Jump to content

Rotary sander vs random orbital?


Featured Posts

I need to prep the cabin sides prior to painting. The paint is very old - I don't need to go back to bare steel but I would like to get the top coats off because they aren't well bonded. I tried a random orbital sander with a coarse 60 grit paper but it's hard work and not really cutting into the top coat adequately. I could use a mini angle grinder with a sanding disc but because you don't use the whole disc the result is uneven. So, I've never used one, but would a cheap rotary sander like this one with coarse grit discs do the job any better? I was just thinking it's flat and even and because the whole disc revolves it's a bit more aggressive than a RA sander and is likely to be less effort. Is that the case or not? Does the whole disc revolve 360 degrees or does it just vibrate? Whatever I end up using to remove the topcoats will be followed by a palm sander with medium grit paper.

 

https://www.toolstation.com/shop/p21389?r=googleshopping&rr=marin&utm_source=googleshopping&utm_medium=feed&utm_campaign=googleshoppingfeed&gclid=EAIaIQobChMI0fXn_OuF3QIVAp3VCh2SmwbTEAQYAiABEgKPM_D_BwE

 

Thanks

Edited by blackrose
Link to comment
Share on other sites

The pro body workers kit is a Dual action orbital sander, not sure if the one you linked to is dual action. Its the same action as a rectangular random orbital sander but with the rotation as well. Of course the action of both is not truly random, you have to keep it moving the whole time.

For fast removal of paint a belt sander is best but you have to be good to use one without it running away with you into the cut!

  • Haha 1
Link to comment
Share on other sites

11 minutes ago, Boater Sam said:

The pro body workers kit is a Dual action orbital sander, not sure if the one you linked to is dual action. Its the same action as a rectangular random orbital sander but with the rotation as well. Of course the action of both is not truly random, you have to keep it moving the whole time.

For fast removal of paint a belt sander is best but you have to be good to use one without it running away with you into the cut!

I borrowed a neighbour's belt sander last weekend and while it wasn't bad, the belt speed was a bit slow even on the fastest setting. It did speed things up but the result was a bit patchy.  

Link to comment
Share on other sites

I've got a Bosch 150 mm orbital sander ,GX150 ? that I've had for 13 years and it's excellent. It has the advantage that spares,pad etc are readily available. The pad can be bought with different levels of density dependent upon the surface worked on. For the life of me I can't be sure of it's action (It's on the boat so can't check). Are you aware that you can get different quality of discs ? ( I don't mean grit grade}. I.ve always got mine from a vehicle refurbishment supplier in boxes of 100. Not cheap but well worth it. I suspect you might be using Screwfix type discs. They're rubbish!. Also you need to change the discs VERY frequently. Far more frequently than your wallet says you should. Some years ago I watched a professional  vehicle sprayer prepare the sides of his fathers boat prior to spraying it.. Using an air driven DA sander he used each disc for well under 10 seconds.  On the matter of a belt sander don't use one I can still see where I gouged a panel years ago. It only takes one slip.

 

Frank

 

 

  • Greenie 1
Link to comment
Share on other sites

I bought a similarly cheap and cheerful own brand random orbital sander from B&Q years ago (unnamed grey thing), and have had  lot of success with it. I tend to go for medium to coarse disc initially and then a finer one to finish but it saves so much time it's no big deal doing things twice.  It is worth avoiding the suspiciously cheap discs as suggested. 

Link to comment
Share on other sites

My Bosch DA, similar to Slim’s, is a cracking bit of kit, I’ve had it for many years. I can only endorse his positive comments and advice re discs, it’s worth paying for quality ones that cut the mustard - and paint! They are commonly found in yards that I work for. With finer discs, they can prepare the surface for painting and to rub down between coats. Much quicker and easier than using a palm sander, in my experience.

 

Link to comment
Share on other sites

The Aylesbury Canal Society wet dock has some sort of rotary /orbital sander complete with dust extraction. I've no idea what make or model, but it is very effective at sanding down paint (old and new), even with Screwfix discs, and the dust extraction means the workplace stays much cleaner. While not really recommended you can happily sand at one end of the boat while someone is painting at the other.  

Link to comment
Share on other sites

I use a Meguiar sander polisher. It is dual action rotary and variable speed. It takes 150mm hook and loop sanding discs or polishing pads in standard mode but different size base pads can be fitted from 50mms to 175mms diameter for different size sanding discs or polishing pads. The base pads are widely available. It is 230v. There are many similar makes of machine used in the painting and bodywork industry. With the same machine i can sand, compound and polish. Similar machines can be bought for something like 80 quid, although mine was quite a bit more. It gets heavier than normal use so needs to be good. 

Link to comment
Share on other sites

Thanks for your posts. I've bought the rotary sander I pasted the link to in my original post. I plugged it in and switched it on and it does fully rotate at up to 12,000rpm. It actually looks pretty good. No idea about the brand though - for that price it might be crap. Anyway I've got some 50 grit hook & loop sanding discs so I'll give it a go tomorrow and report back. 

Edited by blackrose
Link to comment
Share on other sites

3 minutes ago, blackrose said:

Thanks for your posts. I've bought the rotary sander I pasted the link to in my original post. I plugged it in and switched it on and it does fully rotate at up to 12,000rpm. It actually looks pretty good. No idea about the brand though - for that price it might be crap. Anyway I've got some 50 grit hook & loop sanding discs so I'll give it a go tomorrow and report back. 

I guess you already know this but if your paint is thick and you find that it’s melting and smearing, slow down the speed. 

Link to comment
Share on other sites

43 minutes ago, David Mack said:

 

How can you tell?

Because that's what it says in the specs. I've no reason to doubt what they say. 

 

DETAILED DESCRIPTION

• Hook and loop system
• Variable speed
• Dust collection system
• Quick adjustable auxiliary handle

Base size: 125mm. Orbital diameter: 2.5mm. No load speed: 4000-12000rpm.

 

I realise it won't spin that fast under load. 

45 minutes ago, WotEver said:

I guess you already know this but if your paint is thick and you find that it’s melting and smearing, slow down the speed. 

Ok, i didn't, but now you mention it that makes sense, so thanks. 

Edited by blackrose
Link to comment
Share on other sites

Bosch stuff is great, 40+ years in the motor industry tells me that. Paint work is all about the preparation you put in, the best paint wont cover bad prep. Get it right first time. Cheap materials will cost you dear in the end.

Link to comment
Share on other sites

1 hour ago, Mike Hurley said:

Bosch stuff is great, 40+ years in the motor industry tells me that. Paint work is all about the preparation you put in, the best paint wont cover bad prep. Get it right first time. Cheap materials will cost you dear in the end.

be aware that there are different grades of Bosch gear.

Green cased tools are intended for Home / DIY usage and tend to be cheaper built and closer to the limits on their motors etc.
Blue cased tools are intended for commercial use and tend to be able to take a real pounding

Link to comment
Share on other sites

3 hours ago, Joe Bourke said:

I use a Meguiar sander polisher. It is dual action rotary and variable speed. It takes 150mm hook and loop sanding discs or polishing pads in standard mode but different size base pads can be fitted from 50mms to 175mms diameter for different size sanding discs or polishing pads. The base pads are widely available. It is 230v. There are many similar makes of machine used in the painting and bodywork industry. With the same machine i can sand, compound and polish. Similar machines can be bought for something like 80 quid, although mine was quite a bit more. It gets heavier than normal use so needs to be good. 

I’ve got their MT300 or 320.... can it also be used as a sander with the right discs? Or is yours a different model?

Link to comment
Share on other sites

8 hours ago, Richard10002 said:

I’ve got their MT300 or 320.... can it also be used as a sander with the right discs? Or is yours a different model?

The MT 320 i think replaces the G220. Both are sander/polishers , so yes it is for sanding as well. I have different size base pads for different jobs. The G220 is about 140 quid and still for sale, the MT320 is about 240 quid. There are other similar and cheaper machine s. 

 

Link to comment
Share on other sites

Well, the rotary sander has dust extraction - it's supposed to go into a bag but it doesn't work. Most of the dust ended up all over me. I suppose I should have connected my wet/dry vacuum to it but it makes it more difficult to move the sander where you want it. 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.