Glorious 24-Grit!

[Matthew Schenker]

Everyone,
The mission: remove numerous lines of dried Titebond III glue from both surfaces of a hard maple butcher block top measuring 30" long by 22" wide.

Here's my chance to extol the virtues of 24-grit sanding discs!  Yes, 24-grit.  The scary stuff...the baddest grit in the Festool lineup...the ones Bob Marino sold to me with the caution, "Be careful with that stuff," as if it were some kind of illegal substance...the stuff that's so coarse it will draw blood if you do so much as rub your hand against it in the box.

Last night, I took out a 24-grit sanding disc and loaded it onto my Rotex RO150, then put the sander in "Rotex" mode and set it for a speed of "6."  As you can see, I'm a major risk taker, and I live on the edge (although I did wear ear protection).

Yeah, that's right, the meanest sandpaper on Festool's most powerful sander in its most aggressive mode, at its highest speed.

Less than 30 minutes later, the top was completely free of glue and nicely leveled.  No dust anywhere, a clean surface ready for finish sanding.

Just call me the sander demon.

Matthew

 

[Bob Marino]

Matt,

Sooooooooooooooooooooo you think that's something? I had a new cement slab (1 1/2" high, 15" wide 20' long) poured around the walls in my basement. The edge was as rough as can possibly be and the top needed smoothing. The ROTEX 150 in rotary mode, Saphir 24 grit made short work of that project. Anfd then sanded most of the older paint off the cement floor (Saphir 24,36, 50 grit). The only time there was any dust was when I used the sander against the short 1/12" high wall. Other than that - dust free. Now for the rest of the basement!

Bob

 

[Matthew Schenker]

Bob,
It's like Festool X games...extreme woodworking sports.
Matthew

 

[Dave Ronyak]

I have some of that "bad stuff" 24 grit for my RO 125, but haven't tried it on concrete - yet.  I bought it for my ?final" attack on cracks in old plaster.

Bob,  I'd like to paint the concrete floors of my garage/shop with a two-part epoxy paint.  But my floors were "sealed" by the contractor with some organic (clear) sealer the day after the concrete was poured using a household type tank sprayer.  This type of sealer never truly cures (X-links) because it becomes tacky if contacted with mineral spirits or denature alcohol or lacquer thinner.  Any thoughts on how to best prepare such a floor - to remove that organic sealer?  What type of Festool abrasives do you recommend that I try?  I was thinking I may have to obtain some of those diamond coated disks that were discussed back on the old Yahoo FOG, and grind away the surface, then etch it with Muriatic acid (Bill E's unfavorite potion).

Here's the source info for those diamond disks

[From joe machotka
Sent: Monday, May 15, 2006 6:25 PM
To: FestoolOwnersGroup@yahoogroups.com
Subject: RE: [FestoolOwnersGroup] RO125FEQ - Diamond Grit Disks

I ordered them from www.applieddiamondtools.com. Phone
number is 314-406-8651 They are in the St. Louis area
I believe. They have any and all grit sizes available.
Each pad runs about 10 bucks for the dry.
Joe]

One of my concrete floor areas does not have a polyfilm vapor barrier under it.  I am planning to treat that floor with Moxie 1500 concrete and masonry sealer which I have used with success on concrete walls and concrete block.  Moxie 1500 penetrates the concrete/mortar up to ~7 inches, strengthens the concrete and greatly reduces its permeability.  I want to store dried lumber in this room, but need to reduce the moisture ingress through the floor first.  In my basement, Moxie 1500 treatment of a concrete block wall followed by a couple of coats of Dry-Loc made sealed it quite well - no evidence of further seepage in 3 years.

Dave R.

 

[Toolpig]

Bob -- you must've gone through a new piece of paper every 2 minutes!!

I used 24 & 36 grit to get old dirt and poly off a red-oak floor that hadn't been re-finished in about 50 years.  The paper would stop cutting well after about 5 minutes (and yes, I used the vacuum and the paper wasn't clogging--at least as far as I could tell).  I will say, however, that the Saphir worked much better than the Rubin.  I didn't try the Cristal because I couldn't find it in the coarser grits.

TP

Matt,

Sooooooooooooooooooooo you think that's something? I had a new cement slab (1 1/2" high, 15" wide 20' long) poured around the walls in my basement. The edge was as rough as can possibly be and the top needed smoothing. The ROTEX 150 in rotary mode, Saphir 24 grit made short work of that project. Anfd then sanded most of the older paint off the cement floor (Saphir 24,36, 50 grit). The only time there was any dust was when I used the sander against the short 1/12" high wall. Other than that - dust free. Now for the rest of the basement!

Bob

 

[Dan Uhlir]

  I was gonna paint the floor in my garage too, but then i thought surely i must have something else to do, same with murcrappy acid maybe i don't need to use that #@$%
                    thanks dan

 

[Bob Marino]

I have some of that "bad stuff" 24 grit for my RO 125, but haven't tried it on concrete - yet.  I bought it for my ?final" attack on cracks in old plaster.

Bob,  I'd like to paint the concrete floors of my garage/shop with a two-part epoxy paint.  But my floors were "sealed" by the contractor with some organic (clear) sealer the day after the concrete was poured using a household type tank sprayer.  This type of sealer never truly cures (X-links) because it becomes tacky if contacted with mineral spirits or denature alcohol or lacquer thinner.  Any thoughts on how to best prepare such a floor - to remove that organic sealer?  What type of Festool abrasives do you recommend that I try?  I was thinking I may have to obtain some of those diamond coated disks that were discussed back on the old Yahoo FOG, and grind away the surface, then etch it with Muriatic acid (Bill E's unfavorite potion).

Here's the source info for those diamond disks

[From joe machotka
Sent: Monday, May 15, 2006 6:25 PM
To: FestoolOwnersGroup@yahoogroups.com
Subject: RE: [FestoolOwnersGroup] RO125FEQ - Diamond Grit Disks

I ordered them from www.applieddiamondtools.com. Phone
number is 314-406-8651 They are in the St. Louis area
I believe. They have any and all grit sizes available.
Each pad runs about 10 bucks for the dry.
Joe]

One of my concrete floor areas does not have a polyfilm vapor barrier under it.  I am planning to treat that floor with Moxie 1500 concrete and masonry sealer which I have used with success on concrete walls and concrete block.  Moxie 1500 penetrates the concrete/mortar up to ~7 inches, strengthens the concrete and greatly reduces its permeability.   I want to store dried lumber in this room, but need to reduce the moisture ingress through the floor first.  In my basement, Moxie 1500 treatment of a concrete block wall followed by a couple of coats of Dry-Loc made sealed it quite well - no evidence of further seepage in 3 years.

Dave R.

Dave,

  I honestly don't know what to tell you about getting rid of that sealer 100%. I would try to find out what sealer it is and get the proper "remover" for that sealer. I used the Saphir because concrete slab needed to be sanded down and the floor has some old peeling paint that needed to be sanded off (not all the paint needed to be sanded down to bare concrete). Perhaps for that, Saphir was overkill. If I wanted to abrade the older paint, remove loose, peeling paint, perhaps the Cristal would be a better way to go - maybe 120 grit or so. If you have a smooooooooooooooth concrete floor, Saphir may be too aggressive - especially in the lower grits. My floor was poured 80 years ago and was rough and uneven and I gave Saphir a whirl. What I was looking for was aggressiveness and a strong paper backing that would stand up to the very reough concrete edges - and it did!
Try this link to see if they have a sealer stripper for you.
http://www.custombuildingproducts.c...eavyDutyCleanerStripper.aspx?user=arc&lang=en

  Bob

 

[Bob Marino]

Bob -- you must've gone through a new piece of paper every 2 minutes!!

I used 24 & 36 grit to get old dirt and poly off a red-oak floor that hadn't been re-finished in about 50 years.  The paper would stop cutting well after about 5 minutes (and yes, I used the vacuum and the paper wasn't clogging--at least as far as I could tell).  I will say, however, that the Saphir worked much better than the Rubin.  I didn't try the Cristal because I couldn't find it in the coarser grits.

TP

Cristal starts at 40 grit - that's pretty aggressive. Mayube Saphir 24, followed by the Cristal 40 or 60.

Bob

 

[CharlesWilson]

Dave,

Maybe you could temporarily bind some sand or other type of grit (using the solvent that makes it tacky) into the organic coating first, and then go at it with the Rotex when it dries. That might help prevent the disks from getting loaded with the coating.

Keep us posted. I would like to know what works.

Charles

 

[Dave Ronyak]

Thanks for you ideas - the chemical stripper and the addition of some powder to help prevent clogging of the abrasive disk sound good to me.  The concrete of the garage/shop is very smooth - hard polished - then the sealer was sprayed.  Parts of it are semi-gloss.  The storage area does not appear to be as well sealed, and it is the area that most needs improvement.