# Using an ROS on veneer plywood before finishing waterlox?



## jcox (Mar 28, 2012)

I have some walnut veneer plywood that I am making into a bed. I recently (i.e., today) picked up the Festool ETS 125 ROS and was thinking of using it to smooth out the slight rough spots on the veneer before I get into finishing the wood with multiple coats of waterlox original/sealer and satin finish. I bought the plywood from a good local lumber shop, and so the veneer should not be the microscopically thin stuff you might find at a BORG; however, I've only handsanded veneers in the past and am unsure whether I can use an ROS without burning through the veneer and ruin the panel.

Any thoughts? My plan was to do a 180 grit, and then a 220, before beginning to lay layers of waterlox down? Should I skip the 180? Skip the 220? Abandon the idea of using an ROS, or try a different grit level entirely? If it's possible to use the ROS, I really want to as it would save me a lot of time considering the number of sheets of walnut-veneer plywood I will be using on this project. However, I also don't want to set myself up for failure if it is impossible or requires a level of skill to do that I do not yet have.

Thanks for your thoughts or any insight you might have!

Jake


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## pmayer (Jan 3, 2010)

With high quality plywood you should have no problem sanding using a ROS with those grits. You could start at a more aggressive grit than that if you want. Try it on a piece of scrap first, obviously to determine just much sanding yours can handle before you burn through. If you hold your ROS flat (no tipping) and apply little pressure, I bet you could sit in the same spot for at least 30 seconds with 180 grit before burning through. Would be an interesting test. The other day I was doing a test with a hand plane after I tuned it up to see if I could take shavings off a sheet of good quality plywood. This was good quality, not great quality, purchased at a home center. I found that I could take 5-6 shavings (extremely fine) before seeing the next layer in the plywood. So, if you can use a hand plane on it, a ROS is not a problem. But beware of cheap plywood, as I have also sanded through the veneer on some low end plywood within seconds.


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## AandCstyle (Mar 21, 2012)

I have sanded good veneer ply with no adverse results. IMO all you don't need to start with 180 G, just use 220G. That will save you a little time. However, be aware that the ply will not take stain the same as hardwood. IMO you need to sand hardwood one level finer than the ply, i.e. 320G on the hardwood in this case. The reason is that the glue squeezes up through the veneer so the stain doesn't penetrate as well. The 320G on the hardwood balances this out. Does this make sense? In any event, test your entire finishing schedule on scrap first. HTH


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## bigblockyeti (Sep 9, 2013)

Before sanding, measure the veneer thickness so your assumption of non-microscopically thin surface can be confirmed before ruining what's probably not cheap plywood. +1 to working on a sample of like or similar material so you know what you'll be dealing with from a material removal standpoint.


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## woodchuckerNJ (Dec 4, 2013)

My opinion, which is just an opinion, is a 1/4 sheet sander. I think ROS which I have leave too many swirls and take off too much material. you are only looking to finely sand…Even hand sanding would work quickly, Some good Norton 3x or klingspor with a corked block will take only a few swipes to level.


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