Best sandpaper for removing finish remnants on furniture?

[raccoonhands]

After stripping finish off with MC, I (obviously) need to sand to remove the last of it. I'm using granat 120/150 with an ETS 125. By the time I'm halfway through sanding a table leaf the paper's performance has degraded enough that I need to change it. It blows my mind when I read about people using the same disc for hours. By the time I'm at the end of the table leaf, I'm basically just burnishing the wood. My sandpaper expenses are out of control. Am I (hopefully) doing something wrong, or do I need different paper? A different sander? I've tried other, cheaper brands and I can't say I notice a difference.

 

[woodferret]

Abranet ACE HD 80.  Then Abranet 80, 120.  Use protection pad.  Switch to Granat 120 if you want.

 

[raccoonhands]

Thanks for the recommendations! I'm a little hesitant to go down to 80 as I'm usually working on old furniture with relatively thin veneers. Maybe it's worth giving it a very careful try.

 

[woodferret]

Ah, that'd make a difference.  No HD then   Switch to a card scraper, but it's probably in a dish or something hence why you're having issues.

 

[raccoonhands]

Oh man, card scraping 25 sqft of dining table... [blink] Better get that thing sharpened up!

 

[semenza]

I am pretty sure the problem you are having with the Granat wearing out is that the finish is clogging it. Granat seems to be a different beast in that regard (from my experience) at 120 and above than at grits below 120.

Too bad it is veneer or I would say start at 60 or 80 grit.

Seth

 

[alltracman78]

Have you tried a mesh paper like granat net or cubitron? With an interface pad? Less chance of it clogging up.

 

[Michael Kellough]

I tried Granat Net recently sanding paint and drywall and never had to discard disk due to clogging, unlike when using Brilliant. The Net abrasive wore out sooner than I hoped but overall was much more productive sine it didn’t get ruined by corning.

 

[Cheese]

I'd opt for the 3M Cubitron paper...give it a try. I'm a big fan of Granat but I've noticed that Cubitron physically feels "sharper" and I've had great success with the paper. There are some recent special offerings on Cubitron at 30 cents a disc...can't beat that pricing. Try it and if you don't like it, just go back to Granat.

The coating you're trying to remove makes a huge difference in what material you use to remove the coating. Think...removing water based coatings versus oil based coatings. Both require different removal media and different methods.

 

[RJNeal]

Sound like you need an abrasive cleaner stick/block.
I’ve have sanded fresh stain off of 2 x10 cedar with on of my RO sander. I got about square foot done and used the cleaner.
The sheet of paper lasted. I did 3 sixteen footers, plus a few 2 x 6’s.
I’ve also have sanded down a 6 by 11 butcher block island with years of oil treatment.
Those cleaner work great.

 

[rvieceli]

Here’s an example of the cleaner.
https://www.harborfreight.com/sandi...etN555djQEf-CXi8Y7T-1QwzjfttiZLoaApLbEALw_wcB

Methyl Chloride is nasty stuff tends to be hard to get everything cleaned off. What’s left gums up stuff fast. You might want to try sanding first without stripping and see how that works.

Ron

 

[leakyroof]

Any chance there's a coat of Shellac in that old finish you're removing?  It can gum up paper. While I'm not there to try it on your issue,  sometimes the sanding Belt Cleaner Sticks can be applied to corned up, or gummed up Granat to get a fair amount of the 'Corns' out of a Disc, saving it and getting you back into production.

 

[Tom the Remodeler]

I'm a little curious why you're using a sander to remove the finish, rather than dissolving? If it's an antique piece of furniture, the base coat of finish is likely shellac, which will simply dissolve in alcohol. This still takes some patience and skill, but it removes the cost of abrasives and the risk of sanding through the veneer...

In terms of burning through abrasives, as pointed out by others, you'll want to start with a more aggressive grit if you're clogging.

In terms of people sanding for hours and hours without changing grits, I'd make the gentle suggestion that they wore out their pad long ago but don't have the experience to identify the situation. If I'm sanding raw wood, I find I need to replace the abrasive every 15 minutes or so, depending on species, grit, etc....

One of my colleagues who is a historic furniture repair specialist has a saying "Sand paper is cheap, you shouldn't be..."

 

[Peter Kelly]

Second-ing the card scraper. Done right, the surface finish is much nicer than a machine sanded one.

 

[raccoonhands]

I'm a little curious why you're using a sander to remove the finish, rather than dissolving?

I'm stripping pretty thoroughly with methylene chloride first. Mostly lacquer finishes.

 

[Crazyraceguy]

I would guess that there are a few issues going one here, starting with the sander itself. The ETS125 is a finish sander, with a tiny 2mm stroke. This alone makes it unsuitable for anything "aggressive", in the first place, even less-so for finishes than have a tendency to clog. Shellac, nitrocellulose lacquer (not catalyzed) and paint all fit into this.
Since you are already stripping, I would go as far with that as you can. It will save time and material in the long run. Then go to the sanding, but with a longer stroke sander. Dust extraction is your friend here. You have to get that swarf out of the way. Re-sanding that dust is what clogs paper. This is the "corning" that [member=10952]leakyroof[/member] mentioned. This is the little balls that cling to the paper. It is essentially melted finish and wood dust combined into a plastic like glue. In most circumstances, the first recommendation to cure corning is "let the finish dry longer", which doesn't apply here. The second is "go one grit more coarse". This can be sketchy with veneers. Older ones are usually thicker, but it's not worth the risk.

After all that..
Strip more, maybe change strippers too?
Scrape what you can
Sand with a more aggressive sander. 5mm stroke would be best, but even 3mm is 50% more than what you have.
Start with 120, if you still get corning or clogging, go to 100. The jump to 80 may be too much to recover from later.
Keep the sander moving and the surface clean. Concentrating in one place digs holes and garbage under the sandpaper clogs the paper, builds heat, creates swirl marks.

Hope that helps

 

[jronman]

In my experience with old finishes, a vac is not enough. You need to ensure the vac has proper airflow. A dirty filter is not much different than no vac at all. The airflow won't be enough to keep up with dust production or cool down the pad. It will result in you getting the caking and gumming others have mentioned above. Low power on the ct vac is plenty airflow from my experience with the cordless sander. The Rotex 150 in Rotex mode needs max airflow. That thing gets hot during extreme sanding. I used a product called Citristrip on the last project I refinished. It was something I applied before sanding that I had to wipe off. I think it did alright on the finish. It wasn't perfect but much better than only sanding. I was also trying to remove the stain and stain just takes more sanding.