The Acoustic Guitar Forum

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

Reply
 
Thread Tools
  #16  
Old 12-05-2019, 08:37 AM
Rudy4 Rudy4 is online now
Registered User
 
Join Date: Oct 2012
Posts: 8,795
Default

Quote:
Originally Posted by redir View Post
Probably a good idea to put a few coats of polyurethane or something on the MDF dishes too. MDF is awesome stuff but holly hell yeah it's dusty when you cut it and probably very toxic too. And if you get it wet you ruin it.
Definately a good idea, I finished mine off with a couple coats of wipe on poly.
If you do seal make sure you do BOTH sides to prevent warping.
Reply With Quote
  #17  
Old 12-05-2019, 11:45 AM
Rudy4 Rudy4 is online now
Registered User
 
Join Date: Oct 2012
Posts: 8,795
Default

Another thing about quick-n-dirty double layer MDF radius dishes is they aren't so precious that you can't use them as you want. For on-off projects I use throw away brace clamps made from 3/4" plywood and screwed directly to the work dish with 2" drywall screws.

Reply With Quote
  #18  
Old 12-05-2019, 09:38 PM
printer2 printer2 is offline
Registered User
 
Join Date: Dec 2012
Location: Middle of Canada
Posts: 5,096
Default

I made a pair of radius dishes out of MDF using a router, what a mess. But I am happy to have them. No finish on them and they are still fine. I have tried other methods just for the heck of it just to see what would happen. Gluing a top and back that were arched just by the radius of the braces glued on them. Then glued onto rims that had a taper heel to butt but no compensation to account for an arched top. The rims edges and linings were sanded flat on a flat surface. All kinds of ways to build.
__________________
Fred
Reply With Quote
  #19  
Old 12-07-2019, 02:09 PM
endpin endpin is offline
Registered User
 
Join Date: Oct 2008
Location: Fort Worth, Texas
Posts: 433
Default

The Irving Sloane method was to position a "sanding stick” with a pivot hole about in the center of the guitar slightly raised from the finished height of the sides and spin it around it around the sides, neck heel and tail block.
Reply With Quote
  #20  
Old 12-08-2019, 01:38 AM
mirwa mirwa is offline
Registered User
 
Join Date: Sep 2013
Posts: 3,109
Default

Re radius dishes

The cheap way is to mark out some pieces of pine to the desired radius and glue them down





Alternatively get someone local to make one up for you That has a cnc machine

These are the ones I make for myself in house



__________________
Cole Clark Fat Lady
Gretsch Electromatic
Martin CEO7
Maton Messiah
Taylor 814CE
Reply With Quote
  #21  
Old 12-10-2019, 01:46 PM
Neil K Walk Neil K Walk is online now
Registered User
 
Join Date: Aug 2006
Location: Pittsburgh suburbs
Posts: 8,309
Default

Quote:
Originally Posted by ClaptonWannabe2 View Post
Can a radius bar not be used for more than just sanding braces? It can be rotated around like a propeller instead of a steering wheel,no?

Also, bars are easier to duplicate IMO.
I tried to do this with a pair of 2x4s and using a StewMac jig for radiusing braces as a template. It worked okay but you have to make sure that the sanding beam stays at a uniform height in order to simulate the functionality of the dish. To do that, I...

1: I wrapped 80 grit sandpaper around each "wing" of the sanding bar and opted to staple it, but there are probably better ways to keep it put while sanding.
2: drilled a hole through my work table,
3: ran a threaded rod about 8" or so long through the hole,
4: threaded a nut/fender washer with a locking washer underneath the table
5: put another nut/locking washer/fender washer on top of the table to stabilize the threaded rod,
6: drill a hole all the way through the center of the sanding beam
7: a second nut/washer/locking washer to regulate the height of the sanding beam so that it stays a consistent height. NOTE: I put the nut on top of the beam, but there were high spots. I found this out the hard way.







The biggest downside of this approach is that it's hard to keep the threaded rod stable, which is why I used locking washers. I should also stress that the thread rod should go all the way through the beam so that it doesn't rock, only turn I need to figure out a way to set the low point for the sanding bar. In the end, I did the bulk of the material removal with a block plane then did the cleanup with the sanding bar.
__________________
(2006) Larrivee OM-03R, (2009) Martin D-16GT, (1998) Fender Am Std Ash Stratocaster, (2013) McKnight McUke, (1989) Kramer Striker ST600, a couple of DIY builds (2013, 2023)
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 01:33 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright ©2000 - 2022, The Acoustic Guitar Forum
vB Ad Management by =RedTyger=