random orbit sanders and 1/2 sheet orbital sanders

[Stephen]

Hello,

How good are random orbital sanders? I bought a Bosch green 1/3 sheet orbital sander many years ago but it takes forever. I've read the excellent uk.diy power tool FAQ and it agrees that orbital sanders are slow and suggests that random orbital sanders are much faster. I remember borrowing a random orbital sander (green Bosch 400 something?) a couple of years ago to remove some paint but I don't remember it being that good. However it was a while ago and I can't remember the details; perhaps my technique was wrong or I was using the wrong type of paper?

In addition to removing paint from wood, I've also got a wall I would like to give a quick once-over before papering, would you recommend a random orbital sander for this or would a 1/2 sheet be better as it would cover a bigger area at once? I don't see many 1/2 sheet sanders for sale at the moment, have they gone out of fashion? Is it worth buying a known brand like Bosch or do the Aldi/Titans etc. do as good a job?

Thanks, Stephen.

[John Rumm]

PEX400 probably...

The thing to remember with paint stripping, is it is never going to be that fast however you sand it. It tends to clog paper quickly. A random orbit at a slowish speed with a coarse (40 or 60 grit) paper will probably work best.

The only faster options would be a flap disc in an angle grinder - but that will be much harder to control and have a good chance of gouging.

Half sheet will probably give you the flattest overall result due to the larger pad size. Other than that you are probably better off with a random orbit.

For 1/2 sheet you will need to look at the more professional tools. If you plan on doing much sanding then it is worth spending extra on them since they tend to get much smoother and cause less fatigue and vibration at your end of it.

Some RO sanders have selectable orbit sizes - for faster stock removal or finer finishing.

[The Medway Handyman]

The mutts nuts IMO.

With a 40 disc they give excellent stock removal, approaching a belt sander but with 100% control. You can go up to 240 grit for fine finishing.

Like garlic bread - the way forward.

[Stephen]

Is that a good model to get or are there better ones?

Perhaps I was just impatient? I've got some skirting board to sand; I filled over the nails and knots with wood filler but I put too much on! What's the best device for sanding that?

I notice there are quarter sheet sanders now. When would you use those? Surely for small work you would be better with a delta sander to get into the corners?

Is the jump from 1/3 sheet to 1/2 sheet noticeable? Does it make any difference to speed or quality of finish?

Thanks again.

[John Rumm]

Its a reasonably decent budget one. I have one, and find it ok if not doing too much in one go.

The RO will do that nicely. The thing to remember is that you don't always get the fastest removal rate with the maximum speed - sometimes a slower rate, coarse paper and gentle pressure will take off material quickly.

Probably nice for furniture making. Quite often you might be sanding smaller stuff before assembly. The light easy to handle sander can be an advantage - especially if it can be held with one had comfortably (i.e. hand resting on, rather than needing to grip and support the body as you would a delta)

With the exception of the Fein multimaster, most delta sanders have fairly poor sanding performance IME. Hence they are only worth using for the corners, and one would want to switch to something more effective when space permits.

1/2" is bigger and heavier. You can cover an area faster. Some are designed with a bigger orbit size that makes for faster removal (Makita do one with a 5mm orbit IIRC). You will get a slightly flatter result with a big sander, since it will not ride any curves as well. Rather like using a longer plane...

[The Medway Handyman]

Never used a Fein, but my Bosch PMF180 copy is without doubt the best delta sander I have tried - streets ahead. The rubber backing pads do wear badly mind you - does that happen with the Fein?

[John Rumm]

What the velcro covered things? They last quite well if you take care to not overheat a corner - at which point it can start losing hooks, and then the paper does not stay put as well.

[Stephen]

I've got the green Bosch one, perhaps that's why it takes me ages?

[Dave Plowman (News)]

I have one and it's fine. But got a larger one from Lidl for a fraction of what it cost (many years ago) which also has far cheaper discs. I hardly ever use the Bosch now.

[John Rumm]

To clarify, I was talking specifically about *delta* sanders there - i.e. the ones with a small triangular pad, designed for corner work etc.

The green bosch is better than some of the breed (I tried a nutool one once - it made lots of noise and vibration, but never seemed to actually sand anything!) - but still slow. The multimaster (and judging by TMH's comments) the various MM clones, perform much better than the traditional delta sander due to the different type and speed of motion they employ.

[The Medway Handyman]

Ah. Exactly what happens with the Bosch.

[Jules]

I've found with mine (a cheapy Ryobi thing* bought on a whim) that it's actually the sandpaper material which separates from the velcro backing... I've had that happen on a couple, now (3M pads, I believe). Actual hook portion fine, so far.

• does the dust collection actually work on the better brands / models?

cheers

Jules

[Stephen]

So was I! Sorry for the confusion, I have both a green Bosch 1/3 sheet sander and a green Bosch delta sander. My earlier post was about the

1/3 sheet sander and this later post about the delta sander but I didn't make that clear.

That's reassuring. Because it's small and light I have been tending to pick that up and use it first, however, I will now follow the advice in your earlier post and only use it for corners and use the 1/3 sheet sander for everything else (whilst looking into the 1/2 sheet and random orbital options).

Thanks again.

[Stephen]

Is that a blue Bosch? I think there was a post here or in the FAQ saying that the velcro backing pads must be considered a consumable. I understand this velcro fastening is also used on the random orbital sanders; do these suffer the same problem?

By the way, what sandpaper do you use? I have been using the Silverline triangles from Toolstation, simply because they were cheap. However, I find that they have to be changed frequently so I do wonder whether it would be more economical to use a more expensive brand that lasted longer?

Thanks again, Stephen.

[John Rumm]

On the MM its not bad if you hook up the vacuum cowel, fibre washer and use the punched pads. Its not perfect, but is about as clean as you are going to get a sander. There is something about the oscillatory action (rather than orbital) that seems to throw less into the air in the first place - it tends to pour off the thing you are sanding in a nice little waterfall.

[Jules]

Yes, at least it doesn't spread it everywhere, I suppose. It's just that given how much actually makes it into the bag on mine vs. how much I sweep up elsewhere, I can't really see why they bothered :-)

[John Rumm]

I expect he means the PMF180 multi tool (green). There is a blue cordless version that came out recently.

Not really - much bigger area to wear out and you are less likely to overwork a small part of the disc.

For the multimaster I use the Fein ones - they last amazingly well - I bought a few extra packs with the tool and have still not finished the ones that came with it. Its also worth noting they are not quite the same shape as "normal" delta pads - they have a radius on the edge such that there is no lateral movement at the sides of the pad.

Not really used ordinary delta machines enough to comment. TS alox pads seem about par for the course on the RO though.

[Stephen]

I used to empty the dust box on my sander, it certainly filled up though I can't remember if any escaped and fell to the floor. I've since bought an adaptor to fit the sander to the vacuum and now it catches pretty much everything.

I think I read (in the FAQ?) that the system serves two purposes: not only to collect sawdust but also to draw air through the sander and cool the motor.

I have had a couple of pads where the velcro stays on and the paper falls off but I always thought they were bad batches.