Sanding Tuffeau (Limestone)

[aas]

Hi,
I would like to hear your recommendations on the best sander and paper for sanding Tuffeau. It can be a fairly soft sort of limestone, it sands easily by hand but creates a lot of dust. I have used my Mirka hand sanding block with Abranet, hooked up to the DC.
However, we have a product to repair it which is a sort of powder of limestone which we mix to make a paste - in French 'un enduit' (I can't find the right words in English), which is the right colour, it looks like stone when dry.
I'm using this to repair a damaged fireplace and make the stone mouldings that were worn away and virtually missing after a couple of hundred years.
When it drys, it is quite hard, and using Aluminium Oxide paper on a cheap delta sander, the paper lasts a couple of minutes.
I have already applied this to a pretty smooth finish, but there are areas want to sand after having to touch up.
I sold my sanders earlier this year with the intention of getting a Rotex 150, but then never did! I'm currently leaning towards a Rotex 90. Other uses would be light plaster sanding; wood : i.e. window cills, worktops, old doors, staircases;  - all of which I need to do in the next month.
So I need to know, what is the best machine (1 only for know), and what is the best sanding paper...

 

[Holmz]

There are concrete and stone disks for stone.
https://www.braxton-bragg.com/index.cfm/fuseaction/store7catalog.level/bc/0,8442/
You want a variable speed unit - The vipers work OK, and there are a bunch from Romainia or Bulgaria which certainly must be in you area.
Find a custom concrete shop.

I used these
https://www.braxton-bragg.com/index.cfm/fuseaction/store7catalog.level/bc/0,8442,9850/
on a DX90 festool for the corners...
It was not fast, but not a lot of corners either.

Something like the makita 9337 with the talons works well, or a Scarab by Werkmaster (Au Canada) if you have extra euros.

 

[aas]

Thanks, the vipers look OK; also the corner diamond pads - I'm leaning towards a Rotex 90 for the other tasks, I guess the diamon pads on this would work a treat.

The Scarab or anything like that will be way too agressive.

 

[Holmz]

...
The Scarab or anything like that will be way too agressive.

I doubt it.
They have 1200 and 2000 pads for the scarab, I have only used ~200 or less.
(They polish marble counter tops with those things..)

The vipers with fines are also not what I call aggressive.

 

[aas]

OK, I'll have another look. One of the problems is that the repairs are harder than the original stone, which can be gouged with a finger nail in places, so sanding necessitates a lot of care.
A 240 grit on the drywall sander is OK for the stone, but doesn't touch the repairs, and it's too big a head.
Also, as I'm currently restoring the fireplace, there are lots of little angles and the moulding that I have re-made. Some of this has to be done by hand, but I need something effective for the flat surfaces and angles.
I think the Corner Diamond Pads will work a treat on a Rotex 90, although I can't see anything 90mm round that will do the surfaces, and I really don't want to be buying two sanders this week.

 

[Holmz]

Just whack some screens onto a hand unit which accepts screens with no motor... and then "heave ho" away on the piece.
They commonly use lithium for bi-polar disorder, for hardening concrete. It may also work on limestone, so I would check with a the concrete fellows. It is like Fluoride for teeth.

(OPE/CRM-114)