Auto body sandpaper recommendations

[mike758]

I stripped a truck using those black abrasive discs on an angle grinder, and now I'm looking for sanding discs for my DA sander to prep the metal for priming, and some paper for block sanding the primer. I'm a rookie in autobody, so I don't know the value brands or good paper or whatever. My friend recommended Rhynostick for the discs

 

[bmwpowere36m3]

Always used Mirka, Sia and 3M... haven't used Rhyno too much.

 

[dnschmidt]

Indasa is the best bang for the buck unless you have a wholesale account with Klingspor, which I do, and then their PS33W - which they have renamed to something else - is. Mirka is fine, Norton is very good and 3M is the best - but not the best value. Like everything else 3M makes it works but you pay through the nose for it. Standard autobody grits are 80, 180 and 320. You go to primer after 180 and you go to topcoat after 320. Some fell that you should go to 400 or 500 after primer and before topcoat but I believe this is overkill. If you're doing a blend than you scuff the adjacent clearcoat with 800.

 

[bmwpowere36m3]

We finish at least 400 wet (hand block) after primer... 600 if its metallic before top coating (that's 3M wet/dry). DA is almost always reserved for pre-primer work.

 

[don long]

I always use Mirka paper for my bondo work because it hooks up to my vac. tools even the hand blocks.
I prime over 120 grit and block my primer with 220 grit. then I reprime and block with 400 grit paper wet then to insure that I don't get sand scratches in my top coat I go back over the area with 800 wet paper and it's ready to spray my top coat (always wipe a wax and grease remover product over the surface prior to painting and I also wipe it down with a tack rag just prior to applying my first coat of paint.)
If you are painting a new panel with the factory sealer on it just skuff with 500 grit dry paper and shoot

 

[Hammer1963]

I will second the Indasa recommendation. The Red Ryno line is hard to beat for the price. I purchase mine through my Medallion-Rubberseal rep. I have seen it listed on Amazon as well.

 

[Mastermind]

I never liked the rhino, seemed to gum on me. Maybe material back in the day. Currently using smart. Norton is my fave d's paper.

 

[southalabama]

Dad's always been partial to 3M and Norton.

 

[cneal1992]

I have been in the autobody industry for 6 years now and have used norton and 3m sandpaper. Norton is alright in my opinion but 3m is my favorite. But , as others have said , you will pay higher price for the 3m. I finish mud work with 150 or 220 and finish block my primer with 320. Then i da the primer with 400. If you are applying sealer 400 is all you need. If it is a blend then 600 or 800 depending on what line of paint you are using. Hope this helps.

 

[Bill Bowman]

^^^Why in the world would you block your primer with 320 grit, and then **** it up with 400 grit on a d-a? Sounds like you're "killing" your block sanding with the d-a, but I've only been doing this bodywork stuff my whole life.

 

[dnschmidt]

You only "**** it up" if you overdo it. There's an excellent reason to finish with a small orbit 3/32" DA (which is what you use for dry color sanding anyway so it's can't be the root of all evil) and that's to get the curved areas that you can't easily get to with a block. Use an interface pad and only one pass to randomize the scratch pattern. With P400 paper (this is the final grit prior to base recommended to me by Jon Kosmoski at one of his seminars - that's good enough for me) you've not going to affect the panel straightness you've achieved using P180 to start and P320 to finish with the straight blocks. I've been doing it this way for 30 years without issue, particularly sand scratch swelling due to missing an area with P320 on a block leaving some exposed P180 scratches, which is the issue.

 

[theoldwizard1]

3M, but I don't do body work.

 

[cneal1992]

You arent gonna **** anything up if you do one even pass the whole length of the primered area top to bottom. and if you do find it is dicked up its probably crappy body work to begin with. It gets the straightline scratches out of the primer. Everybody has different opinions on how to do things. That is how me and over the 40 other guys ive worked with have always finished our primer

 

[cneal1992]

And yes using an interface pad and not tilting your da hepls to not screw anything up