ABRASIVES COMPARISON - multiple types, grits compared by 4 testers

Over the last several weeks I have accumulated a stash of different abrasive brands and grits and these have been sent out to three other testers, as well as myself. There are 25 discs in all to be compared from 80 to 1500 grit. The four sets didn't quite match up 100% as there was a shortfall on a few discs, and my set was the one the copped most of those shortfalls. This was because I am quite familiar with the missing discs (hence why they are missing :;).



A few things to observe before I get to my results:

• The testers were all required to have a Festool ETS 150 sander because the discs that I procured were in the Festool 17 hole pattern, and I wasn't prepared to spend my life's savings on acquiring all manner of DE hole patterns to get some variety happening. This should have no reflection on the results (either an abrasive is good at cutting, or it's not). All of the discs to be tested are 150mm.


• Two of the other testers are professionals, and another is a gifted amateur with a scientific background.


• I have my sander hooked up to a 36mm hose which results in much better extraction than the standard 27mm hose. I mention this because none of the abrasives so far have left any detectable dust on the job.
  


• I am very familiar with two of the brands tested, Jöst and Festool Rubin 2, having used both of them extensively for the past 2+ years. In that time I have developed a preference for the Jöst discs with one exception, the 60g. I have found this particular grit to be not as aggressive as I would have thought, and needs replacing more often than I'd like.


• In particular I have found the finer grits of Jöst (400 and up) to be ridiculously durable. It seems that the finer they get the longer they last (up to 3000). The Festool Rubin 2 range finishes at 220g, so from there up to 500 I have been using the Granat range and have been somewhat underwhelmed by them. I have never used the Festool Platin very fine grits as they are just too expensive by comparison (local RRP is $4.60 per disc compared to the Jöst equivalent "SG2" at around $2.00 including freight from Germany).


• The other discs included are two different types of Klingspor, and Abrasives Industrial, a Perth based company that imports jumbo abrasive rolls from China and processes them here into the various shapes and hole patterns. There were only two types of Klingspor included in the 80g range.


• Also, in the 80g range only there were two types of Jöst - the standard Superpad (yellow) and the newer Abrafilm (and I was omitted from both of these due to short supply).


• I will not supply the various pricings just at the moment until the rest of the results are in.

Some notes and observations on the individual brands and types (and sequenced in the order that I tested them, for want of a better reason):



JÖST

• These abrasives are made in Germany and have to be specifically imported (i.e they are not sold in Australia).


• They have a patented DE hole pattern that suits any sander's holes. They achieve this by covering the disc with hundreds of 2mm holes rather than 9 to 17 larger holes. This means that the holes don't necessarily line up very numerously with the sander's holes. It also results in some dust staying on the back of the disc, and this is no big deal - it does not affect the general extraction at all and in my extensive use of them I have noted that the amount of dust left on the job is the same as the Festool 17 hole pattern - nil that I can wipe off with my fingers.


• The range of grits is from 40 and 60 in Red, 80 to 600 in Yellow, and these are all known as Superpad. The range then goes on from 800 to 4000 in "SG2" and these are on a 3mm thick sponge substrate with no DE holes at all, as the dust is fine enough to be sucked through the sponge at these grits. The same applies to the Festool Platin discs.


• Very occasionally I get some little tears just at the edges of the discs, depending upon what I am sanding. This has never been a problem for me, and doesn't seem to affect performance or leave undue scratch marks.


• The second Jöst range is Abrafilm, and as the name implies, they are a film substrate rather than paper. This significantly increase the strength of the substrate. In the 40 to (I think) 150 range the abrasive is Aluminium Zirconia, and from there up to 3000 the abrasive is a ceramic. Caveat - I need to check the crossover point, and get a better description of the "ceramic".

ABRASIVES INDUSTRIAL

• This company imports large rolls of abrasives from China and cuts them to size in Perth.


• They have two ranges of abrasives. The range we tested is an Aluminium Oxide grit on film substrate, with a grit range 40 to 1200. The other range is a more expensive ceramic grit on film substrate, grit range 40 to 2000.


• The die that has been used for punching the 17 hole pattern has deformed the coarser grits to the point where they will not stick properly to the sanding pad - the hole edges are raised up by up to 2mm which prevents the rest of the disc making proper contact. Care had to be taken to ensure as much contact as possible, so that the disc didn't fly off. Having said that, I did not experience any problems because of this improperly formed hole (on the only grit tested so far - 80g), but this deformity needs to be addressed. It remains to be seen how it affects the more delicate fine grits (the hole deformation is different).

KLINGSPOR AlOx range

• This range is locally available, as Klingspor have an Australian distributor (or branch). I brought my testing discs in from the USA because I had a source and also a box of other goods to be despatched, so it was convenient at the time.


• Manufactured in Poland.


• Grit range is 60 to 1500and available in packs of 10 or 50.


• Stearate coated


• Very large range of sizes, shapes and hole patterns

FESTOOL RUBIN 2

• Limited to shapes, sizes and hole patterns to suit Festool Sanders


• Grit range 40 to 220 (can then switch to Granat, and then to Platin 2 to go up to 4000)


• Probably manufactured in Finland

KLINGSPOR Aluminia Zirconia range

• This is a heavier duty range, which has a coraser grit range of 36 to 220


• 50 packs only


• Stearate coated


• Not sure if they are available locally yet.


• Discs only, with a good range of hole patterns

Ok, that will do for this post. I will post my results once the others have told me they are finished. As the proponent of this testing cycle I feel obliged to do as thorough a job as possible, and as empirically as I can. However, I do not have the required instruments to do a thoroughly scientific job (or the knowledge :roll:). Nor do I expect that the testers will go to quite the same lengths.



So far, I have sanded 1.8 kilometres, that's right 1800 metres, 1000 strokes of 930mm up and back of 415mm wide hardwood. :D



I have gotten past the 80 grit discs yet. :doh: