Cutting into a Martin makes me ask about what is Martin HPL

Ralph124C41 · #1 09-20-2021, 04:03 PM

First I have to confess I found out about a video on another guitar forum. In the video a Martin 000-X2 is cut in half to show the interior construction. But after watching the video, I have one major question..

1) The Youtube reviewer says the HPL back and sides are "AKA plastic or essentially plastic." Is that right?

The reviewer also on Youtube answers a question from somebody by saying, "It’s (talking about HPL) just solid plastic now. Not sure it was ever anything different."

I doubted his answer. But then I went to the following site ... and now I still don't really know what Martin HPL ... not the HPL used in construction ... is actually made of, but it does sound as if the wood percentage is very little.

In fact, one sentence on this page cites "

"Also, by adding some sawdust filler, he (American chemist, Leo Baekeland in 1896) obtained a plastic material with a very deep color. In 1907, he was named after his own name Bakelite, and he applied for and patented it. This is the predecessor of today’s high-pressure laminated decorative panel HPL."

and a later passage cites the "plasticity" of the material.

"Finally, in the 1950s, based on previous research by scientists, modern HPL materials were first commercialized in the United States. This material is very revolutionary, it is different from traditional composite panels, and some other materials. Its plasticity and insulation make it a wider range of applications;"

The article is
https://martinguitarsstore.com/what-...martin-guitar/

It just makes me wonder what Martin HPL is actually. Is it more closely akin to plastic than I thought? And ... does it really make a difference?

Oh, yes the video:

It's on Youtube. I keep forgetting the rules here. Can I post it or just give directions or what? The guitar company is not a sponsor here.

Godfather · #2 09-20-2021, 04:34 PM

After contacting Martin about the possibility of selling them wood veneer for their High Pressure Laminate (HPL*) guitars, and the reply I received, I believe it to be an all plastic/non wood material…..but it was not specifically quoted as such. It was a vague reply indeed.

*The one HPL guitar I recently played did not sound bad. YMMV

Brick is Red · #3 09-20-2021, 04:52 PM

A link to at least one of the other two videos in their new series appeared in a thread or two here.

If you’re trying to ascertain whether the HPL on Martin X series guitars is laminated wood: No, it is not. Is Martin’s HPL wood? No, it is not. It is what Martin and the countertop makers say it is.

Good to know there’s a new video in this series to watch later.

printer2 · #4 09-20-2021, 04:58 PM

There are carbon composite guitars. The HPL lives in that arena. Is it the same thing as your plastic cup? No. Does it sound good to you? That is the main question (Says a guy wit too much wood in the basement.)

Rudy4 · #5 09-20-2021, 05:09 PM

If you want to know more about HPL you'll be better served by looking for information about countertop laminate such as Formica or Wilsonart material.

You can turn standard countertop laminate over and the backside offers a fairly attractive alternative for instrument body material. I've actually used it for fret board top surface and it performs well. It just doesn't look great IMHO.

What it is and how it's made:

https://www.compositepanel.org/produ...ure-laminates/

Brucebubs · #6 09-20-2021, 05:09 PM

The sawdust from D-28's and D-18's is mixed together with adhesive under high pressure to produce 'mahogwood' or 'rosegany' ... or HPL for short.

Typically HPL will produce the scooped mids of rosewood and the scooped high and low ends of mahogany.

sstaylor58 · #7 09-20-2021, 05:56 PM

Quote:

Originally Posted by Brucebubs

The sawdust from D-28's and D-18's is mixed together with adhesive under high pressure to produce 'mahogwood' or 'rosegany' ... or HPL for short.

Typically HPL will produce the scooped mids of rosewood and the scooped high and low ends of mahogany.

Now that is funny!

Ralph124C41 · #8 09-20-2021, 06:06 PM

Btw, the video reviewer gave "grades" for different categories, such as just a 5 out of 10 for sound. But for interior construction he gave a 9 or a 10 and for construction elements such as resistance to cracks etc, he gave I think something like 47 out of 50.

Still, the O.D. part of me wants to know what Martin HPL actually is. As I said, that link I provided to "clear up" the confusion only made me think Martin HPL is plastic, or more plastic than I thought. (It's a Soylent Green moment to me.)

But as others have said ... so what? It works. I know it's not solid wood. I know it's not layered wood (like in Seagull guitars). I know it's not what I think of laminated wood generally is, that is bands or strips of wood all glued and pressed together.

Jimi2 · #9 09-21-2021, 12:25 AM

I had a chance to play a Martin X series all HPL recently - was interested in having a guitar that wouldn’t be susceptible to humidity changes that doesn’t carry the cost of carbon fiber. It was one of the OM size ones at guitar center, and it really didn’t sound that bad. I couldn’t quite get over the the weird, plasticky feel though. Maybe I could get used to it.

AndrewG · #10 09-21-2021, 03:48 AM

Formica? It's a layered fusion of Kraft paper and phenolic resin-essentially the same as Bakelite. Just guessing as Martin don't specify the source.
https://umgf.com/viewtopic.php?p=2595837#p2595837

Silly Moustache · #11 09-21-2021, 04:17 AM

HPL ?

AndrewG is a former chemist and tends to understand such things far better than I , but I thought I'd add this :

https://plasticsheetsshop.co.uk/what-is-hpl/

John Arnold · #12 09-21-2021, 06:27 AM

When I first heard that Martin was making Formica guitars, I cringed. For a few years in the early-1980's, I was in the business of cabinetmaking, including fabricating counter tops faced with Formica or Wilsonart. The material is super hard and durable (when glued to a solid surface), and can be obtained in an almost endless array of colors and patterns, many of which imitate wood or stone.
BUT....
This material was never engineered to be used as a structural element. It is brittle, and hard to glue with anything other than a rubbery contact cement, CA glue, or epoxy. To the best of my knowledge, Martin is not using those glues to assemble the bodies, though they may have used CA to attach the bridges on those ill-conceived models with Formica soundboards.
I have repaired Formica Martins with loose braces, and I currently have one in the shop that was dropped, causing the seams to separate. The glue appears to be some kind of wood glue, which is not suitable for a nonporous surface.

Phenolic resin, paper, and a photograph of a natural material. Zero wood content.

These guitars are all about reducing labor cost, since there is no finishing required.

The sound of the guitars is IMHO overly bassy, due to the high density of the material. The only reason the guitars do not weigh a ton is because Formica is less than half the thickness of a normal wood guitar.
Thin + brittle = bad combination.

Gdjjr · #13 09-21-2021, 07:38 AM

This is a touchy subject- and somewhat political, so I won't go there- but- sustainability is what substitute woods are all about. A part of Martin's creed is now sustainability- as a leading manufacturer they are, well, leading, with what they currently believe to be the most cost effective substitute- I bet they and others are constantly experimenting with other than wood substances- they are the future, get used to it.