How to do PRS style recessed controls with the Kirjes Bowl Sander (Unboxing and demo)

In this video I unbox and demo the Kirjes bowl sander. I use the sander to finish carving the control recesses on a PRS style guitar build.
I bought all the components separately but it is available in this handy kit: www.classichandtools.com/kirj...
I have no affiliation with Kirjes or Classic Hand Tools but I am sharing because I am really impressed with the tool for this particular job, it's a real time saver.

[@ChrisFranklyn]

Not only a time saver, with my knackered hands a day of hand sanding those would ruin my thumbs for the week. ...and that was a classy walk into shot at the start! 😂

[@ADFinlayson]

Strutting on set like he owns it

[@LJG781]

I use a forstner bit about a half inch larger than the knob, then soften the edges... so far I'm very happy with the results

[@ADFinlayson]

I used that method on my first build, it works ok but it doesn't melt in to the shape of a carve top as fluidly as a round nose bit. These round bobbin sanders however are just for tidying up afterwards, not the initial shaping.

[@HrafnMusic]

Good shout! I'd found the much larger "scuff balls", but they seem to be very much single use. Once you clear the dust from them, they're basically soft and fluffy. These look like they'll do the job nicely.

[@ADFinlayson]

I think I've tried one of those too actually, they're like few bits of scotchbrite attached to a coach bolt? It didn;t do much in terms of sanding.

[@doobedoobedo1]

A small round nose router bit, template and bushing works for me

[@frankiechan9651]

oooh - another tool that's been added to the list of "may be ultra useful".
Thanks - I'd been looking at grinding a spade bit but much prefer this.

[@ADFinlayson]

Perhaps I didn't make it clear in the video. This is to be used in conjunction with a ground spade bit or router bit to quickly tidy up the tearout or router burn.

[@BBGuitars]

Have you ever tried a router cove bit with bearing guide, mounted in a drill press? Just change the bearing to match the size of your pot hole, can leave some tearout if you go too fast but more accurate than trying to balance things.

[@ADFinlayson]

Yes I did try that on some scrap when I was starting out. But do that with a bit of soft quilted maple and I think there will be an expensive disaster, my drill press does not spin nearly fast enough to a turn big router bit like that, it doesn't spin true enough either

[@kennycube5126]

I used to use the whole Kirjes system in a past job. A green motor with the highest quality flexible shaft and then the inflatables. It's expensive but a mighty fine tool. Don't go skipping any of those grits or you'll see those circles 😀

[@ADFinlayson]

Thanks for the info, any benefit in going as high as 320 in your opinion? I was just going to go 240 then move back to final hand-sanding

[@kennycube5126]

@@ADFinlayson Yeah that'll be fine. I look forward to seeing the results 👍

[@ADFinlayson]

@@kennycube5126I'm doing a finishing video on this one, stay tuned.

[@michaelkaufmann2729]

How deep are your recessed controls? Thanks for the "tooltip".

[@ADFinlayson]

tbh I'm not sure but probably not more than 5-6mm, it's important not to go too deep because you need to maintain the diameter of the recess or your knobs with foul the top. The diameter is around 40mm

[@TxStang]

mounted in a drill press i bet would have a lot better control

[@ADFinlayson]

the pots themselves are angled slightly meaning the recesses they sit in need to be a bit angled too, so it was easier to do it in the hand drill