With regards to inserting a venture underwater, the straightforward means out is to only stick it in some type of waterproof container, cowl it with sizzling glue, and name it a day. However when it’s good to maintain water out for a number of years, issues get considerably more durable. Fortunately, [Patricia Beddows] and [Edward Mallon] from the Cave Pearl Undertaking have written up their years of expertise waterproofing knowledge loggers for long-term deployment, making the method simpler for the remainder of us.

It begins with the precise board itself. Many SMD boards have not less than some flux left over from the meeting course of, which the duo notes tends to drag water in beneath elements. So step one is to wash them completely with an ultrasonic cleaner or toothbrush, although some elements similar to RTCs, MEMs, or strain sensors must be dealt with with important care.

Precise waterproofing begins with a coating like 422-B or nail polish which every have execs and cons. [Patricia] and [Edward] typically apply coatings to PCBs even when they plan to in any other case seal it because it affords a closing line of protection. The lower edges of PCBs must be protected in order that water can’t seep between layers, although care must be made for connectors like SD playing cards.

Encapsulation with quite a lot of supplies similar to sizzling glue, warmth shrink tubing, superglue and baking soda, silicone rubber, liquid epoxy, paste epoxy (like J-B Weld), and even wax are all commented on. The most important drawback is {that a} materials might be waterproof however not water vapor proof. Because of this condensation can construct up inside a housing. Temperature swings can also play havoc with sealings, inflicting gaps to look because it expands or contracts.

General, it’s an unbelievable information with useful suggestions and tips for anybody logging knowledge underwater for science and even simply making an attempt to waterproof their favourite watch.