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I would like to use plexiglass as my project enclosure (so everybody can see my messy design!)

My questions:
What to use for gluing. Superglue leaves nasty residue film on everyting and if not accessible it looks crappy.
(So what if they use it to get fingerprints.)
It needs to be strong, fast drying and absolutely invisible.

How do you polish plexiglass? ( The cut edges need to be polished)
I recall using toothpaste, but there must be something made specificly for plexi.
Thanks for reading.
Vaclav AA7EJ

If I recall correctly, "plexiglass" is an old trade name that DuPont Corp. used for their version
of a particular acrylic material. Every plastics manufacturer had a trade name for their various products.

So, first you must know exactly the generic or technical name for the material you are working with.
Then, you can find the correct adhesive for that particular material, and how to cut, mold and/or
machine that material.

You can Google the trade name of the material you want to work with, and then find the correct
methodologies for working with that material

All of these "plastics" ...whatever they are called commercially, are specific polyresin formulations,
each requiring different working techniques.

There is no "one adhesive fits all" situation. If you use the wrong technology with a particular
material, you wind up with a ugly, unstable, cracked and warped mess.

Roland F. Harriston, P.D.
****



vaclav_sal wrote:

acetone is the best for gluing

On Wed, Jan 26, 2011 at 10:03 AM, vaclav_sal <vaclav_sal@...> wrote:

I would like to use plexiglass as my project enclosure (so everybody can
see my messy design!)

My questions:
What to use for gluing. Superglue leaves nasty residue film on everyting
and if not accessible it looks crappy.
(So what if they use it to get fingerprints.)
It needs to be strong, fast drying and absolutely invisible.

How do you polish plexiglass? ( The cut edges need to be polished)
I recall using toothpaste, but there must be something made specificly for
plexi.
Thanks for reading.
Vaclav AA7EJ

[Non-text portions of this message have been removed]

I would like to use plexiglass as my project
enclosure (so everybody can see my messy design!)

My questions:

What to use for gluing.

====

Besides that, I saw on Modern Marvels they use a torch heat to make the sawed off ends clean and ice like.?? This was the kind of plexiglass used for bank tellers.?

I would try it out on scrap plexiglass and do some experiments first.


Jong















[Non-text portions of this message have been removed]

Vaclav

You may polish it with fine sandpaper then rubbing compound. Remember, if
you are polishing the edges you want to keep them flat and square if they
are to be glued to another piece of plastic, therefore, sand and polish
against a flat surface to avoid rounding them over. You can also use a
jointer or power plane very effectively. Put the edges together that you
wish to join with some blue masking tape and take acetone in a syringe and
run it along the seam. It will wick into the joint and that's it.

James "Jim" M. Geidl, K6JMG

No trees were harmed in the sending of this message; however, a large number
of electrons were terribly inconvenienced.

--- In Electronics_101@..., "vaclav_sal" <vaclav_sal@...> wrote:

I would like to use plexiglass as my project enclosure (so everybody can see my messy design!)

My questions:
What to use for gluing. Superglue leaves nasty residue film on everyting and if not accessible it looks crappy.
(So what if they use it to get fingerprints.)
It needs to be strong, fast drying and absolutely invisible.

How do you polish plexiglass? ( The cut edges need to be polished)
I recall using toothpaste, but there must be something made specificly for plexi.
Thanks for reading.
Vaclav AA7EJ

Almost everything you need will be available at Tap Plastics:


MEK (methyl ethyl ketone) is often used to join acrylics as all you really do is melt the surfaces together. There is a special 'dropper bottle' that has a metal needle to dispense directly into joints. It doesn't take much and the surface tension of MEK is probably zero. It flows everywhere. Cant the assembly such that the MEK is flowing down into the joint.

You can sand the edges to get them fairly smooth and then hit them lightly with a torch. Practice on some scrap first.

There are some plastic polishes available on the web site.

I frequently use acrylic sheets to build electronic projects because it is easier to obtain than aluminum sheets and is very easy to cut and assemble.

Richard

BUT, you have to be really really careful not to round the edges...and it
happens real quick. Richard suggested practicing on some scrap and that is
a great idea.



James "Jim" M. Geidl, K6JMG

No trees were harmed in the sending of this message; however, a large number
of electrons were terribly inconvenienced.

solvent glueing is the old?tried and true method
?
"And of what kind are the men that will strive for this profitable preeminence,
through all the bustle of cabal, the heat of contention, the infinite mutual
abuse of parties, tearing to pieces the best of characters? It will not be the
wise and moderate, the lovers of peace and good order, the men fittest for the
trust. It will be the bold and the violent, the men of strong passions and
indefatigable activity in their selfish pursuits. These will thrust themselves
into your government and be your rulers."- Excerpt from "Dangers of a Salaried
Bureaucracy" addressed to the Constitutional Convention members by Benjamin
Franklin in 1787





________________________________
From: vaclav_sal <vaclav_sal@...>
To: Electronics_101@...
Sent: Wed, January 26, 2011 10:03:28 AM
Subject: [Electronics_101] Working wiht plexiglasss - little off the subject

?
I would like to use plexiglass as my project enclosure (so everybody can see my
messy design!)

My questions:
What to use for gluing. Superglue leaves nasty residue film on everyting and if
not accessible it looks crappy.

(So what if they use it to get fingerprints.)
It needs to be strong, fast drying and absolutely invisible.

How do you polish plexiglass? ( The cut edges need to be polished)
I recall using toothpaste, but there must be something made specificly for
plexi.
Thanks for reading.
Vaclav AA7EJ




[Non-text portions of this message have been removed]

BUT, you have to be really really careful not to round the edges...

On the TV show, it did round the edge (ever so slightly).? But they wanted that effect.

But why would rounded edge be bad?? Would that create a place for the "crack" to start?? Or you are saying that complete square edge would look better attached to another 90 degree edge.

Just curious. I have no opinion either way.


Jong















[Non-text portions of this message have been removed]

I think teller glazing is polycarbonate (Lexan) for impact resistance
?




________________________________
From: jong kung <jongkung01@...>
To: Electronics_101@...
Sent: Wed, January 26, 2011 10:21:37 AM
Subject: Re: [Electronics_101] Working wiht plexiglasss - little off the subject

?

I would like to use plexiglass as my project
enclosure (so everybody can see my messy design!)

My questions:

What to use for gluing.

====

Besides that, I saw on Modern Marvels they use a torch heat to make the sawed
off ends clean and ice like.?? This was the kind of plexiglass used for bank
tellers.?


I would try it out on scrap plexiglass and do some experiments first.

Jong

[Non-text portions of this message have been removed]




[Non-text portions of this message have been removed]

They have a special glue for plexiglass and you polish it the same way as
metal. For a trick painted look, paint it on the inside and let the color
show thru or you can paint it on the outside just as you would metal. You
can tap and screw it together if your pieces are thick enough and cut it
just like wood. Hope this might help



73 Tom kf5feo



From: rtstofer [mailto:rstofer@...]
Sent: Wednesday, January 26, 2011 10:31 AM
To: Electronics_101@...
Subject: [Electronics_101] Re: Working wiht plexiglasss - little off the
subject







--- In Electronics_101@...
<mailto:Electronics_101%40yahoogroups.com> , "vaclav_sal" <vaclav_sal@...>
wrote:

I would like to use plexiglass as my project enclosure (so everybody can

see my messy design!)

My questions:
What to use for gluing. Superglue leaves nasty residue film on everyting

and if not accessible it looks crappy.

(So what if they use it to get fingerprints.)
It needs to be strong, fast drying and absolutely invisible.

How do you polish plexiglass? ( The cut edges need to be polished)
I recall using toothpaste, but there must be something made specificly for

plexi.

Thanks for reading.
Vaclav AA7EJ

Almost everything you need will be available at Tap Plastics:


MEK (methyl ethyl ketone) is often used to join acrylics as all you really
do is melt the surfaces together. There is a special 'dropper bottle' that
has a metal needle to dispense directly into joints. It doesn't take much
and the surface tension of MEK is probably zero. It flows everywhere. Cant
the assembly such that the MEK is flowing down into the joint.

You can sand the edges to get them fairly smooth and then hit them lightly
with a torch. Practice on some scrap first.

There are some plastic polishes available on the web site.

I frequently use acrylic sheets to build electronic projects because it is
easier to obtain than aluminum sheets and is very easy to cut and assemble.

Richard

MEK is the common plexi solvent welding material, also another material
called resin-bond, or craftics cement 44
The joint is only going to be as good as your prep work.
The cleanest joints are completely true, fine finished to a 200 grit and
then capillary filled on a floating bed using very fine wire to suspend
the sheet.
Most vendors simply flame polish with a torch, better vendors use a
combination of sanding papers up to 2000 grit and plastic polish, and or
a slow buff and a white polishing compound.
These are labor intensive methods.

typically rounded edges are done with a round over router bit, then the
faces are polished.
It is all a matter of taste, and structural requirements.
High end shops will anneal the material after each machining, solvent
welding and polishing step to relieve all stress and prevent crazing in
the future.

(sorry I used to own a aquarium and filtration manufacturing company in
the 90s, this was my daily work)

Square tight fits make for a strong joint. I glue a facing dish to my table
saw blade before cutting to get square cuts, then just hit the edge lightly
with sandpaper before gluing. Glad you brought plexiglass up as I need to
build a go box for my radio gear, one where the radio stays mounted and you
just grab it and go, take it out set it up connect power antenna and you are
transmitting. Either that or make out of wood.



73 Tom kf5feo



From: jong kung [mailto:jongkung01@...]
Sent: Wednesday, January 26, 2011 10:58 AM
To: Electronics_101@...
Subject: RE: [Electronics_101] Working wiht plexiglasss - little off the
subject

BUT, you have to be really really careful not to round the edges...

On the TV show, it did round the edge (ever so slightly). But they wanted
that effect.

But why would rounded edge be bad? Would that create a place for the
"crack" to start? Or you are saying that complete square edge would look
better attached to another 90 degree edge.

Just curious. I have no opinion either way.

Jong

On 26/01/2011 16:03, vaclav_sal wrote:

I would like to use plexiglass as my project enclosure (so everybody can see my messy design!)

My questions:
What to use for gluing. Superglue leaves nasty residue film on everyting and if not accessible it looks crappy.
(So what if they use it to get fingerprints.)
It needs to be strong, fast drying and absolutely invisible.

Methylene chloride dissolves it, and can be used to "solvent-weld" it.

How do you polish plexiglass? ( The cut edges need to be polished)
I recall using toothpaste, but there must be something made specificly for plexi.

Toothpaste works well, but you can buy a special polish.

Leon
--
Leon Heller
G1HSM

Wow, thanks everybody.
What a well informed and experienced group.
Now I need to find a source of thinker that 1/4 inch.
In TX (Houston) that should not be a problem, hardware stores are everywhere!(Right next to Starbucks)
Vaclav AA7EJ

--- In Electronics_101@..., jong kung <jongkung01@...> wrote:

I would like to use plexiglass as my project
enclosure (so everybody can see my messy design!)

My questions:

What to use for gluing.

====

Besides that, I saw on Modern Marvels they use a torch heat to make the sawed off ends clean and ice like.?? This was the kind of plexiglass used for bank tellers.?

I would try it out on scrap plexiglass and do some experiments first.

For glued edges, you don't need it to be polished. And in my experience, and from my plastics people at PSI in Tacoma, never glue flame-polished edges.

Steve Greenfield AE7HD

On 1/26/2011 8:03 AM, vaclav_sal wrote:

I would like to use plexiglass as my project enclosure (so everybody
can see my messy design!)

My questions:
What to use for gluing. Superglue leaves nasty residue film on
everyting and if not accessible it looks crappy.
(So what if they use it to get fingerprints.)
It needs to be strong, fast drying and absolutely invisible.

How do you polish plexiglass? ( The cut edges need to be polished)
I recall using toothpaste, but there must be something made specificly
for plexi.
Thanks for reading.
Vaclav AA7EJ

Maybe this will help. My brother and I used to make telescope mirrors
from metal, glass and plastic. And we used many different kinds of
polishing compounds, from very rough to extremely fine, like rouge.
Then we would keep "candling" the mirror until it was perfect. Made
some great Newtonian 8-inch scopes that way. Never had to nerve to make
a Argunov--Cassegrain telescope. Just the thought of grinding a hole
through the center of a newly made mirror creeped us out.



Barry

My questions:
What to use for gluing. Superglue leaves nasty residue film on everyting and if not accessible it looks crappy.
(So what if they use it to get fingerprints.)
It needs to be strong, fast drying and absolutely invisible.

How do you polish plexiglass? ( The cut edges need to be polished)
I recall using toothpaste, but there must be something made specificly for plexi.

Don't know about Invisible Glue but You can use Fine Wet Sand Paper to polish your edges.


Ben

--- In Electronics_101@..., "Ben L" <bhleavi@...> wrote:

Don't know about Invisible Glue but You can use Fine Wet Sand Paper to polish your edges.

A good start is to draw a knife blade along the cut edge, hold the blade vertical to the edge, two or three passes will give a good result but you have to be careful not to slip off and leave a scratch on the face.

Tony