Reverse Sanding?

[Thom Schuck]

I have noticed over on YouTube that some turners are doing power sanding with their machines running in reverse. Can anyone please tell me the advantage of reverse sanding? Is it dust collection? I have a Laguna 1216 and have my dust collection set up on the front of my lathe. I turn sitting in my wheelchair with the 4” hose tuned at a 90* so it does not interfear with my legs. It seems to work well in my dust collection. Can you folks give me a heads-up? Thanks!
Thom Schuck
Portland, Oregon

 

[Gerald Lawrence]

I do not use it on every bowl but I do find that sometimes have torn or raised grain . In this case the reverse sanding clears the problem much faster. Also sometimes there will be little fuzzies that lay down when turning in one direction and reverse gets these off quickly.

 

[Terry Vaughan]

I usually do the outsides in reverse. I find the wood going upwards helps support the weight of the sander and gives more control. The dust extractor inlet is at the far side of the bowl, so if sanding a bit above centre height the dust plume goes towards the inlet. Also I have better visibility. Do have to make sure the chuck is screwed on tight of course.

 

[Doug Freeman]

I typically alternate spin direction when changing grit. It changes the scratch pattern making it easier to see if previous scratches are gone, and there is a bit of “direction” from sanding. If the surface has some humps or dips, like a 1 turn item, reversing evens out material removal at irregularities. Also, run your hand in both directions after sanding. Generally in the opposite direction of sanding the surface will feel slightly rougher, the lower the grit the more obvious.

 

[Dave Landers]

I run the lathe in whatever direction is moving opposite of the portion of the sanding pad I'm using. So if I'm using th right side of the sanding pad, and it's going down, I'll run the lathe in reverse so the wood is going up.
Could achieve the same thing by reversing the drill, but my current setup doesn't make that easy (so I don't)

 

[Mark Jundanian]

As mentioned alternating directions can knock down some tear out and changes the direction of the dust plume. Why not give it a try it and see if it benefits your rurnings and your techniques. Keep an eye on the chuck. Be sure the chuck is tight and the set screw engaged.

 

[Dean Center]

These are really interesting observations. Thanks for the question Thom.

One thing we all have observed is that the inside of a bowl or open form that is least smooth from the turning, and therefore needs the most sanding, is on the upper sidewall, just counterclockwise from the end grain, or just 'ahead' of the end grain as the piece spins. In forward direction, this area seems to be 'skipped.' (probably not actually skipped over, but a function of grain direction and cutting unsupported fibers) If you sand in reverse, this area would be 'emphasized', rather than skipped, and the sanding would be more effective. (and done on supported fibers)

 

[Jonathan Silwones]

Doug points out the importance of learning to sand by observing scratches and how they react to your technique. Mark is explaining the mechanics crucial for effective (and efficient) power sanding. Their methods should be the first thing taught at any ‘how to sand’ demonstration. (Hope you two don’t mind my plagiarizing your words!)

 

[robo hippy]

Well, this may be more important if you are hand sanding than it is if you are power sanding. Part depends on which grit you start with. For sure, with coarser grits, you will have more long bits of fiber, and if you sand the entire bowl in one direction, then there will be a lot of fiber laying down. This would be eliminated with sanding in reverse. With the power sanding, I can do the same thing. Generally I engage the sanding disc at about a 45 degree angle. I sand with both the top side of the disc engaged, and the bottom side of the disc engaged. This gives me different scratch patterns so I can see if I am missing getting any scratches out. Hope this makes sense. My bowls are just smooth even curves, and no detail work at all, so I can sand the entire outside and inside without having to worry about erasing details.

robo hippy