Living near salt water - Page 1
Forum section: electronics / repair

author: joeqsmith
author_rank: Super Contributor
timestamp: May 02, 2018, 11:28:03 pm
content: I have been working on some old scope parts that friend of mine gave me. Those of you that live near salty waters, whats the normal life of your electronics? A month? What a mess....

author: DaJMasta
author_rank: Super Contributor
timestamp: May 02, 2018, 11:42:47 pm
content: If you can keep it in air conditioning, you should be able to get a normal lifetime out of it. If it's always humid and you can see the beach......... you are asking for it. Consider it the tax for living that enviable lifestyle.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 03, 2018, 12:09:38 am
content: Quote from: DaJMasta on May 02, 2018, 11:42:47 pmWith caveats that is exactly my experience. Within 50-100 meters of the beach lifetime can be measured in days depending on equipment and wind direction. Go a few hundred meters inland, get in a good temperature controlled and dehumidified environment and it lasts a very long time. At least until the next major hurricane.

author: Cerebus
author_rank: Super Contributor
timestamp: May 03, 2018, 12:31:35 am
content: Quote from: DaJMasta on May 02, 2018, 11:42:47 pmObviously not a man who's lived on the North Sea. Not all maritime environments are warm and sunny.

author: Cerebus
author_rank: Super Contributor
timestamp: May 03, 2018, 12:49:07 am
content: Speaking as a man who was brought up within 200 yards of the English Channel: I never found that environment had much of an effect on electronics in a domestic indoor environment. However, nobody would be insane enough to try and get electronics to survive outside in that environment without a very carefully designed enclosure. To give you an idea, most motor vehicles would get penetrating rust within about three to five years of being introduced to that environment, sooner in some cases. Everything outdoors, and I mean everything, has a film of salt on it. Any dew or other condensation immediately turns that into a highly conductive paste. Clean windows develop a grey haze the first time there's anything more than a light onshore breeze. If you have things, like electronics, that will be damaged by salt and you need to transport them, in anything but the fairest weather, you put them in a proper case. Once you get about 1000 yards inland things get better, but a properly windy day can still throw salt spray that far.

author: GerryBags
author_rank: Frequent Contributor
timestamp: May 03, 2018, 01:59:37 am
content: I spent ten years living on a big old Grand Banks woody on the Essex rivers, Crouch and Roach mainly, and anything metal corroded very quickly. Electronics was a black art to me at the time, a complete mystery, although I used a lot of bits of kit I was screwed when they broke down and that did happen frequently.Marine grade electronics, which was apparently mainly about the sealing and cooling issues from sealing, definitely have their place, as I remember getting the skipper of the Brownsea Island ferry down in Poole Harbour, Dorset, to help me get a pinnace I owned from the Isle of Wight to London, as I was still learning to navigate then. All I had was a cheapo chartplotter I'd installed, so this guy brought his laptop with complete charts of the UK coast, with a USB GPS antenna, and set it up in the cramped little wheelhouse. It might have been OK on the air-conditioned bridge of the Brownsea Island ferry, but the gunwhale outside the wheelhouse doors of my pinnace was about 4 feet off the water... and there was a reaaaaally thick fog. The laptop sputtered and died after 15 minutes and didn't work again so we had to rely on my shitty little chartplotter. With no radar, a wooden boat and the busy shipping lanes around the Solent it was a moderately nerve-wracking trip, and an object lesson on why computers guaranteed to work in marine environments cost a few grand rather than a few hundred (early 2000's).

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: May 03, 2018, 02:22:24 am
content: I am situated 70 meters above sea level and about 100 meters from the salish sea - what we now call the protected channel between Vancouver Island and the mainland and haven't seen any unusual corrosion effects indoors. The local micro climate is definitely marine airmass temperate rainforest, moss and mold grows on everything. Although the portion of the island I am at is the driest, as it is in the lee of the mountains. There also isn't as much wave action on the east side of Vancouver Island as the west, so less aerosolized chloride or other ions. The two harshest most corrosive environments for industrial controls/electronics that I know of are pulp mills and hog barns. Airborne SO2 and SO4 in pulp mills as well as other nasties wreak everything. Regular conformal coat is like nothing in those places.

author: Ian.M
author_rank: Super Contributor
timestamp: May 03, 2018, 03:02:18 am
content: Yes, repairing small boat electronics is always *interesting* in the Chinese curse sense rather than the intellectual one. When you have gadgets that need to be able to survive significant chunks of salt water repeatedly slamming into them, (a typical Thames Estuary ebb tide with a stiff Easterly blowing will do that in spades, as will being caught out between the Flemish off-shore banks in any sort of a blow) their seals have to be 100% properly designed, defect free and undamaged.When they are not, the invasion of green blue copper chloride/carbonate 'fur' all over the PCB is always a depressing sight on the bench. You clean up as much as you can and if it isn't too bad, patch up the traces and vias that have been eaten away, but you are at best only fighting a holding action, as the failed seals often have design flaws and there is no good way to alleviate them. Also the copper chloride corrosion cycle is particularly insidious - it has the gift that keeps on giving:Copper(II) chloride in the presence of *any* moisture, etches metallic copper to form copper(I) chloride. Copper(I) chloride in the presence of oxygen, carbon dioxide and moisture forms copper(II) chloride and copper(II) carbonate.Its actually the same reaction as is used for commercial PCB etching, except they add hydrochloric acid which drives it much much faster than the very weak carbonic acid (formed from dissolving the atmospheric carbon dioxide in water) can. Therefore once the copper surface is sufficiently pitted that you can no longer totally remove the corrosion (and thus the chloride ions), it will recur, and the only chances of stopping it are to exclude moisture and air from the copper surface. A good solder-through clear lacquer is your friend . . .