The Acoustic Guitar Forum

Go Back   The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Build and Repair

Reply
 
Thread Tools
  #1  
Old 02-06-2019, 07:25 PM
plectra1.3 plectra1.3 is offline
Registered User
 
Join Date: Feb 2019
Posts: 3
Default Aluminum acoustic guitar

Hi everybody, I'm new to this forum so I hope I do it right.

I am in the process of building an all aluminum acoustic guitar but I don't know what thickness of material to build the body out of. Should it be the same thickness as that for a wooden guitar? (2) Should I brace the same as wood?

If anyone has done this before and has some answers they'd be willing to part with I would be very grateful, Thanks.
Reply With Quote
  #2  
Old 02-06-2019, 07:29 PM
ChalkLitIScream ChalkLitIScream is offline
Registered User
 
Join Date: Apr 2017
Location: Ontario, Canada
Posts: 774
Default

Im no builder, but even I know that builders thickness different woods differently.

An aluminum guitar is going to sound much different for sure, and Im also sure youd need to tweak much of the build.
__________________
GWL Dreadnaught (2012)
Yamaha AC3R (2016)
Revealing soon... (Taylor xxx-xx) (2018)
Reply With Quote
  #3  
Old 02-06-2019, 08:03 PM
JonWint JonWint is offline
Registered User
 
Join Date: Mar 2016
Location: 1 hr from Nazareth
Posts: 339
Default

Quote:
Originally Posted by plectra1.3 View Post
Hi everybody, I'm new to this forum so I hope I do it right.

I am in the process of building an all aluminum acoustic guitar but I don't know what thickness of material to build the body out of. Should it be the same thickness as that for a wooden guitar? (2) Should I brace the same as wood?

If anyone has done this before and has some answers they'd be willing to part with I would be very grateful, Thanks.
I'd like to build one some day. Maybe wood B/S and alum. top. I'll try 3003 in 0.040" with no bracing and compare to the stiffness of a wooden top. I'll wheel a shape similar to that of a wooden top. If that is too stiff, maybe 0.032" with or without braces.

I know Martin had an alum top guitar but have never found any specs for it. I did research for info but never found anything of use.
Reply With Quote
  #4  
Old 02-06-2019, 10:06 PM
tadol tadol is offline
Registered User
 
Join Date: Aug 2008
Location: Berkeley, CA
Posts: 3,186
Default

Id look at resonator guitars for inspiration, and figure that aluminum is a completely different material than wood, and about all you can take from traditional guitar building is the shape -
__________________
More than a few Santa Cruzs, a few Sexauers, a Patterson, a Larrivee, a Lynch, a Cumpiano, and a Klepper!!
Reply With Quote
  #5  
Old 02-07-2019, 05:35 AM
bostosh bostosh is offline
Registered User
 
Join Date: Jan 2017
Location: San Diego, Ca
Posts: 79
Default done it already and it sounds good - secret project

"' If anyone has done this before and has some answers they'd be willing to part with I would be very grateful, Thanks. ""

Your Welcome Plectra

The Martin aluminum was glued to a wood soundboard. old patent

Sheet aluminum has no strength must be backed up by something.
Outer sheet skin and backup support inside, (done a lot of aircraft)
__________________
Been doin this, way too long.....
Reply With Quote
  #6  
Old 02-07-2019, 05:43 AM
bostosh bostosh is offline
Registered User
 
Join Date: Jan 2017
Location: San Diego, Ca
Posts: 79
Default attaching the braces

Quote:
Originally Posted by JonWint View Post
I'd like to build one some day. Maybe wood B/S and alum. top. I'll try 3003 in 0.040" with no bracing and compare to the stiffness of a wooden top. I'll wheel a shape similar to that of a wooden top. If that is too stiff, maybe 0.032" with or without braces.
How would you attach the bracing to the top sheet?
__________________
Been doin this, way too long.....
Reply With Quote
  #7  
Old 02-07-2019, 05:48 AM
Mooh Mooh is offline
Registered User
 
Join Date: Dec 2001
Posts: 1,475
Default

Quote:
Originally Posted by bostosh View Post
How would you attach the bracing to the top sheet?
Weld.

I'd be tempted to do an archtop with a soundbar.
Reply With Quote
  #8  
Old 02-07-2019, 06:23 AM
bostosh bostosh is offline
Registered User
 
Join Date: Jan 2017
Location: San Diego, Ca
Posts: 79
Default

OK i have witnessed welding on .062 sheet, (Cessna door cracks)
The top outer surface will suffer.
how about bonding ?
that is how satellites get lightweight
Why not machine it from a solid plate?
__________________
Been doin this, way too long.....
Reply With Quote
  #9  
Old 02-07-2019, 07:02 AM
printer2 printer2 is offline
Registered User
 
Join Date: Dec 2012
Posts: 3,638
Default

Forget welding, too thin. Glue would be best, look up aircraft construction. To be light enough to be a top you would mainly have a thin sheet top and the braces carry the load. Make a wooden top and load it down at the bridge plate and measure the deflection, do the same for the aluminum and adjust till you get the same deflection. Would it be ideal? Probably not but it gives you a starting place.
__________________
Fred
Reply With Quote
  #10  
Old 02-07-2019, 07:24 AM
ruby50 ruby50 is offline
Registered User
 
Join Date: Dec 2013
Location: Eastern Shore MD
Posts: 376
Default

Knew a guy years ago that was a welder with every conceivable certification. A test for one of those certs was to weld 2 cigarette liners together - those aluminum foil liners inside the pack.

Epoxy would hold the wood brace to the aluminum skin. Would you do deflection testing to pick the top material??

Ed
Reply With Quote
  #11  
Old 02-07-2019, 07:33 AM
JonWint JonWint is offline
Registered User
 
Join Date: Mar 2016
Location: 1 hr from Nazareth
Posts: 339
Default

Quote:
Originally Posted by bostosh View Post
How would you attach the bracing to the top sheet?
I'd use spruce braces bonded with epoxy onto aluminum. Epoxy top to sides.

An 0.040" top with a shape would be stiff enough to withstand string tension with little or no bracing. English wheel would be used to shape about 1/4" transverse belly and fall-off to the end block.

Aluminum back and sides could be TIG fusion (or filler) welded but it would be a lot of work. I've built a couple cars with aluminum bodies.
Reply With Quote
  #12  
Old 02-07-2019, 07:49 AM
fazool's Avatar
fazool fazool is offline
AGF Sponsor
 
Join Date: Dec 2012
Location: Buffalo, NY
Posts: 14,232
Default

Before undertaking this "blindly", I suggest spending some time learning about
aluminum and wood and how they compare.
__________________
Fazool "The wand chooses the wizard, Mr. Potter"
Taylor GC7 | Taylor GA3-12 | Taylor SB2-S | Ibanez AC240
Reply With Quote
  #13  
Old 02-07-2019, 08:35 AM
JonWint JonWint is offline
Registered User
 
Join Date: Mar 2016
Location: 1 hr from Nazareth
Posts: 339
Default

Looks like it has been done before. Found these photos some time ago.

[IMG][/IMG]

[IMG][/IMG]
Reply With Quote
  #14  
Old 02-07-2019, 10:26 AM
ruby50 ruby50 is offline
Registered User
 
Join Date: Dec 2013
Location: Eastern Shore MD
Posts: 376
Default

Since there is no humidity reaction, would you have to dome the top? I think you could leave it flat like a uke and that would make the neck geometry SOOO easy

Ed
Reply With Quote
  #15  
Old 02-07-2019, 11:19 AM
JonWint JonWint is offline
Registered User
 
Join Date: Mar 2016
Location: 1 hr from Nazareth
Posts: 339
Default

Greater the dome; greater the section stiffness. Would also resist the tendency of the area between the bridge and fret board from going concave.

Last edited by JonWint; 02-07-2019 at 11:27 AM.
Reply With Quote
Reply

  The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Build and Repair

Thread Tools



All times are GMT -6. The time now is 04:31 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Copyright ©2000 - 2018, The Acoustic Guitar Forum
vB Ad Management by =RedTyger=