DA / RA Sander Questions

[JonnyAlpha]

Hi;

I started a thread here when I was about to buy a Clarke DA Sander. I still haven't bought a DA sander so just needed an update.

What's the difference between DA and RA?

Budget depicts around £50 - £80 so I have been looking at a couple. An acquaintance has been using one of these GMC models and seems to be happy with it?
I have also been looking at an Ebauer model from Screfix.

They are both around the same wattage but £30 difference.

Also looked at a Bosch one from B&Q but the build quality looks questionable compared to the others and its only 220Watt?

I only really need this to strip and prepare the paint work on my Mini restoration.

Also could anyone recommend 150mm discs of varying grades, can only seem to find 240 and coarser?

Any comments ?

 

[anjum]

DA rotate about an eccentric axis whereas RA rotate around a fixed axis i.e. like an angle grinder.
The best way is to see them and see how they feel in your hand for balance.
They will never be as light as an air powered one but they use a large compressor.

 

[armalites]

DA means Dual Action, can run in random orbit or fixed mode ie two mode, normally air

RA are random orbit sanders not like angle grinder, not sure why they are called RA maybe Random Axis and it tends to be a name more commonly used on electric

So basically they are the same the pad oscillates and doesn't spin(except in fixed mode for a DA)

You can buy 150mm/6" DA discs as fine 3000 grit

 

[WorkshopChris]

They will never be as light as an air powered one but they use a large compressor.

Have you used these, just a light and they dont get as cold as the air sanders.

http://www.mirkareseller.co.uk/cero...-ceros-electric-orbital-sander-240v-p-38.html

Fantastic bit of kit i have one on my upgrade at some time list.

 

[brightspark]

il pass on those I bought a couple of air sanders made in japan for 20 quid . only needed the plastic air switch buttons replacing that cost 15 quid for 2 and they work perfect

 

[anjum]

I thought by RA the o/p meant Rotary Action.

Chris - those look very good, can't justify the price at the moment, maybe later.

 

[WorkshopChris]

I cant either at the moment but i know a few people who use them, they are getting hugely noticeably reductions in running costs. a modern switch mode supply at a few amps compared to a 3+ hp motor chugging away 6 hours a day.

 

[JonnyAlpha]

I thought by RA the o/p meant Rotary Action.

Chris - those look very good, can't justify the price at the moment, maybe later.

Sorry I meant Random Orbital.

 

[JonnyAlpha]

DA means Dual Action, can run in random orbit or fixed mode ie two mode, normally air

RA are random orbit sanders not like angle grinder, not sure why they are called RA maybe Random Axis and it tends to be a name more commonly used on electric

So basically they are the same the pad oscillates and doesn't spin(except in fixed mode for a DA)

You can buy 150mm/6" DA discs as fine 3000 grit

So for sanding down a car for spraying and flatting between coats do I need 150mm or 125mm (I was considering a Makita 125mm?, although the specs say 123mm, a little out of my price range though)

But back to the question, the GMC or the Erbauer?

 

[richie00boy]

The 125mm sanders have better dust extraction so actually are as quick on a panel as the 150mm and less messy.
I have a 125mm erbauer one and done a bedroom, lounge and a few car panels and would recommend it.
Just avoid the cheap burgundy discs, they are only any good on wood and clog badly on paint.

 

[armalites]

Personally if you have a compressor that's suitable for spraying then I would get an air powered DA, they are air hungry but not so bad in random orbit mode, they are cheap as chips and bomb proof if kept oiled. Worth spending the extra £5-10 for a velcro pad if it doesn't have one and the discs can be had on ebay for £10-20 for 50.

 

[JonnyAlpha]

Personally if you have a compressor that's suitable for spraying then I would get an air powered DA, they are air hungry but not so bad in random orbit mode, they are cheap as chips and bomb proof if kept oiled. Worth spending the extra £5-10 for a velcro pad if it doesn't have one and the discs can be had on ebay for £10-20 for 50.

I have a second hand Snapon 2 or 2.5HP, it runs an FMT LVLP 3006 Spray Gun fine (Compressor stays on though) I bought a cheap DIe Grinder and either its rubbish or my compressor will not run it, it spins for about a second and then dies!! So not sure if I could run a RO Sander on this compressor :-(

 

[Keith 66]

I have had a Sealey ER150 electric random orbital sander for 25 years, best sander i have ever had. Built like a tank. Most of the diy sanders come with velcro pads, good car trade pint shops sell stick on discs as well. I far prefer the stick on ones.

 

[DrDeAtH]

So for sanding down a car for spraying and flatting between coats do I need 150mm or 125mm (I was considering a Makita 125mm?, although the specs say 123mm, a little out of my price range though)

But back to the question, the GMC or the Erbauer?

Go for the 150mm Erbauer. It's a a good heavy sander, but quite comfortable to use.