Sanding wedges?

[melandy]

So I'm building a 000 from a kit, and I'm to the part where I need to level the kerfing. The directions say that I need a 5 degree wedge and a 1.5 degree wedge to attach to a sanding board to get the angle correct on the sides to match te curvature of the top and back.

 

I don't have a bandsaw, which I suspect would make this an easy task. I started cutting the 5 degree wedge with a hand saw... not going all the well. The angle is coming out very approximate.

 

Anybody got any tips?

 

Thanks,

-A

[gitnoob]

I think this is the point when most people decide to invest in a couple of radiused sanding dishes -- they're also useful for radiusing the braces and as a caul for gluing the braces.

 

Do you have a plane? To make the wedge, I'd rough cut it with a saw and then plane it to perfection.

 

If you don't have a plane, a rasp and file should get you there as well.

[10ae1203]

you could cut close to the line and sand if you do not have a plane. sand on a table. put the paper on the table sandy side up.

 

if you have a crappy handsaw you will have a hard time sawing to a line.

 

a good hacksaw will not cost nearly what a good handsaw will, and will work well enough for your needs.

 

a good coping saw could do the same.

[Freeman Keller]

For my first several builds I made some radiused clamping cauls at about 16 and 25 foot radius. However I did use a bandsaw to make them. A saber saw would work almost as well. I also used the cauls to clamp the braces to the top and back, finally broke down and made some radius dishes. You could also lay it out and just put a shim on one side of a sanding stick.

 

Here is a picture of what I used - I would be happy to make a couple for you if you would like. It is sitting upside down on the guitar while I am checking the head block

 

[melandy]

 

Here is a picture of what I used - I would be happy to make a couple for you if you would like. It is sitting upside down on the guitar while I am checking the head block

 

 

Hey Freeman, that would be awesome! I'll PM you my snail mail address.

 

For the others that posted on this thread, thanks for the tips. I do have a hacksaw and a plane... I'll probably use the hacksaw to finish that 5 degree cut that I started and clean it up with the plane just for the experience, but I definitely trust Freeman's handiwork better than my own.

 

Thanks again everyone!

-A

[Freeman Keller]

I'll try to get them done tomorrow and in UPS but it might not happen until later in the week. I'll make a 16 and 25 - those are pretty generic radiuses and should be close enough for most work.

 

I checked out your blog and its looking good. Personally, if you are using the outside mold I wouldn't worry about the inside - that will just get in the way. You've seen Neils and mine with the spreader - that works pretty well. When I make a mold (another use for a band saw) I keep the inside cutout pieces and use them to make the waist spreader - glue two together so they are about 1-1/2 - 2 inch thick, chisel a depression and use a turnbuckle to expand it.

[guitarcapo]

While it might seem less accurate, you can get decent results with by hand with a regular flat sanding block. You just hold it at a small angle and sand. Any variation is usually overcome by the clamping pressure joining the back (or front) to the sides.

[melandy]

Personally, if you are using the outside mold I wouldn't worry about the inside - that will just get in the way. You've seen Neils and mine with the spreader - that works pretty well.

 

I noticed that it was going to be impossible to get the inner mold out once I got the second set of kerfing on, so I made some cuts to make it a 4 piece mold instead of a two piece mold. This changed it from "impossible" to "cumbersome".

 

I'll probably make a couple more cuts to convert it to a waist spreader... or just make a new one from scratch depending on where I made that first set of cuts.

 

And Freeman, please don't worry about timing on sending me the cauls... beggars can't be choosy!

 

Thanks again,

-A

[Freeman Keller]

I noticed that it was going to be impossible to get the inner mold out once I got the second set of kerfing on, so I made some cuts to make it a 4 piece mold instead of a two piece mold. This changed it from "impossible" to "cumbersome". I'll probably make a couple more cuts to convert it to a waist spreader... or just make a new one from scratch depending on where I made that first set of cuts. And Freeman, please don't worry about timing on sending me the cauls... beggars can't be choosy! Thanks again, -A

 

Even with a waist expander it is important to test that it will come out thru the soundhole or maybe you'll end up adding a side port or two.

 

The sanding caul is turning into a neat project - I'll post some pictures

[melandy]

 

Even with a waist expander it is important to test that it will come out thru the soundhole or maybe you'll end up adding a side port

 

 

that makes entirely too much sense. While that would have been obvious in hindsight, I could easily see it biting me in the arse instead.

[Freeman Keller]

 

that makes entirely too much sense. While that would have been obvious in hindsight, I could easily see it biting me in the arse instead.

 

 

Let me tell you about the time I thought I would just stick the bridge plate clamping caul on with a little double sticky tape (wait till you start wrestling that SOB around thru the sound hole). Three c-clamps can't apply all that much pressure, eh? Let me tell you about trying to work a spatula blade between the caul and the bridge plate, breaking it (the spatula) - all this thru the soundhole on a parlor (so you have even less working room). That was one of the reasons the KBK Bridge Caul got invented.

 

Or when I made the Weissenborn and put a little wedge in the square neck to hold the sides spread - at the last minute I thought "hey dumbie, tie a string on that puppy so you can get it out". Or the one I'm working on now - I told myself 16 times to put the side marker dot in the fingerboard BEFORE I glued it on, sure enough I had to make an extra long bit to drill the holes over the top when I forgot. Or.....

 

One of the things you will learn about this building game is that you often wake up in the middle of the night thinking "how am I going to do xxxxxx" Dry run everything you do - you'll have a lot less teeth marks in your old hind end.

[tim Mcknight]

The problem with using tapered sanding sticks to level the kerfed lining to the sides is that you must rely on the sides to be an exact match to the back and or top radius. You can get it close but you can also induce a lot of stress into the glue joint if you clamp (ie force) the top or back to an ill fitting rim profile. If you are certain that the rim shape is an exact match to the top and back radius then you have no worries. This logic certainly builds a good case for using a dish of the appropriate profile.

[Freeman Keller]

 

The problem with using tapered sanding sticks to level the kerfed lining to the sides is that you must rely on the sides to be an exact match to the back and or top radius. You can get it close but you can also induce a lot of stress into the glue joint if you clamp (ie force) the top or back to an ill fitting rim profile. If you are certain that the rim shape is an exact match to the top and back radius then you have no worries. This logic certainly builds a good case for using a dish of the appropriate profile.

 

 

That is a good point, Tim, but for most of us buying or making two radius dishes for our first build it a pretty big expense. The radiused cauls are much easier to make and you can use them both to back up clamping the braces on (one brace at a time) and for sanding the rims. I used them on my first couple of builds and finally broke down and got dishes.

 

Here is a really cool trick for gluing braces without a radius dish, it doesn't work for sanding

 

http://www.kennethmichaelguitars.com/contourtool.html

 

Also, if you make two of the cauls like I am going to do for Melandy you can easily make the sled for routing a radius dish. I'll talk about that when I do the write up about the cauls (been out of town and haven't had a chance to make them y et)

 

Also, I agree 100 percent about building any stress into the guitar. Its pretty easy for that to happen with the back because of the compont curve - both the doming from side to side and the fact that it is thinner at the neck block. Even the upper bout top can be stressed depending on whether you choose to flatten it for the neck extension or not.

 

btw - good to see you on our little group

[tim Mcknight]

Good counterpoints Freeman. Sometimes my thought process is geared towards building more than one at a time Thanks for the welcome BTW. Its been far too long since I visited here too...