Perfectly Rounded Fret ends

[Barticus]

I use one of these:

Amazon.com

It's made by 3M, commonly known as a Combi-Flap Wheel. It's a sanding flap wheel with alternating layers of sandpaper and Scotchbrite.

I couldn't immediately find a picture of me using it, but I chuck it in a fairly slow speed (like 500 rpm) electric drill. I run it slowly down the edge of the neck, tilted at 45 degrees, over all the ends of the frets and the edges of the fingerboard between them. It gently rounds the ends of the frets and the edge of the fingerboard, and blends them together. It gives the whole edge of the neck a nice worn-in feel.

I make one slow pass down the edge, with the drill motor angled down. This rounds off one side of the end of each fret. Then I turn the drill motor so it's angled over the fingerboard, and make a slow pass back towards me. This rounds the other side of the end of each fret. Then, turn the neck around and do the same two passes on the other side of the fingerboard; away from me with the motor down, and back towards me with the motor up. The whole process takes about 3 minutes and doesn't require any magnifiers or painful hand work. I use this process on both Nickel-Silver and stainless frets.

Note: Before doing this, I file the ends of the frets flush with the edge of the fingerboard, then file the ends at the beveled angle, all using a large smooth flat file with "safed" edges. So, there's a tilted-back flat D-shape surface on the end of each fret. The Combi-Flap wheel process rounds that off. It's not the Hemisphere-like shape that you are showing (which I personally don't like the feel of). It's more like a Quartersphere. Very smooth feeling. I've been using this technique on all of my basses for many years, and my customers love it.

Big Warning: Do Not, Under Any Circumstances, slip and allow the edge of the Combi-Flap Wheel to ride up onto the front surface of the fingerboard! This causes deep scratches and the screaming of profanities. I have done this myself. You need to guide the wheel along the edge carefully.

You can do this process in the drill press, too. Put the Combi-Flap Wheel in the chuck and feed the neck along over it. You have to do one pass fingerboard up, angled down 45. The return pass is fingerboard down, angled down 45. Carefully!!! I usually prefer to clamp the neck down stationary in a holding fixture, and do the process with the hand drill.

I looked quickly and couldn't locate any pictures. Speak up if my description isn't clear enough.

Edit, 6 years later: The Amazon link at the top is wrong; try this one:

https://www.amazon.com/3M-Abrasive-Combi-S-Aluminum-Diameter/dp/B0002FU75G/ref=sr_1_5?crid=3TJE3TMEIWK49&dib=eyJ2IjoiMSJ9.f6JV_r7eRI41A2ZQQ_2-oLZVfn_PMfhUWdRHhPhT1rmfBSuX8MVLOj53TlaENpUANP1nRS13GzjTjiLb9DiCvYDykw5aEJo2_tQTFT5gnRv4GlU9jzgphgJp4q_OpI3v7izc6ub7uE0nSJZu8H-HdlRZd6RlFSMoo40OJrbva9dHCJYHrpmETv5AB6n12vmp8o3r31-31aaCqNCX-nF2lk36PJK330AqFRuCjCDYHos.fzng4eN5uAclTE2v_-3YPecM3UgD9LjWOhxybTLl6Bw&dib_tag=se&keywords=3M+Combi-Flap+wheel&qid=1713291622&sprefix=3m+combi-flap+wheel,aps,354&sr=8-5

These are what you want, although this is a pack of 10. I've seen them individually hanging in hardware stores for about $8.

This is an awesome thread @Bruce Johnson and exactly what I was looking for today. I realize it’s 6yrs old, but helps with my SBO builds.

I just tried to buy the 3M Combi wheels on Amazon and now they’re only available in a 10 pack for $199.

Is anyone aware of a retailer where I can buy singles so I don’t have to buy the 10 pack?

 

[rojo412]

I'm kinda shocked at how pricey these have gotten (despite their functionality being worth their weight in gold, in all honesty).
Last one I got was on Ebay. It wasn't this, but if it were me, I'd at least try one of these:

2" Flap Wheel 180 Grit | Sanding Polishing Die Grinder Drill Buffing Scotch | eBay

Whether you're looking to remove scratches or the texture on a cast part, these are the wheels that will get the job done. (1) 2" Flap Wheel in 180 Grit. 1" wide with a 1/4" shaft (best used with a die grinder, can be used on a high speed drill too ).

www.ebay.com

Though in bulk at $20 each, if actually 3M, that's a pretty good deal. I'd be half tempted to split a box with you... unless more people want to get in on the deal. These do last quite a while, so 5 of them is a lifetime supply for me.

EDIT: These also look decent for half that price:

Amazon.com

 

[Barticus]

I'm kinda shocked at how pricey these have gotten (despite their functionality being worth their weight in gold, in all honesty).
Last one I got was on Ebay. It wasn't this, but if it were me, I'd at least try one of these:

2" Flap Wheel 180 Grit | Sanding Polishing Die Grinder Drill Buffing Scotch | eBay

Whether you're looking to remove scratches or the texture on a cast part, these are the wheels that will get the job done. (1) 2" Flap Wheel in 180 Grit. 1" wide with a 1/4" shaft (best used with a die grinder, can be used on a high speed drill too ).

www.ebay.com

Though in bulk at $20 each, if actually 3M, that's a pretty good deal. I'd be half tempted to split a box with you... unless more people want to get in on the deal. These do last quite a while, so 5 of them is a lifetime supply for me.

EDIT: These also look decent for half that price:

Amazon.com

Yep those are the ones, sold by Amazon not some unknown seller. I ordered some, lemme know if you need any

 

[Bruce Johnson]

Yep those are the ones, sold by Amazon not some unknown seller. I ordered some, lemme know if you need any

Hmmm.....I notice that McMasters carries them individually....for about $20 each. I'm sure they're made by 3M.

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[Barticus]

Hmmm.....I notice that McMasters carries them individually....for about $20 each. I'm sure they're made by 3M.

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

Thanks Bruce, I ordered a medium and a fine for $35… big difference!

 

[rojo412]

Yeah, that's definitely going to be part of my next McM order! Thanks Bruce!

 

[chinjazz]

Yeah, that's definitely going to be part of my next McM order! Thanks Bruce!

Hi Folks, and maybe @Bruce Johnson

It’s been a few years and I’m pretty much down the it’s last go round on my original
Scotch-Brite™ Finishing Sander - 9416NA. It’s got a very worn groove in the center of it, but I’m able to get more rounds on the outside edges.

Think this 240 or 320 grit below is equivalent to the original?

1:1 Cloth to Nylon Mesh Flap Sanding Wheel, with Shank, Cushioned, Very Fine Grade, 2" Diameter, 1" Wide

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[Bruce Johnson]

Hi Folks, and maybe @Bruce Johnson

It’s been a few years and I’m pretty much down the it’s last go round on my original
Scotch-Brite™ Finishing Sander - 9416NA. It’s got a very worn groove in the center of it, but I’m able to get more rounds on the outside edges.

Think this 240 or 320 grit below is equivalent to the original?

1:1 Cloth to Nylon Mesh Flap Sanding Wheel, with Shank, Cushioned, Very Fine Grade, 2" Diameter, 1" Wide

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

Hey chinjazz;

I've seen those Combi-Flap wheels listed at McMasters. They are made by some company other than 3M, but I assume that they are decent quality. McMasters doesn't sell cheap junk.

I've got Combi-Flap wheels ranging from 80 grit to 400 grit, and in my experience, any of them will work for this job of blending fret ends. The coarser ones may cut a little faster, but they all end up at about the same level of finish. The flaps of ScotchBrite (Nylon Mesh) seem to leave the frets at about a 800 grit level shine.

I'd chose the 240 grit one.

I just checked that ebay link that Barticus put up last fall, and it's still good. They are 180 grit and look to be identical to the 3M ones I bought 20+ years ago. Only $9 each. That's about what I paid for mine back in the '90's. I wonder if these are import knockoffs? Or leftover unbranded 3M stock?

Pardon Our Interruption...

www.ebay.com

 

[Barticus]

Hey chinjazz;

I've seen those Combi-Flap wheels listed at McMasters. They are made by some company other than 3M, but I assume that they are decent quality. McMasters doesn't sell cheap junk.

I've got Combi-Flap wheels ranging from 80 grit to 400 grit, and in my experience, any of them will work for this job of blending fret ends. The coarser ones may cut a little faster, but they all end up at about the same level of finish. The flaps of ScotchBrite (Nylon Mesh) seem to leave the frets at about a 800 grit level shine.

I'd chose the 240 grit one.

I just checked that ebay link that Barticus put up last fall, and it's still good. They are 180 grit and look to be identical to the 3M ones I bought 20+ years ago. Only $9 each. That's about what I paid for mine back in the '90's. I wonder if these are import knockoffs? Or leftover unbranded 3M stock?

Pardon Our Interruption...

www.ebay.com

Based on your recommendation, I bought them from McMaster-Carr and they are very good quality, I’ve never had the original 3M. I think I bought the 240.

 

[chinjazz]

Hey chinjazz;

I've seen those Combi-Flap wheels listed at McMasters. They are made by some company other than 3M, but I assume that they are decent quality. McMasters doesn't sell cheap junk.

I've got Combi-Flap wheels ranging from 80 grit to 400 grit, and in my experience, any of them will work for this job of blending fret ends. The coarser ones may cut a little faster, but they all end up at about the same level of finish. The flaps of ScotchBrite (Nylon Mesh) seem to leave the frets at about a 800 grit level shine.

I'd chose the 240 grit one.

I just checked that ebay link that Barticus put up last fall, and it's still good. They are 180 grit and look to be identical to the 3M ones I bought 20+ years ago. Only $9 each. That's about what I paid for mine back in the '90's. I wonder if these are import knockoffs? Or leftover unbranded 3M stock?

Pardon Our Interruption...

www.ebay.com

Thanks so much Bruce!

I’ll definitely order at least 2 for the future. I re-read this thread again and just “winged” it today and got good results with my original. Just went slow and maybe 2-3 passes in each direction.

I just finally launched my Son (UCF grad!), I think I’ll have time to make more basses ¯\_(ツ)_/¯. Have a great one!!

 

[chinjazz]

Based on your recommendation, I bought them from McMaster-Carr and they are very good quality, I’ve never had the original 3M. I think I bought the 240.

Awesome! Thanks Barticus!
Adding to my cart….