Do waterproof chartplotters normally come with silica pouches packed inside?

[KAL]

Sent my Standard Horizon 180 back to Yaesu last year, as it developed a very annoying and dangerous patch of condensation on the inside of the screen whenever it warmed up or was in the sun. Very efficient service; they said they'd replaced the seal and sent it back.

First trip out this year saw exactly the same problem happen, so I've taken it home, got the back off and, lo and behold, I found 3 silica gel pouches inside!

Now I know they are designed to absorb moisture, but they would also release it, surely, whenever there was sufficient heat to decompose the hydrated crystals?

In the mean time, I've got it sitting on the top of our dehumidifier, then I'll put it back together once it's had a good dry.

Would you put the gel pouches back in? They looked really incongruous there and I wonder if it was the technician's attempt to 'solve' a problem, that has rather backfired? If its IP rated, surely it shouldn't need silica pouches stuffed inside?

Confused!

 

[actionoptics]

I handle a number of water proof items in my workshop esp binoculars, telescopes and cameras but the only ones which have silica gel 'pouches' inside are removable from the outside so they can be dried when the indicator in the gel changes colour to show that some moisture has entered. All the others and that is probably 99% rely on being dry when assembled, probably purged with a dry gas and then effectively sealed to keep all the water out.
Telescopic rifle sights are prone to leaking so I dismantle, 'cook' the whole lot for a time in an oven, rebuild and purge. Only ever had one back for a second try.
Pouches inside would, as you suspect, absorb any moisture then let it back out again, inside !

 

[KAL]

Thought so, thanks!

Just weird that they would have packed them into the unit and sent it back to me to use!

 

[nigelmercier]

I don't see the problem. The gel will keep the interior drier than without, and won't suck in any extra moisture. I've done the same on a few items, no problems so far.

 

[jwilson]

If it's still under warranty I'd complain loudly but politely now. Had similar problems with a Garmin plotter that eventually died from repeated water getting inside, but outside the 1 year warranty of course. I've just bought a SH180 to replace it, mainly because of the advertised "3 year waterproof warranty".

The old Garmin 3005C was a sharper screen image but always far too dim to see in bright sunlight. The SH180 has a lower resolution screen but is at least still visible in the sun.

 

[neilf39]

Assuming the unit was sealed but not in a humidity controlled environment then the pouches were probably to absorb any remaining moisture in the trapped air. Would have though one small pouch would be enough. You would need a fair bit of heat to re-dessicate the crystals (such as in an oven) assuming they are reversible ones so don't think it would occur in normal use conditions.

The 180 spec says it is only splashproof (IP56? although they don't even claim that) so doesn't sound like it is hermetically sealed. I would expect over time that damp air would slowly get in and exhaust the bags through atmospheric expansion/contraction over a year or two.

If you have taken it apart then you may as well renew the bags and seal it again and keep using it.

 

[KAL]

Assuming the unit was sealed but not in a humidity controlled environment then the pouches were probably to absorb any remaining moisture in the trapped air. Would have though one small pouch would be enough. You would need a fair bit of heat to re-dessicate the crystals (such as in an oven) assuming they are reversible ones so don't think it would occur in normal use conditions.

The 180 spec says it is only splashproof (IP56? although they don't even claim that) so doesn't sound like it is hermetically sealed. I would expect over time that damp air would slowly get in and exhaust the bags through atmospheric expansion/contraction over a year or two.

If you have taken it apart then you may as well renew the bags and seal it again and keep using it.

You're right - I never spotted that it was only splashproof! Anyway, I've removed the dessicant, dried the unit thoroughly over a dehumidifier for a few hours and reassembled. I just won't leave it out at the helm in the rain if I can help it.

What on earth is the point of a plotter that's only splashproof? Ah well - we live and learn.