Pontoons soft in garage, hard in sun, normal?

[SpearRib]

My pontoons feel soft when in the garage but go quite hard when outside, Im not sure if Im meant to pump them up more. I dont have a presssure gauge sadly, so need to do it by feel.

[treerat]

They will harden as they warm and the air expands. I suggest you don't pump them up when soft if they are going hard enough when warm or you'll over pressure.

Once at normal temp they should sound like a tight drum when you slap them.

[SpearRib]

Ok cool, no drum, put some air in :-)

There is a hand pump in the boat.

[SpearRib]

took it for a run today, they did harden up in the sun. but it seemed like in the chop (1ft) the tubes were wobbling like jelly. Also they could be pushed down by hand and felt softish to sit on. They sounded like a drum to hit but didnt feel hard like a drum.

They dont lose any air though.

Perhaps just needs a little top up?

[Peter_C]

You can not guess the pressure, you NEED a pressure gauge.

[SpearRib]

Ill see if the PSI is on the spec plate.

[SpearRib]

ok its not on the spec plate on the boat. anyone know what psi caribe c13 should be?

[seaquest1]

dont know for your 1
but tubes are normaly around 2 to 3 psi
if you had automatic presure relief valves fitted
it will not over inflate hope this helps
#

[SpearRib]

should there be movement of the tubes in chop?

i was going about 35kph across a foot of chop and the tubes wobbled like jelly.

[SpearRib]

No reply from caribe yet so im hoping someone on here will know the operating psi.

[BogMonster]

Yes it's normal. I was sitting on mine outside the garage the other day in direct sunshine and the pressure relief valves were whistling gently to themselves with the tubes almost too hot to touch, put it in the garage and a cold night inside meant they were too soft to use the following day. Cold water has much the same effect (very noticeable here with typical water temp of 4 C - you can be fine when you launch but after 10 mins running need to top up the tubes because the air in the rear chambers has cooled right off).

A rule of thumb (literally...) is to estimate the displacement if you prod the tubes hard with your thumb. I'd say if you can easily push them in more than half an inch or so, they are probably too soft.

I used to be paranoid about mine overpressuring in strong direct sunlight in my old boat, which is why I've got PRV's in the current one so I can keep them pumped up hard without having to worry about an expensive bang!

[9D280]

Your usage pattern will also matter: SDtanding on a traile ri nthe sun will toast the tubes nicely. Put it in the water and you get instant cooling! (why I always do the last pump of a sib afloat if I can)

On a summer's day I will normally leave the garage with the toobs "wobbling" in my rear view mirror. in about 10-15 mins they have "solidified", and then after launch I need to top them up. Likewise if I recover late i nthe evening I;ll jsut leave them "up" for the trip home. If it's the middle of a hot afternoon I'll let a bit of air out. (I don't have relief valves, but will be fitting them whenI get round to re-toobing it.)

[SpearRib]

well no response from caribe so i rang some dealers, all had different responses, ranging from 3.0 to 3.5 hahaha. so whats the point of a pressure gauge if i dont know the correct pressure.

[Peter_C]

The point is "we" have no clue what our boats are at pressure wise. 3 psi is pretty good for "most" tube sets. You will get the proper tube pressures soon enough. Someone else must own a Caribe and have the manual/knowledge.

Case in point: Saturday I was bringing my tube pressure up for Sundays adventure. I inflated the keel pushing on it until it felt right, and banging on the tubes until they felt right. Then got out the pressure gauge, and checked the tube pressures. The keel was at 6psi (Should be at 3.5 psi), and the tubes were at 2 psi (Should be at 3 psi). I can get the rear tubes very close by how the conical ends feel and do not fold over. The front tube is harder to determine. Especially on my SIB the pressure makes a big difference in how it rides, and more importantly, handles.

[SpearRib]

Good point. Im ordering a bravo gauge today.

Can I inflate push pull caribe valves without a halkey roberts adatpor for hand pump. The pump the boat came with didnt come with an adaptor, so I presumed there must be a way?

Also should 3.0psi be its pressure in the garage or on the water?

[Peter_C]

Originally Posted by SpearRib

Can I inflate push pull caribe valves without a halkey roberts adatpor for hand pump. The pump the boat came with didnt come with an adaptor, so I presumed there must be a way?

Someone else is going to have to answer that one. I have different valves, and built my own gauge adapters.

Originally Posted by SpearRib

Also should 3.0psi be its pressure in the garage or on the water?

I store my boat with less than .2 psi in it. Totally flappy when cold. When hot it gets maybe .5 psi in it and the tubes become firmer.

When ready to head out on the road, I bring my tubes up to a good pressure for the day/weather. In other words if it is sunny and hot I keep them softer at the house to the launch site. Often when pulling the boat at the end of the day knowing it will no longer be cooled by the water, I let air out of the tubes before trailering home.

Once out on the water I check the pressures and top up as needed. I only have a hand pump for on the water though. Wish I had a nice electric pump...

[SpearRib]

Wow thats a lot of work, Im sure its worth it. I need a lazy mans version :-)

Yeah Im not sure how to check if caribe valves can take air in without letting it out which is the only way i can see it working without the halkey adaptor.