How to Glue/Adhere/Attach Wood to Plastic (Polyethylene and Polypropylene) With 100% Silicone Caulk

100% silicone caulk makes an excellent glue/adhesive when attaching wood to plastic like polyethylene/polypropelene. Given that construction adhesives cannot grab onto hard plastics since plastics are non-reactive, 100% silicone caulk is an excellent alternative.

Parts:

• 100% Silicone caulk (be sure it is not acrylic)
• Caulking gun
• Wood (using cedar wood shims here)
• Hard plastic like a trash bin
• Heavy duty cutters or snips

Step 1: Preparation

1. Use the heavy duty cutters/snips to cut open the silicone caulk spout.
2. Use the puncture tool on the caulking gun to puncture the inner seal at the bottom of the spout.
3. Load the silicone caulk into the caulking gun.
4. Open the cedar wood shims and test place where you want the shims to go on the hard plastic

Step 2: Apply Silicone Caulk and Attach

1. Using the caulking gun, put silicone caulk onto the wood shim in a rough "S" pattern.
   
2. Use a wood paint stirrer or your finger to smooth it out.

Step 3: Place Wood on Plastic

1. Place wood on plastic
   
2. Press firmly into place
   
3. Repeat steps with additional pieces of wood
   
4. Give the silicone caulk about 24 hours to cure.

Comments

[drewwiens0]

I can confirm that 100% silicone caulk does not stick very well to high density polyethylene. Sitting right next to a project where all the silicone is falling off when I barely touch it. Polyurethane caulk was better, but not by much. The only adhesive I've had luck with is high temperature hot glue. I haven't tried cyanoacrylate.

[tytower]

I don't think that will stay attached very long . You have 3 different materials all with different rates of expansion and contraction and you didn't even clean the plastic first?

[matt392]

This technique was used to attach wood to the bottom of a plastic trash bin to repair a large crack. So far, it has lasted a NYC winter and NYC Sanitation workers handling of the bin.

[matt392]

Also, a business colleague of mine has used this technique to attach letters to the outside of a pizzeria in Brooklyn, NYC. He reported that they stayed attached for years.

[matt392]

Silicone caulk not only has very strong adhesive properties, but it is also quite flexible.