Sanding off lacquer finish

[Packard]

When I demoed my kitchen cabinet doors, I salvaged the center panels which were made of 5/8” thick oak. 

The largest pieces yielded 10” x 22” panels. 

Yesterday I made four shelves for a bathroom wall cabinet.  I cut the shelves to sizes and started sanding off the factory lacquer.  I wanted to make quick work of this and I started with 60 grit discs.  They cut very slow.

I switched to 80 grit and those cut much faster. 

They were different brands of sanding discs. 

So is 80 grit going to sand faster than 60 grit in this case?  Or are the 80 grit discs just a better product?

 

[luvmytoolz]

I find it depends on the discs. If I use Festool Granat discs they seem to cut really well for a long time until they're pretty well worn. If I'm using Alu-Oxide discs they cut really well initially but seem to wear faster and once they reach a particular point they just caress the timber. Granat also doesn't seem to load up like Alu-Oxide discs do. For paint/lacquer work Granat would be far better than Alu-oxide.

If you want a really aggressive one that lasts absolutely ages, cubic zirconia discs are your friend! They're insanely good and long lasting.

 

[leakyroof]

Plus 2 for Granat on Finish Stripping. When Brilliant 2 was still 'king' for General Finish Sanding or Finish Removal if you didn't need the Crystal or Sapphir abrasives, and Granat had basically just came out, I wondered why Commercial Shops were rapidly ditching all their other Festool Abrasives for stock just Granat in all job sites. Granat blows Brilliant 2 away for cutting power, and staying sharp to keep that sanding power going. I stopped wondering once I'd bought and used enough Granat.  [embarassed] [embarassed]
  Now I slowly use up my supplies of Brilliant 2 in various sizes for different Sanders, and wonder why I'd bought so much Brilliant 2 in the past.... [doh] [doh] [doh]

 

[Oldwood]

I find that taking off a lot of the finish with a cabinet scraper with an aggressive hook saves on sanding paper.  A card scraper will work, but a scraping plane will make the job go a lot faster.

 

[Crazyraceguy]

When I demoed my kitchen cabinet doors, I salvaged the center panels which were made of 5/8” thick oak. 

The largest pieces yielded 10” x 22” panels. 

Yesterday I made four shelves for a bathroom wall cabinet.  I cut the shelves to sizes and started sanding off the factory lacquer.  I wanted to make quick work of this and I started with 60 grit discs.  They cut very slow.

I switched to 80 grit and those cut much faster. 

They were different brands of sanding discs. 

So is 80 grit going to sand faster than 60 grit in this case?  Or are the 80 grit discs just a better product?

As [member=75933]luvmytoolz[/member] said above, it's not just the grit size that matters, but the actual grit "chemistry" and whatever coatings are applied. These kinds of additives make a difference in how well the grit sheds the swarf, rather than clogging up. Softer finishes can get quite gummy when sanded, so some super-hard grit that would be good on metal, might clog right away on paint. This makes it seem bad, but it's just the wrong combination. That's why there are so many different types of sandpaper.

 

[Packard]

Thanks for the replies.

Because the discs are from two manufacturers, I cannot tell from this experience if 60 grit or 80 grit will cut faster.

However, if all the sanding discs are from the same manufacturer and are of the same type, which would you start with?  The 60 grit, the lowest grit number I keep in stock or 80 or 120?  Something else?

 

[luvmytoolz]

Assuming a good quality disc, I usually start with 120 for general timber work, and for furniture move up through the grits quickly.

Anything below 120 grit I use to get stains or paint removed, dents levelled, etc. 60 grit can be a pain to remove all the scratches from, so I reserve that for construction work and my drum sander.

 

[Packard]

If I observe any dents, I first try raising them with steam.  I take cotton fabric and soak it in water and then place it over the dent.  I then “iron” it with a regular household iron until steam forms copiously. 

In most cases that will remove “dents” (caused by impact) but not divots (where some material has been lost).

 

[Crazyraceguy]

Some papers are coated with some kind of stearate product that resists clogging. In the hand it a feel like it is not as sharp or even like there is less abrasive applied, but it's kind of a false notion. It reduces clogging of the grit so well that it works better and reduces heat build-up a lot.
Another thing that leads to clogging is too fine of a grit. This just polishes the top of the material, rather than cutting into it. I always start out pretty coarse, even if it is only for a short time. Once the top skin is cut down some, you can go finer, this keeps you from scratching the substrate and having to deal with that later.

 

[Packard]

When I refinished the floor in the guest bedroom, I rented a four-head random orbital floor sander.  For small rooms these are very good.

The 6” sanding discs came in grits from 40 past 100.  I bought some 40 grit to take down the old finish.  But the instructions said to first take a light pass with a much higher number grit and then switch to the 40 grit.

I did not understand that back then, and I still don’t understand it now.  It did seem to work better though. 

The belt floor sander is faster, but you have to always go in the direction of the grain and you need to rent an edge sander too.  And you risk making divots in the finish if you are not careful.

The 4-head ROS will get close to the walls and you can move in any direction.  For the 12’ x 12’ room, that was going to be better for me. 

In any event, the finer, then coarser, then finer grit directions have bothered me for the last 20 years.