How to Use and Store Sandpaper - Luthier Tips du Jour Mailbag
In this episode, Robbie O’Brien shows how he uses and stores sandpaper in his shop.
Video Transcription
[on-screen text reads: Luthier Tips du Jour Mailbag]
Mailbag question: Can you share with us how you use and store sandpaper in your shop?
Robert O'Brien: Today's Tips du Jour Mailbag question comes to us all the way from Taiwan. "Dear Robert, recently, I visited your shop and I learned how you use and store your sandpaper. This was very useful to me, and I think others would also benefit from this. Would you mind sharing this info. Neil in Taiwan."
I think this is a great idea. So let's go over to the bench and I'll show you what Neil's talking about.
How I use sandpaper
So here's a piece of sandpaper. What a lot of folks do when it comes time to sand is they take a whole sheet of paper, fold it in half, and start sanding. What happens is you wind up wasting about half your sheet of paper. So here's a more economical way of using it. Fold it in half, then fold it in half again. So actually, you've got a quarter sheet. Put that on the edge of your bench. Now I've got a quarter sheet of sandpaper. I then take that and fold it into thirds.
All of the sanding blocks in my shop are just smaller than that quarter sheet that has been folded into thirds. I can now use this side of the sandpaper, this side of the sandpaper. When those are worn out, I can then open it up and I have a bonus piece in the middle waiting for me. Also, folding your sandpaper into thirds keeps it from sliding around and being inefficient as you work because the sandpaper is providing friction on itself and that works very well. I think you'll find you'll use a lot less sandpaper if you use your sandpaper in this fashion.
How I store sandpaper
Now, how do you store the sandpaper? Let me show you that. Here's a trick I learned from Brazilian luthier Antonio Tessarin almost 20 years ago. Tuna fish can. Take the folded up piece of sandpaper, store it in there like that. I actually have two of them on my bench, one for my higher grits and one for my lower grits.
Once you take the piece of sandpaper out of your box of paper and rip off a piece, rather than trying to stuff this back in there, I then take a file folder. Open it up, and then I write the grits on here. It's very easy to just store that extra piece of paper right there under the appropriate grit number and next time you need a piece of sandpaper, you already have some ready to go.
Sandpaper grades
So now you know how I use and store my sandpaper. There's one thing I did not mention and that is the grade of the sandpaper. There's two types of sandpaper: the North American grade, which is the CAMI grade, and the P grade, which is European grade. Now, up to about 320, 400, they're pretty equivalent. Once you start getting above that into your higher grit, say 800, 1000, 1200, 1500, the P grade is actually equivalent to about half of what the CAMI grade is.
So what that means is if you're mixing the two grades and you're working on finish of your guitar, you can go 800, 1000 and then if you go 1200 or 1500 P grade, you're actually putting scratches back into your finish. So keep that in mind. I talk about that in detail in my online guitar building courses. So take a look at the chapter on finishing to learn more information about that.
So Neil, thank you very much for your question. I hope you and the other people in Taiwan as well as other folks around the world find this information useful and happy sanding.
[on-screen text reads: More Luthier Tips and online courses available at www.obrienguitars.com. Private and small group guitar building and finishing instruction available.]
