How to Install Underwater LED Boat Lights – Part 3: How to Use 3M Marine Adhesive Sealant

How to Use 3M Marine Adhesive Sealant

In Part 3 we’ll go through how to use 3M Marine Grade Adhesive to create a water tight seal when installing Liquid Lumens Mavericks Underwater Boat Lights on a Supra SL550.

This is Part 3 of our series on How to Install Underwater Boat Lights, to see to Part 1 click here, or for Part 2 click here.

During the video, we teach you how to properly prep the surfaces that will be bonded together and give you some tips and tricks to working with Marine Adhesives, like the 3M 4200 we used in the video.

If you want to skip ahead to one of the key steps in the process, here are the timestamps for the step-by-step:

1:15 – Step 1: Clean both surfaces to be mated with Acetone or other appropriate cleaner.

1:52 – Step 2: Prepare marine grade adhesive for application.

2:31 – Step 3: Fill any holes that aren’t being re-used, and the 4 new screw holes, with marine adhesive.

2:51 – Step 4: Apply marine adhesive to the back of the boat light fixture.

3:09 – Step 5: Spread the marine adhesive evenly across the back of the light, leaving a small gap at the edge of the light (typically the area outside the outermost machined trough) so that the adhesive has room to spread towards the edge after it’s tightened onto the boat.

3:25 – Step 6: Finish filling any wire or screw holes that need marine adhesive.

3:58 – Step 7: Use two screws to align the light before the light makes contact with the boat (to avoid making a mess). With screw tips positioned into the drilled holes, slide the light into it position on the boat.

4:28 – Step 8: Tighten first two screws about half way into the holes.

4:39 – Step 9: Add any remaining screws and tighten half way into holes.

4:43 – Step 10: Using a low torque setting to avoid stripping the screws, finish tightening the screws down with a drill. Then finish tightening by hand, being sure not to over tighten or strip the screw heads.

5:14 – All Finished!

Now repeat the steps in this “How to Use 3M Marine Adhesive Sealant” tutorial for any additional light fixtures and go enjoy your new Liquid Lumens Underwater Boat Lights! Stay tuned for more of our how to videos. Additional Underwater Light Installation Instructions are also available here.

Please comment below and share your own install photos, videos and tips with us on social media. Let us know in the comment section how we did and what other content you’d like us to see from us in the future. Thanks for watching!

More Posts

The Depth of Lake Powell

  Lake Powell—the second largest manmade lake in existence—spans 185.5 miles from Southern Utah into Northern Arizona. Its formation began in the 1960s through the

Read More »

What are Lumens?

This is Part 1 of a 4 part series discussing Lumens, Candela, Lux and how those three measurements of light performance impact LED lighting in

Read More »