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Should I add a brush sander to the back of my wide belt sander?8/7
I have an SCM 42Ē double head sander. One option that was available for the sander from the factory was a brush sander/buffing wheel on the back if the machine. The unit has its own motor and looks like it would just bolt on the back of the sander. Iím wondering is anyone out there can tell me if this type of sanding wheel will cut down or eliminate our orbital sanding. I use a 120g / 220g belt sequence and orbit sand by hand after. The only thing we sand is edge glued solid wood panels. No doors or anything with crossgrain scratches. The flap or brush will be sanding with the grain. We use rubio monocoat for finish. No stain so blotchiness isnít a issue. Thanks!
I don't think the brush would help. Why do you need to use an orbital sander after the wide belt?
You can see the long scratches in areas where the grain curves. Do people recommend not sanding after the wide belt? I feel like itís required. The 220 belt does a good job but not hand orbital good.
Get with your abrasive person. I would think you could get a finish that would be acceptable with the right abrasive. You might have to work on belt speed and conveyor speed to get the right combination.
Worth a shot before you begin to modify/replace the machine.
A wide belt is not a finishing sander, and I don't try to treat it like one. A brush sander will not sand the hard grain as well as the soft and you will not have a flat surface after using it. Not popular for this generation of woodworker's, but I love a good stroke sander. 150 off a stroke sander is like 220 everywhere else. You can feather out any tear out on hardwood, and really put on a fine job. Hardly ever see them these days!
We still use our stroke sander! Great for curved/concave work too.
Have you thought about a gang orbital sander? I see them sell for fairly cheap on the used market. Might be worth it if your sanding a lot.
Might not translate but our segmented platen sander is a finish sander. We are sanding plywood but I think there are the same challenges. We run it through twice opposite directions so it cuts the raised fibers from the prior pass. In testing the finish is the most uniform straight out of the wide belt.
Jeremiah can you describe how you are sanding and what abrasive you are using. Drum Drum, Drum Platten.....
Another vote for stroke sanders. I would love to have a feed through sander that produces a finish ready surface. I am willing to believe they exist, but I would guess quite costly. Bill, can you give some specifics?
All the shops I am familiar with do further sanding after the wide belt, usually with hand-held random orbital sanders. A stroke sander used skillfully is far faster.
We have a Butfering widebelt. Two head, Drum, combination head. For finish we use silicon carbide abrasive off the platen only. As I said we run it both directions to cut the raised fibers from the prior pass.
The sander new several years ago was $60 +/-. Paid for itself many times over.
You can't just pick any abrasive and speed. There is some science there. We took a Stiles training course on sanding and maintaining the machine. Again that course has paid for itself many times over.
Without some type of oscillating head or finish sander beyond even going to 220 (which is crazy for us, 180 max) I cant see how you could NOT finish sand. Even with no cross grain the sanding scratches are brutally obvious.
I am not an expert by any stretch but there are a lot of things at play here.
Size of the platen, how hard is the platen? Abrasive, what is the abrasive they are not all the same? What is the conveyor speed, what is the belt speed? What sequence of belts are you using, what is the abrasive of the belts leading to the final sanding?
I'll bet SCM has a wide belt expert that would be willing to help. I would call SCM and find him or her. If you said their wide belt could not produce finish quality I bet they would disagree. We had tons of samples from abrasive companies to get the right abrasive. We sand to 180 by the way. Do you think a cabinet company that produces 1,000's of cabinets a day is RO sanding them all, not a chance. It can be done.
One issue I see here is the sequence of your belts. You are likely putting too deep scratch with a 120 grit to take out with the 220 grit. You could consider two passes and have two grits (go 120 / 150 grit, then 180 / 220) in between. This should greatly minimize your need to orbital sand after.
I travel the country as a technician for SurfPrep abrasives, teaching folks how to work through issues like this.
If the grain is all straight and homogenous then staining right out of the wide belt is easy. Once you add in knots, burls, and curls things get a bit more complicated.
Hand sanding is often the best option. They key is teaching the hand sanders how not to over sand.
Color consistency is also a major issue going from the wide belt to hand orbital sanding. It is extremelyimportant that both operations work together.
I would be happy to talk to you about your options. PM me and we can talk it through.