Cleaning up a wavy pattern from sanding with ROS

I’ve never seen that before from an ROS, it reminds me a bit of lumber from the mill that cut with the BS in a bit of a wave pattern. I got better results from my ROS when I read somewhere about moving the ROS slowly enough for the orbit to cover it’s own scratches, it’s not slow motion but I used to be in the habit of moving the ROS quickly thinking the boring job would be finished faster, when it turns out better technique was actually better and a bit faster. My best idea would be to see if it is actually from the sawyer and try to sand it out. Sorry not much help, but it’s a thought, and go ahead and order/get the scrapers, once you’ve got them you’ll always have a spot where they come in handy.

-- I've decided 1 mistake is really 2 opportunities to learn.. learn how to fix it... and learn how to not repeat it

Appears to be planer marks from gong though it to fast, or bandsaw marks from milling. I use a belt sander first then the ROS as a finish up. Sometines I even use a hand scraper prior to using the ROS.

-- Respectfully, Paul

I haven’t used sweetgum before so I don’t know if its a charismatic of that wood. Sometimes wavy surfaces are due to poor sanding technique ,such as putting excessive pressure on your ROS or tilting the sander as you sand. You need to let the sander do the work not apply too much pressure. A card scraper is a good idea or just a flat sanding block not curved or even a belt sander if you have experience with one otherwise they can be a project killer. Some ROSers are more aggressive than others that could contribute to the problem especially if a bad technique is used. Another approach is if your technique was not good ,start with 60 grit do a very even pattern and work your way up through the grits up to 150 or 180 . 60,80.100.120.150.180.

-- https://www.artisticwoodstudio.com/videos

The photo just appeared after I posted ,I think I’d start with a belt sander then go through the sanding steps in my other post. If you don’t have a lot of experience with a belt sander just make sure you don’t leave it in one spot too long keep long flowing movements. start with 60 grit on your belt sander.

-- https://www.artisticwoodstudio.com/videos

Looks like we were all typing at the same time… LOL

-- I've decided 1 mistake is really 2 opportunities to learn.. learn how to fix it... and learn how to not repeat it

What they said or

Get a #4 and a card scraper

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

Thanks for the quick replies. I was hesitant in using a belt sander as I don’t have experience in using one and didn’t want to remove too much material. Plus, I don’t have one. But I’m known to go and buy things like that on an as needed basis, so if I need it for this I’ll get one.

I didn’t see any marks left from the sawyer, here is a photo of that same side before I sanded it.

Actually I can see some,I think the sanding made them more apparent.

-- https://www.artisticwoodstudio.com/videos

Well, if that’s the case should I just go back to the ROS with maybe a lower grit? I have 80 on hand.

If that’s the lowest grit you have you could try a area an see how it looks.

-- https://www.artisticwoodstudio.com/videos

When you can it would be good to purchase a whole range of sand paper starting as low as 36 grit up to 220.

This might help in general

http://lumberjocks.com/a1Jim/blog/43345

-- https://www.artisticwoodstudio.com/videos

This might help too

https://www.youtube.com/watch?v=5gNwIL-hbuw

-- https://www.artisticwoodstudio.com/videos

I would not use a belt sander. It will hog off the wood too fast.
I’d go with the 80 grit on the ROS and see how well it takes out the blade marks.

Those are definitely marks from the blade at the mill. Sometimes the saw blade can actually compress the softer woods a bit when cutting, so they are not as apparent until you take off the first rough surface.

Nice piece of wood, though!

-- Tsunami Guitars and Custom Woodworking, Cleveland, TN

I would not use a belt sander. It will hog off the wood too fast.
I d go with the 80 grit on the ROS and see how well it takes out the blade marks.

Those are definitely marks from the blade at the mill. Sometimes the saw blade can actually compress the softer woods a bit when cutting, so they are not as apparent until you take off the first rough surface.

Nice piece of wood, though!

- Tennessee

Thanks! I especially like the other end of it where some spalt was discovered after some sanding. I am trying to be cautious on that end as I want to keep the current look and not sand too much of it away. I’m planning to cover it all with epoxy when it’s done being sanded as there is some rot and the checking is deep.

Cabinet scraper can be had fairly inexpensively and much less tiring to use than a card scraper. Like a Stanley no. 80?

-- Tom - Measure twice cut once. Then measure again. Curse. Fudge.