Sandpaper lifetime

[easilyconfused]

Kind of a silly question because it depends on the sandpaper quality but how long does yours last on average. I use the find-everywhere Norton quality all purpose aluminum oxide paper that isn't too pricey but it seems like I'm switching every 10 minutes and not getting the last grits scratches off before I am frustrated with it not cutting anymore. I'm going by hand by the way. Anyone else seem to wear out so fast or is it just a matter of poor quality and the better stuff lasts longer? Or is there a different type of grit that wears better when used with metal?

[markb]

I've been hand sanding a knife and have concerns also, using a no name brand that I got at a local tool store.
I've read at other knife forums that grits from different brands vary so stick with one brand.
3M wet dry seems to be a popular choice, I'm going to try it and compare.

[Steve Sells]

Ao will never last long being used on steel.

[viking-sword]

I have always favored silicon carbide/wet/dry paper for my hand sanding. It holds up much better than A/O does and I use a lubricant while sanding, such as water, or odorless lamp kerosine oil. This floats away the particles and does not allow the paper to load up near as fast. This type of paper can be found at the automotive stores and most any of the knifemaking cataloges. Wes

Edited April 27, 2009 by viking-sword

[Ecart]

I'm glad I came across this thread. I have a simular problem with Ace Hardware brand paper. I asked this same question on another forum and the answers were the same as here. It is good to cross reference sometimes. I can get any grit of 3M brand wet/dry paper I want from a local auto parts store- I already checked, so after I finish the knife I am sanding on now, that's where I am going for the next batch of paper.

[Dodge]

Until I started blacksmithing about 9 years ago, I never heard of using ao paper on anything harder than wood or plastic. I grew up around cars and metal fabrication, however, and for metal the least I was taught to use was emery cloth. It's still ao but the cloth just holds up better than paper and comes in just about as many grits (Think abrasive belts). The only paper sanding I've done on metal, either bare (for high polishing or painted (cars), was with wet or dry so it can be rinsed thereby extending the life of the product. Get ao paper wet and its bye bye grit. AO paper for wood and plastics; emery cloth and/or wet or dry for metal. That being said, I have used ao paper on metal, with the mind set that it isn't going to last long but that was all I had handy.

That will be 2 cents please
Scott

[easilyconfused]

Sorry dodge, those 2 cents will be going to the next piece of sand paper. I'll have to keep an eye out for something better in the right size and grit. Gonna make a straight edge for the 1" belts and use it like a draw file like I've seen some people use because 1" belts are easier to find in the area than sheets.

Another question, does emery cloth go below 200 grit? I've yet to find any that does around here and that's where I use the Al-Ox.

Edited April 28, 2009 by easilyconfused

[Fe-Wood]

Here are my favorite brands- not sure if they offer wet/dry compounds as I use them on wood and metal dry. great grit and adhesives. They last a good long time
Mirka gold, link: Mirka Abrasives.
Klingspor, link: KLINGSPOR Abrasives, Inc.
Norton, Norzon, Link: Norton
They are expensive but so is throwing away junk that didn't do the job in the first place...

Edited April 28, 2009 by steve sells
url correction

[GNJC]

Hello,

I used to do a bit of jewelling and found that emery paper was going through my hands too fast. I fixed this by sticking clear plastic film to the back of it. I use the same thing now with iron and steel; at a guess I would say the paper lasts at least three times longer this way, so it is economical.

Here in the UK the trade name for the plastic is Fablon, but we can also get the same sort of thing at a much lower price from hardware shops, supermarkets and places that deal with students' supplies (they use it for covering books); I hope its as easy to get in North America.

G.

[JamesBBrauer]

I recently put a Norton 3x Zirconia Alumina (sounds like refractory additives) on my 4x36" belt sander and was surprised that it actually lasted longer than the previous belts I have tried. It looks like it is worn down, but it still does a good job sharpening the mower blade, and did well on a bunch of de-burring and weld prep for the two gas forges I am working on. It did snag on a burr and get ripped down to a smaller width, but this happens to about every belt I put on there. I would recommend this product.

I've also used 3M and Norton wet-dry to run from 150 grit, on up to the 3000 grit range to sharpen chisels and plane baldes. The wet-dry seems to last pretty good relative to the 150 grit paper targeted to sanding wood. Speaking of grit, I think I read in Fine Woodworking that the grit is based abrasive falling through a screen with that many holes per square inch. If the grit ends in a 'p' it might be metric mesh or a vendor specific designation.

And I guess most of you already knew that sander belts have a direction, based on how they scarf the two ends together. Took me about 10 years to figure that one out, but after running through a bunch of low end belts where the mounting direction actually mattered, I started to look on the back side.

[Dodge]

Another question, does emery cloth go below 200 grit? I've yet to find any that does around here and that's where I use the Al-Ox.

I'm not sure what steps there are below 200 but I know there is a grade that is called crocus cloth. I believe it has to be 1000, 1500 or finer. My experience with it is polishing bearing surfaces in automotive engines.

[Fe-Wood]

Also, you might look up a product called micro mesh

[kbaknife]

Quality of sandpaper is one thing, but EVRYTHING in knifemaking seems to only be the preparation step for the next one.
Though you may have considered it before, allow me to give some advice when it comes to sanding out scratches:
When you're "sanding out" scratches, you're not really sanding scratches.
You're sanding everything that is NOT a scratch!
The scratches don't leave until you bring all of the rest of the material DOWN even with the BOTTOM of the scratches!
To put it simply, the MORE scratches you have, the less material you have to sand DOWN to the bottom of the scratches!
So, do a REALLY good job with the sanding belts as you grind.
If you just do a quick grinding job, then you've left yourself a LOT of handwork, because you've only done a rudimentary job of grinding and only have a few scratches.
Go through your belt progressions slooooowly and completely, and when you get done, the hand work is a breeze, because you won't have any deep scratches left.

[brucegodlesky]

Good description of the process Karl.
I've been in the autobody bidness for prit near 40 yrs and 3M has been at the top of the heap for me during all those yrs.

[kbaknife]

Bruce, I re-built and re-finished 7-9 foot concert grand pianos for 5 years.
Nuthin' worse than a lingering scratch in the middle of the lid of a 9 foot, mirror polished black lacquer Steinway!
Do every grit to its completion before moving on to the next one!

[markb]

Nuthin' worse than a lingering scratch in the middle of the lid of a 9 foot, mirror polished black lacquer Steinway

Wow!
My little knife just got sooo easy.

I just put a deep set of parallel gouges in with a mis-pull on the draw file.

thanks for the perspective.

Mark