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VHB tape for post signs?
Posted by Jeff on October 30, 2024 at 2:18 pmhi gang
do any of you use VHB tape for attaching sign channel to composite or aluminium?
do you just use VHB tape and hope that it works? 🤨i want to install some 8×4 signs on posts with sign channel on the rear, but i don’t want to have rivets all over the face of the sign.
i am told that VHB will do the job “on its own” and I am happy to give it a go but i do not want it blowing off and hitting a car or someone, in a few months time.any advice or tips on the best stuff to use would be great! 👍
p.s. i have used this in the past but not for large signs with only tape holding them.
Jeff replied 1 week, 1 day ago 6 Members · 10 Replies -
10 Replies
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Hi Jeff,
i have used VHB in the past without any fixings but not at 8×4 size.
I would be sceptical and i think you will find most people will say a mechanical fixing is needed especially at this size. -
Experimented once with 8×4 sheets and VHB tape to answer this question- the ‘flex’ of the sheet made the rails pop-off when we moved it!
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Hi Jeff,
assuming you are covering the sheet with vinyl, we would use VHB and also countersink rivets before applying the graphic.
Obviously you lose some strength by countersinking but you can buy countersink rivets and use more of them. If you look closely you may be able to see them through the graphic but by and large, they disappear -
thanks for the advice guys. 👍
mike, i have not used those rivets before, do you not need a special tool to fit countersink rivets?
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i am of the same opinion. i wouldn’t feel confident that a tape would hold a large sign.
i saw a vhb test done on youtube a while back but i have just had a look and i cant find it. these three videos came up though.
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Thanks for the videos mark, it gives a bit of reassurance. 😬🤣
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Around 15-20 years ago I was introduced to 3M VHB tape by a company called Kreiffe or Grieffe or something like that, they had a green and black logo. Vague, I know!
Anyway, the tape was introduced to me as a rivetless tape for free-standing signs.
I remember saying, “I do not think a tape would ever be as good as rivets”.
His response was. “The largest traffic sign in the UK was held together entirely by VHB tape, only”. 😬🧐The application process that we were shown was:
* Clean both the channel and the panel surfaces thoroughly with isopropyl alcohol.
* Cross scratch/score the surfaces and clean again.
* Apply the tape to the channel rail and roll over it with a firm rubber roller.
* Apply the channel to the cleaned and scored area, and repeatedly roll over the channel to make sure there has been pressure applied the entire length.
* Allow a bonding period to allow the adhesion to build, and you are done.
* This should not be applied to cold metal. We would always glaze over the surface with a heat gun before and after it is applied.Since back then, they have added…
* Use 3M surface cleaner
* Apply 3M PrimerIn all those years, I do not think we have made a sign larger than 4ft x 4ft with “only” sign channel and VHB tape to hold it.
I am not saying it cannot hold. I do not think 3M would be selling it for this purpose if this was the case. I am just saying that I have purposely not used the “tape only” to fix the channel to a sign bigger than that.
I have always been a belt & braces guy, I just prefer the peace of mind that the sign is not coming down.A different scenario…
Many years ago, we had multiple channel ACM composite panels come down in very high winds at one customer’s site, over a single weekend.
When I went out to inspect the damage, which was in a quarry. I couldn’t believe that the channel, clips, poles and even the rivets were still perfectly intact, but the ACM sign panel was 50+ yards away! I retrieved the 5 affected composite sign panels and every one of them showed the same problem. The winds were so strong that the rivets had been torn through the soft ACM face and out the back. These were not big signs, maybe around 3x3ft and 6x3ft max.
From that day on, for any ACM free-standing signs we make, we apply 75-100mm of VHB at every spot a rivet will be placed. The VHB is there simply to help spread the load over a larger area at the fixing point. The ACM was Rynabond, so not a budget brand, nor a lite version of the material. The next step up is to move to a solid aluminium sheet.I will just add:
Be sure to check the type of VHB tape you are using. 3M have a white and a grey version. Some VHB tapes are for acrylics and composites, others for metals etc. And not all VHB tapes are 3M. It is best to make sure you use the correct tape to bond the material you using. -
thanks rob, informative as always mate.
i will take your tip and use the tape as well as rivets. hoping that this way it will reduce the amount of rivets needed.
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