Adhesive For WaterProofing Solar Panel on Enclosure

I'm trying to attach a small solar panel to an outdoor enclosure while still running wires into it. I was originally using velcro and running the wire to the bottom into a cable gland; however, I now have a larger enclosure which can house the solar panel on top (picture attached).

What kind of product can I use to "glue" the solar panel to the top of the enclosure so that water doesn't get inside of it around the edges? It'll be sitting outside 24/7. Thank you!

Sikaflex has products that would work well for external effective adhesive 291 for example

Silicon (non-acid) as used by electrical services would work.
Assume you don't need it to come apart easily..??

It does not need to come apart easily. bluejets could you post a link to an example product?

Garden lights use hot-glue for small solar panels.
You could pre-heat the panel and box with a hair drier.

You need something that remains permanently sticky as no conventional adhesives will chemically bond to ABS/PVC/polycarbonate and the materials used in a solar panel.

From easiest to find to hardest:

  • skinning mastic.
  • synthetic rubber dissolved in Toluene. Brand names vary from country to country.
  • “high tack” hot melt adhesive.
  • Polycarbonate sealant such as seal-once or Fulaseal 701.
  • Potting silicone used for underground cable joints.

Don't have to go overboard with that.
Solar panels like that won't last more than three years outside anyway.

For stick mostly forever I would use Scotch 3M 5200 Adhesive and Sealant - used in the marine industry, sticks to anything including you. Available in a couple of colors at most well stocked hardware store's or marine/boating stores

A couple of cautions - clean the surfaces well with a degreaser or adhesive remover (I sometimes use Acetone0 - many items have mold release agents on them - also mask around the area you are sticking to with masking tape - makes clean-up easier and looks neater

Evo Stik Sticks like Sh*t and Gorilla Heavy Duty Grab Adhesive seem to be similar and are very good. Probably easier to get than Sikaflex. The Gorilla version seems to have a longer shelf life in a partly used tube.

Best to apply them while naked because they just love getting on your clothes :slight_smile:


It does not need to come apart easily. bluejets could you post a link to an example product?

Depends which country you are in.

This is the style of thing i had in mind which might help you chase down at your local hardware store.

Contrary to some comments, it will stick like s***t to clay and seal in to the bargain.
Sikaflex was another suggestion which would work equally well.

What's wrong with cheap silicone caulk? It's good enough to seal penetrations into your house.

What's wrong with cheap silicone caulk?

In my experience it is a poor adhesive compared to the other things mentioned here.


Yes, silicon will not work for long. It peels off very easily and leaves a residue that prevents anything else sticking. It’s use should be limited.

Solar panels like that won't last more than three years outside anyway.

I wasn't aware of that. Is the size the reason it won't last longer than 3 years? I assumed they should last at least 5 years. I want at least 5 years from my Arduino project box sitting outside.

If that's the case, then hot glue + hot air gun to soak the box and solar panel may be the best option.

Large solar panels are behind glass, but you uploaded a picture of a cheap one encapsulated in epoxy resin.
How long they last depends on where you live (level of UV light?).
Look at the lights in the gardens around you.
Most of them here (NZ) are milky/white after a few years.
You might be able to get 5-years out of it. Who knows.
Just use HotSnot (glue gun), and a small breathing hole in the bottom of the box.