Some time ago I was on a small boat and we capsized. My camera (canon xti) got soaked in seawater and stopped working. I tried drying it and took out the battery and memory card, but it won't turn on. If I attach the lens to my new camera, will it break my new camera? Is there any hope for repairing or fixing my old camera? Thanks
Salt water is certainly one of the easiest way to destroy a camera. The salt can cause corrosion which is impossible to undo. I would avoid connecting anything to it as an internal short-circuit can damage the other item.
Something similar happened to me once where flash reader fell. I wanted to see if it still works, so I put in a Compact Flash card which got fried. Of course, I did not know and simply concluded that the fallen one was broken. I therefore inserted latter the CF card into another reader which short-circuited and starting outputting smoke. Needless to say, from one incident I ended writting off 3 items. The 1GB CF card cost $1000 CDN at the time :(
At this point, probably, the best bet would have been to submerge it completely in distilled water after the initial incident and then place it in either dry rice or with a bunch of silica gel packets after to suck out the moisture.
The point of the distilled water is to remove any salt or other mineral deposits that might cause damage and then the dry rice or silica gel is to get the moisture out of it. It still isn't a particular promising prognosis in either case, but without removing the heavy salt content that would be deposited as the sea water dried inside your camera, large amounts of corrosion and potentially conductive mineral deposits would occur that would destroy both optics and electronics alike.
Now that it has been some time for corrosion and possibly moisture damage to become permanent, I wouldn't try attaching it to a new camera. Any number of things could go wrong, from short circuits to spreading mold or fungus spores from the old lens in to the new camera body (from where it might go to a new lens).
If you want to find out for sure if your lens is toast, the best bet would be to send it in to Canon (or whoever made it) to have them test it. They can test it without a camera body and see if it works. They can also evaluate if it can be repaired, though if it was a cheap kit lens, you are probably better off to just get a new one.
Your camera and lens are almost certainly beyond repair.
For future reference, here is my approach. It's happened a few times with various items of electronic equipment. Sometimes it works, sometimes not. "All care, no responsibility".
Remove all batteries and other power source immediately.
You have seconds at best in most cases. A main LiIon battery must be removed asasap.
If there is a backup battery (coin cell etc) a little longer may be OK.
Power and a conductive path can led to rapid corrosion in seconds and death of electronic components. Getting power of asasap is THE most crucial first step.
Using clean hand-hot tap water scrub the equipment extensively and rinse repeatedly. Some items will be water-damageable :-(. Use a cleaning brush etc that will not cause damage. You want to clean as intensively as reasonable without overdoing it. Only you can be the judge of this.
Shake dry, towel dry, let what water will run out run out. Inspect for any water traps that retain large volumes.
Dry for a long long long time. Sunshine in a ventilated plastic bag is OK - gets warm and moisture can leave. Do not let it get so hot as to do damage.
I have placed equipment in a closed cardboard box with entry and exit holes and run warm air from a fan heater through it. Temperatures can be toasty but not so hot as to do damage. As a rule of thumb (or hand) if a hand placed in front of the incoming air stream finds the air "nice and warm but not overly hot" most gear will be OK.
Drying time can be hours for a simple device with no crevices and hidden holes through days or even weeks.
When you are CERTAIN that it is wholly dry, try a power up. Be prepared for death (of gear) smoke etc.
Does it work?:
I have saved
a pager dropped in saltwater (pocket, bend over, oops, run, stream ...),
a portable phone dropped into concentrated sodium hypochlorite solution (pool chlorine ...) and a few other misc things.
I failed to save either a DSLR or its lens when a boat captain (apparently purposefully) thought it would be fun to broadside a wave and soak the dolphin spotters (and their cameras). I immediately took them to the galley and did the whole EXTERNAL cleanup procedure (as both appeared to have not internalised water and I was not too happy how they would survive it, but both died of internal corrosion some months later. The insurance company obliged with new gear of latest equivalent models :-).