An experiment with water.

[Kim]

Hi-
Recently I read a post where Dee suggested using small strips of a sanitary napkin to take up small water leaks inside a housing. This got me wondering about some types of baby nappies (the full panty ones that take up moisture). I have just conducted the following experiment:
I cut two equal strips (about 1X3 inces) of a SN and a nappy. I sealed the edges with tape. I put them onto a plate and then added a measured amount of water to see if there was any difference in the retention properties.
Results: The SN absorbed about 30cc of water until it wouldn't take up any more.
The nappy absorbed about 120cc of water - whereupon it expanded so much that the tape seal burst (obviously still needs a little work to stop this from happening!)

The nappies have some kind of powder inside that absorbs water and turns to a sort of jelly - very effectively! I presume that the jelly is mainly harmless - after all - they use this with babies! With a little more design (probably using the outer material from the nappy for a cover) I think that this might provided a very useful strip to keep your camera dry!

Any thoughts or further suggestions welcome!

 

[archman]

What about Charmin, the Quicker Picker Upper!

 

[Kim]

What about Charmin, the Quicker Picker Upper!

You've lost me there - is this something American??

 

[marpacifica]

Yes, Charmin is an American brand of toilet paper. They came out with an advertising campaign in the 70s that featured Mr. Whipple, a storekeeper who watched his customers lika a hawk to prevent them from squeezing the packages of super-soft Charmin. He'd say "Don't squeeze the Charmin!" That commercial annoyed the hell out of me when I was a kid, but b/c I still remember it today I guess it was effective.

The "Quicker Picker Upper" I think is for a brand of paper kitchen towel -- Bounty?

 

[archman]

dang, I hate it when I mismatch my commercials!

 

[IslandHopper]

marpac.... are you on Saipan ?

And those nappies are great at absorbing water, but you'd still get a lot of fogging.

Then again, if your housing is leaking, a fogged lens is hardly a big concern

 

[Kim]

marpac.... are you on Saipan ?

And those nappies are great at absorbing water, but you'd still get a lot of fogging.

Then again, if your housing is leaking, a fogged lens is hardly a big concern

I'll try the dessicant bags for the fogging - with a prepared nappy pad as backup for eventual small leaks.

 

[marpacifica]

Archman, at least it's just commercials you're mismatching. I put two contact lenses in the same eye this morning...

Island Hopper, yep, I'm on Saipan, the other rock in the middle of the Pacific Ocean.

As for nappies, I haven't used those, just the cut pieces of sanitary napkin along with a pack of dessicant. No fogging issues with my PT-010, although I had lots of problems with fogging with my Reefmaster Sealife DC200 b/c the housing was so small and the camera put out a lot of heat. With the smaller Sealife housings space is an issue and the instructions warn you not to stuff anything else in the housing and to put the dessicant capsules only in the indicated places b/c wedging them elsewhere could bend the plastic housing just enough to break a seal.

 

[Wristshot]

Kim, if you have access to a sewing machine, could you stitch 1x3 sections of the diapers (nappy) and then cut them out? That might keep them together without relying on the tape. Do the edges just need to be held together (like with stitches) or do you need to contain things (like with the tape)?

Just trying to learn and understand,

Wristshot

 

[quimby]

The nappies have some kind of powder inside that absorbs water and turns to a sort of jelly - very effectively

Hey Kim I thought that youngan would be in college by now....
Anyway that might be something like psyllium husk, it absorbs something like 100x its weight in water and gels as you mentioned and is used as a dietary suppliment and as a thickener in foods. Just thought Id add and harass