What material are the actual pickguards?

[Hotzenplotz]

Yes, that is my question.


In former times there was plexiglas used for the plates.

What kind is the actual, white material? Perhaps polycarbonate?

Does anybody know more about?

[jingle_jangle]

It's still acrylic--whatever the brand name. Plexiglas was a trademark of Rohm and Haas, who no longer make it. Chemically, it's methyl methacrylate, polymethyl methacrylate, or polymethyl acrylate.

It's formulated by hundreds of companies worldwide and can be purchased under many brand names. Perspex and Acrylite are only two of the most common.

[Hotzenplotz]

Yes, I know, there are a lot of brand names.

Plexiglass is PMMA, independently from the company that is producing it. (I could have asked better this way)

So I ask if it is polycarbonate or polyacrylate. That is the chemical name, both.

But You already said it is some kind of acrylate, thank You. The reason for the question is that I want to cut some scratchplates for me. I want to use the right material - but clear for painting in gold.

[johnhall]

If you're intending to use clear material, I would personally use polycarbonate (Lexan). There are some challenges to painting acrylic that you may not want to deal with; we know how to control the conditions and use special materials in production that you might not care to learn on your own or have easy access to. Polycarbonate is quite a bit more expensive but simple to work with. It's also pretty indestructible.

[jingle_jangle]

The main issue with painting acrylic has to do with the type of acrylic. Cheaper acrylic (which is extruded material, and usually has a plastic film protective covering) will sometimes craze along the surface and cut edges as the solvent in the paint attacks the acrylic.

Cast acrylic is the premium stuff, can usually be distingished by its paper protective covering (although it's always best to ask or specify in advance, as this is not a hard and fast rule) and paints like a dream.

No matter which acrylic you may use, keep denatured alcohol away from it...

Polycarbonate is great stuff: very impact-resistant, takes paint well. It should be noted, however, that it has a violet cast along its edges, whereas acrylic has no color shift at all.

[Hotzenplotz]

Thank You!


So I will try to use polycarbonate. Some call it "lexan" or "makrolon", depending from the producing factory, right.

As I know polycarbonate is the same like cd's. Unbreakable under normal conditions. And better for painting, because PMMA affects very often fissures when it is painted.

In a few days You can see the result of it...

[ken_j]

Having used polycarbonate for a number of engineering projects over the years I have found that while it is a strong material be cautious of solvents and certain cleaners. I have seen polycarbonate break down looking like shattered tempered glass when using the wrong solvent to clean it. This happens in a matter of seconds.

[johnhall]

Having used polycarbonate for a number of engineering projects over the years I have found that while it is a strong material be cautious of solvents and certain cleaners. I have seen polycarbonate break down looking like shattered tempered glass when using the wrong solvent to clean it. This happens in a matter of seconds.

I think you may have seen acrylic rather than polycarbonate, because the solvent cracking issue is precisely why I mentioned using polycarbonate in the first place. My own experience is that it doesn't solvent crack.

[ken_j]

Put some 1,1,1-trichloroethane on it. Unfortunately this chemical is found in more items than one would think.

[jingle_jangle]

Polycarbonate is not universally resistant to solvents. In addition to the 1,1,1-trichloroethane mentioned by Ken, there a number of solvents and categories of solvents which will cause crazing. These include toluene, methyl ethyl ketone, ethanol, methanol, methyl-isobutyl ketone, acetone, xylene, benzene, and ethylene and methylene chlorides.

While trichloroethane is most often used as a degreasing solvent in industry, all of the other above-mentioned solvents can be present to a greater or lesser degree in lacquer and urethane paint solvents.

Polycarbonate tends to yellow with exposure to sunlight. Cast acrylic does not. Polycarbonate is far more impact resistant than acrylic of the same gauge, but has a much softer surface, making it more susceptible to scratching. Acrylic, in addition to being more scratch-resistant, can be polished back to full luster, which polycarbonate cannot. Polycarbonate is 50% lighter than acrylic per cubic unit, and 15% of the weight of glass.

So it really comes down to which characteristics are appropriate for your application, and whether cost is a factor. Last week I purchased some 1/4" cast acrylic and some 1/4" polycarbonate for machine shields, and the polycarbonate was twice the cost of the acrylic per square foot.

[Hotzenplotz]

I need it for a set of scratchplates for my guitar.

I know to keep away a lot of substandes that are harmful when they get in contact with polycarbonate.
Mostly I use a clean and dry cotton cloth directly after playing for wiping.
(From time to time I use a mixture of 50% Water and 50% liquid carnauba wax without abrasives - John Hall recommended that mixture in another thread a few month before, right Sir?)

And I would not put the guitar into direct sunlight. It is a midnightblue one. Not good for the body as well.

Finally a scratch plate is a scratch plate. Why shouldn't it look a bit like? - If there a "deeper" scratches I got a good polish for that. Works fine, already tested...

Let's go...

[jingle_jangle]

Sascha, no prejudices here, if that's the impression I've given. Just getting information into the thread.

BTW, good idea about not putting MID into sunlight for long periods. But the color won't fade--the expansion and contraction of the wood and parts from heat will probably hurt the instrument in the long run.

But--spotlights? Shoot...you're being way too careful...

[ken_j]

My comments were not just because what could be in the paints & thinners but what could be in contact/tuner cleaners. Although I switched to Cramolin and now Deoxit years ago, it was precisly due to some cleaners not being friendly to plastic parts. If you should ever have the need to clean your pots be sure to use one that is plastic friendly or remove the pots from the pickguard.
When drilling and cutting out an item like this I would generally use a coolant for drilling and counter sinking holes. Water based coolants are idea for this but impossible to find in small quantities. I would also recommend dilling/counterboring all the holes prior to cutting it shape. You will be far less likely to crack it.

[johnhall]

I think you may have seen acrylic rather than polycarbonate, because the solvent cracking issue is precisely why I mentioned using polycarbonate in the first place. My own experience is that it doesn't solvent crack.

Okay, let me rephrase this then.

I've never had a Lexan part crack or craze while working on it or in contact with the solvents I've ever used for finishing or cleaning. On the other hand, I can't tell you how many Plexiglas parts I've managed to screw up. This experience goes back to the early 60's when I made pickguards for my own guitars, the late 60's when I was a Plexiglas sculptor in art college and, of course, through the years as I've made custom parts for myself and others.

Maybe I'm just lucky (or unlucky), so your mileage may vary.

Now, lasering plastic is a whole 'nother story.

[coolhandjjl]

.....the late 60's when I was a Plexiglas sculptor in art college.....

Did you go to Art Center John?