Sanding down an old, well-used cutting board with RO90, HELP!

[idratherplaytennis]

So. I am more or less a newbie when it comes down to it on the Festool stuff- having recently purchased a RO90 and an ETS EC 150/3. I am not much of a newbie to sanding etc etc- I have the gist of that down, and I've seen dozens and dozens of videos of the rotex and other sanders- so I know what they are capable of.. part of why I got one.

HOWEVER... I have come across an issue. We are sanding down about 30 years of varnish or some sort of clear-coat on 30+ cabinet doors and drawers, and the two sanders are going at it like champs- I actually have to be very careful not to eat through the veneers (I'm used to a 2.6mm orbit finish sander- not random orbits to say the least, but I'm getting the hang of that..). The issue is we have 2 well used cutting boards, but they are still quite flat- yet they need a massive overhaul in the sanding and re-finishing department. I knew the rotex was the way to go so that I could get down past all the gouges (the tenants used them well for the last 25 years) and burn marks, however after a minute or less at 80 grit, as suggested per my local guy who I got the sanders from, there was massive buildup on the granat paper. I was able to clean it off pretty easily with a wire brush just gently scraping it back and forth- but this leads me to believe I need to do some sort of prep work for sanding down the cutting boards.

Does anyone have any recommendations on how to do this? I tried doing a few searches, however I mostly only came up with 2 methods- one or both of which could possible be questionable. One suggests washing the boards really well with hot soap and water, and probably the scouring side of a sponge, while another method which I read more for cabinet doors and drawers, suggests getting the grease and muck off with mineral spirits. I'm not exactly in a time constraint- but I do want to get this all done sooner than later and I figure if I need to really wash the boards well- that will take at least a day (in the current Southern California heat) to adequately dry out before I can attempt to sand them.

Anyone else have any opinions? Normally we would have just tossed the boards and bought new ones and done a lot of cutting down work to make them fit the existing cabinets, but because the boards are pretty darn flat- I thought this would be a great opportunity to give the RO90 a work out (and more then that... to prove the justifiable expense to my Dad [big grin])

Edit:

For clarification, I ran the RO90 with 80 grit Granat at a 6 speed with max suction on the CT26. Not sure if for the heavy duty stuff, the 6 speed is too high. About to go read anything else I can find in regards to this.

 

[jacko9]

I haven't done this since I worked in a butcher store while in college 50 years ago but, we used to use a wire brush and soap and water on the end grain butcher blocks at the end of the day.  I know what you mean about clogging up the granat while the grit is still unused.  You need to get the layers of gunk off and a cabinet scraper will do the job quite easily before you sand.

Jack

 

[bkharman]

[member=54742]idratherplaytennis[/member]

I think the suction is too high.  You are essentially pulling the 90 down to the surface like a suction cup.  I would back it off to minimal air draw and see what difference you get.  The only time I crank up the suction when sanding is if some of the holes in the sander are open to the air (think edge sanding).  If you have the pad sucked down to the surface, you will have all sorts of issues.  Was the sander running around like a bucking bronco?

I do also agree that you probably want to get all of the "muck" off of the board as well.  I would use a simple card scraper first.

If the surface is really flat you should be fine for the sanding.  If it is wavy, you might want to think about using a router sled to plane it down or rent a belt sander to take 1-2mm off.

good luck and let us know how you fare.

cheers.  Bryan.

 

[idratherplaytennis]

I just finished washing each board twice with some Dawn (I swear that's the best dish soap for removing anything!) and the water was mostly clean after the second wash. After the first washes it was super nasty like if you mixed BBQ sauce with water almost (helped to have a bbq sauce bottle soaking with water to clean out next to me... haha) so I think that was part of the issue. The sander wasn't going all over like a bronco but the board wasn't clamped down well (I still need to get a good setup to clamp down my sanding surfaces). However- I think it had the potential to go nuts if the paper didn't gunk up as fast as it did, probably mostly due to the grease or dirt or whatever oils were on it.

I have a pretty good router that I could use (a Bosch 1617EVS) so I would consider the router sled (only one of the 4 sides is wavy enough that it could be an issue), however I would first have to make one. I wouldn't shy away from making one, I've seen plenty of youtube videos and understand the value of them, however I just don't have the time or space at the moment to do it (My dad finally retired and is in the process of his OCD sorting out our garage so everything is a mess at the moment- one reason I'm using one of those folding plastic tables, hahaha). That said- I did purchase the hard pad for hitting the boards and I wouldn't hesitate to try it out assuming I've solved the gunking up issue.

Also- thanks for the tip on the suction. I'm totally new to dust collection in general, and that could explain how it made it a little tougher for doing the (again, un-clamped) drawer faces. It also didn't help that I was trying this out at eye level where I'm new to the rotex. That said, I will definitely drop down the suction for both sanders and turn it up based on if it's leaving any dust behind. I at least have peace of mind that with the suction cranked up, it's nearly totally dustless sanding.

And in regards to Jack- it's not end-grain, but the basic cutting boards that slide out of the cabinets. I'm definitely looking forward to the day I start making end-grain cutting boards. If it gunks up again, however I will definitely take a wire brush to them because it sure as heck won't cause any damage they haven't already seen. I just need to remember to take pictures because if this all works out the way I hope it does... it will serve some amazing before and afters.

 

[idratherplaytennis]

I had to do some thinking and to add-on, for now, I'm going to run over to Rockler tomorrow morning, pick up some bench cookies to help stop the sliding around on the tables I'm using (for now), and grab a card scraper as well. It's about time I got both of those and it's a significantly smaller price to pay to help prep for sanding.

 

[Tinker]

quote >>>...I'm using one of those folding plastic tables...

 

[Holmz]

Do you have a hand plane?

 

[rvieceli]

It sounds like those boards may have at one time been oiled and re-oiled properly. The problem with sanding that stuff is that it doesn't create dust, it makes a slurry that doesn't get sucked up and just gums up everything.

Try to start with some sort of a scraper. A card scraper or even a single edge razor blade used like a card scraper.  See if you can get some of the gunk off.

I'm assuming these are boards that fitted into the cabinet and then pullout for use. Have you considered flipping them over and using the bottom side? Or has that been done before and both sides are bad?

 

[KBJ]

Hey idratherplaytennis, I'm in LA Too! We should start a local Festool Addicts support group. Haha.
You've gotten some good suggestions here on trying to refinish, I'm just curious though, for all of the time and energy spent trying to wash, scrub, scrape, and sand these old boards.... I think I would have grabbed some new hardwood and glued up another real quick. I've had many kitchens with those slide out boards and can't remember anything particularly special about them.  Now if you just want to play with the new sander and try saving these.... well I get that too!  Besides,  Your dad should see the value of the other sanding you're doing and the lack of dust. 

 

[idratherplaytennis]

It sounds like those boards may have at one time been oiled and re-oiled properly. The problem with sanding that stuff is that it doesn't create dust, it makes a slurry that doesn't get sucked up and just gums up everything.

Try to start with some sort of a scraper. A card scraper or even a single edge razor blade used like a card scraper.  See if you can get some of the gunk off.

I'm assuming these are boards that fitted into the cabinet and then pullout for use. Have you considered flipping them over and using the bottom side? Or has that been done before and both sides are bad?

Very much so, this. I made another unsuccessful attempt today after sanding a bunch of doors down. The boards felt somewhat dry to the touch but scraping with a wire brush just helped with making more "slurry." I have a feeling you're right as well- they are just VERY well used and most definitely have been oiled to the point that they probably just won't sand. It would be one thing if they were like my very unkempt cutting board I use which I've never oiled... I know I know.. but it's not.

And yes... it's definitely a better idea to take and make some new boards. All 4 sides were WELL used and also had some pretty deep burn marks. For the time I've invested into playing with the RO90 and the product shown- I could have been well into new boards being made. That said- I might hang on to them for awhile, store them away in a garage and maybe one day they'll dry out.... hahaha, then I can sand away. That said.. it's off to the drawing board for the new board.

Also- in regards to the table- it's a good one, it's one of those tan Lifetime brand tables- but I got 4 bench cookies and that completely eliminated any sliding around. I should have gotten some sooner for use on that and any of the benches I've used instead of just plopping down towels. I did also purchase a card scraper and burnishing tool today, and got a great lesson by a guy at Rockler on tips on using it and keeping it sharp. I might just use the cutting boards to practice that on as well.

In regards to the suction- I have also dropped it down to the minimum or just above the minimum and the DC is still great. Hit some doors with compressed air and nothing came off. Only when wiping my hand across did some dust remain- which in my book is a GREAT time saver. The suction almost seemed to be too much for the RO90 on the cabinet doors, which I found my most efficient method at stripping down to stain-able surface at 80 grit to be followed by the ETS EC 150/3 on 80 grit to smooth that out, and then on upwards in grits. The new problem is figuring out what to do with these poor doors that are nearing the end of their refinish life. They've already been sanded and refinished at least once before- apparently, and the veneers won't stand up to another refinish.

Thanks for the suggestions and tips.

 

[Tinker]

Quote>>> It sounds like those boards may have at one time been oiled and re-oiled properly. The problem with sanding that stuff is that it doesn't create dust, it makes a slurry that doesn't get sucked up and just gums up everything.

Try to start with some sort of a scraper. A card scraper or even a single edge razor blade used like a card scraper.  See if you can get some of the gunk off.