How important is a platen?

[Jeff Monson]

I finally found a good deal on a used Grizzly widebelt, only downfall is no platen, model is a G9962Z. I want to upgrade from my Jet 22-44 drum sander, so I'm looking for some input on whether or not this is a major move up or just a lateral move at best.

[Stewart Lang]

That sander will definitely be a step up from the Jet.

A platen is nice and helps with the sanding scratches, however wide belts usually oscillate which also makes a difference with sanding scratches. Platen would be nice, but it's still definitely a step-up.

[Dave Cav]

That will be a huge improvement over the drum sander. Much faster throughput, easier grit changes. I wouldn't worry about the lack of a platen. I have a 37" Safety Speed and I almost never use the platen. About the only time I do is on the final pass on a table top at the highest grit (usually 180 or 220) and I still ROS sand it after the widebelt.

[Richard Coers]

Inspection of the drum will be critical. Any damage and it will telegraph in the wood. Also find out the age of the machine as the coating on the drum does not last forever. Never use a solvent to clean the drum, I prefer Simple Green.

[Jeff Roltgen]

Not to be contradictory, but I'm exactly the opposite of Dave. I have the 43" Safety speed and almost never run without the platen. Here's how I understand it from both observation and instruction over the years:
- Drum only for more aggressive sanding. Think of it as a cutting tool, like a jointer or planer head - present for a short duration as you take a deeper bite with coarser grits, avoiding the burn you may experience if the platen were down, creating longer friction duration, increasing likelihood of burning. = a vote for no platen, especially if your doing more thickness reduction with the sander.

- Platen down for more surface area and a better appearance for the finer grits. Since my planer stays well tuned and uses the spiral head, it's a pretty darn good surface. Ideally, I plane to 1/64" (.016) over target thickness, and knock off half that on each side as I approach desired thickness. I use 180 grit 90% of the time, and have been instructed to remove no more than .006" - .008" per pass, allowing that fine grit to do it's job without burning by overloading the grain size. Very light RO work for final stain prep. Sales rep convinced me to run a lighter air pressure for belt tension and use paper vs. cloth back belts. I've run both, and feel there is a vague amount of improvement in surface quality for paper vs. cloth. FWIW.


Each of us develops methodology to suit how we work, but personally recommend you procure a platen so you have the chance to find out for yourself. My experience says, you'll notice the difference if your shooting for finest finish with minimal manual sanding afterword.

[Alan Lightstone]

Funny, I never use the platen on my Grizzly. I'll have to give a try using it. So, at least in my case, I haven't found it necessary.

Let me plead ignorance here. What exactly is the purpose of the platen?

I definitely found the Grizzly a huge step up from my Jet 16-32. Though I do wish I had model larger than 27".

[J.R. Rutter]

An 8" diameter, 65 shore hardness drum should be capable of fine finishing if it doesn't have gouges in the rubber. There are pros and cons to a platen. They do leave a shallower scratch than drum alone because the dust from the trailing edge acts as a cushion. Drum alone with smaller contact area leaves a sorter scratch pattern that is also more open, which you want for finishing. One key to getting a good finish is using a larger diameter drum, which Grizzly did on this design. 65 shore is medium hardness for a sanding drum (IIRC) so is also a smart design choice for versatility. I would say that if you don't mind switching belts for finish sanding, this widebelt will be miles ahead of any drum sander.

[Kevin Jenness]

What exactly is the purpose of the platen?



The idea is to lengthen the scratch pattern and make it shallower as well as to diminish or eliminate any chatter from belt splices or snake tracks from oscillation. It should be used on finish passes only with a very light cut on the order of .002".

For solid information on operating a wide belt sander look here https://surfprepsanding.com/articles/

[David Kumm]

Given a choice I'd take a steel drum with a platen but if the machine is solid, close by, and a good deal, I would not pass it up because it lacked the platen. I do want adequate power though. 5hp/ft width is a good number. Dave