Fixing broken solar panel glass with a silicone encapsulant

Fixing broken solar panel glass with a silicone encapsulant

I had a new solar panel propped up against a tree and it got knocked down by the wind and shattered (PSA, don’t do this).  The panel was still giving good current, however with the broken glass water would have quickly worked its way in and started corroding the components.  Rather than replace the panel I decided to make an effort to repair it (the warranty was voided anyway).

Broken solar panel
Broken solar panel – what have I done?

After giving it some thought I settled on a clear Silicone Encapsulant from Quantum Silicones called QSil 216.  This is a liquid silicone that cures into a solid flexible rubber-like material which protects electronics from moisture and vibrations.  It has a low viscosity and works its way around components as it cures sealing everything together.

QSil 216
QSil 216, ready for mixing

In the video you can see how I used a piece of wood to apply the product.  I had a comment that this may scratch the solar cells, however the glass was still mostly intact and covering the cells so the wood never touched them.  Here is what it looked like after I finished:

Repair job finished
Repair job finished

Temperature and Humidity during the cure process

The data sheet for this says it’s supposed to cure in 4 hours at room temperature, what I found is that it took MUCH longer.  I had it curing for a total of over 36 hours between 65 and 80 degrees Fahrenheit (that’s 18 to 27 for those of you in the rest of the world) and about 35% relative humidity.  Thanks to one of my sensor projects I have a log of the temperature and humidity in my garage over time so I was able to produce a report during the duration of the curing process:

Temperature and Humidity during the cure time
Temperature and Humidity during the curing process

It cures clear, and in the video above you can see it’s highly flexible.  Here is a close-up of the cured product that remained in my mixing cup when I was done:

Clear Stuff
Clear stuff

As far as I can tell it’s working fine after the repair.  However it’s October, I have it mounted in a area that gets a fair amount of shade, and I don’t have any identical OEM panels I can test against so I don’t know for sure how we’ll it’s doing as compared to when it was new.

If anyone has a good suggestion for how I might test the output of this panel as compared to original specifications I’d love to hear your ideas.  Please post in the comments!

Hope this helps if you find yourself in a similar situation.


Notify of
Newest Most Voted
Inline Feedbacks
View all comments
3 years ago

How has it done with oxidation over time? Any yellowing or less transparency in the last 6 months?

3 years ago

Good day to you. I need repair 3 solar panel. Each solar panels front glass dimension is 155×98 mm. How much need Qsil216? Which are the best these products: Sylgard 184, Qsil 216, Syl cell 1084, Cell gard.

Reply to  Gereltod
1 year ago

Hi there,
I am unable to find Syl cell 1084 and Cell gard products online. I will appreciate any pointers to the manufacturers or sellers of these products. Thank you.

2 years ago

In event that the damage was much to pill or create a hole through the solar panel glass , would Qsil216 close the gap and cure well

Reply to  Emmabeat
2 years ago

If the hole is completely through the panel then you would need to plug it else I think the Qsil would flow through the hole while you wait for it to cure – as you can see from the video it took a good deal of time to finally cure and it was fairly viscous until it finally did. Once cured it wouldn’t flow through the hole, but it’s still quite flexible…so maybe affix a hard surface at the base before sealing with the Qsil216.

Can I ask – how did you put a hole through it?

1 year ago

I have read contradictive report with this product.
Many people report that it will peel when you ant to clean it from the regular dust (pollution)
What is your input on this?
Is it possible to clean it?

Would love your thoughts, please comment.x