Glass vs. plexiglas for display boxes

[Nick Schepis]

I have plans to build some display boxes of various sizes in the near future. They will range in size from an autographed electric guitar to a pocketknife.

These will rarely be opened after completed.

My first inclination is to use plexiglas because I can buy it in sheets and (I presume) I can cut it to size myself with the woodworking tools I already have.

Any experiences or suggestions are welcome.

[Jamie Buxton]

Yeah, plastic is easy to manipulate in a wood shop, so that's good. And it doesn't break into dangerous shards. On the down side, plastic attracts dust, is easily scratched, and feels flimsy.

[Andrew Seemann]

Acrylic and polycarbonate are easy to cut and size, glass less so. Glass doesn't yellow with age, acrylic and polycarbonate might, depending on location, coating and around of UV light. Acrylic and polycarbonate don't break easily, glass can.

Given the option, myself I would probably use polycarbonate or acrylic. It is much easier to work with and shouldn't yellow as long as you don't put it in direct sunlight all day long.

Note that you want to use a fairly fine toothed bandsaw blade with thin acrylic/polycarbonate; it can be prone to cracking while cutting otherwise. It doesn't want to be cut too fast (chipping and cracking) or too slow (melting); the right speed will become apparent pretty soon. If you have to do a lot of drilling, you might want to grind some flats on the edges of your drill bit. Acrylic and polycarbonate prefer to be worked with neutral or slightly negative rake tools; the cut can propagate into the work at an angle away from the cut with positive rake tools (like normal wood working tools).

[johnny means]

The only real upside to mineral glass is scratch resistance.

[John TenEyck]

If these are going to stay on the wall, on a shelf, or otherwise stationary I would use glass. Easy to clean and looks better. Plexiglas is the right stuff when transport is a regular requirement, but not otherwise to me.

John

[Keith Outten]

You can reduce the dust attraction problem by lightly rubbing acrylic with a used dryer sheet. It will reduce the static charge in the plastic and this works on your face shields and just about any other type of plastic material. I use dryer sheets, on my Polaris RZR ATV when I am trail riding, on my windshield and it does a great job when the trail dust is really bad. Been using dryer sheets on my shop face masks and plastic lens glasses for decades. My wife saves the dryer sheets in a ziploc bag for me so they stay clean.

When you mentioned display boxes I assume that you don't necessarily mean framed boxes, rather boxes that have acrylic on all sides. If this is true you will find acrylic is very easy to bend with a heat gun so you can reduce the number of seams you have to glue.

[johnny means]

If these are going to stay on the wall, on a shelf, or otherwise stationary I would use glass. Easy to clean and looks better. Plexiglas is the right stuff when transport is a regular requirement, but not otherwise to me.

John

Why would you think glass looks better? Unless you get into Corning Gorilla Glass or similar exotic high dollar products, Plexi has better clarity and higher light transmission with less glare.

[Brian Holcombe]

Why would you think glass looks better? Unless you get into Corning Gorilla Glass or similar exotic high dollar products, Plexi has better clarity and higher light transmission with less glare.

This is my experience as well, I've used glass because I had a good local source, but recently for all of my professional work I've moved to Acrylic. I have recently used Mar-resistant UV filtering Acrylite acrylic and it's really beautiful stuff, easily as nice a product as the better forms of framing glass and come at a lower risk in use.

My local source for glass decided to quadruple their pricing for reasons beyond my understanding and also pickup same day turned into pickup a week or more later. Too much wasted time and running around. Nice to simply plug all of my info in and get the product in a few days.

I had one client I have been framing for with acrylic for 5-6 years, all of it still looks brand new and indistinguishable from glass. Acrylic is half the weight, so on larger projects I can bump up the thickness of the acrylic to avoid drooping or flexing so that big sheets are still flat in appearance.

[Matthew Hills]

Brian,
How do you cut the acrylic to size? And what thickness do you use?

My attempts to use acrylic or poly carbonate haven’t been totally happy—messy and prone to either melting or rough cut. (I’ve tried both table saw and band saw. And feel like I’m still missing something)

Matt

[Nick Schepis]

When you mentioned display boxes I assume that you don't necessarily mean framed boxes, rather boxes that have acrylic on all sides. If this is true you will find acrylic is very easy to bend with a heat gun so you can reduce the number of seams you have to glue.

Yes, an understated, but attractive hardwood frame with a clear insert to display the item most probably hung on a wall.

Probably something along the lines of this:

382361

[Brian Holcombe]

Brian,
How do you cut the acrylic to size? And what thickness do you use?

My attempts to use acrylic or poly carbonate haven’t been totally happy—messy and prone to either melting or rough cut. (I’ve tried both table saw and band saw. And feel like I’m still missing something)

Matt

Matt, I order it cut exactly to size. You can buy router bits specifically made for plastic, I’m sure the same is true for saw blades.

i use .080, .092 and .118” all depending on the application.

[Andrew Seemann]

Hi Matt,

Standard woodworking table saw blades have a positive rake which will crack and chip plastic. You can get special plastic cutting table saw blades that have a neutral (0 degree) rake angle, basically the front of the tooth is flat and not angled forward or sideways. Sometimes the tooth is even angled slightly backwards (negative rake angle). Plastic has to be cut with a tooth that scrapes. Any forward angle will cause a crack to form and angle into the plastic away from the cut. Using a standard angle woodworking blade on acrylic or polycarbonate can be quite dangerous actually.

For a bandsaw you want a blade with as little hook as possible and for thin material definitely not a skip tooth blade. Thin plastic cuts better and safer on a bandsaw than a table saw, but it wants a pretty fine blade.

[johnny means]

A less than ideal blade hook can be negated with a slow feed sled, when cutting hard plastics. I've even just run a blade backwards in a pinch. I prefer to cut oversized than route or joint to size. This reduces the need for sanding in applications where a clean edge is called for.

[Jim Barstow]

There are 2 overwhelming reasons for NOT using glass:

1. Earthquake
Not sure where you live but earthquakes can happen anywhere (and are now happening up where fracking is common).

2. Safety around kids
Not sure what the specific building code rule is but glass cabinets are supposed to use safety glass.

I use museum plexiglass unless I need antique glass (design not age). I get the antique glass tempered to make it safe. It's
not cheap but using non-safety glass is dangerous.

Museum grade plexiglass is truly amazing. It is so clear it is almost invisible. I've had to check at times thinking that it really wasn't there.

[Art Moore]

I use a lot of plexiglass for Doll Cabinets, usually .093 Optiplex from the Big Orange box store. When cutting it, I make a template from 1/8 or 1/4 hardboard and then use Blue painter's tape on both sides where the cut is going to be. Same thing when drilling, tape both sides and go slow, with a light touch.

[andrew whicker]

This is my experience as well, I've used glass because I had a good local source, but recently for all of my professional work I've moved to Acrylic. I have recently used Mar-resistant UV filtering Acrylite acrylic and it's really beautiful stuff, easily as nice a product as the better forms of framing glass and come at a lower risk in use.

My local source for glass decided to quadruple their pricing for reasons beyond my understanding and also pickup same day turned into pickup a week or more later. Too much wasted time and running around. Nice to simply plug all of my info in and get the product in a few days.

I had one client I have been framing for with acrylic for 5-6 years, all of it still looks brand new and indistinguishable from glass. Acrylic is half the weight, so on larger projects I can bump up the thickness of the acrylic to avoid drooping or flexing so that big sheets are still flat in appearance.

Will your vendor cut 45 chamfers too? Like you can make an entire cube of acrylic?

[Andrew Seemann]

Hi Art,

Grinding a small flat on the cutting edges of the bit will make the plexi much happier when drilling it. It will be less stressful on the plexi and you:)

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[Brian Holcombe]

Will your vendor cut 45 chamfers too? Like you can make an entire cube of acrylic?

I haven’t had the need, but worth contacting them to see if it is possible: acrylite-shop.com