bang for the buck sandpaper

What’s the cheapest sandpaper in bulk that still lasts a long time?

What style do you like for composite hand sanding? On a roll, in sheets, etc?

Normally I use the cheap stuff but it breaks down fast, especially with wet sanding.

3m or Mirka for sure. It’s not cheap, but it just lasts so much longer. Which is more important than you realise with sandpaper. As soon as you lose the bite and have to start pushing to get the same cut, that’s when you start digging in and mess up your surface.

Totally agree. Sandpaper isn’t a place to skimp. Festool is also very good but a bit more expensive than Mirka or 3M.

I do composites for a living and the sandpaper I use is the kind with sticky backside big sheets 12x18 for floor sanding , get it from home depot but its stored in the tool rental section not with the regular sand papers, its the most expensive sandpaper and the best bang for the buck

Thanks for the advice. The best stuff at HD is always with the contractor supplies instead of the homeowners stuff. For example, you can get a huge roll of duct tape in, wait for it, the HVAC duct section. It’s better quality and way cheaper than the stuff up front in the paint section.

I am curious, are you guys finding sand-paper that really lasts a long time when used on carbon fiber?

Maybe it’s because I wet sand but no sand paper ever seems to last long for me.

I use metal files for any shaping and rough sanding and after going through a lot of expensive 3m sandpaper very quickly, I ditched it and just bought a bunch of cheap smooth sandpaper packs off eBay.

I got a pack of 70 sheets for $12 last time which went from 350 up to 2000. It doesn’t last as long as 3m stuff but the difference is not that big. I just use a fresh piece for each job and it’s so much cheaper that it still works out more cost effective for my work.

Maybe I’m doing something wrong…

It’s relative. What would you consider a long time?

It isn’t as important when doing finishing sanding, as all that really happens above 400 grit is it takes a bit longer to rub out the previous grade scratch marks. But you aren’t going to dig a hole with 600 grit paper because you used it a bit too long, unless you are really going crazy with it. For me, I know that if I’m using 3M or Mirka paper, then I will get rid of every last scratch from the previous grade and be able to get a truly polished finish. Rather than using cheap paper and polishing it up only to find that you now have a surface of polished scratches.

It’s pattern work where it really makes a difference. Use some 80g Mirka Abranet and then compare it to the cheap 80 grit paper you get from a hardware. Even when totally clogged, the Mirka still has good bite to it and so you don’t need to push as hard which means you can keep an even pressure and get truly flat finishes. A box of 50 sheets of Abranet costs about $180AU, so works out to be $3.60 a sheet. You can get a 10m roll of the cheap stuff for about $8, so the Abranet is super expensive. But I guarantee I could do the job in a fraction of the time, waste less energy and bog, and get a significantly better result.

Really it comes down to matter of opinion. If the cheap stuff is delivering you results and you’re happy then there’s no reason to change.