Acrylic vs. Lexan

[jmercer]

Acrylic vs. Lexan for making scales.

What are the advantages and disadvantages of both?

As noted in another thread today, to much heat weakens Acrylic.

I've only made one set of scales so far and I used Lexan in hopes they would be stronger and more durable. Truth is I had a piece left over from another project. It was a chore hand sanding and shaping the Lexan for sure.

My first attempt at making scales. DD Satinwedge scales had warped and shrunk to where the toe was hitting the wedge.

[Geezer]

That is a good set of scales and on a Duck they are a good choice.

To me, Lexan is a bit too soft/flexible for my use. I need to make it a bit thicker than I prefer.
If you wish to save time while contouring, break apart a pair of scissors, wrap the separate handles in friction tape, and use the sharp edges as scrapers, not as a knife; vertical to the surface. Do this after heavy sanding and filing.
~Richard

[jmercer]

Since posting I found this page interesting.

"Plexiglass vs Lexan Matchup"

Plexiglass (acrylic sheet) aka Lucite, Plexiglas, Perspex, Acrylite

92% light transmission - clearest plastic sheet available - about 15% cheaper than polycarbonate
large variety of colors available
light pipes through the sheet edges
does not yellow or discolor in the sun - 10 year warranty regarding 2% loss max.
optically water clear in all thicknesses
inert - no outgassing
thermoplastic - working temp of 180F continuous
burns very nicely after you remove a flame source - fire rating UL94HB
scratches - can be restored by sanding and buffing
resistant to breaking - when breaks pieces are large and dull edged
recyclable
easily bonds with solvent adhesives to itself and other plastics
hydroscopic (will absorb a small amount of moisture on side facing moisture (warps)
available up to 4" thick as a monolithic cast sheet, and thicker via custom casting


Lexan (polycarbonate sheet) aka Tuffak, Makrolon

88% light transmission - very clear - about 15% more expensive than Plexiglas acrylic sheet
limited colors available (white, black, bronze, gray, sign colors)
light does not pipe through sheet edges
untreated sheet discolors in 5-7 years of sun exposure - UV coatings available to extend 15 years
inert
optically clear - loss of some light transmission in higher thicknesses (5% in 1/2")
thermoplastic - working temp of 275F continuous
self-extinguishing fire rated 94V0 - UL rating depending on thickness
scratches - cannot be restored by sanding and buffing
resistant to breaking (virtually impossible to break)
recyclable
easily bonds with solvent adhesives to itself and other plastics
bullet resistant grades are available - all grades of BR levels
hydroscopic (will absorb a small amount of moisture on side facing moisture (warps) and therefore difficult to thermoform without pre-drying
available up to 1/2" thick as monolithic extruded sheet, up to 2" as a molded sheet
Applications:


Plexiglas Acrylic Sheet:
Safety glazing (up to 17 times stronger than glass)
Boat windows and hatches
Machine Guards and Electrical covers
Display cases
Brochure holders
Picture Frames
Lighting
Anywhere you need a clear, impact resistant, easy to cut and maintain sheet

Polycarbonate Sheet:
Safety glazing (unbreakable)
Bus Windows
Machine Guards and Viewing ports
Anywhere you need a clear, unbreakable, high working temperature, easy to cut sheet

[criswilson10]

A few more notes on polycarbonate
When burning it gives of dioxin (highly poisonous).
Not recommended for laser cutting (due to poisonous fumes), but water jet cuts quite nicely.
Polycarbonate will absorb moisture out of the air and I've seen a steel shelf rust from indoor humidity underneath a square of polycarb after about 6 months.

[jmercer]

Thanks for that heads-up!

Well this kills anymore Lexan scales.

"Water vapor isn’t the only substance that polycarbonate sheet can absorb. Researchers have discovered that polycarbonate can also become saturated with oxygen."

Outgassing: Problems Arising Out Of Thin Air

Hygroscopic Plastics

[mainaman]

I have never used lexan, but I have used tons of acrylic. Never had issues with heat. Buffing does not heat it up at all.

[karlej]

I also have used a fair amount of acrylic as scale material. Other than the smell I have not found any drawbacks. Use in a well ventilated area.

[mainaman]

I also have used a fair amount of acrylic as scale material. Other than the smell I have not found any drawbacks. Use in a well ventilated area.

Interesting observation. I guess it depends on the type of acrylic but I have not encountered many that have any smell. I have noticed some smell a bit more than others but nothing like bone or horn or G10 for example.

[karlej]

Interesting observation. I guess it depends on the type of acrylic but I have not encountered many that have any smell. I have noticed some smell a bit more than others but nothing like bone or horn or G10 for example.

I get most of my acrylic from Woodpenpro.com. Monster 1 x 6 Inch Acrylic Blanks, Acrylic Pen Blanks, Acrylics They have a nice selection and you can easily get 2 set of scales from a blank. I have also used polyester from Masecraft Supply and it smells no better. I do think it is just a bit stiffer than acrylic but not much.

[mainaman]

I get most of my acrylic from Woodpenpro.com. Monster 1 x 6 Inch Acrylic Blanks, Acrylic Pen Blanks, Acrylics They have a nice selection and you can easily get 2 set of scales from a blank. I have also used polyester from Masecraft Supply and it smells no better. I do think it is just a bit stiffer than acrylic but not much.

I think polyester is a bit more "stinky" but to me they do not really smell much. The dust they produce on the other hand requires a lot of precaution.