[dave2k]

On multiple occasions I have found a substance that appears on my grip and k-5 following use around a swimming pool. The substance appears to be a white residue, perhaps similar to what can be found on the battery terminals of a car. I shoot a lot of swimming competitions and my camera does get splashed a times, but not at a level that I would consider to be significant. The substance appears in the same location each time, centered around a screw on the grip. There is some blackness in the substance as well, almost appearing as carbon from sparks. As seen in the photos, the substance appears on both the camera and the grip. The substance is easily cleaned off. To me it looks like some kind of a short circuit due to the presence of pool water between the surfaces. However, I've not seen any functional problems when this has happened. I've not had any malfunctions and my battery life seems fine. The pictures don't clearly show the blackness that appears to be from some type of spark or short circuit. The substance and pattern appear consistently when this occurs. I'm interested in theories regarding the source, potential outcome and possible remedies for this problem.

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[Adam]

Looke like just plain residue to me- is the outer portion of the grip supposed to be sealed, or just the insides? If it's not, I would be sure to wipe it down after your camera gets wet, just it case!

[rfortson]

Doesn't look good to me. What do the cells inside look like? Is there any corrosion inside that you can see? Looks like some sort of galvanic reaction, which you shouldn't be seeing.

[dave2k]

No sign of anything abnormal on the inside. It definitely looks like something involving an electrical reaction, but no performance issues at all.

[pezmaker]

I don't really see anything there to short. Remember, short circuit requires a circuit to complete. I don't see anything there that would complete a circuit with that screw when wet - I don't see the stains reaching the data pins/port. I'm guessing it's just chlorine residue after the water has evaporated out, and some slight corrosion of those screws.

You could check the screws to the tripod post or other metalic bits (other than data pins) with a multimeter to make sure there isn't anything weird, but I doubt you'll find anything. Chlorine is a corrosive, and it could be slowly munching at those screws (hence the greenish hue and the black bits?)

Has your camera been dropped? It sort of looks like there's a little ding at the front bottom, where the seals of the grip might not be able to seal to the camera, letting that little bit of water in.

[sterretje]

My first thought would be chlorine. Specifically if those are indoor pools with the high humidity, the air will contain chlorine.

[dave2k]

I agree that there is no apparent way for a short circuit to occur. However, the residue location and the pattern are very similar each time. There is no pre-existing damage to the bottom of the camera or the top of the grip. There is no sealing between the grip and the body except around the electrical connections by design. I'm sure water droplets enter the gap at various times in a number of locations, but I've only seen this residue in this location. I believe there is something that is causing a reaction with the pool water. Otherwise I'd expect to see this residue in other locations. And the pattern is quite distinct with distinct edges that do not appear to be random to me.

[Northern Soul]

Chlorine is highly reactive - I suspect there is a tiny chip or mark on that screw head, and the chlorine in the air is reacting with it to make some sort of metal chloride salt.

[dave2k]

I think I will give the area a thorough cleaning and then apply a thin layer of silicone sealant to the screw and the affected area. That should do no harm and it might interfere with the factors that are causing this problem. I think the chlorine is reacting with something, and perhaps the sealant will prevent it. The swim competitions have just ended for my area of interest so it may be quite a while before there is another test. Thanks for the suggestions and advice.

[BillH]

On the surface, it appears moisture, possibly chlorinated, gained entry between the body & grip.
Whether the white residue is from chlorinated pool water, calcium carbonate residue from another water source, vapor & / or from contact with the mounting screw(s) (probably aluminum but of unknown grade spec listings) causing some oxidation (aluminum susceptible to chlorine attack with some grades), etc., it doesn’t appear that any electrical action / transference took place. It would take an analysis of the white residue to help determine the substance & associated cause, but looking at the residue pattern, including around the phillips head screws, it looks like it is of moisture origin which pooled in that area at one time then evaporated(?), IMO. No timeframe is given on when the discovery was made (after every shooting event?), if the grip was removed / installed in a potentially wet environment, etc.

[GeneK100D]

I suspect that the residue is due to galvanic action between dissimilar metals instigated with the addition of chlorinated water. The chlorinate water may have etched away some of the protective coating on the screws and plate and fostered the corrosion that you have noted. Sealing with a thin coat of silicone or even some black paint, may prevent the reoccurance in the future.

[forensicscientist]

I'll give this a stab...(no pun intended), although its been 25 years or so since wet labs....

The chlorine from the pool (cl2) reacts with water to yield HOCl and HCL...both exceeding "aggressive" towards any type of metal...i.e., the screws in the battery grip. Would appear moisture is getting in between the grip and the sole plate of your camera. As for the white powdery appearance, as the water evaporates, it leaves the dissolved salts behind...in your case, probably mostly calcium.

Eventually it will eat up the screws of the grip, and camera too. I'd remove the grip after the shoot, wipe everything down with a damp cloth and let it air dry really well. Same for camera. The sealing will likely keep dust and moisture out....but the material that makes the seals may not be able to within stand the long term attack from the chlorine. That said, I have no idea what type of material Pentax uses for the seals...so the last part is just a guess....

Take it for what it's worth...

[Schraubstock]

Hi

I would remove the screw and clean it with a wet tooth brush. Try to clean the female thread inside as well with a small brush. Better still get a replacement screw. (Either from PENTAX or a watch repair shop) Clean as thoroughly as you can. Take out only one screw at a time if you want to do them all around the area. They are holding a reinforcement plate underneath. Make sure it is all dry before going on with the next step. Which is, apply as mall amount of Vaseline under the screw head and the female thread and put the screw back. I would also apply a bit of Vaseline in the general area. Do not use Silicone!

I think something has seeped under the screw head which will carry on as a catalyst there. Cleaning from the top will not get rid of it. If you do nothing, other than just cleaning up I am afraid the screw will slowly be eaten away for greater damage.

Greetings