LumberJocks

Cleaning up a wavy pattern from sanding with ROS

  • Advertise with us

« back to Wood & Lumber forum

Forum topic by garlandkr posted 01-02-2016 03:36 PM 642 views 0 times favorited 26 replies Add to Favorites Watch
View garlandkr's profile

garlandkr

57 posts in 965 days


01-02-2016 03:36 PM

Topic tags/keywords: sanding sweetgum

I’ve read that using a ROS can remove the soft wood quicker than the grain which leaves a wavy pattern. Had I known that before starting I would have gone with a different approach.

I am working with a slab of Sweetgum that has some twist to it that will remain with the piece. I used 100 grit in the ROS at about 10k rpm and went over the twisted corner with multiple passes. Now there is a wavy look to that end in a few areas.

What are some methods to remove this? I don’t have a card scraper but have considered buying one for this use case. Also, the top right area is angled due to a twist in the board so a plane is not going to be usable. Maybe a block of slightly curved wood with sand paper attached could do the job? If so, how should I apply the strokes, with the grain?

EDIT: I’ve gone back with the ROS and 60 grit and it looks promising. This is after about 2-3 minutes worth of sanding. There are a few spots which appear to have fewer lines running so I think I’m on the right track.


26 replies so far

View ChefHDAN's profile

ChefHDAN

805 posts in 2310 days


#1 posted 01-02-2016 03:50 PM

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

View pjones46's profile

pjones46

986 posts in 2103 days


#2 posted 01-02-2016 03:51 PM

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

View a1Jim's profile

a1Jim

115202 posts in 3038 days


#3 posted 01-02-2016 03:53 PM

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.

-- http://artisticwoodstudio.com Custom furniture

View a1Jim's profile

a1Jim

115202 posts in 3038 days


#4 posted 01-02-2016 03:57 PM

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.

-- http://artisticwoodstudio.com Custom furniture

View ChefHDAN's profile

ChefHDAN

805 posts in 2310 days


#5 posted 01-02-2016 03:58 PM

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

View TheFridge's profile

TheFridge

5764 posts in 946 days


#6 posted 01-02-2016 04:00 PM

What they said or

Get a #4 and a card scraper

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

View garlandkr's profile

garlandkr

57 posts in 965 days


#7 posted 01-02-2016 04:09 PM

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.

View a1Jim's profile

a1Jim

115202 posts in 3038 days


#8 posted 01-02-2016 04:13 PM

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

-- http://artisticwoodstudio.com Custom furniture

View garlandkr's profile

garlandkr

57 posts in 965 days


#9 posted 01-02-2016 04:21 PM

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

View a1Jim's profile

a1Jim

115202 posts in 3038 days


#10 posted 01-02-2016 04:25 PM

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

-- http://artisticwoodstudio.com Custom furniture

View a1Jim's profile

a1Jim

115202 posts in 3038 days


#11 posted 01-02-2016 04:30 PM

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

-- http://artisticwoodstudio.com Custom furniture

View a1Jim's profile

a1Jim

115202 posts in 3038 days


#12 posted 01-02-2016 04:41 PM

View Tennessee's profile

Tennessee

2410 posts in 1975 days


#13 posted 01-02-2016 05:41 PM

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!

-- Paul, Tennessee, http://www.tsunamiguitars.com

View garlandkr's profile

garlandkr

57 posts in 965 days


#14 posted 01-02-2016 06:07 PM


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.

View ElChe's profile

ElChe

630 posts in 797 days


#15 posted 01-02-2016 06:16 PM

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.

showing 1 through 15 of 26 replies

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com