3M VHB Bonding Tape

[maccauley123]

Has anyone used or even heard of 3M Very High Bond (VHB) tape? I saw it mentioned in an article in Good Old Boat about bonding new windows to a new companionway door and it sounds like great stuff. A bit pricey but for what it sounds like it is capable of it sounds awesome. If it lives up to its description I wish I had known about it when I was installing new windows on my boat.

From link below:
Extraordinary strength, conformability, versatility and UV- and weather-resistance makes 3M™ VHB™ RP great for bonding:
Glass • Painted Surfaces
Metal • Many plastics
Sealed wood

3Mâ„¢ VHBâ„¢ RP Tape - 3M US

[hellosailor]

Yes, I think that's the one they use to install huge windows in skyscrapers. Exceptionally good stuff and very well suited for jobs like boats.

[shogan50]

Yes, it works as advertised if you strictly follow the instructions, paying particular attention to surface preparation/cleaning. We use it quite a bit. I've never put it to the test in a marine environment, but I've heard that they build a lot of commercial box truck boxes and residential vinyl windows with it.

[GaryHLucas]

I am planning on using it to install my new windows without using bolts in about 3 weeks. I bought 1/8" thick. I plan to to recess it about 1/8" behind the plexiglas all the way around. Then I'll fill the gap to a nice bead with sealant all the way around. That should allow the plexiglas to expand and contract without breaking the seal. I'll let you know in about 5 years if it worked!

Gary H. Lucas

[DonScribner]

We use it extensively in our industry. Don't count on taking anything off once the tape has cured. Check out the video. I especially like the part where they haul away a few dinning cars with VHB. And the smoking semi tires is cool too.

YouTube - 3Mâ„¢ VHBâ„¢ Tapes tug of war

[svHyLyte]

Originally Posted by GaryHLucas

I am planning on using it to install my new windows without using bolts in about 3 weeks. I bought 1/8" thick. I plan to to recess it about 1/8" behind the plexiglas all the way around. Then I'll fill the gap to a nice bead with sealant all the way around. That should allow the plexiglas to expand and contract without breaking the seal. I'll let you know in about 5 years if it worked!

Gary H. Lucas

Gary. Perhaps I'm dense but I don't understand what your are describing above. In any case, some friends of ours with a sister-ship to our boat that replaced their fixed port lights with 3M VHB 5962 several months ago just finished a passage from Rodriguez Key to the Dominican Republic through the Bahamas and Turks and Caicos, sailing hard on the wind for almost the entire trip. Except at one approximately 1" long spot where our pal admitted he skimped on primer (between the tape and the side of the coach roof), he had no seepage or leaks on the port lights at all (and he did not use "caulking" or "sealents" of any type other than the tape) despite the entire yacht being immersed more than several times. The "primer" is not needed between tape and the Plexiglas but is between the tape and the ship's skin. Note, however, one only gets "one try" to position the "Plexiglas". If it isn't aligned properly to begin with, there'll be no adjusting it.

FWIW...

[DonScribner]

If I were to write instructions for our manufacturing personnel, they would sound something like this:

LEAVE the paper on one side and press it to the glazing. Roll it on with a rubber wall paper roller. Peel the paper off of 1/2" at one corner letting the little tab hang outside the edge of the glazing. Position the glazing on the hull, bare-tape corner last. Mark the opposite top corner for reference. Now, with that 1/2" adhered to the hull, pull the little tab slowly, revealing the tape to the hull. You have a locked location but can pivot it slightly to get the location perfect. By the time you complete one edge, you'll have a hinge point that will keep the glazing accurately positioned and allow it to be about 1" from the mounting surface. Slowly remove the rest of the paper and roll the glazing into place. VHB tape is designed as an adhesive, not as a sealant, regardless of how well it seems to perform. Also, some glazing materials break down when exposed to the elements. I would highly recommend the silicone. Use masking tape around the perimeter and around the edge of the glazing to make a really nice looking shape similar to a sealed gasket. Shoot in the silicone and tool it. Un-tooled, the silicone's seal is questionable at best. GE makes a spray that works really well. Spray it on the silicon, and use a plastic spoon to tool it, one, continuous movement around the perimeter. Then, remove the masking tape immediately. Now, grimace because you just got silicon all over your hands! Use the GE spray to get it off.

This method works well, at least it did for my four port lights.

[GaryHLucas]

About 15 years ago I had a greenhouse customer that wanted to silicone the joints on hundreds of glass panes on his greenhouse. He had already bought a case of silicone in caulking gun cartridges. The first window took him about half an hour, and what a mess. I then took the gun from him and sealed the next window in under a minute, with a real nice looking bead. The secret to silicone is that you must PUSH the bead ahead of the nozzle! You want to point the nozzle in the direction of travel, and allow a small ball of silicone to ride just in front of the nozzle. I don't use masking tape and I try not to tool it unless I really goofed. Usually a wet finger tip is better than any tool too.

Gary H. Lucas