed to be in danger of over inflating due to getting hot.

rokar · 01 April 2012, 20:20

Hi peter c,

I am pretty happy with the stiffness in the tubes at 2 - 2.5lbs. Living on the coast makes it easy to keep them inflated correctly. What I am concerned about is that I will be on the water for a week at Lake Shasta in June. 50 degrees at night and 80-90 during the day. I assume that you are familiar with lake?

rokar

jyasaki · 02 April 2012, 06:51

Quote:

Originally Posted by Peter_C

Hmmm...damn you RIB.net you are costing me more money!

You have a boat. You will always be spending money.

Quote:

Rather my complaint should be another dang project into the list, which is a long one. Off to spray for poison oak again.

Okay, that was a kind of weird tangent.

jky