*This post is NOT sponsored by Indasa or its distributors. Indasa provided me with their products to review and educate my readers. This article strictly reflects my own views and opinions and not the opinions of Indasa.
Links below are NOT affiliate links.
Over the past 7-years I’ve been using the Festool ETS 125 (125 mm or 5 inch diameter) random orbit sander. When I first started using the ETS 125 there were limited hook and loop abrasive disc options that were compatible with the Festool hole configuration (8+1-center hole). For that reason, I stuck with Festool’s Rubin line of abrasive discs. I knew the holes would line up properly for proper dust extraction and that I’d get a good amount of longevity from the discs. The problem was the cost. At $36 per box of 50, Festool’s Rubin line is expensive comparatively to other brands.
The Festool ETS 125 has been my primary random orbital sander for the last 7-years.
In May of 2020, Indasa, an abrasives coatings company based out of Portugal, sent me samples of four of their product lines (Rhynogrip White, Red, Plus, and Ht Line) to test in my shop. The Rhynogrip White Line is Indasa’s economy line. I was sent P120, P180, P220, and P320 grit varieties with a velour backing (hook and loop), and Festool hole pattern. I tested the P120 and P180 grits on a computer desk build made of 12mm Baltic Birch plywood.
Paper Backing
Paper backed abrasives come in a variety of weights ranging from A through G, with A being the lightest and most flexible to G being the heaviest and most sturdy. Grits between P36 and P120 come in a D-weight, while grits of P150 and finer come in a C-weight paper backing. Paper backed abrasive products are ideal for light to medium sanding of flat surfaces. They’re not as sturdy as cloth and film back products but are less expensive to manufacture. They offer a greater overall flatness than cloth backed products, but are less consistently flat than film backed products. Paper backed products also generate less heat than cloth backed products; however, they’re more prone to tearing and abrasive grain shedding. It makes sense for the P120 and lower abrasives to be made of a heavier paper weight due to the heavier cutting demands of the lower grits. Whereas P150 and greater are less aggressive and therefore are suitable to a lighter weight backing.
Rhynogrip White Line offer D-weight paper backing on P120 and lesser grits, and C-weight paper backing on P150 and higher grits.
Grain and Lubricant
The Rhynogrip White Line grain is comprised of aluminum oxide (ALOX) grains. ALOX has been the standard abrasive grain for several decades and has almost completely replaced silicon carbide (brittle), due to its resistance to fracturing. ALOX is an excellent stock removal tool leaving an open pore rather than compressing fibers. Having open pore wood fibers is ideal for woodworkers that intend to use stains, dyes, oils, and hi-build finishes. Higher grits tend to produce more heat due to clogging and will often burnish the work piece, essentially closing the pores of the wood. On P150 grits and greater, the Rhynogrip White Line has an ALOX lubricant which prevents heating and clogging of the wood fibers and cutting grain of the abrasive. These are all very practical features that I would expect from a quality sandpaper.
The Rhynogrip White Line uses an aluminum oxide (ALOX) cutting grain and is coated with a lubricant on grits of P150 and greater.
Performance
I started by sanding the Baltic Birch plywood panels of the computer desk with P120 on my random orbital sander. I used pencil scribbles on the panels to ensure I didn’t miss any spots. Once all the pencil lines disappeared I moved on to “breaking” the edges of the plywood panels with a sanding block. I then used P180 on my random orbital sander to finish sand the panels. I did not use pencil marks on the plywood panels while sanding at P180. I did not feel it was necessary to ensure a good even cut quality on the panels at this stage.
Using a pencil to ensure I cut the entire panel with P120.
The P120 was able to cut at a reasonable rate. I moved the random orbital sander first against the veneer grain and then with the veneer grain at approximately 1 linear inch per second. I’ve found that at this speed I’m able to get several rotations of the orbital sander to fully cut the wood fibers and not leave swirl marks or pig tails. I used a single P120 disc to sand two (2) 18”x42” panels, thirteen (13) 18”x29” panels, and twenty (20) 5”x29” drawer parts. This took approximately 1-hour to complete. I was able to effectively sand all the components without any noticeable degradation in cut quality or speed. There was mild shedding of the abrasive grain along the perimeter of the P120 due to the sander “catching” and/or “banging” the edge of a work piece. However, the shedding of the abrasive grain was not a noticeable amount that would warrant replacement of the disc.
I moved the random orbital sander first against the veneer grain and then with the veneer grain at approximately 1 linear inch per second.
I used the P120 velour backed roll and 5”x2-3/4” sanding block to break the edges of the plywood parts. I’ve learned that paper backed ALOX abrasive discs on a random orbital sander are not made to break the edges of work pieces. The edges often catch the vacuum holes of the abrasive disc causing the grain to shed. Rather, I like to use a sanding block to do this task. The abrasive is less likely to shed and I’m able to get better control of how much material I’m removing. The sanding block and Rhynogrip White Line velour backed roll was perfect for this task.
I used the P120 velour backed roll and 5”x2-3/4” sanding block to break the edges of the plywood parts.
I was able to break the edges without seeing any signs of abrasive shedding.
I finish sanded all of the plywood panels with P180. Again, I used a single disc to complete this task and it took me approximately 1-hour to complete. The paper remained cool during the operation and did not show any signs of clogging or burnishing. There were no signs of abrasive shedding and the disc was still able to effectively cut after 1-hour of sanding. After progressing through P120 and P180, there were no signs of swirl marks or pigtails. The P180 was successful in eliminating the scratch marks of the previous P120 grit.
The P120 showed minimal signs of shedding along the perimeter of the sanding disc. The P180 showed no signs of shedding.
Value
A box of fifty (50) 5” Rhynogrip White Line 8+1 velour backing sanding discs will cost you between $14 ( https://2sand.com/indasa-rhynogrip-5-inch-8-hole-white-hook-loop-sanding-discs-50-box) and $17 (https://indasa-direct.com/collections/indasa-sanding-discs-grip/products/indasa-5-rhynogrip-whiteline-9-hole-vacuum-sanding-discs-fits-festool-59-series?variant=29081903956073) depending on the distributor. That’s between $0.28 and $0.34 per disc. Given a working time of 1-hour per disc, you can expect to spend between $2.25 and $2.72, per 8-hour working day, per user during continuous sanding. Obviously, I’m not testing this along side other competitive lines. However, based on my experience with Festool Rubin at $36 per box fifty (50), I’d have to use two Rhynogrips White discs to equal one Festool Rubin.
Conclusions
The Rhynogrip Whiteline is a budget friendly line that will accomplish most medium to fine woodworking tasks. The Whiteline offers a D-weight paper backing at P120 and below and C-weight paper backing at P150 and greater. The sanding discs show good resistance to tearing in flat panel applications using a random orbital sander. During light hand sanding with a sanding block to break edges, the abrasive grain resisted shedding. The Whiteline discs showed mild shedding when rolling over sharp corners or "edge banging" using the orbital sander. The aluminum oxide abrasive showed a good level of longevity with the ability to completely sand both sides of approximately 62 square feet of Baltic Birch plywood using a single disc without signs of degradation in cut quality. This resulted in approximately 1-hour of total sanding time. At $17 per box of 50, the Indasa Rhynogrip Whiteline would be an economical, high-efficiency choice for flat panel sanding and hand sanding applications.
Completely sanded approximately 62 square feet of Baltic Birch plywood using a single P120 and P180 sanding disc.