re-topping an Hippner 8 string with a falcate spruce top.

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johnparchem
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re-topping an Hippner 8 string with a falcate spruce top.

Post by johnparchem » Sat Jul 11, 2015 9:07 am

A player that I know had a very damaged Hippner 8 string guitar. He had two accidents with it and had destroyed the lower bout of the top. He thought it a total loss so I asked him to bring it over.

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I pulled it apart, all and all it looks very nicely made and is in good condition other than the top. The WRC top was amazingly thin at 1.1 mm. It had a spruce lattice bracing. It probably sounded great but it was a little fragile as a gig guitar.
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The top was a total loss. I thought about trying to keep the old bindings\purflings because the linings that support the top were wide enough. I ended up pulling them as my top was a mm thicker than the old. I would have needed to drop the new top in. I have matching koa bindings that I can use as a replacement.

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The insides looks good. I got the fret board off cleanly so I will be able to reuse it. There were some cracks in the sides that were repaired, with the top off I cleaned up those repairs and make them more permanent. I also had to fix a few other side cracks.

I currently have the instrument re-topped and I am in the process of french polishing the top. I did use a falcate pattern, the molds I have for my Hauser guitars worked fine. I also followed tomigv suggestion and used CF under a 1 mm bridge plate.

To add a bit more lateral stiffness I built A new BRW bridge with CF laminated in the block a mm below the top of the bridge.

To match the geometry of the original guitar I built the top in my solera that is dished out for a 25' radius.

Here a few pictures

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Basic brace pattern with bridge plate. (a cut down version of the SS bridge plate form the book.

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Used my solera in a gobar deck

I was able to match the Koa bindings and BW purfling no problem
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Built the bridge in my handy classical bridge making tool. A simplification of the jig in the book. I cut the wings with a razor saw and a band saw and then used a rasp to shape them.

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I still have about .6 mm to remove from the bottom of the bridge so the weight will still come down
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The French Polish is getting close.

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Right now the top is tapping at 194 Hz, a little lower than I hoped at this point.

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Mark McLean
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Re: re-topping an Hippner 8 string with a falcate spruce top

Post by Mark McLean » Sun Jul 12, 2015 9:57 pm

Well, that thing really was a mess but you have done a beautiful reconstruction. It looks very pretty with the spruce top. Nice job in matching the bindings, and bringing all of the other elements together.
I am building a falcate nylon at the moment (only 6 strings I am afraid) so I am interested to look at how you executed it. I was not intending to use a bridge plate for a nylon string, but I know that some classicals are made with them, I presume for more cross-grain stability. What was your thinking on that? Is the fact that it is 8 strings, and a longer bridge, a factor in the decision?
Great work - I bet that the original owner is thrilled.

Mark

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kiwigeo
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Re: re-topping an Hippner 8 string with a falcate spruce top

Post by kiwigeo » Mon Jul 13, 2015 8:08 am

Mark McLean wrote: I am building a falcate nylon at the moment (only 6 strings I am afraid) so I am interested to look at how you executed it. I was not intending to use a bridge plate for a nylon string, but I know that some classicals are made with them, I presume for more cross-grain stability. What was your thinking on that? Is the fact that it is 8 strings, and a longer bridge, a factor in the decision?
Great work - I bet that the original owner is thrilled.

Mark
Hi Mark,

My first falcate classical had a bridge patch but the current build doesn't. If you build a Gore style bridge you have two layers of CF that mean the bridge is plenty stiff enough without a bridge plate.
Martin

johnparchem
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Re: re-topping an Hippner 8 string with a falcate spruce top

Post by johnparchem » Mon Jul 13, 2015 8:13 am

kiwigeo wrote:
Mark McLean wrote: I am building a falcate nylon at the moment (only 6 strings I am afraid) so I am interested to look at how you executed it. I was not intending to use a bridge plate for a nylon string, but I know that some classicals are made with them, I presume for more cross-grain stability. What was your thinking on that? Is the fact that it is 8 strings, and a longer bridge, a factor in the decision?
Great work - I bet that the original owner is thrilled.

Mark
Hi Mark,

My first falcate classical had a bridge patch but the current build doesn't. If you build a Gore style bridge you have two layers of CF that mean the bridge is plenty stiff enough without a bridge plate.
I normally do not have a bridge patch, I added it for the extra tension of the 8 string. Given that I had a patch I put CF under it and built a bridge with one layer of CF a couple mm from the top of the bridge, the way Trevor shows for the SS bridge.


Today I glued on the fret board, sorry I did not take pictures and installed the bridge. I normally use locator pins but I glued some K&K pickups on the bridge plate, and did not want to drill through them with locator pins. So I set the bridge carefully, using scale and compensation measurements and boxed in the location with tape. With the bridge taped down. I traced the profile with a scalpel and cleared out the shellac from the bridge location. Here are some pictures.

I still have finish touch up and surprise, none of my saddle blanks are long enough for an 8 string saddle. But it looks like the re top came out looking ok.

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Re: re-topping an Hippner 8 string with a falcate spruce top

Post by johnparchem » Wed Jul 15, 2015 6:22 am

I did a tap test with the finish and the bridge on, although I know in a classical the extra stiffness can actually raise the resonance of the top I was surprised that it went up nearly 10 Hz. With this tap test I ended up with 203.6 Hz for T(1,1)2 up fro 194Hz; T(1,1)1 = 107Hz and T(1,1)3= 149Hz.

I need to wait a few days for the finish to cure and I have a set of strings on the way. I am excited to hear how it sounds.
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kiwigeo
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Re: re-topping an Hippner 8 string with a falcate spruce top

Post by kiwigeo » Wed Jul 15, 2015 8:37 am

T(1,1)3 249 rather than 149Hz?

The bridge patch plus the CF in the bridge would be adding a fair bit of stiffness to the top.
Martin

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Re: re-topping an Hippner 8 string with a falcate spruce top

Post by johnparchem » Wed Jul 15, 2015 8:59 am

Yes thanks for the correction; 249 for the back.

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Re: re-topping an Hippner 8 string with a falcate spruce top

Post by johnparchem » Mon Jul 20, 2015 10:11 am

I strung her up and she sounds pretty good. So far I am using the original nut and saddle unchanged. I need to take about a MM off of the saddle, to nail the action. I think my bridge slot was not quite as deep as the original bridge. I also need to take a bit off of the nut slots. I am going to wait a few day to let the top settle in on a tonerite before I finish the setup.

With strings, T(1,1)1 ended up at 101 Hz T(1,1)2 is at 193 Hz and T(1,1)3 is at 243 Hz pretty close to my target.

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