Festool RO90 Rotex Sander: Triple Threat?

Written by on January 6, 2013 in Power Sanders, Product Reviews, Tools, Uncategorized with 16 Comments
Rotex Sander

Not another “What’s in the Box” review…

Festool RO90 Review

The Festool RO90 DX Rotex sander is one of the most innovative paint prep tools released in the past couple of years.

Aptly marketed as a “multi-mode” sander, the RO90 is capable of doing the jobs of more than one sander.

In tools, we all want the Holiest Grail – “the one that can do it all”. Or at least the one that can do the most in its class – whether it’s a brush, sprayer, a sander or a vacuum.

The RO90 wins “best in class” by default…there are no other sanders similar enough to it for comparison. The 90 gets innovation points for pioneering the class. It also contends for the title of broadest skill set, not only within the Festool brand, but perhaps in the sander category as a whole. Can we have a small sander that will strip exterior siding fast and then turn around and finish sand a cabinet face frame or piece of furniture, with equal quality and dust control across the sanding spectrum?

My company has spent 18 months exploring the range of this FestoolUSA supplied tool and what it can do to accelerate paint projects.

[Related: Scott Burt Festool Review in APC ’12]

What it is NOT

Sometimes the best way to understand a new tool technology is to know what it is not.

Marketed as a “Multi-Mode” sander, the RO90 is not like other detail sanders, profile sander kits, or “multi-master” type of tools that we have all seen. Those tools are handy, occasional use tools, but they are not full fledged sanders. They are specialists that spend more time off the job than on it. That’s pretty much the deal on the “multi” side of things.

The Festool RO90 is an everyday workhorse sander that works in three different modes for three different types of sanding, each mode capable of going both broad and deep into problem solving on paint jobs. If you put this tool in your truck everyday, you will likely use it every day. Let’s face it, much of our time as painters is spent either sanding paint off of surfaces, or sanding in between coats of putting paint on surfaces.

While it is equipped with a more diverse skill set than other sanders, the RO90 shares the basic DNA of the Festool sander family.

Rotex Sander Review

Standard features of most Festool sanders, including the RO90:

  • systainer (tool case) that fully integrates with Festool system for organization and efficiency
  • detachable “plug it ” style power cord that connects to Festool vacs for auto start feature
  • industry leading connection of sander dust port to vacuum hose
  • superior dust collection when connected to any Festool vac
  • wide available range of high grade Festool abrasives for all sanding applications
  • variable speed control

Rotex Pedigree:

Festool makes more than a dozen power sanders that are highly competent in sanding disciplines in the paint, carpentry and woodworking fields. Their flagship line of sanders is called Rotex, and the RO90 is the third and newest entry in the line.

At 3 1/2 inches in diameter, the RO90 is smaller and more versatile than it’s Rotex siblings, the RO125  (5″) and RO150 (6″), which have set benchmarks in sanding since the 70’s.

Rotex Sander Review

In aggressive material removal mode.

Classic Rotex sander features:

  • multiple modes of operation
  • random orbital mode for finish sanding
  • gear driven mode for aggressive sanding/stripping
  • ability to polish to extremely high grit levels

The RO90 brings more sophisticated utility without compromising Rotex standards for power and performance.

RO90 – the most unique Rotex

This is a Rotex platform scaled down to a 3 1/2″ diameter pad and with increased modal functionality – a robust little version of its larger siblings, with a twist.

The 3 modes of RO90 operation are:

  • random orbital finish sander
  • aggressive material remover
  • triangular detail sander

A Review of the Modes

Random Orbital: The Festool RO90 is certainly competent as a finish sander in its random orbital mode. This is not where it excels, though. If this were baseball, it would be like putting your shortstop at second base –its arm strength, range and athleticism over qualify it for the position. The RO90 has a larger stroke than most dedicated orbital finish sanders, and its physical design makes it awkward for extended fine finish sanding tasks because it is cumbersome to use with one hand. While capable in this mode, it causes user fatigue after a half hour or so. What it lacks in comparison to dedicated orbitals, it compensates for systemically through abrasive quality and dust extraction (which is phenomenal). This leaves you with an above average finish sanding result, ideally suited to smaller scale apps.

Gear Driven (Rotex) Mode: The RO90 is a beast in this mode, and this may be the biggest benefit for such a small sander to offer. The pad motion is eccentric in this mode, which in real terms translates to very aggressive and capable of cleanly stripping absurd layers of paint. This is where the RO90’s design becomes a strength. It is built to be best operated with two hands, and with proper technique, it is easy to control during aggressive sanding for extended periods (hours).

[Related: Basic Psychology of Low Grit Sanding]

Technique is everything, and you may have to adjust yours to get along in this mode. If you try to fight it, you will probably lose. If you win, the results won’t be pretty anyways. So, it is best to work “with” the sander. Proper technique includes a hand wrapped around the top front of the housing and a hand balancing it at the rear, near the cord. Front hand guides the sander, rear hand balances it laterally. This way, the pad stays flat on the surface being sanded, which results in best control, finish and dust extraction. The dust extraction in this mode is very impressive. This is the small belt sander effect you have been looking for.

Bottom line on technique: As yours improves, the sander will need to give you less and less feedback.

Triangular/Delta Mode: The term “detail sander” needs to be understood here. This is not an intricate profile sander. The delta mode offers triangular attachments in different lengths to allow you to sand into corners, tight spaces and reach into crevices with the same level of effectiveness as you do out in the open road with the stock round attachment in the other two modes. Delta mode eliminates hand sanding into awkward areas, or having to break out a detail sander. The pad base swaps out quickly from round to triangle and with no tools required, just the flip of a switch. In comparison to the other two modes, the dust extraction in Delta mode is less effective because the sander is working in an orbital motion. With no spinning type action, it is more difficult for the tool’s dust extraction to draw the dust. At the same time, dust mostly stays on the surface and does not become airborne. The RO90 is capable of surprising aggression in this mode, making for seamless and quick transitions from open road into corners during sanding.

[Related: 5 Tips for Finish Sanding Rail Systems]

Any “multi” tool has aspects of its skill set that are adequate but not stellar. It is not the job of the generalist to be perfect (that’s what specialists are for), it is the job of the generalist to deliver convenience and solutions to as many task challenges as possible.

Practical Compromises in this design:

  • lacks the physical balance and symmetry of Festool finish sanders
  • unlike pure Festool orbitals, not very effective in drywall patch sanding
  • rear end motor housing is heavy, causing front of pad ‘lift’, making user technique critical
  • for the most part, requires two hands for ideal operation (unlike Festool orbitals)
  • efficiency of dust extraction with delta attachments is below average by Festool standards
  • delta pads should be HT (high temperature) to reduce wear on the pointed edges of the delta base pads
Rotex Sander Review

Aggressive corner work in delta mode.

That said, there are work-arounds. The delta pads are symmetrical, so by rotating the abrasive orientation on the pad, all three points of the triangle can be used as the leading edge in sanding. This effectively triples abrasive life at the outer extremities, but is still hard on the tips of the underlying base pad hook and loop. These slight drawbacks are a function of the literal strength of the sander: its power.

Pound for pound, the RO90 is arguably the most powerful Festool sander, capable of both detailed and aggressive work. At 3.3 pounds, the RO90 is less than a pound heavier than the smallest Festool orbital sanders (ETS125/DTS400/RTS400). That is an engineering accomplishment, given how much is going on in the chassis of this tool. The power to size/weight ratio is hard to beat. In terms of sheer functionality, the only Festool sander that can match the RO90 in flexibility and accessory options is their linear sander, the LS130. That is where the similarities end. The LS130 is a bit of a specialist, while the RO 90 is the ultimate generalist.

Ultimate Generalist

Rotex Sander Review

Most likely to be found at top of ladder.

How has it taken so long for a manufacturer to realize the value of the 3 1/2″ diameter?

One of the most common sizes for dimension lumber in America is 1×4 (nominal), which is actually 3/4″x3 1/2″. Historically, the most common size for random orbit sanders has been 5″ – just a little cumbersome for 1×4, and not quite ideal for larger widths like 1×6, 8 or 10. The RO90 capitalizes on the reality that the world of wood finishing is full of square stock profiles that are 3 1/2″ or smaller.

The RO90 is ideal in those smaller dimensions, and still has the power to get more aggressive than a traditional random orbital in widths larger than its own diameter. It is rare to find a sander that is so comfortable working on pieces that are both larger and smaller than itself.

With its small diameter, the RO90’s physical range includes, but is certainly not limited to: trim packs, cabinet face frames, furniture, stile & rail type cabinet door/drawers, spindle rail systems, clapboard reveals, and the endless inside corner and crevice work that have historically been a hand sanding burden. Typical power sanders are not noted for this level of utility. This is not typical.

It would be difficult to find one sander that is capable of accomplishing so many different types of tasks, particularly in the often extreme sanding discipline of low grit paint stripping on exterior siding or trim. Teamed with CT extraction, the RO90 works to a HEPA certified standard, which takes some of the headache out of RRP work for painters and remodelers alike, and keeps painters and jobsites running profoundly cleaner.

This onsite efficiency usually translates well to profit margins on paper. As a generalist, the RO90 touches on many of the basic competencies of other more specialized sanders, and Festool offers an abrasive grit range of 40-4000, across eight different lines of abrasive. For all painting tasks, I prefer their Granat line, which comes in grits ranging from 40-500. Granat routinely lasts 3 times as long as other abrasive brands I have used.

Rotex Sander Review

With delta attachment…

Overall, we rate the 3 modes of the tool highly. Especially the gear driven and delta modes, which exceed anything else we have seen. The random orbital mode, which is the easiest to compare to the rest of the sanding marketplace, produces a better quality result than other brand random orbitals we have used, perhaps due as much as anything to the systemic advantage of abrasive quality and premier dust extraction. But it is not as exceptional by Festool standards as the other two modes – mostly for the ergonomic/balance reasons outlined above. In other words, finish sanding is less fatiguing using a true Festool orbital, which is typically expected to be a one handed exercise with minimal vibration or physical exertion. The 90 can certainly deliver similar results, preferably just in shorter doses, which is perfectly acceptable in a multi-function convenience tool. If you don’t habitually sand for long extended periods, it is a negligible concern, and you can safely park your other brand random orbitals, right next to the old cheapo mouse.


Final Analysis

At $390, this is not an impulse buy. And, it is not a disposable or “throw away” tool. Having used Festool sanders, abrasives and vacs for several years now, and also having observed the corporate values that the tools are backed by, Festool is clearly only interested in competing with Festool. They are not concerned with making a better or cheaper tool than someone else, but rather a more effective tool than they themselves have made before –measured by the tool’s capacity to provide efficient solutions to real problems.

The RO90 reflects this approach with unique strengths, features, functionality and ability to solve both typical and unusual problems for painters. Because the RO90 is easy to use in so many different types of situations, it serves both beginner and advanced Festool users in a wide task range with industry leading dust control. Like most Festool offerings, this tool works optimally as a system with a Festool vac and abrasives. FestoolUSA provides a 3 year warranty and 30 day no questions return policy, so there is little risk involved in checking out their gear.

No sander can be all things to all people, but the RO90 stands a far better chance than most. If you are the type of person who does all kinds of sanding, this is all kinds of sander.

Please share your experiences with this tool, or questions, in the comment section below!











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16 Reader Comments

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  1. Steve marshall says:

    Im about to pull the trigger as well for a 90.
    Cash is tight but your are right time is money. With 3000,sf to prep I believe this wil be paid in savings of time. Just tough figuring time without it. With 18 layers of lbp on my 252 yr old house that should provide ample basis for comparison.

    • Scott Burt says:

      Hi Steve, 3000 sf of what type of surface? Is it clapboard siding and what is the reveal? If it is under 4″, this is your hot rod. If you are facing larger surfaces, let me know and I can shoot you a quick look at the new EC-Tec Brushless sanders with larger pads. But for smaller exposures, the 90 is really hard to beat. Especially where lbp is concerned. Going with an oversized pad in the interest of perceived speed only compromises dust extraction.

  2. Mike says:

    Excellent article Scott, After reading this, I pulled the trigger and bought one. Here is what I have noticed: In gear-driven mode, the RO90 moves a lot of material; pretty impressive. I used 60 grit and a setting of about 3 on the speed control. I have not done much with the random orbit so will decline comment. I must say I am pretty disappointed with the triangle attachment although I am clearly using it in a way that it doesn’t like to be used – and that is on the vertical trim of window sills, where there is only maybe half an inch of space to sand. I found it almost impossible to control the unit evan at lower speeds. I found my cheapo 1/4 sheet sander to work much better for this (although not ideal) which brings me to my wish-list for Festool. They could easily make a small square head that fits on the unit that would function like a 1/4 sheet sander. This I think would work well. I also have a bit of a horror story with the Triangular pad. You weren’t kidding when you listed the need for high temperature pad. I decided to briefly try the higher setting of 6 and in no time at all found that I had pretty much melted the hook and loop pad (and I was purposely not pressing hard at all) Knowing how much Festool charges for everything, I hate to see what it’ll cost to replace it. That’s the great thing about non hook and loop sanders. You can use your own paper (something Festool would probably not encourage) and you don;t have to worry about melting stuff at higher speeds.
    So far, I haven’t seen any adverse effect on the round pad, but haven’t used a higher speed than 3 or 4 either. Has anyone used higher speeds with the round pad? The sand paper woks well but is fairly expensive considering the small size of the disc. Curious to see if any third party manufacturers have attempted to make stuff that would fit the Festool line?

    • Scott Burt says:

      Stick with it, Mike. The 90 does have a little bit of a break in period. Keep using the delta (triangle) attachment, it will grow on you. As to abrasives, their Granat (blue) line is the best. We have dabbled in putting other mfr abrasives on and it is not as effective. Festool stuff is designed to be used as a system. It is just a matter of figuring out which grits you use the most, and stocking up. I am willing to pay $1 a piece for something good. Keep us posted on your success with the 90, it is a killer tool.

  3. Martin Guest says:

    I use an RO90 combined with a Mirka 915 extractor… What a fantastic machine! My work is primarily Kitchen and Furniture Painting. The RO90 is a wonderfully versatile sander with awesome power… I don’t know where I would be without it.

    Ps. Mirka Abranet is a great alternative to Festool’s Brilliant 2 ‘paper’.


    • Scott Burt says:

      Thanks for the info, Martin!

    • Mike says:

      Martin, interested to know if you have tried the Ceros sander?
      and was wondering about trying the Abranet on My RO 90. Do you use the Mirka inbetween pad (can’t remember the proper name right now) so that the hook n’ loop doesn’t get worn out on your RO 90?
      I know it would have to be cut to size.

      • Scott Burt says:

        Good to see you on the site, Mike. Hope the paint gods have been good to you this summer.

        • Mike says:

          Thanks Scott.
          I’ve been painting a house that was in such bad shape that I convinced the owner to let Me re-side it. My Carpenter friend and I wrapped the house in tyvek then screwed in T1-11 siding with groves. House will look new when it’s done. This is something for other painters to think about when the prep is at a stage where it’s better do just start from scratch.

  4. What about LBP removal? Has anyone checked with our enemy the gov

    • Scott Burt says:

      Matthew, that is where the extractor (vac) rating comes in. The Festool vacs are independently certified to be full unit hepa (not just the filter, but the whole unit). To date, this is the highest available standard to meet rrp.

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