Wide Belt Sander Choices

More advice on selecting a widebelt sander. April 27, 2011

I am thinking of buying a wide belt sander. The main use would be to level polyester fill coats. I need to level flat panels to 320 grit. I am having trouble trying to decipher all of the terms used - platens, 1 head, 2 head, 3 head, oscillating, digital eye, etc. I will be looking for a used one, so I would like to make sure I am looking for the right thing.

Forum Responses
(Finishing Forum)
From contributor C:
You have lots of options. You will need one with a platen. This is a felt pad which the belt travels over. It is softer than a drum. Also, how wide and what type of volume are you doing? Machines range from $10,000 up.

From contributor J:
Make sure you do a lot of research before buying, as you have a very specialized need. For this type of sanding you will probably want to look at a single head machine with a segmented platen. Having the platen segmented allows you to gradually reduce the downward pressure of the platen towards the edges of the panels, keeping you from sanding them over.

2 or 3 heads will not be of help for what you want to do. As contributor C said, the platen is a pad that sits between the drum and your work piece, leaving a better finish than the drum alone would. Electronic eye is the means the machine uses to keep the belt from shooting off. I'm not sure if/how the digital eye differs?

I would also recommend finding a machine that has very good somewhat local service. The machine I used to run was incredible. Bought new I believe it was in the $60k range. It required a week of training to learn how to run her. After a few more weeks of running panels we had the techs fly back in from Italy to give us another week to really tighten the machine up, as well as fine tune our operating skills.

Sanding finish and veneered panels is a much different animal than just running solid wood through a widebelt. My knowledge is limited, but hopefully others will chime in and point you in the right direction.

From contributor C:
If you think you can get by with 1 pass, then get a single head machine, but if you think you need to start with 220 grit, then 320, then get a 2 head machine. It is also useful to get a variable speed belt to minimize heat buildup. What are you going to be sanding? Most machines range from 36" to 52" width. Check out Exfactory online. You will see a vast selection of different machines and price ranges. Do you need to do raw wood sanding too? Definitely a lot of questions you need to ask. Where I work, we have 2 SCMI machines. 1 is a single head while the other is a 3 head machine with segmented platens and variable speed head.

From the original questioner:
What are segmented platens?

From contributor C:
Most simples machine use one piece of felt covered in graphite to apply pressure on the belt. This gives a softer finish than the hard rubber feed drum. With a segmented platen the machine has eyes on the front of the machine, normally about 1" wide each, so a 36" wide machine will have 36 eyes. These will read the width of the piece being fed into the machine. The sanding head will have 36 individual pneumatic fingers, which will apply pressure onto the sanding belt. This allows the pressure to be set to avoid snipping on the front edge or to avoid over sanding the edges.

From the original questioner:
Thanks. This helps a lot to understand the basics before making the wrong decision. I need a sander for leveling fill coats of polyester. I am doing more and more of this work and leveling by hand is a real pain. I am currently working on a 16 ft boardroom table and leveling it has made me want to buy a wide belt

From contributor C:
2 more things to consider are, do you have adequate electrical supply? Most sanders have between a 15-20 hp motor with 220v 3 phase. Also, you will need adequate dust collection. Sounds like you will need a 52" wide machine.

From the original questioner:
52 in would be ideal. I have 3 phase 230V, but I definitely would need better dust collection.