DA sander for bodywork advice

[Little Jerry]

Gents

Apologies if this has been asked before....but can anyone recommend a good 6" DA sander that has a large orbit that is suitable for 80 grit type roughing up bare metal before epoxy primer. Most likely will need to be pneumatic from a price point of view - are there any electric sanders that do this work or are they more finishing sanders? I like the idea of electric as I would assume they are quieter than their pneumatic counterpart, but I want to get the tool designed for this job.

Appreciate any help.

Adam

 

[carbon]

80 grit is to coarse. Usually 120-180 grit is recommended for surface prep for epoxy primer, but check the data sheet for the product you intend to use.

 

[Turbo]

Air sanders are lighter to use but they are very air hungry so you need at least a 3hp compressor to feed it & even then you will run out of air. But air sanders are inefficient, you are running a 3hp motor constantly to supply the sander, an electric version is going to be only 1hp so 1/3 of the running cost!

If you have any cordless tools maybe you could look at getting a cordless sander to suit your batteries.

Whatever you decide on I would suggest you add dust extraction to your sander. Not only good for your lungs but significantly increases the life of your sanding discs. Also buy good branded discs & for your use you will need the blue zirconium. Standard alu oxide are useless on bare steel!

 

[steveo3002]

some of the elec ones would also work as a polisher if that intrests you

 

[Burdekin]

I asked a similar question two weeks ago: https://www.mig-welding.co.uk/forum/threads/what-da-sander.118862/page-2#post-2000627

 

[Little Jerry]

Thanks mate....I need to get better with the search function...I see you bought the metabo electric sander...looks like a very nice unit. If those tools were $400-$500 AUD I'd bite the bullet but it's a hard sell at $1000 over here given the limited use I have for them.

Am I correct in saying that a 5mm orbit DA palm sander (whether electric or pneumatic) will do the job of prepping bare metal / working with body filler etc like the 3m unit below? Or do I need one of the bigger DA units like in the second pic? Or do they do the same thing, just a different housing design?

 

[carbon]

They both do the same thing. I have used both but prefer the palm sander. I use a rupes that’s very similar to the 3M one but it has a 3mm orbit and maybe a little slower. If you can use with a vacuum connected as it seems to make discs last longer

 

[steveo3002]

if this is a one off home job not a full time body shop i would get something like this and accept it for what it is, should do the job okay

https://www.argos.co.uk/product/8647300

 

[Little Jerry]

80 grit is to coarse. Usually 120-180 grit is recommended for surface prep for epoxy primer, but check the data sheet for the product you intend to use.

The datasheet is not clear for bare metal (Lesonal EP440). Out of interest - is there an issue with using 80 grit? i thought it would give it something good to bit into. I have a contact for a local Lesonal technical rep so I have it down as one of the questions to ask.

 

[carbon]

This is from the tds

Original finishes – sand with P180 to P280 grit dry, or P600-P800 wet.
Steel – remove all traces of rust and abrade thoroughly until a clean surface is achieved.

If you use 80 grit you will probably have to use either more epoxy or some filler to fill the scratches that are left.

 

[Jack_K]

Since you are in Australia I can recommend a Shinano SI-3100 (and any other Shinano tools). They are easy to get and what I think is a good price. All my Shinano tools have been a lot better than the China/Taiwan made tools I have bought. My SI-3100 seems to use less air than a 3" China/Taiwan sander I bought which I have since replaced with a Shinano.

 

[Little Jerry]

Jack, I just saw this post but funnily enough I had ordered the Shinano SI-3100 a couple days ago after coming to the same conclusion....low cfm but importantly for me it is rated at 76db which is pretty quiet for this type of tool