Anyone know of a clear electrical potting epoxy? - Page 1
Forum section: electronics / projects

author: ballsystemlord
author_rank: Frequent Contributor
timestamp: June 04, 2025, 05:08:42 am
content: Hello,I've found black and white, but I wanted something a bit more transparent.Does anyone know of a clear or semi-clear electrical potting compound?Thanks!

author: Jeroen3
author_rank: Super Contributor
timestamp: June 04, 2025, 06:23:44 am
content: Electrolube sells optically clear potting compounds.Eg: UR5634RP250G

author: Geoff-AU
author_rank: Frequent Contributor
timestamp: June 04, 2025, 06:40:04 am
content: If you're using it for any sort of voltage above ELV then definitely buy an electrical potting compound.For my pool light (30VAC) I used non-electrical, slow bio-casting epoxy as I wanted to fill the entire pool light (50mm depth) with epoxyhttps://www.amcsupplies.com.au/product-category/resin-art-supplies/clear-cast-epoxy-resin/Still working fine 4 years on.The Electrolube UR5634RP250G says max 50mm thickness which is pretty good really.

author: Solder_Junkie
author_rank: Frequent Contributor
timestamp: June 04, 2025, 02:41:01 pm
content: The max thickness is because the resin can heat significantly during curing due to being exothermic, and can crack, as well as damage components, with expansion/contraction while curing.I have used epoxy resin potting compound to encapsulate parts in cup sized containers, it gets hot enough to melt thin plastic in those quantities.

author: ballsystemlord
author_rank: Frequent Contributor
timestamp: June 04, 2025, 04:03:18 pm
content: Thanks for the recommendations guys. amcsupplies doesn't ship to the USA. I might be able to find something similar being sold here.I intend to use it for low voltage applications only.I don't need a very deep pour. 20-50mm is sufficient.Thanks

author: ZGoode
author_rank: Frequent Contributor
timestamp: June 04, 2025, 06:45:52 pm
content: Since you mention its low voltage, I would just use a standard deep pour epoxy. Totalboat makes two different ones, depending on how deep you need. They're USA based so it should be easy for you to get here.

author: joseangel
author_rank: Contributor
timestamp: June 04, 2025, 07:30:29 pm
content: Quote from: ballsystemlord on June 04, 2025, 05:08:42 amDepending on your specific requirements, you may also use a transparent/translucent potting silicone, for instance,https://www.dow.com/en-us/pdp.sylgard-184-silicone-elastomer-kit.01064291z.html

author: floobydust
author_rank: Super Contributor
timestamp: June 04, 2025, 07:37:40 pm
content: MG Chemicalsoffers various potting compounds in smaller volumes, you don't need to buy a bucket.Generally, you need to know your temperature range, parts that will not take the thermal expansion/contraction and shear off the board hence the term "electronic potting compound", as well soft (serviceable) or hard, and one-part or two-part, heat/UV/air cure etc. and a few other properties to consider.If this for production - then go to the big manufacturers like Henkel, Dow they will give free samples and have app engineers to pick their best product.

author: jonpaul
author_rank: Super Contributor
timestamp: June 05, 2025, 05:35:22 am
content: Clear RTV Silicon Rubber is usually used.All epoxies need a filler, which is usually black or white.Jon

author: Jeroen3
author_rank: Super Contributor
timestamp: June 05, 2025, 07:43:30 am
content: You don't want an epoxy, you want polyurethane. It's different chemistry.

author: joseangel
author_rank: Contributor
timestamp: June 05, 2025, 05:20:53 pm
content: As usual, there is a vast range of products and many chemical formulations available. There is no such thing as a one size fits at all, however there are more common formulations. For instance, for conformal coating protection one could argue that acrylic is common and a good compromise of sorts, however, there are urethanes, polyurethanes, vinyls and other stuff... The same applies to "potting" or encapsulation.I find this resources very useful and find myself returning from time to time to refresh the formulations, pros and cons. I like it because the information is relatively manufacturer agnostichttps://mgchemicals.com/category/potting-compounds/https://mgchemicals.com/category/conformal-coatings/

author: MisterHeadache
author_rank: Regular Contributor
timestamp: June 05, 2025, 08:50:39 pm
content: We use a lot of polyurethanes and silicone gels to seal electronics on our automotive sensors. Both are very good at keeping liquid water/water vapor away from electronics and can be found in a variety of chemistries and opacities, including very clear formulas (especially the silicone gels).Downsides are gels are very soft and easily damaged, so we use them inside enclosures safe from getting poked. Also the urethanes are horribly hydroscopic before curing and must be stored in inert gas environments - a real pain for using large buckets in production over a few weeks.