What is the best cordless sander for removing interior paint?

[dazzystar]

Hi All,

I have a mammoth task of either removing or at the very least keying the surface of all my interior window frames and sills and most likely the staircase too. Is a delta sander or random orbital sander the way to go and what size grit(s) do I need. Any brands better than another on both the sander and paper? I'm in the Bosch (green) 18V eco-system so would prefer Bosch if possible.

Cheers
Daz

 

[opps]

Tough to answer... I am a profession decorator so I can justify spending £500+ on sanders and then the dust extractor (read: vacuum cleaner) that makes my life so much easier.

If you can only justify one sander, a random orbit will will flatten the finish much faster than a delta sander. However given the size of the disk, you will need to resort to hand sanding in the corners.

I treat existing paint as a kind of filler which can be sanded flat.

When working indoors, I seldom burn paint off, preferring to sand the paint back.

Abrasives? I tend to gravitate towards 80 grit for paint removal, higher grades for smoothing in between coats. I tend to max out at 240 grit. Higher than that and you risk polishing the surface and impairing adhesion.

If you are only looking at providing a key, purchase some 180 grit silicon carbide paper. It should be about £2 per metre. If rounded profiles such as spindles, effin' expensive, but at about £9 per meter, Abranet mesh is brilliant. And it does last quite a while.

 

[dazzystar]

OK. Thanks very much. A delta sander makes sense then as I can get into all the little corners, etc. with it. As I'm going from a dark grey to a white finish, is there anything I can do to prevent me doing loads of coats?

 

[opps]

OK. Thanks very much. A delta sander makes sense then as I can get into all the little corners, etc. with it. As I'm going from a dark grey to a white finish, is there anything I can do to prevent me doing loads of coats?

Are you using oil based paints or water based paints?

One or two coats of white Dulux Trade oil based undercoat will obliterate the dark grey. The key caveat being that you will need to wait longer for the paint to cure before applying waterbased finishes over the top. If you apply them too quickly, you will get "fish eyes"- the water based paint effectively pulls away from the solvents in the oil based and creates craters.

I am old skool. I am not particularly fond of waterbased undercoats.

Perhaps @Wayners can recommend one that will obliterate the grey in as few coats as possible

 

[dazzystar]

It'll be all water based paints I'll be using.

 

[opps]

It'll be all water based paints I'll be using.

Fair enough. I spent many years using waterbased primers on naked MDF, but 99% of the time I would then use oil based paints to finish the units.

I think you need @Wayners to help you going forward. He is a fellow decorator he seems to be a fan of waterbased paints.

TBH, as someone that respects his opinion, I look forward to his answer.

Best of luck

 

[dazzystar]

Thank you.

 

[Wayners]

I think a festool RTS 400 cordless will work with the new pads that came on market this year..
They mould well to architecture.
Use with 120 grade paper if you want to key old gloss to paint.
Mesh is better for filler. Paper for gloss as harder surface.

You will need some kind of HEPA dust vacuum though.

 

[dazzystar]

Thanks. Festool is certainly not in my budget unfortunately. Bosch will have to be the one due to cost. I'll grab some of those SurfPrep but not sure what you mean by Mesh is better for filler, paper for gloss?

 

[Wayners]

Powder filler is soft. You need to vacuum sand so mesh sanding has 100s of holes so its dustless.

Paper has 6 ish holes. If you use on soft dusty filler it's not really dustless like mesh, however paper is tuffer than mesh.
Paper is great for gloss or 2 pack wood filler.

So mesh on soft dusty filler where fine powder get taken away.
Paper sanding sheets on gloss and 2 pack hard wood filler.

Although. If you are wanting to create a key on old gloss 120 mesh is ok if you go steady. Has a tendency to buckle at the edges if driven hard, but its great for taking gloss dust away. So depends.

Get yourself a pad saver whichever sander you get. Velcro saver. Just replace pad saver then Vs entire bottom plate

 

[cdbe]

Not sure I'd attempt hours of hard sanding with a battery tool but I've never tried.

 

[endecotp]

As I'm going from a dark grey to a white finish, is there anything I can do to prevent me doing loads of coats?

Good undercoats, including water-based, are properly opaque; you don’t need to worry much about the change in colour.

 

[Wayners]

Create a key by rubbing down.
Use zinsser degreaser paint cleaner..
Cleaning surfaces is very important.

Use BIN aqua. It's brilliant stuff. Good opacity and don't half stick

 

[opps]

I think a festool RTS 400 cordless will work with the new pads that came on market this year..
They mould well to architecture.
Use with 120 grade paper if you want to key old gloss to paint.
Mesh is better for filler. Paper for gloss as harder surface.

You will need some kind of HEPA dust vacuum though.

Apologies for going off topic, but...

I love Festool sanders but I have not had much luck with the RTS 400. My first one, I seldom used, So little that it was out of warranty when it first failed. All of a sudden it became extremely slow. I purchased another, again, not used very often. I lent it to a friend. And yet again, it started running really slowly. This time it was under warranty. Festool repaired it. A couple of years later, it started to run slowly.

I haven't replaced it. I have 6 other Festool sanders that have been very reliable.

During covid, I did take the RTS apart and noticed that it has other design faults, eg the rubber "skirt" at the bottom is prone to splitting. When it works, it is a lovely sander, but when sanding flat surfaces, you have to ensure that you turn down the airflow on the dust extractor because the sander will try to stick to the surface.

I would love another RTS type sander, but 2 sanders developing the same fault three times is a red flag.

My only other Festool sander that failed was the first generation 150mm random orbital (Ro90), to be fair, I pushed it too hard and the nylon teeth wore down...

Some of my Festool tools are 30+ years old (eg DX93). It is only the RTS that has disappointed me.

 

[mattylad]

MY wife loves her little mains powered sander, one that uses pads shaped like an iron, cheap and gets into the corners well.
Why not get both, an orbital for the big areas and t'other for the corners.

Both need vacuum cleaner attachments and you need a mask.