# Help! Belt sander is not sanding flat!



## Tempus Fugit (May 23, 2014)

I bought a second hand, 4" handheld belt sander and it doesn't sand flat. Only the middle area of about 1" in width sands the plane of a flat surface. Even when I press down on the sander, there isn't much improvement. Does this just mean that I need a new belt? Or, is it a feature on the sander itself to flatten and "bulge" the surface of the belt intentionally? Or is it a more serious issue that needs replacement?

I don't want to return it to the guy, who I purchased from via Craigslist, as it's a bit far away and he recently lost a job so I ended up buying a few things from him to help him out while buying the tools I needed.

Thanks in advance!


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## mikeswoods (May 18, 2009)

Remove the belt and inspect the platen (thin spring steel plate that the back of the belt runs against)
and the cork backer pad under the platen--

One or both need replacing---the belt needs a flat backer--the platen and pad do that job.


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## Tempus Fugit (May 23, 2014)

mikeswoods said:


> Remove the belt and inspect the platen (thin spring steel plate that the back of the belt runs against)
> and the cork backer pad under the platen--
> 
> One or both need replacing---the belt needs a flat backer--the platen and pad do that job.


Thanks I'll check that right now. :smile:


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## Al B Thayer (Dec 10, 2011)

Please understand there may be nothing wrong with the sander. I've been woodworking since 1964 and I can't make one sand flat either.

Al


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## Oneal-Woodworking (Apr 14, 2013)

Al B Thayer said:


> Please understand there may be nothing wrong with the sander. I've been woodworking since 1964 and I can't make one sand flat either.
> 
> Al


I know plenty of guys with tools that are beyond my ability to safely and properly operate on my own without messing things up.

It makes me want to learn more. :thumbsup:


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## Tempus Fugit (May 23, 2014)

Ok, I just fiddled with it. First, I vacuumed any debris away. Lots of little saw dust everywhere.

Next, I loosened up the belt - I didn't take it off though, since I wanted to a somewhat minor "fix" to see if that'll solve the issue. Then, I jimmied the belt so that it's correctly positioned. And, I made sure the belt was real tight in place by screwing down the spring resistant screw.

And, I made a test run, and I think it really flattened out! At least, it's much flatter than before. I didn't do a comprehensive test but I did see a huge improvement. I think the belt was not tightly held into place and/or some debris may have been stuck in between the belt and the platen - but I'm not entirely sure.


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## GeorgeC (Jul 30, 2008)

Using a belt sander takes a lot of experience. How well you are able to sand is more about technique than tool. Always keep the sander moving.

George


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## hwebb99 (Nov 27, 2012)

It takes a huge amount of practice to use a belt sander effectively. I use my ROS or drum sander for woodworking and leave the belt sander in the corner.,


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## Tempus Fugit (May 23, 2014)

I didn't change my technique between the before and after trials, so I don't think that's it. 

I really do think that the bulge came from a loose belt. 

The sander is always moving when used.


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## FrankC (Aug 24, 2012)

Hand held belt sanders are not finishing sanders, they hog off material really quick so are better used for operations such as scribing a counter top to a wall.
To flatten a top you go against the general sanding wisdom and run them across the grain so as not to get a wavy surface. The surface is then gone over with a random orbit sander to prep it for finishing.
They do have one use that no other sander has:
http://bertiesinn.com/BeltsanderRace/beltsanderrace.html


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## Oneal-Woodworking (Apr 14, 2013)

hwebb99 said:


> It takes a huge amount of practice to use a belt sander effectively. I use my ROS or drum sander for woodworking and leave the belt sander in the corner.,


How much practice one needs can be greatly reduced if the guy learning how to use it is the *same *guy that has to replace the parts he screws up. :yes:

In my experience - A belt sander (properly used) can cut your total sanding time down in a BIG way. Not at all uncommon to spend half the time you 'would have' spent if only using a ROS. 

A lot of the guys that dismiss the value of a good belt sander have either never seen one used properly OR they don't do enough sanding to justify having one. You take one of those guys to a half decent cabinet shop and give him a stack of say 100 cabinet doors to sand with his orbital alone - He will be a good while... :smile: 

If you had another guy set up on a bench right next to his with the same size pile of doors but WITH a belt sander (in addition to the ROS) - The guy with the belt sander is going to skunk him as far as speed is concerned AND he will not end up working as hard as the ROS only guy. :yes:

In a cabinet shop type environment with a half assed decent 'instructor' showing a guy how to operate it and actually 'supervising' and giving feedback to the guy learning - It usually takes less than a few hours for a new guy to figure things out.


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## rayking49 (Nov 6, 2011)

One can learn through trial and error also. My first table top, you could surf on the waves I put in it, until I learned how to use the sander. Once I mastered it, I was able to work it instead of it working on me.Good luck man.


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## Steve Neul (Sep 2, 2011)

You guys should have to learn to use a belt sander like I did. I went to work for a cabinet shop that sanded the face of their cabinets with a belt sander only. Within a week you can sand a cabinet including base cabinets with drawer openings and not have any cross grain. I still do it that way today but I follow with an orbital.


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