Sandpaper

[billd]

What brand or type of sandpaper do you find best for bare wood?  I bought some Mirka (made in Finland) that was highly recommended by a wood worker friend that I find is terrble. I have some KMart special that lasts longer.

Bill

[David Veith]

Any of your 3M Norton Skile? is good The bigger ? is witch type of grit you getting. Silicon carbide, Aluminum oxide. If you are using Flint or garnet. They will give up the ghost earlier. Remember it is designed to wear out. The other good product is the thin sanding sponges. They take on shapes pretty good and are easy on the hand. Don't be afraid to glue sand paper to Popsicle sticks, for some things.
David Veith
Painting Contractor

[Ohioan]

I absolutely LOVE the Norton 3X.  That stuff cuts great, doesn't clog and lasts forever.  Best paper I've found.

[smart dog]

Bill,
I like Norton blue zirconia paper if I can find it.  There are web companies that sell it.  It is the best I have encountered for both wood and metal.

dave

[David Rase]

I have always used a good quality garnet paper.  3M seems to be the brand most abundant in my neck of the woods.
DMR

[FL-Flintlock]

I had the info below posted on my website but since I've been moving things around trying to re-organize it hasn't made it back on there yet.

Abrasives

Aluminum Oxide (AO):  Durable long-life & wear resistant man-made abrasive
known for its penetrating strength at all speeds, does not require high surface contact pressure.
Applications:  Ferrous metals, hardwoods & aluminum.

Silicon Carbide (SC):  Hardest and sharpest manufactured abrasive providing
fast stock removal and cool cutting.  Available backing: Waterproof paper and dry paper or cloth backing material. 
Applications:  Non-ferrous metals, Non-metallics (glass, rubber, plastic, stone, fiberglass, particle board), abrasive planning, final finish on wood & cast iron.

Zirconia Aluminum (ZA):  Ultra-tough synthetic abrasive with a controlled
breakdown self-sharpening microcrystalline structure.  Stronger and sharper than AO.  Available in course grits (24-120) only.  Requires 15-40% more contact pressure than AO for optimum performance.
Applications:  Heavy duty grinding and sanding on all metals, hardwood, resin bonded wood fiber products, fiberglass, plastics and rubber.

Emery:  Dark gray rounded grain that tends to polish the surface rather than abrade it. 
   Applications:  Cleaning and polishing of metal only – very low stock removal.

Non-Woven (NW):  Random 3-dimensional networks of open nylon materials coated with aluminum oxide or
silicon carbide abrasive.  Primarily used for surface conditioning on metal, wood and coatings as well as finish smoothing, polishing, texturing and decorative operations.  Non-clogging in dry or wet use.  Can be used effectively with petroleum, synthetic & solvent-base oils and all soluble oils.

Garnet:  Reddish-brown, medium-hard and relatively sharp natural abrasive.  It is
not as hard or durable as man-made synthetic abrasives.
Applications:  Wood only – particularly well suited and produces an excellent finish on soft sappy woods such as pine, less effective on hard woods.

Crocus:  Iron oxide very soft natural red color abrasive used for fine polishing of
   Soft metals such as gold and finish sanding of very soft woods.



Coating Styles

Open Coat:
Refers to a coating in which 50-75% of the backing is covered by the abrasive grain.  The voids
between the grain particles offer a relief area to help prevent loading of the cutting surface with removed material.  Open coat abrasives are most effective where moderate stock removal is desired for rough finishing of materials such as hard or soft woods, free-cutting plastics, very soft metals and free-cutting synthetics or composites.

Closed Coat:
   Refers to abrasives in which the entire surface of the backing is covered with abrasive grain leaving
no open space.  This is the most common coating style in use and it permits the greats amount of stock removal and long abrasive life.  Suitable for most all applications and materials.



Storage Conditions

Temperature and humidity affect the life span and performance of coated abrasives.  Optimum storage conditions for all abrasives:  Temperature 60-80°F ~ Humidity  35-50%.  Coated abrasives should not be stored in direct sunlight or where they will be exposed to other UV light sources.  Avoid storing in any area where the abrasives may be exposed to direct heat sources like radiators, steam/hot water pipes, boilers, furnaces and so forth.  Never store abrasives near an exterior wall, on a concrete floor or anywhere else they will be exposed to direct or conducted moisture/dampness.

Never hang belts on a nail or peg, if hanging storage is desired belts should be placed on a large diameter smooth surface drum with parallel sides and belts should hang perpendicular to the drum surface.  Where hanging is not desired, belts should be rolled and stored on their edge on a flat shelf, never store belts flat.  Non-woven surface conditioning belts should be stored in the same manner as other coated abrasive belts.

Cut sheets, cloth-backed discs and resin fiber discs and non-woven pads should be stored flat on a shelf.  Cones, points, cartridge rolls, spiral bands, pump sleeves and all similar shaped/formed products including non-woven surface conditioning types should be stored standing on end or edge.  PSA discs and other items that come packaged as a roll should be stored as such in the original packaging or a work station dispenser for that particular product whenever possible.

All abrasive products should be protected from exposure to mist or fumes of oils, solvents, paints, coatings or other similar materials.

Proper use of a high-quality abrasive cleaning stick during dry use of coated abrasives will normally extend the use-life of coated abrasives by 250-500% depending on the application. 





My Notes:
   
General metal finishing of most all ferrous and non-ferrous metals is best accomplished with coated AO abrasives and/or diamond coated hones, files & rifflers - unlike standard files, diamond coated tools will not create drag lines and cut in any direction greatly reducing work time and effort.  Zirconia coated abrasives are best suited for power-driven heavy hogging (roughing) production applications – in non or low powered applications it is almost impossible to obtain the surface contact pressure required to fracture the grains so as to take full advantage of the increase cost and life-span capabilities of this abrasive.  Ceramic is another high-cost abrasive best suited for special-purpose and production applications.

One of the most effective contour control sanding aids I have found are the foam hand pads for use with PSA discs.  They give far more control over where you’re removing material and they will remove uneven high spots on the surface unlike sponges that ride over lumps.  Sanding sponges do have the nice sharp corners that are handy to get into areas where you want a sharp corner but they can also be problematic if you don’t see them cutting a groove where you didn’t want a groove cut.  If you want contour finishing, you don’t want to remove surface lumps like relief carving and don’t want sharp corners, non-woven pads are the way to go.  Non-woven pads won’t clog like some coated abrasives and they also don’t leave behind the mess of little steel wires all over the work and stuck in your skin like steel wool.  Gray non-woven pads work wonderful wet or dry to smooth finishes between coats.  If wet sanding is desired, the pad can be wetted instead of the work which greatly reduces the amount of water the work is exposed to.  (Gray = 0000 steel wool ~ Green = 000 steel wool ~ Maroon = 00 steel wool ~ Brown = 0 steel wool)  Stock removal and surface condition are controlled by the amount of surface contact pressure applied when using non-woven abrasives.   

“Cabinet paper” comes in “C” & “D” weight (medium and least flexible) and only in open-coat and grits of 36-150.  Cabinet paper is made for general finishing of wood products that will be coated with a layer-building finish like varnish, polyurethane or paint.  The surface condition obtained with cabinet paper will not be as smooth as that obtained with non-woven or standard closed-coat abrasive and this becomes an issue when using a non-layer-building finish like tung oil.

“Finishing paper” is backed with the most flexible “A” weight paper.   It too is open-coat to help prevent clogging but the combination of flexibility and grit sizes to 320 make this a better choice when you want a nice smooth finish.   

Non-woven surface conditioning belts will not maintain sharp edges such as is desired on the corners of an octagon gun barrel – for this application cloth-backed belts are desired on power driven equipment.


Please feel free to contact me with any questions.
mark@fire-iron.biz

[smart dog]

Hi Mark,
I currently have blue zircona paper in 180, 240, 320, and 400 grits purchased from Supergrit.com a few years ago.  It is the best and longest lasting paper I have ever used.  Usually the paper backing weakens and tears before the grit is worn out.  It does very well sanding wood and metal and does not require any special high pressure to work for my purposes.  The finer grits leave a smooth surface about as nice as garnet paper (but it lasts many times longer).  It is also really effective when working on tough steels.  If manufactures are no longer making the finer grits that is too bad.

dave 

[Tim Crosby]

Remember it is designed to wear out.

 You mean after using it 80 does not become 100, 100 120, 120 150, etc...think maybe I'm a little to tight.  I just have a heck of a time throwing it away while it still has tooth to it. 

Tim C.

[FL-Flintlock]

Dave P.,

My business in PA was building custom commercial & industrial machines and products - 90% of the fabrication work was using metals, the remaining 10% being composites and plastics.  The majority of my abrasives customers are still commercial/industrial so I sometimes get stuck in that "production" line of thinking.

Zirconia is a very tough synthetic abrasive.  When I said about surface contact pressure, let me explain that better...

Normally zirconia coated abrasives are used on power tools and what happens is, they work fine for a while then the cutting action will drop-off to near nothing - this is a sign that there isn't enough surface contact pressure being applied.  When the initial sharpness is lost, that's when the pressure is required to fracture the grains and expose new sharp edges.  Considering the same abrasive being used with hand power only, you're not hogging material off the work and thus the amount of wear the abrasive sees is quite small in comparison with what would be seen if it was running on say a 1" x 21" belt sander. 

Being a mfg direct distributor and not just a retailer, I source the product technical & application information right from the factory in addition to my own experience.  One of my current abrasives customers manufactures gun parts and they were sourcing, as so many people do, the "cheapest".  Well, that came in the form of AO coated belts made in China.  They lasted all of about five minutes before the cutting action was about done with, the operator would then apply more and more pressure trying to keep it cutting but the result was shredding of the backer and/or failure of the joint.  They were paying $0.77 each for the "cheap belts" and burning up 30-40 belts in an 8 hour day.  I switched them to zirconia at $2.75 per belt at the rough finishing station - two belts lasted all day costing them a total $5.50 per day as opposed to the $23+ per day the "cheap ones" were costing them.  Additionally, they had to use 36 grit AO belts to achieve the desired stock removal rate - 80 grit zirconia achieved the same stock removal rate while leaving a finer finish which greatly reduced the amount of follow-up finishing time. 

In contrast, another customer is a boat builder.  Their old supplier talked them into using the high-cost zirconia quick-change discs in their aluminum fab shop.  Performance was very poor, the abrasive held-up but the surface loaded-up quickly making the disc useless.  I changed them to AO discs eliminating the surface loading problem and at the same time they used less AO discs that cost them $0.85ea than they did of the "premium" zirconia discs that were costing them $1.28ea.  On the same note, in their stainless steel fab shop I replaced their $1.28 zirconia discs with $1.51 ceramic disc cutting their usage by more than 60%.  A plastics mfg was going through 150+ cloth-backed PSA discs at $1.00ea per shift - I changed them to a paper-backed PSA disc, they still used 150+ per shift but at a cost of only $0.29ea - $150/shift verses $43.50/shift.

Points being is that not all abrasives are created equally and buying the most expensive abrasive material is not always efficient.

With all that being said, for hand-use the zirconia will last a long time but I think you'll find that a good quality AO will provide a comparable service life at roughly 40% less cost.  Now cabinet & finishing paper is open-coat AO, and yes it'll work on metal but being that it is open-coat for sanding wood, it's not going to produce the same finish or remove as much stock as a closed-coat.  Paper-backed abrasives are not as durable as cloth-backed but again, it depends on the application as to which one will produce the finish and have the workability properties you desire.  SC (silicon carbide) screen cloth and AO non-woven abrasives have come way down in price and are quickly becoming favored in many applications.  On things like gun stocks and other wood carvings where you want to keep the chisel/scraper marks but smooth and de-wisker the surface, the non-woven is really a charm.

[FL-Flintlock]

Remember it is designed to wear out.

 You mean after using it 80 does not become 100, 100 120, 120 150, etc...think maybe I'm a little to tight.  I just have a heck of a time throwing it away while it still has tooth to it. 

Tim C.

Tim,

That's not being "tight" it's being frugal.  To answer your question, breaking down the abrasive does not change the "grit" size - the difference you see in the surface is the difference between actual "cutting" and more of a burnishing effect.  If you look closely at the surface with a 10x or stronger loupe, you'll see the marks from the larger "grit" size abrasive even though the surface may "feel" smoother.  Usually with an oil finish you won't see it with the naked eye but put a poly or other high-gloss finish on it and all those little lines will stand-out like crazy.

The exceptions to that being emery and crocus, both of these do break-down into finer grits but neither will work well on wood.

[billd]

Guys,   Thanks for all the great info.   In my original post I was looking at brand names more than types, I guess I should have asked it differently.   Anyway, I googled blue zirconia and can't find anything other than very coarse disks and belts and strips for air sanding boards. No fine grit sheets??

 And to Ohioian who recommended Norton.......3M makes a paper called Sandblaster. Online in photos it looks identical to the norton 3x, color, grit sizes and description, the packaging and price is even similar.  Do you know if these are the same product? I tried the 3M Sandblaster 120 grit from Lowes and it is the best and longest lasting I ever used. They don't handle Norton.

Thanks again,
Bill