hi sonya and others
those "awful" window locks have been on airstreams a mightly long time.....at least 30 years. they are simple to service, provide a positive locking mechanism and owner adjustable when new or as they wear or the gaskets wear or as the frames wear.
for old streams it's nice to know that the parts are still in use and readily available.....and that the windows can be closed tightly with this simple mechanism.
i've noticed that the red painted versions....a result of "safety" improvements are more prone to stick. i think it's because the metal on metal surface is fouled by paint. the most proper correction therefore, is to remove the handle (use an allen wrench) sand the paint off the friction surface and re-attach.
for a simplier solution or on the non painted variety.....
first make sure the contact surfaces are clean...open the window, go outside and inspect the latch mechanism. open and close it several times and rotate from latched to unlatched positions....open an close lots more.
yes they might need adjusting but usually this is an issue as they wear and need to be tightened some.....seldom do new ones need loosening if properly cleaned and lubed. yes they are tight on new trailers...but that's how they are supposed to be.
because the mechanism is metal on metal, silicone is not the ideal long term lube. a much better choice is graphite or dry ptfe or a light oil....one drop is all that's needed....just make sure the lube gets to the proper surfaces. again when you inspect closely the location is obvious for the "handle closed" position.
if on the other hand the issue is turning the handle, first determine if the handle turns freely when the window is open....if not... lube the threads. if the handles turn freely when the window is open but not when securing the window, they may need adjusting....or a drop of lube/graphite on the flat hook where it engages the window clasp may solve the problem.
again try everything (cleaning and lubing) BEFORE adjusting the lock nut/lever........because if you fail to get the latch properly tighten, after adjusting, it may come loose/off during travel. having a window flop open and shatter is a more "awful" problem than a sticky latch.
while spray lubes are popular, all of the sprays tend to scatter onto the window itself and make them messy. then if you "spray" the glass area with window cleaner, you end up removing the lube during cleaning...so back to square one.
better to apply whatever lube in a droplet form to avoid getting the glass messing at all. try to lube just the metal friction/contact surfaces.
candle wax or bar soap can also be used for the lube with the added benifit of not attracking dirt and washing away if rain gets on the latches.
as for wd-40.....yes there are lots of myths about it....becoming a "solid mass" is a new one.....and i doubt that can happen.....especially since most of the useful properties of wd are a result of it solvent character......
if the window latching mechanisms happen to get soaked with water that's eactly when wd-40 would be most useful.......
the 'wd' stands for "water dispersant" and represents the original purpose of the product.....to 'disperse/displace water' from metal and surfaces/contact points that might oxidize or otherwise deteriorate when exposed to water. the wd 40 displaces the water and replaces it with a light, volitile, short lived lubricantand solvent and anti-corrosive film.
for those interested the wd40.com website is interesting and fun. so is the list of 2000 (and growing) uses for wd-40....
good luck with those window latches!!