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Heat cured waterproofing success
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Heat cured waterproofing success

by meph on Wed Oct 24, 2007 5:28 pm

Thought you'd like to know the heat cured conformal coating worked really well.

In the UK maplin sell Servisol Plastic Seal 60. http://www.maplin.co.uk/Module.aspx?Mod ... &doy=24m10
Comes in a green and white can with loads of warnings. Don't use it inside it absolutly stinks of solvent.

I masked off header pins, switch and contact points of the battery connectors then gave each side 4 coats spraying from all angles and leaving it a couple of hours to dry in between coats.

After leaving it overnight to dry it was still a bit tacky so hearing that it could be heat cured I thought I'd try baking it in the oven. After 2-3 hours (I forgot it and went out) at 100degC on a non-stick tray it came out with a very hard shiney professional looking (IMO) finish all over - and other than a stuck switch still in good working order. At some point the masking must have come off the switch without me noticing and it got coated but by pressing really hard I manged to free it up and you wouldn't know the difference now.

I've a slight concern that water might get under the ICs. I could add more plastic or put some glue around them but I think I'll just see how it goes. cycling around London my bike quickly gets covered in a greasy black film so I might need to clean it at some point.

MikeG
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by Haku on Tue Feb 26, 2008 2:49 am

That's great to hear the conformal coating works well, recently I've had to conformal coat a few circuit boards, first we used DCA SCC3 Conformal Coating spraycan which is a clear silicone resin type and glows up under UV light so you can see if you missed bits.

The clear stuff worked ok with one and a bit coats to try and fully get the board coated but when we tried the DCR SSC3 Red Conformal Coating spraycan it gave the board a completely different look to it, a professional rusty red type colour, you could instantly see where you missed bits and it didn't need a 2nd coat but it also meant you couldn't see any of the component details (chip numbers etc.) which is a good way to hide things.

Both types (there's also black I think) we used were quite evil, the red especially as when wet it stuck to anything and is practically impossible to remove when cured, to spray the boards I went outside, wore goggles and became a world breaker in holding my breath ;) then left the boards at room temp for 20 mins and then cured them at 60C for 80 minutes, they came out perfect.



If all goes well over the next few weeks I'll be ordering a set of 3 SpokePOV's for my front wheel (after a year of first posting to this forum!), then if that goes well I'll order 3 more for the back but that wheel might prove a little difficult because the hub quite large as it's an electric motor, it's not as if I could trim just a few LEDs off the board to shorten it if need be.

But even after all this time I still can't decide what colour LEDs I want...
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by mikeyp on Tue Feb 26, 2008 9:15 am

I used the clear conformal coat the guy used in the first post. It looks great and was really convenient I didn't have to spend ages masking off the LEDs. I did 2 coats each side, and left 20 minutes between coats for it to become touch dry. I then baked them in the oven at 80C for 2 hours. The end result looks great and *should* be waterproofed. That said, I haven't tried them in the rain yet.

If it helps I went for red on the front and yellow on the rear, looks awesome
As for the hub problem, if they're too long, cut them down to BMX length and then change the settings in the spokepov program to bmx wheel and set the hub size in inches. Not a problem.
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by cablemonkey on Sat Jul 26, 2008 3:38 am

I coated all of mine and forgot to mask the damn switch on each one. On two they're "ok" but on the third... it's pretty messed up.

Has anyone found a digikey part that fits in these pads? Ordering from mouser is a real hassle for me (Canadian).

Thanks,

-C.
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Please be positive and constructive with your questions and comments.