UKC

One or two cams got very wet over the weekend and have since seized up, any tips to restore these? I have access to an ultrasonic cleaner which I'm sure would do the trick but unsure if it could damage the cam in any way

Or rinse with warm water and put the sonic screwdriver away? 

Most likely it's the salt that can cause problems....

but also just your standard grit and grime.

simply brush, clean water should get you going. no need to ultrasonic cleaner (albeit I'm sure it will not mess up anything, but it is also not needed).

that dry (compressed air works really well, but simply hanging out to dry is also good). After they are dry, lube with good oil... and remember that you should be doing this (cleaning and lubing) anyway, not júst when they get sticky.

I've not had cams fully seize up, but where the movement gets a bit 'sticky', washing grit and salt away with clean water (& maybe an old toothbrush is helpful here), drying, and then lubricating with Duck Oil seems to do the trick with mine.

whats a good oil... would wd40 do the trick?

DMM have a good page about on Cam Inspection and Maintenance including cleaning and lubricating which includes the line "do not use graphite or lubricating oils that contain degreasing agents such as WD40"

https://dmmwales.com/blogs/knowledge/cam-inspection-and-maintenance

I didn't think WD40 was a lubricant ? I just tend to use GT85 after giving them a soapy wash and letting them dry.

I used to use GT-85, but with the cams hanging up from the krab, so that any excess drains away from the tape until it dries.

WD40 or GT85.  GT85 will leave a residue, more so than WD40.  Apply, work the cams, and remove the excess.

WD40 is a lubricant, contrary to the persistent urban myth that it is not.  You can find its lubrication specifications in the WD40 tech specs download

Ultrasonic cleaner is fine if it's not an industrial one (they might be alright but it obviously depends on how powerful). I wouldn't leave them in for a few days but you'll be surprised at what comes out from just a minute washing. Some manufacturers of ultrasonic cleaning talk about aluminium being to soft for ultrasonic cleaning but the type of damage they're talking about are microscopic surface pitting (at worst) or discolouration due to some of the aluminium oxide layer being removed and reoxidising. You do everything at your own risk of course but ultrasonic cleaning is used on aircraft parts, scuba gear and car parts etc. I've done this to my cams to great effect

It is a lubricant as a secondary role, after primarily being a Water Dispersant (and so "WD" in the name). Those of us old enough to know about distributor caps and HT leads will know what it is intended for (or less likely: people here owning Atlas rockets, the original-original requirement). But true it can be used to lubricate also. A purpose made lubricant is better at that job though

Don't use wd40. It gets everywhere no matter how careful you are and it's the last thing you want all over your hands when you're on a sketchy sea cliff. And it's a crap lubricant anyway.

Metolius cam lube is, unsurprisingly, perfect for the job and not even that pricey. If you're going to go out and buy something you don't have already, buy that. 

After rinsing in clean water, I've used GT85 using plenty to drive out any water , working them to free them up then use rags/tissues to remove as much as possible. I try to do this outside on a dry day.

Generally rinse in warm water, then lubricate with 3in1 oil. Work the oil into the mechanism using the action and wipe away excess with paper towels 

I use warm water and a toothbrush to scrub, followed by 3in1 oil to lubricate 

True, which makes it well-suited for freeing up seized cams that go near sea cliffs....

Distributor caps and HT leads also dislike overnight stops at the top of sea cliffs.  Needs a lot of WD40 and long tow from a coastguard landrover to get started

My understanding is there are things in it that make it more effective at freeing corroded materials and displacing water than straight lubricants (oils) so in that way perfect for seized cams. However, I gather it also has a certain affinity for water (which makes it good at displacing it)  so not ideal as a lubricant. If a cam was really seized I would be inclined to free it using WD but then follow up with a light lube in very small amounts (I've used this approach at work for seized threads and other items). I've not had a cam that badly seized so the GT85 method I mentioned above has been fine.