Ash's acoustic rabbit hole

[Andyjr1515]

It's looking very good, Ash.

As @Bizman62 says, vacuum sanders are pretty good but it will still need careful and thorough vacuuming and sometimes some manual light sanding of the spruce round the edges with a small block and very fine (I use 320 grit non-coloured sandpaper) taking care not to catch the binding or creating an edge or dip in the spruce.  I use a 2cm x 1cm rectangle of plywood with the sandpaper stuck on with double sided tape.

[ADFinlayson]

Yes I've got a few tricks I can use, vacuum, tack cloth and mineral spirits. Hopefully with those 3 it will clean up. I was sanding at 11pm and didn't really want to crack out the vacuum and upset the neighbours. 

I will say one thing though - The lack of end grain is bliss.

[mistermikev]

really starting to look like a guitar (this is the best part!).  Excited for you.

[komodo]

On 9/27/2021 at 7:44 PM, ADFinlayson said:

Holy cow you've been busy.
I have to know, if that an original concert shirt? I saw that show from the 10th row center. I'd listened to Killers for a long time, but Bruce was new and he ripped my head clean off.

[ADFinlayson]

58 minutes ago, komodo said:

Holy cow you've been busy.
I have to know, if that an original concert shirt? I saw that show from the 10th row center. I'd listened to Killers for a long time, but Bruce was new and he ripped my head clean off.

Not an original but I did pick that t and a couple of others up when I saw them on the legacy of the beast tour, it was Bruces 60th Birthday and Nicko had us all sing happy birthday. Best live show I've seen - They had a different set for every song, full size spit for aces high and a lot of the time he was running around with a flame thrower. I should have taken some pics but I was too busy head banging

[komodo]

Haha that's awesome. I've lost count of how many times I've seen them. I do remember Powerslave and Piece of Mind were the coolest tours!
My band in high school was pretty much a Maiden clone band. We did Charlotte, Ides/Wrathchild, Innocent Exile, Killers, Acacia Ave, Powerslave, Losfer Words, Ancient Mariner, Trooper, and To Tame a Land.  Other stuff: Rush, Zep, Kansas, Pat Travers, Dokken, Queensryche, Triumph, YES, BOC, Dio, Ozzy, Sabbath, April Wine. We had this spectacular drummer who could do the most amazing stuff, but his basic time would drift, usually faster as he got excited. LOL Try playing a Queensryche solo pulling behind the beat to rein in your dopey drummer.

Good Times. Back to the build!

[ADFinlayson]

After a bit of a hiatus, I've made a bit of progress on the neck for acoustic #1. I had cut the taper into the fretboard way back when, and got it glued on to the neck at the weekend, then I trimmed the neck excess to the taper of the fretboard. I think that's the first time I've ever trimmed the neck to the fretboard instead of trimming the fretboard to the neck.

Radiusing the fretboard was nice and easy, the heel made for a nice handle. But by the time I got round to slotting and fret installation, it occurred to me that I had made a rod for my own back.

I opted to press the frets in with a caul in the drill press which went quite well, it was just a bit awkward supporting the far end of the board.

I got a good chunk of the carving done last night too with the heel left to finish shaping and the rest to tidy up. I'm hoping that I haven't made the heel block too small to get a smooth transition, a lesson for the next one.

So this is where it's at now, I need to see if I can improve the alignment as the fretboard is pointing slightly off centre to the bass side so I'm hoping that pulling sand paper on that side of the heel will help.

Then it's on to bridge making and positioning which is the bit I am least looking forward to. If anyone has any advice on how best to approach bridge making and locating, I'd be grateful for the pointers!

[ScottR]

Oh @Andyjr1515, Ash is calling you!

I must say, I had forgotten about this project. Good to see it again.

SR

[ADFinlayson]

1 hour ago, ScottR said:

Oh @Andyjr1515, Ash is calling you!

I must say, I had forgotten about this project. Good to see it again.

SR

well hold the phone! I made the bridge tonight.

I started by sanding my bridge blank down to 9mm, then I drew pencil lines to extend the next taper and marked on the bridge 3mm in from the lines (those denote the two Es), then I used my string spacing ruler to mark out the position of the other for strings and drilled 6x 4mm holes. and then I shaped the bridge with the bandsaw and the spindle sander. 

Then I nipped over to my dads and pinched a few of his electrical screws which worked perfectly for what I need 

Then I got the Mrs to hold the bridge steady while I drilled through the bridge holes into the body and screwed it down.

Then I cut a bone blank down short and fed two strings in through the sound hole, the 4mm holes are just small enough to stop the barrels coming through. Then I made a nut and put the two E tuners on and was able to check alignment and see where I needed to locate the saddle. This method worked but it was a bit awkward because the bridge saddle wanted to slide forwards under tension of the top E. but I was able to get some fairly accurate intonation with it and marked the front of my temporary saddle with the scalpel so I knew where I would need to route my saddle channel.

Then I MacGyvered up this little jig to route the saddle slot.

I had a couple of little wobbles on the first pass but that didn't matter because my bit was not big enough to do it all in one, once I was down to depth, I stuck a veneer on to my fence and went at it again and that removed my wobbles and made the slot just wide enough for my saddle blank.

I radiused my fretboard to 12" so I did the same thing with the saddle, rounded over the edges to match the channel and screwed the bridge back down.

Very happy with that! Action is a hair high for my taste and 12th frets air a hair sharp but I think it's all well within tolerance. I need to sand the base of the bridge to match the curve of the sound board so that might be enough action wise.

Now I just need to take it all apart, tidy everything up and throw some lacquer at it while I figured out how I'm going to glue the bridge down.

Chuffed!

[Bizman62]

17 hours ago, ADFinlayson said:

If anyone has any advice on how best to approach bridge making and locating, I'd be grateful for the pointers!

Here's a bunch of tools, starting with the locating gadget: https://youtu.be/4-H3kWbaYoc

And here's how he uses it. He tends to glue the bridge in place and rout the saddle channel afterwards but my logic says that your method of drilling locator holes works as well. https://youtu.be/8-V95KAfzvA?t=745

 

[Andyjr1515]

13 hours ago, ScottR said:

Oh @Andyjr1515, Ash is calling you!

The slumbering bow-legged dwarf  muscle-rippling giant opens his eyes and blinks at the bright summer light.  "Hmmm...I'm sure it was winter when I went for that nap..." 

 

Looking at the progress, I'm not sure that Ash needs any help from me

Couple or so of tips, though, spring to mind @ADFinlayson:

- It's quite important that the neck heel has the correct neck angle as well as the straightness.  Your method is pretty sound to check it, although be aware that the full tension of all 6 strings will tend to pull the top up a touch, and that also affects the action.  I think it would be worth adding the other two strings and pitching everything up a semitone or so above standard pitch and see if you are going to have enough saddle height to get the action where you want it.  If it's looking a touch high, then it's the same sandpaper flossing method, but this time both sides and pulling down to increase the angle while maintaining the straightness.

A decent double check is to lay a straight edge along the frets to the bridge.  The 'rule of thumb' is that the edge should just meet the top of the bridge.  It is again, however, just a rule of thumb because that can also be affected if you have a particularly flexible top that bows more under tension than 'the thumb's' average guitar 

- Handy tip ref carving the bottom of the bridge to the curve - use the 'engineer's blue' technique, but using school chalk.  Pop a wide strip of masking tape on the top, chalk it, then place the bridge and shuffle it up and down/side to side a few mm and then look at the chalk marks on the back.  Scrape/sand wherever there is chalk (ie the high spots) and repeat.  Keep repeating until the bottom is fully chalk covered.

 

But feel free to ignore all the above, as you seem to be making excellent progress under your own steam.  

Gosh...is that the time?  Must be time for a cocoa and another nap...    

[ADFinlayson]

19 minutes ago, Andyjr1515 said:

The slumbering bow-legged dwarf  muscle-rippling giant opens his eyes and blinks at the bright summer light.  "Hmmm...I'm sure it was winter when I went for that nap..." 

 

Looking at the progress, I'm not sure that Ash needs any help from me

Couple or so of tips, though, spring to mind @ADFinlayson:

- It's quite important that the neck heel has the correct neck angle as well as the straightness.  Your method is pretty sound to check it, although be aware that the full tension of all 6 strings will tend to pull the top up a touch, and that also affects the action.  I think it would be worth adding the other two strings and pitching everything up a semitone or so above standard pitch and see if you are going to have enough saddle height to get the action where you want it.  If it's looking a touch high, then it's the same sandpaper flossing method, but this time both sides and pulling down to increase the angle while maintaining the straightness.

A decent double check is to lay a straight edge along the frets to the bridge.  The 'rule of thumb' is that the edge should just meet the top of the bridge.  It is again, however, just a rule of thumb because that can also be affected if you have a particularly flexible top that bows more under tension than 'the thumb's' average guitar 

- Handy tip ref carving the bottom of the bridge to the curve - use the 'engineer's blue' technique, but using school chalk.  Pop a wide strip of masking tape on the top, chalk it, then place the bridge and shuffle it up and down/side to side a few mm and then look at the chalk marks on the back.  Scrape/sand wherever there is chalk (ie the high spots) and repeat.  Keep repeating until the bottom is fully chalk covered.

 

But feel free to ignore all the above, as you seem to be making excellent progress under your own steam.  

Gosh...is that the time?  Must be time for a cocoa and another nap...    

Thanks Andy, that all makes a lot of sense. I hadn't considered that the extra string tension might raise the soundboard slightly (potentially a lot because my soundboard is quite thin) so I will check that, although I am a little concerned about adding another couple of strings while the bridge is just screwed to the sound board with a couple of electrical screws. 

I'm quite happy with the alignment of both the feel and the fretboard joints to the body at this point and there is currently quite a lot of meat on the saddle with quite a tight angle over it to the string holes on the bridge, possibly too tight currently. So I think I'm going to crack on with finishing the neck carve and spraying the body. I think worst case scenario I should be able to tweak the neck angle again after assembly as it's a bolt on. 

Another question: what size should I drill the string holes on the bridge? and what do you use to ream them? I'm conscious that a stewmac reamer £80 and that feels like silly money, any cheaper alternatives? 

 

[Bizman62]

https://a.co/d/aCvS00y

How about that?

[ADFinlayson]

3 hours ago, Bizman62 said:

https://a.co/d/aCvS00y

How about that?

I have one of those and I think the taper angle is much too steep for bridge pins.

[Andyjr1515]

6 hours ago, ADFinlayson said:

Another question: what size should I drill the string holes on the bridge? and what do you use to ream them? I'm conscious that a stewmac reamer £80 and that feels like silly money, any cheaper alternatives? 

I use this one...and it's pretty much the only thing that they sell that isn't a bit eyewatering  :

https://tonetechluthiersupplies.co.uk/english/bridge-pin-tapered-reamer.html

It is, in fact, a standard 3-12mm Silverline 'Repairman's Taper Reamer'...but the infuriating thing about buying reamers is that they all seem to tell you the ream-diameter range...but not the length - so it is impossible to confirm that the actual taper is correct.

Anyway, I reckon that the Tonetech price is pretty decent and so for peace of mind, I'd go for that from them 

 

[Bizman62]

1 hour ago, ADFinlayson said:

I have one of those and I think the taper angle is much too steep for bridge pins.

That one looks just like the one @Andyjr1515 uses. As said, they don't tell the length! Tonetech tell the length of the blade, Amazon seems to tell a mix of the dimensions of the package and the tool: 9.88 x 4.88 x 3.5 inches!!! That'd be quite chunky considering that the narrowest point should be only 1/8"!

This one tells the actual measurements and it looks exactly the same: https://a.co/d/ca98pjy

To me going from 3 to 13 mm within a hair less than 10 cm sounds quite steep. So I took a ruler and a pen and did some drawing and measuring. So, at 2 cm the reamer would be about 5 mm thick and at 2.5 cm it would be about 6 mm. That's 1 mm within 5 mm which tells a ball point pen and a plastic ruler aren't accurate enough! The real change in diameter is about 10 mm within 100 mm which means a 1 mm change within the combined thickness of the bridge, top and the bridge plate (~10mm).

Out of curiosity I studied the subject a little and here's what I found: The bridge pins are tapered to either 3 or 5 degrees. How much of a change is that in thickness within a certain length? Well, then I found this calculator:  https://www.engineeringtoolbox.com/slope-degrees-gradient-grade-d_1562.html. Now if you put in the length of the blade (like 94 mm of the Beilay) and half of the difference between the smallest and the largest diameter ((13-3)/2 = 10/2 = 5mm) you'll get 3.04 degrees which is pretty close to 3 degrees! How much closer do you want?

 

[curtisa]

When I was doing the Yamaha FG 12 string refurb I found that the round rat tail file I had on hand had a taper that was a very close match to my bridge pins. By inserting the end of it into the bridge holes and spinning it backwards (as if trying to unscrew it) while keeping modest downward pressure on it the teeth on the file would ream the holes to match the taper of the pins. Maybe take a couple of bridge pins with you to the hardware store and eyeball them against some of their rat tail files and pick one that matches closely.

[Bizman62]

15 minutes ago, curtisa said:

Maybe take a couple of bridge pins with you to the hardware store and eyeball them against some of their rat tail files and pick one that matches closely.

Even further, use your calipers to measure the thickness at two points at a given distance and find a rat tail file that matches.

That is, unless your reamer by chance doesn't match your pins.

[ADFinlayson]

I have a round tapered second cut file that I think might just to the trick actually, thanks for the tip

[ADFinlayson]

Another little update from last night's activities - I wasn't a big fan of my bridge design so I took the pointy bits off, then I sanded the underside of the bridge to match the body.

Then I used some aquacoat to do a couple of coats of grainfiller on the back, sides and the walnut rosette, sanded the first coat back with 240, then sanded the second back with 320.

Then I reassembled and taped around the neck and the bridge, to make an outline that I could follow to tape off the fretboard area and the bridge area

You can see I taped just inside the outline by a couple of hairs, the idea is I am going to route a teeny tiny rebate on the underside of the bridge so that joint looks seamless.

Then I sprayed a couple of thin coats at lunch time.

Issues you may spot -  You can see just how misshapen it is around the end block, ebony binding and spruce is a nightmare and I've really struggled to get the dust out which is noticeable. The centre seam is a good few mm off the centre line of the bridge so the strings are a good few mm to one side of the sound hole So at this point I'm not too concerned about what it looks like, I just want to get to the end and take the lessons from #1 on to the next one 

[ADFinlayson]

I've made myself a crude neck clamping jig. Bit of cork to pad the sides and I'm coping I can screw the edges down while screwing the bridge down to the inside.

and sprayed some lacquer. It's be way too hot this last week, hasn't cooled down over night either so the workshop has stayed between 25-30ºC which has been a pain for spraying, there is a fine line between orange peel and runs. 

Then wet sanded with 600 and 1000

Followed by medium buff

Then carefully scored round the tape with a scalpel and pulled the tape. Took quite a bit of time to get rid of that orange hairline

And now the bridge is glued in 

So far so good but I've got a nasty feeling that my neck has got out of alignment between me testing it with the outer strings on and taping everything off for paint. Will see what it looks like tomorrow.

 

[ADFinlayson]

Works! There is a bit of a rattle which sounds like it's coming from the saddle which I need to investigate, fretboard is not currently glued down so could be that, could be that the string barrels aren't snug with the bridge plate or could just be that the action is set very low, needs some investigating.

[Andyjr1515]

That looks beautiful, Ash!

[Prostheta]

To me, acoustics have always been the prime example of how the right jig can massively improve all those very specific processes, whether it's bridge placement/drilling or the neck joint. Electrics are simple by comparison. Definitely a good rabbit hole.

[mistermikev]

21 hours ago, ADFinlayson said:

Works! There is a bit of a rattle which sounds like it's coming from the saddle which I need to investigate, fretboard is not currently glued down so could be that, could be that the string barrels aren't snug with the bridge plate or could just be that the action is set very low, needs some investigating.

nice... looking fwd to hearing it.