Advantages of 6" over 5" ROS Sander?

Hi, I'm in the process of replacing my 20 year old 5" ROS sander, and am looking for anyone with advice on which size to replace it with (6" sanders were not available back then).

Here's what I know:

1) 6" sander should remove a lot more material than a 5" sander

2) a 6" sander will likely weigh a little more due to larger size

3) It won't be able to get into corners as tightly due to larger radius

Here's what I think (I'm guessing here):

1) It will be more unwieldy than a 5" due to larger dimensions

2) ???


I'm looking for a sander for primarily cabinet construction - not a lot of compound curves in my near future.

Anyone want to throw in their two cents? Haven't seen a lot of other practical pros and cons to the two different sizes other than the above.

Also I was looking at the Mirka Ceros, if that alters the trade space at all..

Andy.

My 6” Festool ETS 150/3 feels a little heavier than my 5” PC-333 but not markedly so. It sands a given area quicker than the 333 and the paper lasts longer. I don’t know if that’s a product of the size, sander design, or the paper. The ETS does not feel awkward at all, it is a great deal smoother and more comfortable to use than my PC-333 sanders. A 5” sander will get a little further into a corner than a 6” but I don’t see that as a serious disadvantage. I can’t think of any real disadvantages for the 6”.

I chose the Festool ETS 125 (5") over the 150 (6") for several reasons;
1) 2.4# vs 4# easier to use on overhead or verticle surfaces
2) 2mm stroke vs. 3mm = finer finish (I use Micro Mesh to rubout Waterlox)
3) easier to control with my aging hands and arms
4) smaller diameter equates to maybe a 3-4 min. add in sanding a 3' x 6' desk top
5) IMHO all the Festool ROSs are unbelievably smoother and more comfortable than the PCs, etc (the Ceros is very nice too but I had allready sipped the Koolaide so dust collection figured in)

I also have the DTS 400 EQ for getting into corners and RS 2 E half sheet for leveling large surfaces (2.5 mm stroke). Hope this helps.

6" is certainly faster for sanding panels to 150 or whatever. If you're meticulous about blowing off grit when you change grits and don't jump the gun and switch grits too soon, acceptable results can be got with a 6" sander, even one like the Rotex which is really sort of a tool for coarse sanding. As Bill mentioned above, there are some differences from model to model in terms of the size of the circle. Now, if you're planning to orbital sand finishes between coats (I don't, I hand sand between coats) or to rub out, you might want to consider a refined 5" sander. If you want to quickly get from the planer to 150 grit, a 6" sander gets the work done faster. I've spend plenty of time hanging onto a 6" Rotex and it's not as fast as some would have you believe. While it is still the fastest orbital sander I've used, if you want real speed you'll need to look at machinery.

The area covered is 44% greater with a 6" vs a 5". That said, I have several PC390s, and I use them much more often than my 6" Ridgid. They are easier to control and wind down faster. In theory the abrasives should last longer on the bigger sander, and are only marginally more expensive. But it hasn't worked out like that for me. I may as well sell the big guy, I never use it.

I have a 5" PC refitted with a 6" disc. So I can use it either way. I have since bought a DW 5" ROS that is more of a hand fit than is the PC for smaller jobs.

You can have it both ways. Buy the Bosch ROS65VCL. It comes with both a 5 and 6 inch pad. I bought the 6" version; didn't see any need for the 5". I'm really happy with that choice, but if you want both just buy the kit. The Bosch has everything you'd want in a higher end ROS. Specifically, very low vibration, very smooth operation, variable speed, and the best onboard dust collection of any ROS in a recent FWW review. For me, I see no need to hook it up to a vacuum, although it comes with an adapter so you can. It's also substantially cheaper than a Festool.

I think the 6" might be more stable than it would be with a 5" pad on it, but that's just a guess. What I do know is that it sands extremely well and leaves no visible swirl marks. I've even sanded veneered plywood with it w/o problems. It's extremely easy to control and a joy to use.

John

I run Dynabrades so the sizes are not interchangeable. I have 5 and 6" and while at times the 6" is the one to have, about 75% of my sanding is done with the 5". Dave

For a given RPM of the sander, theres more than surface area at work here. The outer rim of the 6" moves 20% farther per revolution than it does on a 5". This increases the rate of stock removal as well.

Jim

Yea they were available. the first one I was aware of was the Porter cable, and it had the same body for the 5" and the 6", I think, only the counter weight was different. that was probably actually over 30 years ago.

In general though the 6" will give you a little more power, but it will be heavier and more unwieldy, more difficult to manuever. The 5" is much easier to wield. I like my dewalt variable speed okay, but it definitely could use more power. Oddly enough I used a borowed one last fall ( a single speed) and it semed to have all the power you could want. I don't think I was drinking at the time, but I could have ben under the influence of something else.

The 6" will cost a lot more, some many times more. The Bosch right angle goes for about $250. You can probably get the Porter cable for about $150, but it works with a hood over the pad for dust collection and that interferes with your sight. I don't think the power is great, but the power on the Bosch isn't great either. I haven't used a PC in ages.

I pull out the 6" (Bosch right angle in my case) when I need more power. Grinding a teak deck for one example. Wouldn't touch it with a 5" though I know people that have done it. The Bosch random orbit isn't even powerful enough for this. A 7-8" polisher grinder would be the thing. But people will do anything won't they?

I have both. I use a 5" Porter Cable that has a rudementary dust collection scheme using discs with holes in them. I also have a nice AirVantage 6" air powered DA that I bought for doing auto paint sanding that does a great job on wood. Advantage of that one is the variable speed and that the range of grits available from auto paint stores is way better than the box stores. It also has an interface pad that makes sanding curved surfaces easy.

The 6" will give a flatter surface than a 5". A half sheet sander will give an even flatter surface. I also find that it's easier to make sure the pad stays flat to the surface with a 6" than with a 5".