Lighter sanding, than with the biig beltsander

[Roly Nelson]

Most of my woodworking involves the use of my 3 inch belt sander. However, when confronted with sanding members flush with thin, faces of finish plywood, my wonderful powerful sander is often much too aggressive. Therefore, I have found that cutting a 3/4 inch wooden block the width of my standard power sander belts, and inserting it within an old sanding belt, gives me the control of moderate, non-aggressive flush sanding, without the danger of damaging the adjacent surfaces.

I simply make the insert the same witdth as the sanding belt, and slightly shorter than the interior of the belt. I then slip in a thin wooden wedge at the end of the belt and use this two-sided sanding block, as a much better controlled method of getting the job done. It is much less aggressive, and I find that it is a much better method to maintain a more controllable sanding conditon, since you don't have to wait to lift the belt sander, to see how much damage has been done by that aggressive monster, hidden below the grits of the belt. Just a thought
Roly .

[angib]

While swapping from power sanding to manual sanding is seen as 'going over to the dark side' by many men, it is exactly what many professionals concerned with exactly shaping a surface do - here are three people using a 'longboard' that I bet has been carefully chosen to flex only just enough to follow the shape of the boat hull they are working on, but not to flex enough to follow any local bumps that they are trying to remove.



I see they have named the photo 'torture board' which can be true - manual sanding isn't light work. I have seen my former boatbuilder boss set up a crew of 8 guys working on one longboard to get a yacht hull smooth enough to take a championship.

Here's a nice demo of the difference between a rigid longboard and one of chosen flexibility:



Roly, using old belts is a nice idea, but the other lovely product is longboard sheets. These are 2.75"x17.5" sheets to fit a traditional 2.75x16 longboard. If you buy the old self-adhesive type, not the newer Velcro type, the sheets can be cut up and stuck onto any hard or semi-hard backer to make sanding blocks that will make something actually flat, and not just make it a glossy version of its current wavy shape.



I'm a fan of cutting up pieces of MDF or timber to make sanding blocks that are shaped to a particular job. For example, cutting two 45 degree chamfers along a small piece of 1x3 gives you a sanding block that works right into a 90 degree corner. Stick a piece of longboard sheet onto the chamfered faces and you've got a dedicated sanding 'machine' which you don't have to struggle to hold sandpaper onto. It's even possible to cut the longboard sheet to stick to just one face of a sanding block and you can sand one surface right up to a joint without harming the surface next to it.

The big problem is that as soon as you go looking of 'longboard' anything, all you get are links to longer-than-usual skateboards which you have to wade through to get to the abrasives!

[halfdome, Danny]

Roly, Being a cabinetmaker all my working years I've seen many a project damaged by someone with a heavy hand using a belt sander on veneer.
It's takes years of daily practice to learn the light dance with the belt sander.
People tend to bear down on the heel of the sander and that's where the trouble begins.
I always sneak up to cross grain or veneer with a light constant circular motion and have had great success over the years doing it this way.
I was taught to start the belt sander in the air and lay it on the wood, but care must be taken.
Others were taught to start it on the wood which can be a disaster if you're not careful.
I don't grab the beast with a firm grip, it needs to be held with a light but secure grip to do the dance.
I don't bear down, just let the weight of the sander do the work and go along for the ride.
Pretty much says it for any sander, let the sander do the work & don't bear down.
If the platen is worn then your sanding will suffer.

I have several hand sanding blocks with used belts like you describe but use them for breaking edges etc.
Danny

[oakinteriors1]

Most of my woodworking involves the use of my 3 inch belt sander. However, when confronted with sanding members flush with thin, faces of finish plywood, my wonderful powerful sander is often much too aggressive. Therefore, I have found that cutting a 3/4 inch wooden block the width of my standard power sander belts, and inserting it within an old sanding belt, gives me the control of moderate, non-aggressive flush sanding, without the danger of damaging the adjacent surfaces.

I simply make the insert the same witdth as the sanding belt, and slightly shorter than the interior of the belt. I then slip in a thin wooden wedge at the end of the belt and use this two-sided sanding block, as a much better controlled method of getting the job done. It is much less aggressive, and I find that it is a much better method to maintain a more controllable sanding conditon, since you don't have to wait to lift the belt sander, to see how much damage has been done by that aggressive monster, hidden below the grits of the belt. Just a thought
Roly .

Like this...

[KCStudly]

Mines a little crude, but it does the job when asked.

[Larry C]

I use several different "long boards" in wood working. Some are flexible, some are short. However. my favorite is this one which is about 3-1/2" X 22". I started using sanding belts cut to full length and glued on, but they are costly. I now just cut standard sandpaper sheets and butt them to full length. I use 3M 77 to glue them on. One side only gets the glue. This makes it easy to remove spent paper.
Long-board hand sanding requires a lot of horse power , but really makes it much easier to obtain a flat smooth finish.
BTW/ the diagonal lines on the board are used to stay parallel with wood grain even though the board edges are not parallel to the grain. I hope this make sense

[DMcCam]

My brother uses what he calls a 'D' block which is a variation on the this idea:

Starting with 5/8" plywood, he makes the block the same length as will fit tight into the belt with round ends. This takes a bit to do but you end up having both sides and the ends to use. We usually use old used belts as a starter.

All the Best,

Dave