6" vs 7" polisher

I`m in the market for a 7" polisher but because I`ve spent soo much on equipment lately I`m having to cheap out and go with the lowest cost option that`ll get the job done. I`ve found some relatively affordable 6" random orbital polishers but the cheapest 7" RO is gonna be $100 more.

I`ve never owned a polisher before so I`m wondering what`s the difference between a 6" and 7". The polishing work I`ll use it for is non-automotive, furniture related actually, so it won`t be put through near as much use compared to auto detailing work. They all seem to have the same 5/8"-11 drive spindle for the pad so I guess the only difference would be the motor size, which would determine how big a pad it should turn.

Am I gonna be at any kind of a disadvantage getting a 6" polisher vs. 7". Can the 6" take the same pads as the 7", maybe just cut them down some?

Thanks

Given the thread size you`ve stated, you`re looking at rotary polishers. I`m not aware that there are different "size" polishers based on pad size; there are light-duty, heavy-duty, etc., but the pad size is related to the backing plate size and the pad size you choose. Sure a light-duty polisher might have trouble turning an 8" pad, and a heavy-duty polisher might be overkill for a 5" or 6" pad.

You`re probably better off with a smaller pad because your surface speed at the outside of the pad will be lower, making it less likely you`ll burn your finish. The disadvantage of a smaller pad is that you will be able to cover less surface area, but that likely isn`t an issue on furniture unless you are polishing a conference table.

If it`s a rotary you are after, there are plenty used Makita and DeWalt polishers for sale. Just find one owned by a DIY or a detailer that didnt use it much and you`ll be fine. Should be $50-75.

Ron Swanson -- Welcome to the Forum !
You speak of wanting to get a Random Orbital Polisher.
The best Sander ever, that has been around longer than anyone else`s machine is the Porter Cable Machine here -- https://www.autopia-carcare.com/inf-pc7424.html
Decades ago, some people found that this Sanding Machine could also be used for automotive paint and that is where all the Random Orbitals came from that have evolved into some really nice, really expensive machines, that are used for automotive paint correcting and polishing.
But, since you mention using a machine for furniture refinishing I assume, why not look at the one machine that has decades of use just for that?
Yes, you can get bigger Backing Plates for it and then of course get bigger sanding disks, etc., and you should be able to do whatever you want..
Yes, there are Rotary machines, but they are going to take longer to learn how to use them, they are direct drive, which means the pad WILL always be moving across the surface..
The Random Orbital is just that - randomly orbiting - But I think for wood finishing, this Random Orbital may be easier to use and produce excellent results when you learn how to use it..
The Rotary Machine - direct drive rotation - on all the time... It is capable of - removing - a lot of surface area it is on, pretty quickly..
Both machines can have any number of different diameter backing plates, so that will not be an issue; you just have to get the right sized sanding disks for the size backing plate you want to use for that part of the project..
Good luck with your research !
Dan F

Yeah the above post about used makita or dewy is good info. I have makita and it nice desalt is also great rotary

Smaller pads are easier to work with.