How to use a belt sander?

[dicktimber]

I don't have space or dosh for one of the wide board roller sanding machines.
When I have glued up boards on some occasions I need to use a belt sander to flatten them........
Can anyone advise how you should use one of these wretched pieces of equipment to obtain a flat surface?
I seem to get dips and dig ins........
Does anyone else have a problem with them??

Mike

 

[JonnyD]

What type of belt sander have you got? If your model has a sanding frame as an accesory you will find you will get good results using one. I have a festool 75e and sanding frame and can happily sand veneered surfaces and boards with it without the sander digging in.

Jon

 

[The Shark]

Hi Mike,
Some belt sanders come with a frame which is supposed to enable large boards to be sanded flat without dig-in.
Mine did, but I confess I have never used it.
I have found that not putting extra pressure on the sander works - i.e. let the weight of the sander do the work. Might take a little longer, but has worked for me.
Hope this helps

Malc

 

[dicktimber]

The belt sander is..A Green One from Aldi!!!!!
With no frame.
Maybe that's where I'm going wrong.
I was down my local wood shop where they make kitchen worktops.
They showed me some they had glued up and sanded using a belt sander and they were as flat as a pancake.
Maybe I should invest in a better quality sander.
Any suggestions?

Mike

 

[mailee]

I use an old Skill 4" belt sander without a frame and have no problems. As has been stated do not put any weight on it at all. Allow the sander to do the work and keep it sanding with the grain or just slightly at an angle.
Above all keep it moving, do not stop even for a moment as it will dig in and produce a dip. I always use a belt sander after glueing up doors and have had no problems using this method, even when I have used 80g on occasion! HTH. :wink:

 

[MikeG.]

The width of the sander is the key issue........4 inch ones are actually quite difficult to get to dig in, but 3 inch ones are prone to it.

I often start (or used to at least........I tend to hand plane now instead) across the grain. Think of this as the equivalent of scrub planing. Make sure you are entirely methodical about how long the machine is over any one area.......it is very easy to to go to an edge, hang on a second, then go back away from an edge.....and in that manouvre spend more time at the edge thatn you do on the adjoing bit of the board.

I would then swap to sanding with the grain. I will admit to applying a little pressure, but get to know your machine!!! With some machines and timbers the standard "no pressure" advice is critical.

Work down through the paper grades, and generally finish with a worn belt. An old 150 belt will polish up most woods beautifully.

Nowadays, I always finish with a blade. If I use the belt sander at all I would then finish with a scraper.

Mike

Mailee............I have some 40 grit belts, and have used them!!

 

[Digit]

'How to use a belt sander...' for me the answer is 'don't!'
All I use them for is pain stripping, wide boards I plane, slower but more certain I think.

Roy.

 

[Russ]

I use a Makita 9401, its heavy and really grinds the wood down.
The method I find best is to sweep the sander from left to right against the grain (with an 80 grain) while slowly moving down the board, usually do this on the floor using my knees to stop the board from shooting across the workshop then flipping the board 180 to get an even finish... then attack with a finishing sander...

 

[joiner_sim]

I cleaned up this coffee table: http://www.freewebs.com/simonswoodwork/coffeetable.htm with a cheap CLARKE 3" belt sander, 80 grit belt. The trick is to keep the belt sander moving at all times! Don't let it stop, go back and fourth and at a slight angle every time, to cover up the belt sanded lines. I finished the top off with a M akita orbital sander, starting with 80 grit, the 120 grit and thengrey silicone carbide paper; 180grit.