I just built a display gauge for my LC1 WB02 controller and i have a lot of spare polyester resin laying around. Just wondering if it's a suitable potting compound or will it cause the PIC and other stuff to act funky?

How thick? It's prone to overheat and crack if it's >1/4"

It would be about 1" from top to bottom. There shouldn't be much heat being generated though, it's just a PIC driving some 7 segment LED's. Would i be better off with silicone or something more flexible?

i think he ment the resin would overheat and crack, ive had this happen on many things, if you lay it in, more than 1/4" thick without mat or something in it, it will crack from the heat being given off from the hardening process.

matthew

Ahh, i see what u mean, no matter, i decided not to pot it anyway but here it is. Just accepts an analogue input from 0-5 volts and displays the afr from 10.0 to 19.9.




The place i got my LC1 from wanted an extra $150 for the gauge so i made this one for like $5

I'm sure it would be fine. no components that need airflow for heat disapation, are there?

Looks good. Ordinary polyester resin isn't a good choice for potting. Polyester shrinks slightly as it cures, which can introduce significant stresses into the electronic components, and then it's very brittle after cure. Potting isn't really necessary for most electronic assemblies, as long as they are mounted in some kind of enclosure, kept dry, and not regularly exposed to corrosive atmospheres (e.g. salt air). Also consider that after cure any potting compound is virtually impossible to remove for repairs or modifications.

If you still want to experiment with potting, silicone rubber is a good material to try. I've used ordinary silicone bathtub caulk successfully, but it's better if you can find one of the silicone rubber sealers that don't include acetic acid in the formulation (i.e. no vinegar odor).

[This message has been edited by Marvin McInnis (edited 01-10-2008).]

quote Originally posted by Marvin McInnis: Looks good. Ordinary polyester resin isn't a good choice for potting. Polyester shrinks slightly as it cures, which can introduce significant stresses into the electronic components, and then it's very brittle after cure. Potting isn't really necessary for most electronic assemblies, as long as they are mounted in some kind of enclosure, kept dry, and not regularly exposed to corrosive atmospheres (e.g. salt air). Also consider that after cure any potting compound is virtually impossible to remove for repairs or modifications. If you still want to experiment with potting, silicone rubber is a good material to try. I've used ordinary silicone bathtub caulk successfully, but it's better if you can find one of the silicone rubber sealers that don't include acetic acid in the formulation (i.e. no vinegar odor).

yes - even better
"aquarium sealant" is a good silicone with no acetic acid
hot glue
rubber cement