HD28 Kit - First Build

[Rick S]

I have my sides in the mold. The sides meet nicely but barely at the neck joint with about 3/8 inch overlap to be dealt with at the tail block. I have my lines drawn on the side where I need to make the cuts.

[tippie53]

The key to setting up a kit ( yes you may need to trim it ) but before you cut it open the mold and but the sides together and allow the mold to close . You want to see the waist just come up a bit off the mold. You then use the spreader to set the waist against the mold.
The sides will set against the mold tightly. There is a line here so you want to see about 1/8 inch rise off the waist. Watch the side set as you tighten the spreader and you want to see the side set close against the mold sides.
If you do need to trim use the mold as your center line . The tail piece will cover the joint. Make sure you mark true center for your top and back . Also mark the center line on the neck block using the neck to mark the center . The neck block may not have the mortise on true center.

[Rick S]

The key to setting up a kit ( yes you may need to trim it ) but before you cut it open the mold and but the sides together and allow the mold to close . You want to see the waist just come up a bit off the mold. You then use the spreader to set the waist against the mold.
The sides will set against the mold tightly. There is a line here so you want to see about 1/8 inch rise off the waist. Watch the side set as you tighten the spreader and you want to see the side set close against the mold sides.
If you do need to trim use the mold as your center line . The tail piece will cover the joint. Make sure you mark true center for your top and back . Also mark the center line on the neck block using the neck to mark the center . The neck block may not have the mortise on true center.

Excellent tip John. I tried this and it solved my problem with needing clamps and a third hand to tighten the spreader. When I open the mold, but the ends together and then re-close the mold, the gap at the waist increased to about a half inch so I think a little trimming is called for. My lines I have drawn would trim a little over an 1/8th from each side.

[Rick S]

7/30/2011

I still have a few more days before I can start gluing anything up so I'm taking measurements and dry fitting things. I have a concern about my X bracing. Everything I've read and seen suggests that the joint at intersection of the X brace should fit snug. My X brace joint fits fairly loose but yet the angle of the joint is preventing the braces from laying out on the bracing template drawn on the top by a fairly good margin. I'm sure I can sand more wood off of the joint to allow them to lay out in position but it seems to me way too much wood has been removed. Is it common for the X braces to start out this way or is there something wrong with the joint on my braces?

The X bracing now magically matches up perfectly with the pre-drawn guide lines on the top. I'm not sure what I did differently but it looks like it will work now.

[Rick S]

August 4, 2011

My razor saw came in the mail today so I was able to trim about 1/8 inch off of each of my sides at the tail block. Used John's technique to load the mold as follows:

1. Open one end of the mold
2. But the end of the sides together in the mold
3. Close the mold and look for the sides to raise at the waist 1/8 inch.
4. When the proper gap at the waist is reached with the mold closed, tighten the spreader to close the gap at the waist.

To start, I trimmed off less than what I thought I would have to and then checked. I'm glad I played it safe. It fit snug on the first cut and i wouldn't have wanted any more trimmed.

Next step is to radius the top and bottom of the rims. I watched John's bending sides and setting the geometry videos again. My approach to radius the top and back will be as follows:

1. Use a 16 foot radius concave radiusing dish with my version of John's radiusing jig to pre-radius the back. Radiusing the back seemed straightfoward enough. Center the mold and rims in the jig and lock the mold down with dowel pins. Mark the top with chalk and drive the bus until the chalk is removed evenly.

2. True up the top by using a sanding disk on the flat side of my 28 foot radius disc. Mark with chalk and drive the bus. After sanding, check four points around the mold to make sure that the gap between the bottom of the sanding disc and the mold is the same all the way around.

3. After truing up the top, start planning out the geometry. Divide the top into three sections - 1) Bridge to tail end, 2) Bridge to end of fretboard, 3) neck joint to end of fretboard. 1) and 3) are both domed or initially radiused with a 28 foot radiusing dish leaving the middle section 2) flat. Apply chalk and drive the bus. When done, use the flat disc to flatten the radius of the rim at the neck. (Question: is this the step that eliminates the 14th fret hump?) After flattening this area, press down on the disc at the neck and check to make sure that the disc raise up about an 1/8 inch above rims at the tail block.

If anyone sees where I'll be messing things up with the above process, please let me know. I'll take some pictures along the way and post them. I'd like to get quite a bit done this weekend. I won't get completely done as I need one more sanding disc that I didn't realize I'd need for the flat side of my 28 foot concave dish.

Thanks!

[tippie53]

that is part of it. This is all about setting the side for the top geometry.

[David L]

Please correct me if I'm wrong Ken (or anyone else), Ensuring that a gap does not exist between the bottom of the fretboard and the top of the soundboard will not guarentee the elimination of the 14th fret hump, other things can cause this. Remember, I haven't even completed my first guitar so if I'm wrong I'm willing to take my licks, so when you chastise me for being wrong, please do it in the most kindest manner!

David L

[deadedith]

David, you are wrong and you are an idiot. Please never post again as you cannot understand the most basic principles and I'm surprised you are even allowed around power tools. You will never build a successful instrument or become anything in life at all. I'd feel sorry for you if I did not find you to be loathsome, worse in morals than Jack the Ripper, and deserving of everlasting humiliation.

There! The worst is over!! It is my gift to you.

(All lies, of course, if anyone was wondering :-))

[David L]

Dave B, Thank you so very much from the bottom of my heart! I was so afraid and worried that someone was going to banish me to burn in the eternal condemnation of hades (trying not to break the rule of no religious posting). Had you not been so considerate of my feelings I probably would be contemplating suicide right about now, and by the way, you were probably correct about most of the things you posted, however, the thing that you were most accurate about is that I should never be allowed in a room containing power tools!

David L

[Rick S]

Well friends, it finally happened. My first major, and I do mean major, oops. I cracked one of my sides when it was in my mold. While taking a measurement from the neck end to the tail end so that I could locate where to drill holes for the dowel pins in my radiusing jig, I bumped the top of one of the sides. I heard something akin to an earthquake, a loud clap of thunder or some other catastrophic act of God. I looked down and there was a crack about an inch and a half long where my sides meet at the tail end. The crack started about a half inch below the top of the rim and angled up slightly.

After my initial negative reaction, I thought I can fix this. After all, I've seen about every youtube video on guitar making and repair. I can do this. I've seen cracks in sides fixed many times with super glue. Little did I know at the time but I was just about to make things worse.

I had a plan in mind. The side hadn't snapped back in place yet so my plan was to apply super glue to the exposed crack and then snap the wood back in place and apply pressure until firmly glued in place. I don't know if it was a bad plan or just poor execution but I ended up with a chunk of my side firmly glued to my finger totally separated from the rest of the side.

It took a couple of tries but I finally got the chunk glued back in place. I scraped off the excess glue and lightly sanded the area. The crack is nearly invisible. I'm confident (but i've been confident before) that if I can get the sound box to the final sanding and finishing step it will never be seen.

I do have a couple of concerns. First, even though I did the final glue up on a flat surface, the side is not perfectly flat. My concern is that the side will recrack from the clamps when I glue in the tail block. If I manage to get past the tail block procedure, my second concern is that the crack will tear out when I route the channels for the bindings.

A couple of posts back in this thread there were some pretty colorful adjectives used to describe and berate in good fun a particular poster that questioned one of our resident experts. All of these apply to me at the moment for sure. I'm definitely an idiot.

Do I have some wood for my fireplace?