How to remove 3M VHB tape?
 

I have a client who is trying to figure out how to fix a large mirror
display for a trade show booth.

There is a 4' x 8' plate glass mirror bonded to an aluminum sheet using
VHB tape.
The frame got hit by a forklift and the glass is now being flexed out
1/4" in the middle.
Not good.

I figured out how to fix the frame, but it would require removing the
mirror.
Any ideas?

Ernie Leimkuhler wrote:

I have a client who is trying to figure out how to fix a large mirror
display for a trade show booth.

There is a 4' x 8' plate glass mirror bonded to an aluminum sheet using
VHB tape.
The frame got hit by a forklift and the glass is now being flexed out
1/4" in the middle.
Not good.

I figured out how to fix the frame, but it would require removing the
mirror.
Any ideas?
Get the solvent from 3M.

"Ernie Leimkuhler" wrote in message
...
I have a client who is trying to figure out how to fix a large mirror
display for a trade show booth.

There is a 4' x 8' plate glass mirror bonded to an aluminum sheet using
VHB tape.
The frame got hit by a forklift and the glass is now being flexed out
1/4" in the middle.
Not good.

I figured out how to fix the frame, but it would require removing the
mirror.
Any ideas?


Perhaps you can thread some dental floss or thin piano wire between the
joint and cut through the tape. Some heat from a heat gun might help also.

Try the dental floss first as it is less likely to scratch the coating on
the back of the mirror.

--

Roger Shoaf

About the time I had mastered getting the toothpaste back in the tube, then
they come up with this striped stuff.

"Roger Shoaf" wrote in message
...

Perhaps you can thread some dental floss or thin piano wire between the
joint and cut through the tape. Some heat from a heat gun might help
also.

Try the dental floss first as it is less likely to scratch the coating on
the back of the mirror.

Spectra fishing line is considerably stronger than steel (or dental floss)
of same diameter.
http://users.acsol.net/~wfi/fish-tuf.html

On Sat, 7 May 2005 11:17:29 +0000 (UTC), "Don Foreman"
wrote:


"Roger Shoaf" wrote in message
...

Perhaps you can thread some dental floss or thin piano wire between the
joint and cut through the tape. Some heat from a heat gun might help
also.

Try the dental floss first as it is less likely to scratch the coating on
the back of the mirror.

Spectra fishing line is considerably stronger than steel (or dental floss)
of same diameter.
http://users.acsol.net/~wfi/fish-tuf.html


Spectra (high strength polyethylene) is strong
in tensile strength, but has a VERY low melting
point. If you saw with it, it will probably break.

I would consider using Kevlar* cord. You can get
Kevlar braided line as used for kite lines. It
will work better as a saw than twisted lines.

In fact, it works so well as a saw that it is
considered too dangerous to use when flying near
other people. Don't try to hold it with your
bare hands; use sticks or rings to hold the ends.
Don't leave it attached to anything where someone
could get caught in a loop and cut themselves.
It will go right to the bone.

If you have to knot it, sleeve it with hollow
braided polyester (Dacron) line before tying.
A long narrow loop of fine music wire will push
through the hollow-braid polyester to pull the
Kevlar through. Visit a kite shop, and you will
find sleeving needles (the wire loop), Kevlar
cord, and polyester sleeving material.

Cruder but easier: cut a couple 3/4 x 3/4
sticks and wrap the cord around one several
times and clamp or screw the other tightly
to it to make a handle.

(*Kevlar is a trademark of DuPont. They write me
to complain every time I fail to mention that.)

--
--Pete
"Peter W. Meek"
http://www.msen.com/~pwmeek/

Braided Wire, Hit a glass shop and ask them for some of the braided wire
they use to remove auto glass. It will cut through the tape like a hot
knife.
Or use a heat gun to melt the adhesive. But that could also damage the
mirror.
If the aluminum isn't that that thick you might try a good auto body
suction cup and pull it back.

--
Steve Williams

"Ernie Leimkuhler" wrote in message
...
I have a client who is trying to figure out how to fix a large mirror
display for a trade show booth.

There is a 4' x 8' plate glass mirror bonded to an aluminum sheet
using
VHB tape.
The frame got hit by a forklift and the glass is now being flexed out
1/4" in the middle.
Not good.

I figured out how to fix the frame, but it would require removing the
mirror.
Any ideas?



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"Ernie Leimkuhler" wrote in message
...
| I have a client who is trying to figure out how to fix a large mirror
| display for a trade show booth.
|
| There is a 4' x 8' plate glass mirror bonded to an aluminum sheet using
| VHB tape.
| The frame got hit by a forklift and the glass is now being flexed out
| 1/4" in the middle.
| Not good.
|
| I figured out how to fix the frame, but it would require removing the
| mirror.
| Any ideas?

3M has a PDF document on removal. Did a search for "3M VHB tape" and
got it directly from 3M's site. It's all mechanical systems to air hammer a
skinny chisel in between the parts and a buffing wheel to remove the
residue, though.

I recall having to disassemble things like this before, and it was a
royal pain. Started with a bunch (a bunch!) of thin wedges and a heat gun.
Starting at one corner and working your way carefully to minimize preload on
the glass, slip the wedges in as the adhesive warms up and softens. You
might be able to take advantage of the preload already in the glass, but
there'll be a point where it pops and the glass could break. Maybe putting
shot bags on the glass would help. The tape won't be all over the place,
just applied in strips, so trying to keep the wedges where the adhesive
isn't will keep them from gumming up with adhesive.

"Peter W. Meek" wrote in message
...
On Sat, 7 May 2005 11:17:29 +0000 (UTC), "Don Foreman"
wrote:


"Roger Shoaf" wrote in message
...

Perhaps you can thread some dental floss or thin piano wire between the
joint and cut through the tape. Some heat from a heat gun might help
also.

Try the dental floss first as it is less likely to scratch the coating
on
the back of the mirror.

Spectra fishing line is considerably stronger than steel (or dental floss)
of same diameter.
http://users.acsol.net/~wfi/fish-tuf.html


Spectra (high strength polyethylene) is strong
in tensile strength, but has a VERY low melting
point. If you saw with it, it will probably break.

I would consider using Kevlar* cord. You can get
Kevlar braided line as used for kite lines. It
will work better as a saw than twisted lines.

In fact, it works so well as a saw that it is
considered too dangerous to use when flying near
other people. Don't try to hold it with your
bare hands; use sticks or rings to hold the ends.
Don't leave it attached to anything where someone
could get caught in a loop and cut themselves.
It will go right to the bone.

If you have to knot it, sleeve it with hollow
braided polyester (Dacron) line before tying.
A long narrow loop of fine music wire will push
through the hollow-braid polyester to pull the
Kevlar through. Visit a kite shop, and you will
find sleeving needles (the wire loop), Kevlar
cord, and polyester sleeving material.

Cruder but easier: cut a couple 3/4 x 3/4
sticks and wrap the cord around one several
times and clamp or screw the other tightly
to it to make a handle.

(*Kevlar is a trademark of DuPont. They write me
to complain every time I fail to mention that.)

--
If you use the kevlar line with a bit of epoxy bonded glass dust on it it
will saw very well.

Doug




--Pete
"Peter W. Meek"
http://www.msen.com/~pwmeek/

On Sat, 07 May 2005 04:53:20 GMT, Ernie Leimkuhler
wrote:

I have a client who is trying to figure out how to fix a large mirror
display for a trade show booth.

There is a 4' x 8' plate glass mirror bonded to an aluminum sheet using
VHB tape.
The frame got hit by a forklift and the glass is now being flexed out
1/4" in the middle.
Not good.

I figured out how to fix the frame, but it would require removing the
mirror.
Any ideas?

I happen to know a guy who used to work with adhesives at 3M. He knows
the Tech service guy who does VHB, Who either knows how to remove the
stuff or can find out. Want me to forward your post to him?

Chris
Don't force it - Use a bigger hammer.

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"Chris Cox" wrote in message
...
On Sat, 07 May 2005 04:53:20 GMT, Ernie Leimkuhler
wrote:

I have a client who is trying to figure out how to fix a large mirror
display for a trade show booth.

There is a 4' x 8' plate glass mirror bonded to an aluminum sheet using
VHB tape.
The frame got hit by a forklift and the glass is now being flexed out
1/4" in the middle.
Not good.

I figured out how to fix the frame, but it would require removing the
mirror.
Any ideas?

I happen to know a guy who used to work with adhesives at 3M. He knows
the Tech service guy who does VHB, Who either knows how to remove the
stuff or can find out. Want me to forward your post to him?

Chris
Don't force it - Use a bigger hammer.

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Newsgroups
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typically, don't they just cut it with a blade? if it's in the middle of the
mirror, perhaps piano wire. it's tough to get off.