10:50 <tct> any experiences of applying acrylic based conformal coating from a spray-can to a PCB? Does one need to apply several layers with drying times in-between or do you give it one firm coat and be done with it?
10:51 <upgrdman> ive never does conformal coating, but with paint you always wants thin coats with drying in between
10:51 <upgrdman> to prevent cracking as the solvent evaps
10:52 <jpa-> tct: doesn't the manufacturer provide instructions?
10:53 <tct> jpa-, more looking for general experiences at this point.
10:53 <tct> also still looking whether I want acrylic based or urethan based
10:53 <tct> so happy for any input you guys can provide - incase of existing experiences :)
11:52 <Steffanx> The only experience I have is that a company does the coating for us, but.. no clue what is being used ;)
11:53 <Steffanx> The were supposed to use some automated way, but in the end the pcb+connectors were too complex for the machine.
11:53 <Steffanx> -_-
11:54 <Steffanx> So they do it by hand
12:10 <zyp> haha
12:10 <zyp> sounds like bad DFM
12:24 <englishman> my place also offered a bunch of different coatings. but we didn't need any of the special advantages of the expensive ones so just went with the cheapest
12:25 <englishman> UV protection, good temp coefficient etc
12:26 <englishman> there is a big difference between how coatings are applied, one place had a cool 6axis squirter with <1mm resolution, the other must have misted it on with a dollar store spray bottle
12:31 <aandrew> tct: when I was in industrial power we started out rattle-can spraying the boards and the results were inconsistent because the people doing it were not really paying attention. We then started having the assembly house do it and results was 1000x better for very very little cost difference
12:32 <aandrew> they used a conformal coat which had a UV tracer in it so after spraying, it was optically inspected to ensure coverage with a UV lamp, which I thought was pretty cool
12:33 <aandrew> a few years later we revisited the requirements and tried just a humiseal instead. we found that that worked for 80% of our needs and we upcharged the 20% who needed actual conformal coat, so win-win
12:33 <aandrew> and the service guys were much, much happier too. working on conformal coated boards is awful
12:34 <Steffanx> DFM zyp?
12:35 <Steffanx> ... for manufacturing?
12:35 <aandrew> I'm not sure if it was acrylic or urethane. the boards were pretty much waterproof but looked like they were dipped in a clear version of the liquid plastic you put your tool handles in
12:35 <aandrew> Steffanx: design for manufacture
12:35 <Steffanx> If yes, then no. Since they said the could do it, but in the end the couldnt.
12:35 <Steffanx> They*
12:36 <aandrew> Steffanx: the first board house who told us they could conformal coat really did rattle-can in a cardboard box, when we found out we decided to jsut do it on our own but got the same (shittier actually) results
12:36 <aandrew> a proper application and inspection makes all the difference in the world