Sandpaper question

[zapdafish]

Over the weekend I was removing the old finish, poly, from my work table in order to recoat it using 50 grit paper.  After a few minutes I could tell the ability to remove the finish had drastically been reduced. The paper still seemed fine except for a few places where it started to clump. I would try to scrape them off with my fingernails but it was 50 grit and kinda hard to do. It seemed the clumps grew large enough to cause the sander to lose contact with the surface.

Should I have used a different kind of paper? or is there something else I can use to clean the clumps off the paper easily? I am pretty sure it was rubin as this is the page I ordered it from.  my sandpaper

Once the layer of finish was removed, I had no problems at all taking it to 220 before applying a new coat of finish.

 

[Ken Nagrod]

Rubin is ideal on bare wood.  Not recommended for stripping a finish, from what I understand.

 

[Tim Sproul]

No anti clogging agent in Rubin.  It is made for sanding bare wood.

Try Brilliant, cristal or granat to remove the finish.

And remember that removing finish typically requires slower rpm's to keep the temperature lower.  Lower temps mean less clogging.

 

[semenza]

I really like Cristal for stripping the low grit density really helps resist clogging.

Seth

 

[Brice Burrell]

I really like Cristal for stripping the low grit density really helps resist clogging.

Seth

I like Cristal too, but use it carefully/selectively since it will leave a deep scratch pattern that can take a lot of effort to remove. 

 

[AlexThePalex]

Yup, Cristal's only for the tough jobs, use Brilliant or Granat otherwise.

 

[zapdafish]

thanks, didn't know about the slower speeds either.

 

[AlexThePalex]

thanks, didn't know about the slower speeds either.

Slower rpm's also mean slower work. My time is more expensive than a piece of sandpaper, so I say ...... full throttle and let 'em clog!

 

[Tim Sproul]

Slower rpm's also mean slower work. My time is more expensive than a piece of sandpaper, so I say ...... full throttle and let 'em clog!

Clogging of the abrasive is dependent on:

The finish/surface you are abrading.  Shellac that has cured for only a day/overnight clogs rather easily, for example.

The grit you are abrading with.  p40 doesn't clog as easily as p400.

The speed/rpm of the abrasive pad.  Faster speed = more clogging.

The coating on the abrasive - stearates or other additives reduce clogging.

The dust collection efficiency.  No dust collection = more clogging while high efficiency dust collection = less clogging.

There are a few other parameters too but these cover the major ones.

Economics.  Yes, abrasives are rather inexpensive.  But it isn't so much the cost of paper.  Reducing the number of papers changes = higher efficiency of work.  Reducing the RPM's too much will negate the reduced number of paper changes.  This is one of those things that requires experience to develop a feel for the speed you should abrade it for the task at hand.

And as you go to higher grits when you are flattening newly finished surfaces, those corns/clogs can cause large scratches in your work.....effectively adding to your workload rather than getting closer to the light at the end of the tunnel.

 

[tbellemare]

I haven't used it for all finishes but I have tried it on a few of my own and a few of my customers' and Granat is quite impressive. For the normally sticky stuff, it almost totally resists clogging. It's like 'super-paper'.

It's sold in 10-packs, so you can try it without breaking the bank. I recommend that anyone who is less than totally satisfied with other abrasives, try Granat. The grits larger than 120 also last a LONG time. They wear out the backing before the abrasive surface gives up.

Tom

 

[Brice Burrell]

....It's sold in 10-packs, so you can try it without breaking the bank. I recommend that anyone who is less than totally satisfied with other abrasives, try Granat. The grits larger than 120 also last a LONG time. They wear out the backing before the abrasive surface gives up.

Tom

Tom, in my opinion the backing is the weakest link, I suspect that's no accident.  I'd love to see the low grits have a heavier backing material.   

 

[nickao]

I disagree about the Cristal being only for tough jobs, though it definitely covers that and is designed for that.

Cristal is my go to paper for everything. I love being able to sand wood smooth, jump to painted surfaces and even epoxy  using the same exact paper. For me it's not worth the pennies to get something cheaper and Cristal 120 gives just as smooth a surface as any other 120 paper on my stuff.

Only the grits not offered in Cristal do I bother going to something else, the super low grits specifically. Nothing I have tried lasts as long as the Cristal for my work either, for me its the most bang for the buck and in my opinion the best sandpaper I have ever used to date, period. The only time I bother with anything else is if Cristal is not offered in a grit I need.

I wish Cristal came in 36 to 240, then I would never need anything but Cristal at all.

 

[AlexThePalex]

... and Cristal 120 gives just as smooth a surface as any other 120 paper on my stuff.

That's not my experience. I've used Cristal in 40, 60, 80 and 120 grit and they all left so much scratches that I needed to sand it again with Brilliant to get it smooth. I only use Cristal if I want to remove all paint down to bare wood, and then I have to do a pass again with 120 Brilliant or Granat. Cristal is just too sharp. Great for removing stuff, but not for finish work.