grinder versus Festool rotex

[StevenO]

Need some advice:  I am making a chair seat and I need to hog out and shape a large curved area where one sits--some areas need 1/2 inch of material removed.  Is this best done with a grinder or can one of the the Festool Rotex sanders (e.g., RAS 115.04 E Rotary Sander) do the job, perhaps even better? Thanks in advance.

 

[ScotF]

The RAS would be the best tool for this application and it technically is a grinder that uses sanding pads, but with better dust collection.  I think the Rotex would take too long for this application. 

Scot

 

[Administrator_JSVN]

RAS...

http://blog.festoolusa.com/post/2010/08/01/Charles-Brock-Making-chairs-with-the-RAS-115-Sander.aspx

 

[Brice Burrell]

Need some advice:  I am making a chair seat and I need to hog out and shape a large curved area where one sits--some areas need 1/2 inch of material removed.  Is this best done with a grinder or can one of the the Festool Rotex sanders (e.g., RAS 115.04 E Rotary Sander) do the job, perhaps even better? Thanks in advance.

That RAS and the Rotex sanders are different.  The RAS is a rotary only sander where the Rotex sanders are dual mode sanders, a rotary mode and a random orbit mode.  The rotary mode on the RAS is a lot more aggressive than the Rotex.

 

[ScotF]

Shane - I read somewhere that Charles uses an RO90 to follow the RAS -- any chance you or someone at Festool could ask him to write something on this technique?  His article pushed me to getting the RAS in the first place.  I am on the fence about getting an RO90 for the finish work on sculpted chairs verses using my bigger Rotex or ETS with a supersoft pad or interface pad. 

Sorry if this is a hijack -- did not mean to, but your link prompted the question.

Scot 

 

[Jesse Cloud]

OK, I have the RO 150, the RO 90, and the RAS 115 and I'm sculpting chairs.  Can't say that I totally have the technique figured out yet, so hope fully Chuck Brock will come in and set us straight, but in the mean time, maybe some of my observations could help...

1. The RAS at 24 grit is very aggressive, but also very manageable.  Haven't found a better way to quickly hog out a lot of wood without a total sawdust immersion.

2. In my experience, the Rotex is not as aggressive as the RAS (a good thing in my opinion - I just used the Rotex to put a 'piano finish' on a table top).  The RO 150 is, in my opinion, just too big to do smooth hard line to soft line transitions that you need on a chair.

3. The RO 90 is just the right size to make a smooth transition.  For instance, on the bowl of the chair, you don't really want a sharp edge, but a gentle radius to ease one's butt into the seat without encountering sharp edges.  The form of the RO 90 works just right for this.

4. In my experience, and user error is highly likely here, the RAS just makes too much dust to use indoors.  The RO90 gets almost everything.

5. As much as I like Festools, there are other niche tools that make life easier.  A pair of 1/2 and 5/8 carbide burrs on a power carver can work wonders on those smooth leg to seat transitions.  A good rasp can channel your thoughts...

So, my process is bandsaw first, then RAS, then RO90, then rasp, file, scraper, then RO90 with finer grit and soft pad.

Hope this helps.  Just my way, don't mean to put down any other methods,

 

[Administrator_JSVN]

Guys, I'll see if we can reach out to Charles about his use of the RO 90. Let me see what I can do.

 

[ScotF]

OK, I have the RO 150, the RO 90, and the RAS 115 and I'm sculpting chairs.  Can't say that I totally have the technique figured out yet, so hope fully Chuck Brock will come in and set us straight, but in the mean time, maybe some of my observations could help...

1. The RAS at 24 grit is very aggressive, but also very manageable.  Haven't found a better way to quickly hog out a lot of wood without a total sawdust immersion.

2. In my experience, the Rotex is not as aggressive as the RAS (a good thing in my opinion - I just used the Rotex to put a 'piano finish' on a table top).  The RO 150 is, in my opinion, just too big to do smooth hard line to soft line transitions that you need on a chair.

3. The RO 90 is just the right size to make a smooth transition.  For instance, on the bowl of the chair, you don't really want a sharp edge, but a gentle radius to ease one's butt into the seat without encountering sharp edges.  The form of the RO 90 works just right for this.

4. In my experience, and user error is highly likely here, the RAS just makes too much dust to use indoors.  The RO90 gets almost everything.

5. As much as I like Festools, there are other niche tools that make life easier.  A pair of 1/2 and 5/8 carbide burrs on a power carver can work wonders on those smooth leg to seat transitions.  A good rasp can channel your thoughts...

So, my process is bandsaw first, then RAS, then RO90, then rasp, file, scraper, then RO90 with finer grit and soft pad.

Hope this helps.  Just my way, don't mean to put down any other methods,

Thanks, Jesse -- this is helpful info and I agree that rasps, files and scrapers have their place in sculpting.  With the RO90, do you use the hard pad or do you stick with the one that comes standard?  Any use of the interface pad to ease into the contours of the seat bottom or have you found the size of the RO90 to adequately reach into these contours?  Also, what papers have you been using after the Saphir on the RAS? 

I have found the DC to be adequate for as much material as you remove -- the fines seem to be collected well with the CT and the courser material falls to the floor.  I do find that I have to swivel the hood around to get the best collection point, but I was really pleased with the sculpting I have done.  It is an awesome tool.

BTW, you make some beautiful chairs!

Scot

 

[ScotF]

Guys, I'll see if we can reach out to Charles about his use of the RO 90. Let me see what I can do.

Thanks, Shane!! [thumbs up]

 

[tbellemare]

Gent's:

I think I'm coming in to this discussion a bit late but I'd like to give it my take...

The Rotex Sanders are wonderful at removing material fast but you need to have a firm grip and a solid position with respect to how you want to remove material. The aggressive mode is a gear-driven "rotary/orbital" motion. This makes the pad travel in an "orbital" fashion whether or not you want it to. That's why so many people consider them unruly sanders - The pads are going in orbital motion even if you aren't...

The secondary position on a Rotex sander is Random Orbit mode. It is the same as other Random Orbit Sanders. For instance, the RO 150 has a 5mm Random Orbital motion. That is the same as an ETS 150/5. For most situations, it will produce super fine finishing results and quite fast.

The RAS 115 is VERY different from any Rotex or ETS.

The RAS is a rotary sander. The pad spins. It doesn't have any orbital pattern. It more exactly mimics the motion of a classic grinder or polisher. It is the most aggressive and controllable material remover of all of the Festool sanders sold in NA. It also has the potential to spin really fast and therefore can REALLY remove a lot of material fast.

It has dust collection from around the area where the dust is created using a wide open hole and a brush that is hanging down to corral the dust into that suction hole. It depends on the operator being skilled enough to position the brush such that it will properly capture the dust created. In my limited experience with this sander, it can collect almost all of the material it removes if the operator moves the collection brush in the proper position as the sanding pad is moved about the work piece so that the brush is useful.

There is a side handle that is also used to rotate the collection brush and it is the critical element in debris/dust collection being effective.

Tom

 

[bijeshj]

I was planning on taking advantage of the 10% to purchase another sander.  Post was right timing to help pick up the correct one.

Tom - thanks for the info, very useful.

 

[Jesse Cloud]

.....
Thanks, Jesse -- this is helpful info and I agree that rasps, files and scrapers have their place in sculpting.  With the RO90, do you use the hard pad or do you stick with the one that comes standard?  Any use of the interface pad to ease into the contours of the seat bottom or have you found the size of the RO90 to adequately reach into these contours?  Also, what papers have you been using after the Saphir on the RAS? 

.....
Scot

Hey Scot.
Yes, I like the interface pad.  After the Saphir, I use Granat up to 220, then a white scotchbrite.

 

[Administrator_JSVN]

Guys, I heard back from Charles Brock. Looks like he had already written a blog entry that talks about his use of the RO 90. Go check it out and see what you think:

http://charlesbrock.blogspot.com/2011/04/sanding-sculptured-rocker-part-deaux-2.html

Charles offered to write something in addition to this, if needed. But, I think this pretty well shares his experience with the RO 90 and how he uses it.

The interface pad that Charles refers to is definitely a good accessory if you're going to be working with something like a sculpted chair. The interface pad is a spongy material that goes between the normal pad on the sander and the abrasive. It allows the abrasive to conform to the irregular surface and contours.

 

[ScotF]

Guys, I heard back from Charles Brock. Looks like he had already written a blog entry that talks about his use of the RO 90. Go check it out and see what you think:

http://charlesbrock.blogspot.com/2011/04/sanding-sculptured-rocker-part-deaux-2.html

Charles offered to write something in addition to this, if needed. But, I think this pretty well shares his experience with the RO 90 and how he uses it.

The interface pad that Charles refers to is definitely a good accessory if you're going to be working with something like a sculpted chair. The interface pad is a spongy material that goes between the normal pad on the sander and the abrasive. It allows the abrasive to conform to the irregular surface and contours.

Awesome, Shane -- thanks for following up and posting this link!  This is exactly what I was looking for...

Scot

 

[pezdad]

Hey Scot.
Yes, I like the interface pad.  After the Saphir, I use Granat up to 220, then a white scotchbrite.
[/quote]

Is that white scotchbrite something Festool sells, or do you order it somewhere else?
-Brian

 

[Jesse Cloud]

Hey Scot.
Yes, I like the interface pad.  After the Saphir, I use Granat up to 220, then a white scotchbrite.

Is that white scotchbrite something Festool sells, or do you order it somewhere else?
-Brian
[/quote]

Scotchbrite is a 3M product for hand sanding.  You can get it at a good hardware store, a paint store or a good autoparts store.  It comes in grey, purple, and white (increasingly fine abrasion).  Its very good for getting to curves and such.

 

[Administrator_JSVN]

Festool has Vlies, which is very similar to Scotch Brite. It's available in 80, 120, 180, 280 and 800 grits.

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[pezdad]

Thanks Shane and Jessie! Thanks. I noticed that in the Charles Neil blog post referenced above by Shane, Neil says "They also have a red and gray 3M pad equivalent that makes burnishing very easy" that he uses before using a white Scotchbrite (I assume he does the white by hand). The Vlies D90 S800 would surely seem the equilivent of the gray scotchbrite (which the 3M website lists as 800-1000 grit). The A280 wouldn't seem to be a great replacement for the red scotchbrite (listed as 360-400). I notice that the jump between grits is MUCH higher with these abrasives than with paper backed abrasives - there is no Vlies between 280 and 800 (and scotchbrite coves 360 to 1500 in only 3 types). Is it just inherent in these open weave spongy-type abrasives that you need less of a jump?

Also, I bought the full Granat range up to 400 to go with the RO-90. After I sand up to 400 with the Granat, would I go straight to Vlies 800, or would there be any reason to use the Vlies 280 even though the nominal grit of 280 is much lower than the Granat 400?

 

[Administrator_JSVN]

Also, I bought the full Granat range up to 400 to go with the RO-90. After I sand up to 400 with the Granat, would I go straight to Vlies 800, or would there be any reason to use the Vlies 280 even though the nominal grit of 280 is much lower than the Granat 400?

Sorry if you already said and I missed it, but what type of result are you trying to achieve, what type of finish are you applying, and on what type of material?

 

[pezdad]

Also, I bought the full Granat range up to 400 to go with the RO-90. After I sand up to 400 with the Granat, would I go straight to Vlies 800, or would there be any reason to use the Vlies 280 even though the nominal grit of 280 is much lower than the Granat 400?

Sorry if you already said and I missed it, but what type of result are you trying to achieve, what type of finish are you applying, and on what type of material?

I'm working on a Maloof-style chair off of Charles Neil's plans that I bought, making it pretty much as he designed it and describes in those posts you referenced (Walnut, sanded up to a much higher grit than I normally would). I haven't actually got to those final sanding steps yet, but I am trying to be prepared as I have no reliable local source for the festool abrasives and want to make sure I have the correct ones ahead of time.