18Views2Replies

Author Options:

Mirror acrylic Glue Answered

Hey,

I have been researching the best way to glue acrylic mirror together into a cube the same as the picture attached.

So far I have been told it is quiet hard but Dichloro is what my supplier was able to find out. I have read a lot of health hazards and difficulty getting hold of it. Is there any that would be able to point me in the right direction.

With my normal acrylic i just use a weldbond etc but the mirrored surface would not be suited.

Thanks in advance everyone.

Discussions

0
None
Downunder35m

11 days ago

There are several options apart from the traditional glue.
Let me give you some examples how I get around the pesky task of "sticking" acrylic together:

1: Surface preparation!!
Despite common believe giving the to be glued surface areas a proper sanding help a lot to get proper adhesion!
Unless you have the parts proffessionally cut it makes sense to have them about 1mm bigger than what you actually need.
A piece of sandpaper on a really flat surface (I prefer a pane of glass) allows to create a really flat and smooth edge.
Any imperfections from the cut disappear and you can sand it down to be accurate as much as you dare.
All areas not to be glued should be protected with some sticky tape!
2: Test the fit!
Using clamps, rubber bands or just sticky tape, make sure all parts fit together perfectly before trying to glue any!
You want no visible gaps, no bits poking out and certainly no uneven surface areas.
3: Alternatives to standard glue...
For normal acrylic I prefer to use just acetone.
A quick wipe with a damp piece of paper or similar to soften the surface then a few drops evenly applied - for flat fittings like doubling up on thickness.
To do box like things it works really well to fit the parts dry.
Using a syringe you can let some (little) acetone fill the gap area until it appears "clear" and without air bubbles or trapped air.
Let dry off for about 20 minutes on a normal day then apply again if you still spot some air pockets.
Do not wipe off any tiny run offs or drops!
Instead use a hair dryer on cold of a small fan to evaporate the acetone quickly.
Final curing time depends on how wide the matching surfaces are but usually a few hours is sufficient.
4: Fixing up the haze...
Unless al was perfect and went perfect you will end up with more or less of a mess in terms of haze where the acetone did not evaporate quickly enough.
Fine metal of plastic polishing compount works gret here to get the full shine back quickly.
Do not use stuff that already feels sandy if you rub it between your fingertips!
Autosol make a really good polishing paste for acrylic that goes a long way.

What not to do...
A lot of people love to flame polish their acrylic parts after cutting or sanding.
It gives a really nice shine but there are massive downfalls.
Firstly it is much harder to glue and the polishing is done by the glue when applied and cured.
So it is totally useless for surfaces that will be glued anyways.
Secondly it can cause big problems later on.
Alcohol will be a deadly mix if it gets onto flame polished areas - they turn dull or even crack badly!
Never use too much acetone!
For me it works best to have the joint going vertically so I drop the acetone from the inside corner and if it is too much it will run off to the outside corner but not down a surface.
Do not test the strength until it is fully cured!!
Acetone works fast but it takes a long time to evaporate out of the inner parts of a joint!
This slow process softens the material and allows it to basically flow together and form one solid piece.
Putting strain on it before it is fixed can cause warping or the joint to snap.

Alternatives to acetone.
There are some really nasty things out there that will be recommended by people.
Strongest bond possible, no run offs or hazing....
Fact is that all solvents come with side effects,both on the material and you.
Apart from pure acetone there is only one "household" chemical I would use if a stronger bond is required.
M.E.K. - Methyl-Ethyl-Ketone, or PVC primer from the plumbing department ;)
The stuff is quite nasty in terms of evaporating fast with a lot of fumes in the air, outside use is prefered.
It also causes significantly more hazing than acetone so extra care is required to prevent a massive polishing session.
The hazing is also quite bad even if you evaporate the execc off quickly.
Done right though and the parts usually break in other places than where you glued them together.

Corner finnishing....
A major problem for some people seems to be getting smooth and nicely rounded corners.
Once sanded round there are often small airpockets appearing that seem to ruin the corner work and sanding down more is often no option.
If you keep the dust from sanding the parts flat you can use it with a few drops of acetone to make a "filler".
The acetone will evaporate, the fine dust turns into solid acrylic within the gap ;)
Works also quite well on messed up parts that fail to form a water or air tight seal.
Just let the mix run into the affected area and it will seal it off for good ;)

0
None
Jack A Lopez

11 days ago

Have you looked at the Wikipedia article for PMMA; i.e. poly(methyl methacrylate)?

https://en.wikipedia.org/wiki/Poly(methyl_methacry...

That's another name for the plastic you call, "acrylic". As you can read in the first paragraph, this one is known by half a dozen different common names and trade names, which maybe makes it a little confusing for those who have only heard it called one name, or less.

The section of that article, titled, "Handling, cutting, and joining",

https://en.wikipedia.org/wiki/Poly(methyl_methacry...

has some suggestions for what can be used for glue, including dichloromethane, tricholormethane (chloroform), and also cyanoacrylate cement (commonly known as superglue).

The article itself of couse has links to other Wiki pages for more info about those chemicals.

I have never heard of, "weldbond etc." Maybe that one is something local to stores in your neighborhood.

I know for sure that sheets of PMMA can be joined together, because I occasionally find in dumpsters, strange, custom-made, PMMA artifacts, like shelves and other things for displaying store merchandise.

So I know there are effective ways to join pieces of it together, because I have seen evidence of it. Also when done right, it is pretty difficult to break apart.