Hot tubes

[Sonar]

Another question i have is tube colours.

some colours react to the sun so far as inflation goes. and need additional air release valves.

What colour do the forum members recommend for trouble free tubes.

Lighter or darker I was thinking of blue. But not white.

[chewy]

My grey tubes seem to be affected quite alot by the sun regards air expansion.

[Ian M]

Some colours, principally the darker colours, will get heated more by sunlight than others. What this means is that that darker colurs get hotter! Black tubes will get seriously hot. This will heat the air in the tubes more, and according to Boyles Law, the air will expand. Thus pressure relief valves will be more advantageous in dark coloured tubes.
Of course, this years in colour is grey As well is being one of the better colours for minimising the heating effect of sunlight, it suffers the least from the discolouration that hypalon is subject to when left exposed to the elements.
White tubes will absorb the least energy from sunlight, but it is not the most practical colour.

[Sonar]

Originally Posted by Ian M

Some colours, principally the darker colours, will get heated more by sunlight than others. What this means is that that darker colurs get hotter! Black tubes will get seriously hot. This will heat the air in the tubes more, and according to Boyles Law, the air will expand. Thus pressure relief valves will be more advantageous in dark coloured tubes.
Of course, this years in colour is grey As well is being one of the better colours for minimising the heating effect of sunlight, it suffers the least from the discolouration that hypalon is subject to when left exposed to the elements.
White tubes will absorb the least energy from sunlight, but it is not the most practical colour.

Many thanks for the advise i was thinking blue but on reflection grey is o.k.
with a white hull..

[C2 RIBS]

I have Grey Ribeye tubes and they are no problem, The latest boat the Ribtec has dark Blue tubes. I have had these new tubes sun screen treated straight after delivery as the top man who does great boat valetting stated dark blue tubes will fade and should be treated as a norm about 6 monthly

[Sonar]

Originally Posted by C2 RIBS

I have Grey Ribeye tubes and they are no problem, The latest boat the Ribtec has dark Blue tubes. I have had these new tubes sun screen treated straight after delivery as the top man who does great boat valeting stated dark blue tubes will fade and should be treated as a norm about 6 monthly

Makes the Grey tubes look near on maintenance free for a while longer than darker colours..
Thanks for the input.

[Steve_B]

My last Rib had grey tubes on a white hull, not only looked good in my opinion, but were still as good as new when sold three years later. The only maintainance required was a wash down with a bucket of water plus normal car shampoo after every trip.
I did not find this a chore as it is a great time to give the boat a once over and be thinking of ways to improve or add bits ...

[neilda]

How do you know if the tubes are at the right pressure? Is it just a matter of experience feeling how firm/spongy they are?

I went out one day last year with very flabby tubes which I pumped up, after a couple of hours in the sun they were like concrete - I assume my valves don't discharge the surplus air, but am not sure!

[willk]

Originally Posted by neilda

How do you know if the tubes are at the right pressure?

I'd be surprised if your valves don't have a safety. They don't dump until quite high pressures are reached. I know some owners run their boats quite soft, I'm not a fan of that. I'd say taut, where a hand tap will raise a slight drum effect. However, the tubes shouldn't deform outward from seams or bulge. I'd certainly not pump to this state in shade/cold and then go to a sunny/hot environment - pump in the sun

[Tim M]

Obviously you need to keep an eye on your tubes, but if made well they should be able to handle a fair bit of expansion in the summer. I generally have to adjust them every few weeks as the weather warms up. In the summer I don't generally touch them much unless we suddenly have some weird weather. I used to have an all black boat which got seriously hot in the summer; on really hot days it was uncomfortable to touch the tubes. They would get seriously hard so I would let some air out but never had any troubles with them bursting etc and they weren't fitted with pressure release valves. Black shows salt up really badly, but nothing a quick hose down wouldn't solve. When I sold the boat it was 4 years old and the tubes looked like new, and had only ever been shampooed and rinsed. I now have several blue-tubed boats and they are a nightmare to keep smart!

Like others I very much like grey tubes. They never look dirty even when they are plus don't get too hot.

[Bigmuz7]

Originally Posted by willk

I'd say taut, where a hand tap will raise a slight drum effect.

Agreed and grey worked well for me too (aft were blue) on white hull .. but I had relief valves fitted too just to be on the safe side

[Poly]

Originally Posted by Ian M

and according to Boyles Law, the air will expand.

Boyle's law won't explain the problem fully though. (Actually its not Boyles law that applies anyway - Boyle's law is the relationship between P and V at constant temp). However ignoring the pedantry here:

Even with an extreme temperature rise achievable with sunlight (especially in the UK) you can't get the sort of pressure increase that it would take to burst tubes just from air/heat. A temperature fluctuation of maybe 70 K is about the most that's likely - that is going to cause a pressure change of 25% or so - not enough to blow tubes unless you were already overinflated (and a big stuff would have done for you).

So pressure rises (and tube failures) associated with sunlight must be caused, at least in part, by some other factor, possibly:

(a) Condensation/evaporation.
if tubes are filled at high humidity and then allowed to cool the moisture will condense reducing the pressure. If they are then topped up then when they warm up the moisture evaporated causing a pressure increase. Likewise with any sea/rainwater that finds its way inside the tube during filling/repair.

(b) Heat softening the glue on seams.
If tubes get seriously hot then potentially you weaken the glue - then with (or even without) a slight pressure rise it goes pop.

(c) Atmospheric pressure.
still not going to burst a tube - but its part of the fluctuation.

the point of this post is that (a) and (c) affect all colours of tube much the same...

...oh and in Durham - you don't get enough sun to worry about it!

[neilda]

Originally Posted by willk

I'd be surprised if your valves don't have a safety. They don't dump until quite high pressures are reached. I know some owners run their boats quite soft, I'm not a fan of that. I'd say taut, where a hand tap will raise a slight drum effect. However, the tubes shouldn't deform outward from seams or bulge. I'd certainly not pump to this state in shade/cold and then go to a sunny/hot environment - pump in the sun

Thanks for that....

It's a new Ribeye - would anyone here know if the valves have a safety as standard? There's a new member here asking much the same question too....

[markg]

Originally Posted by neilda

Thanks for that....

It's a new Ribeye - would anyone here know if the valves have a safety as standard? There's a new member here asking much the same question too....

pressure relief valves are seperate valves from your inflation valves

[C2 RIBS]

Originally Posted by neilda

Thanks for that....

It's a new Ribeye - would anyone here know if the valves have a safety as standard? There's a new member here asking much the same question too....

I believe your Ribeye 650 is new and would have the safety/pressure release valves as standard. If you look at the valve position on each tube within about two to three inches is another similar sized grey plastic plate with very small holes in it- this is the auto release valve for each tube. Older Ribeyes were not fitted as standard but I am sure yours will be.

[Bigmuz7]

Originally Posted by markg

pressure relief valves are seperate valves from your inflation valves

Not necessarily

[Ian M]

Originally Posted by Polwart

Boyle's law won't explain the problem fully though. (Actually its not Boyles law that applies anyway - Boyle's law is the relationship between P and V at constant temp).

Arrrgghh - as a diver I should have got this right Please don't tell the BSAC

Originally Posted by Polwart

Even with an extreme temperature rise achievable with sunlight (especially in the UK) you can't get the sort of pressure increase that it would take to burst tubes just from air/heat. A temperature fluctuation of maybe 70 K is about the most that's likely - that is going to cause a pressure change of 25% or so - not enough to blow tubes unless you were already overinflated (and a big stuff would have done for you).

So pressure rises (and tube failures) associated with sunlight must be caused, at least in part, by some other factor, possibly:

(a) Condensation/evaporation.
if tubes are filled at high humidity and then allowed to cool the moisture will condense reducing the pressure. If they are then topped up then when they warm up the moisture evaporated causing a pressure increase. Likewise with any sea/rainwater that finds its way inside the tube during filling/repair.

(b) Heat softening the glue on seams.
If tubes get seriously hot then potentially you weaken the glue - then with (or even without) a slight pressure rise it goes pop.

(c) Atmospheric pressure.
still not going to burst a tube - but its part of the fluctuation.

the point of this post is that (a) and (c) affect all colours of tube much the same...

...oh and in Durham - you don't get enough sun to worry about it!

I really do not want to get into a drawn out public debate on this but .......nowhere in my original post on this subject did I mention tubes getting hot enough to burst like an over inflated childs balloon. I only stated that "pressure relief valves will be more advantageous in dark coloured tubes." because darker tubes get hotter and suffer a greater pressure increase. It is my belief that this will stress elements of the tubes more, seams, materials etc. which over an extended period may have a negative effect on the tubes.
To be fair, you point out yourself that softening of the glue is one possiblity. With temperature and pressure cycling this softening may take on a permanent aspect? I dare say there are a number of other effects that could occur, but not being an expert in these matters, I would not know what they are. Maybe one of our trade members may be able to advise?
What I am reasonably certain of is that raised temperatures are bad; bad for the adhesives, and bad for the tube materials. Further, temperature cycling does seem to be even worse than constant elevated temperatures for many materials. I am assuming that you do not contest the point that darker tubes will get hotter? This being the case if there is any way that I can minimise these effects on my boat, even in a small way, I will take it. Hopefully then if my tubes are 'on the cusp' of catastrophic failure, I may just get away with it, but more importantly, my tubes should not be degraded quite so badly as others over a period of time, with the benefits that this will bring.
My original post was meant to help a fellow rib owner with tube colour choice; the other factor that I mentioned was the effects of exposure to the elements of different tube colours. With these factors in mind I stand by my original post, to the effect that IN MY OPIINION, grey is one of the better tube colours, if not the best.
Oh, and yes, my tubes are predominantly grey, and fitted with over pressure valves. but I will not hold it against you if your tubes are another colour

[Sonar]

...oh and in Durham - you don't get enough sun to worry about it! [/QUOTE]



What no sun I am sure there was some sun about last year i blinked and missed it I expect

[Sonar]

Originally Posted by Ian M

Arrrgghh - as a diver I should have got this right Please don't tell the BSAC



I really do not want to get into a drawn out public debate on this but .......nowhere in my original post on this subject did I mention tubes getting hot enough to burst like an over inflated childs balloon. I only stated that "pressure relief valves will be more advantageous in dark coloured tubes." because darker tubes get hotter and suffer a greater pressure increase. It is my belief that this will stress elements of the tubes more, seams, materials etc. which over an extended period may have a negative effect on the tubes.
To be fair, you point out yourself that softening of the glue is one possiblity. With temperature and pressure cycling this softening may take on a permanent aspect? I dare say there are a number of other effects that could occur, but not being an expert in these matters, I would not know what they are. Maybe one of our trade members may be able to advise?
What I am reasonably certain of is that raised temperatures are bad; bad for the adhesives, and bad for the tube materials. Further, temperature cycling does seem to be even worse than constant elevated temperatures for many materials. I am assuming that you do not contest the point that darker tubes will get hotter? This being the case if there is any way that I can minimise these effects on my boat, even in a small way, I will take it. Hopefully then if my tubes are 'on the cusp' of catastrophic failure, I may just get away with it, but more importantly, my tubes should not be degraded quite so badly as others over a period of time, with the benefits that this will bring.
My original post was meant to help a fellow rib owner with tube colour choice; the other factor that I mentioned was the effects of exposure to the elements of different tube colours. With these factors in mind I stand by my original post, to the effect that IN MY OPIINION, grey is one of the better tube colours, if not the best.
Oh, and yes, my tubes are predominantly grey, and fitted with over pressure valves. but I will not hold it against you if your tubes are another colour

Either way all the comments have been a help to myself while considering a colour for new tubes. Many thanks..
Respect to all Robert

[Poly]

Ian - sorry didn't mean to be argumentative. I think I was actually trying to make the point you did - even if you don't have dark tubes you might want pressure relief valves and even if you do have pressure relief valves on dark tubes - in exreme conditions (possibly not the UK) they may not be enough to stop the damage from heating to adhesives etc.