Flat blocks

Questions about tools and jigs you want to buy/build/modify.

Flat blocks

Postby Steve Sawyer » Mon Sep 17, 2018 7:38 pm

Bill Wells (http://www.williamwellsfurniture.com/) is a member of our woodworking club. Bill apprenticed under Michael Fortune, and as you can see from his web site, he carries on Michael's aesthetic which seems to abhor any straight lines! :) One of the things that Bill has taught us is that if you are shaping and smoothing a convex surface (folks around here might know a thing or two about convex surfaces) it's important to have a rigid, flat backing for sandpaper. This allows high spots to be removed without introducing any hollows or low spots; a soft backing will obediently follow imperfections in a convex surface, making those imperfections worse. Thus Bill uses what he calls "flat blocks" which are pieces of 1/2" thick MDF measuring 2 3/4" x 4 1/2", faced on both sides with sandpaper of various grits. Many of us have cobbled up a little frame in which we will clamp eight of these blocks onto which a 9" x 11" piece of sandpaper can be glued using Elmers or Titebond glue. After the glue has set, the blocks are cut apart from the back using a utility knife, turned over and clamped in the jig again to receive another piece of sandpaper on the back, so each block is 2-sided.

You can make a huge number of these from a little 1/2" x 2' x 4' "handy panel" from a big-box store, and I find them incredibly useful. I always have a stack of at least 3 or 4 of these in various grits on the bottom shelf of the tool cabinet just over my workbench, and I'm reaching for them constantly - fitting something, easing the edges on a piece, final shaping of a neck, shaping the convex curves on the edges of a solid-body guitar.

Flat Blocks.JPG


Flat Blocks 2.JPG
==Steve==
User avatar
Steve Sawyer
 
Posts: 654
Joined: Wed Jan 02, 2013 2:20 pm
Location: Detroit, Michigan

Re: Flat blocks

Postby Barry Daniels » Mon Sep 17, 2018 8:49 pm

I do that too Steve but not in such an organized fashion. Nicely done.

Another thing I like that is useful for curved flat surfaces like a guitar side is a tool David Marks used on his TV show where you make a sandpaper plane with a piece of formica with a couple of wood blocks glued on each end for handles. Glue sandpaper to the formica with spray adhesive and then flex the block over the curved surface. It will remove the high spots yet keep the curve true. Very handy for getting flatter guitar sides.
MIMF Staff
Barry Daniels
 
Posts: 2002
Joined: Thu Jan 05, 2012 10:58 am
Location: The Woodlands, Texas

Re: Flat blocks

Postby Steve Sawyer » Tue Sep 18, 2018 12:09 am

Barry - that sandpaper plane sounds pretty slick. Am I right in picturing something like a compass plane?

I'm definitely gonna run with THAT idea!
==Steve==
User avatar
Steve Sawyer
 
Posts: 654
Joined: Wed Jan 02, 2013 2:20 pm
Location: Detroit, Michigan

Re: Flat blocks

Postby Barry Daniels » Tue Sep 18, 2018 10:38 am

Yes, a compass plane is a perfect comparison. I actually use two layers of formica to get the plane to the right degree of stiffness but still flexible enough to bend.
MIMF Staff
Barry Daniels
 
Posts: 2002
Joined: Thu Jan 05, 2012 10:58 am
Location: The Woodlands, Texas

Re: Flat blocks

Postby Bob Francis » Tue Sep 18, 2018 4:22 pm

Thanks for that reminder Barry.
Bob Francis
 
Posts: 409
Joined: Wed Jan 11, 2012 6:28 pm

Re: Flat blocks

Postby Bryan Bear » Fri Sep 21, 2018 12:21 am

Barry, do you bond the two prices of Formica together? I assume so but figured I’d better clarify.
PMoMC

Take care of your feet and your feet will take care of you.
User avatar
Bryan Bear
 
Posts: 1047
Joined: Fri Jan 06, 2012 1:05 pm
Location: St. Louis, MO

Re: Flat blocks

Postby Barry Daniels » Fri Sep 21, 2018 1:51 am

Yes, I forget what kind of glue I used but probably something flexible like spray adhesive.
MIMF Staff
Barry Daniels
 
Posts: 2002
Joined: Thu Jan 05, 2012 10:58 am
Location: The Woodlands, Texas

Re: Flat blocks

Postby Barry Daniels » Fri Sep 21, 2018 12:03 pm

One other thing. I glued the two pieces of formica back to back because glue won't bond to the show side very well.
MIMF Staff
Barry Daniels
 
Posts: 2002
Joined: Thu Jan 05, 2012 10:58 am
Location: The Woodlands, Texas

Re: Flat blocks

Postby Steve Sawyer » Fri Sep 21, 2018 4:36 pm

How small a radius do you get with your tool, Barry?
==Steve==
User avatar
Steve Sawyer
 
Posts: 654
Joined: Wed Jan 02, 2013 2:20 pm
Location: Detroit, Michigan

Re: Flat blocks

Postby Barry Daniels » Fri Sep 21, 2018 5:07 pm

It will bend to the outside curves of the guitar sides. I do not try to use it for the waist cause it won't bend that far. But you can make them of different stiffnesses for different radii.
MIMF Staff
Barry Daniels
 
Posts: 2002
Joined: Thu Jan 05, 2012 10:58 am
Location: The Woodlands, Texas

Re: Flat blocks

Postby Steve Sawyer » Fri Sep 21, 2018 6:04 pm

Barry Daniels wrote:It will bend to the outside curves of the guitar sides. I do not try to use it for the waist cause it won't bend that far. But you can make them of different stiffnesses for different radii.


Sanding the waist and cutaways was what I was thinking of. I was thinking of not glung the sheets of Formica together so they could be bent into a tighter radius. So far I've been using the rubber mandrels from my OSS to back the sandpaper, and was never comfortable with that, even though the results have been ok. Not sure even a single sheet of Formica could be bent tight enough to sand inside a cutaway, but I'm going to spend some time experimenting with this idea.
==Steve==
User avatar
Steve Sawyer
 
Posts: 654
Joined: Wed Jan 02, 2013 2:20 pm
Location: Detroit, Michigan

Re: Flat blocks

Postby Barry Daniels » Fri Sep 21, 2018 8:37 pm

Yep, the formica would snap before it would bend to that radius. I use a piece of 1-1/2" PVC pipe with sticky back sandpaper to do my waists and cutaways. I may be imagining this but it seems that it is easier to keep inside curves true and flat than outside curves.
MIMF Staff
Barry Daniels
 
Posts: 2002
Joined: Thu Jan 05, 2012 10:58 am
Location: The Woodlands, Texas

Re: Flat blocks

Postby Clay Schaeffer » Mon Sep 24, 2018 8:36 pm

Vertical grade formica might bend tight enough for cut aways, but the pvc would be simpler.
Another use I have found for formica is to glue a piece of worn out hook and loop sandpaper to it and stick it on a R.O. sander and then stick PSA sandpaper to the face and use it as a "hard pad" for flattening surfaces.
Clay Schaeffer
 
Posts: 1185
Joined: Fri Jan 06, 2012 12:04 pm

Re: Flat blocks

Postby Steve Sawyer » Mon Sep 24, 2018 9:10 pm

Good idea about the PVC pipe. I have some thin neoprene gasket material that might make a good covering for the pipe so it would grip the sandpaper better.
==Steve==
User avatar
Steve Sawyer
 
Posts: 654
Joined: Wed Jan 02, 2013 2:20 pm
Location: Detroit, Michigan


Return to Tools and Jigs

Who is online

Users browsing this forum: No registered users and 6 guests

Your purchase from these sites helps support the MIMForum, but only if you start at the links below!!!
Amazon music     Amazon books     Amazon tools     Rockler tools     Office Depot    

The MIMF is a member-supported forum, please consider supporting us with a donation, thanks!
 • Book store • Tool store • Links • 
cron