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PostPosted: Sat Nov 29, 2008 12:54 am 
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Location: Houston, TX
First name: Chuck
Last Name: Hutchison
City: Houston
State: Texas
Country: United States
Focus: Build
Status: Amateur
I located the bridge and drilled the holes and used the hollow bolts and nuts from Stew-Mac to hold the bridge on. Now it's time to glue the bridge on and I'm wondering how I can get the bridge in the exact location when I glue it down. I'm going to use the Stew-mac bridge clamp with a couple deep throat C-clamps.

How do I line up the holes perfect? Should I use the bolts and nuts to hold it down then use the bridge clamp? I'm also wanting to use hide glue so I'm thinking I will wasted precious seconds lining every thing up before clamping if I use them.

How do you guys do it?

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PostPosted: Sat Nov 29, 2008 2:40 am 
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First thing to do is several practice runs without the glue. You'll have about 45 seconds (but if you warm the bridge you can extend that to 1 min or slightly more). You'll find with the dry runs that it won't even take you 45 seconds to get it all done. Before you do any of this, sit down at your bench with a stopwatch or clock and just sit there for 60 seconds, you'll find it's a lot of time.

Have everything ready to go. Make sure you're clamps are at hand, and the locater pins are either in the bridge, the top or right at hand.

What size are the hollow bolts from stew mac? get some solid pins (I use 3/16" steel round bar) to match the size, make sure they are snug in the holes on the top, you don't want them to push down into the box when you're pushing the bridge down over them.

Here's how I would do it, ****again do this as a dry run several times first****.

With the locater pins in the top, make sure you can put the bridge on the pins pretty easily. You want this to take you all of 10 seconds or less. This is you're most important step so make sure you can do it without the glue on first.

Make sure you warm the bridge with a hair drier or heat gun so it's pretty warm to the touch.
Next apply your glue to the bottom of the bridge. Don't bother spreading it, just make sure you have the perimeter covered and several good beads running from one wing to the other.
Place the bridge on the top over the locater pins. Give it a good push down so you can see some glue squeeze out, just be careful not to push really hard.
Place the Stew-Mac bridge clamp on the bridge.
Put your first clamp into the soundhole and onto the bridge clamp. Apply some pressure from the soundhole clamp.
Snug down the wing clamps, just snug.
Work your way between the middle clamp and the wing clamps. You'll find that the wing clamps will be trying to lift up on the entire clamp so you want there to be more downward force from the middle clamp (soundhole clamp) versus the wing clamps.

Look for squeeze out around the entire bridge. Wait about 10 mins and the squeeze out will be relatively easy to clean up with a spruce stick chisel and a damp rag.

You'll find that this really doesn't take much more than 30-40 seconds.

Let us know how it goes. You can always warm the bridge again and pull it off and re-do if something goes wrong.

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PostPosted: Sat Nov 29, 2008 6:00 am 
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Walnut
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Location: Campobello, S.C.
Hi Chuck, Stew-Mac makes plastic locating pins just for what you are doing,http://www.stewmac.com/shop/Tools/Special_tools_for:_Bridges/Acoustic_Bridge_Locating_Pins.html,


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PostPosted: Sat Nov 29, 2008 7:37 am 
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Old Growth Brazilian Rosewood
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Location: Ann Arbor, Michigan
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Chuck my friend I use a Stew-Mac bridge gluing caul that I have added two holes to for the steel registration pins that I use to locate, and relocate the bridge during the gluing process.

Once I properly locate the bridge I drill through the saddle slot corners, top, and plate and pin it in place with the pins. Now I am also free to trace the bridge for masking during finishing as well.

Once the bridge is ready to be glued and with a few practice runs one pin is left in the preheated bridge while I butter it up with HHG. As soon as it is covered with a uniform layer of HHG I locate the mating hole for the one pin and drop the bridge in place and then quickly insert the second pin, cover with the caul, position the clamps and it's done - except for waiting for the glue to cure and cleaning up the squeeze out around the bridge.

What I like about this method is that I can pull the pins after the bridge is clamped, the glue has started to set, and the bridge remains clamped. It's much easier to pull the pins in about 5 minutes then struggling with them after the glue has cured.

With a little practice I can do this in about 20 seconds.

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PostPosted: Sat Nov 29, 2008 10:13 am 
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Brazilian Rosewood
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The short 1.4mm flat head nails from Ace are a squeak fit in a 1/16 drill hole and are great as bridge locating pins using drill holes in the saddle slot. Also try laying your heating blanket on the workbench, run it up to 150 or so and sit your bridge on it while you get everything else ready. Use plenty of glue so you see good squeeze out all around.
Terry

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PostPosted: Sat Nov 29, 2008 2:04 pm 
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Brazilian Rosewood
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If you're just looking for a way to consistently locate it to pre-drilled holes, you can pick up 3/16" nylon dowels (solid or as hollow spacers) at any decent hardware store. I use these for quick locating bridge plate patches with hide glue, though I usually just mark my bridge perimeters with tape (I also don't pre-drill any top holes though).

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PostPosted: Sat Nov 29, 2008 10:23 pm 
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Joined: Thu Jan 24, 2008 8:01 am
Posts: 1399
Location: Houston, TX
First name: Chuck
Last Name: Hutchison
City: Houston
State: Texas
Country: United States
Focus: Build
Status: Amateur
Hesh, I like the idea of using locating pins. Are those the pins from Stew-Mac? I'll be using this method on my next guitar.

David, for this project I'm going to go with your idea of using nylon dowels. Thanks for the hot tip. I have a bridge to glue on a friends guitar that has pulled loose.

You know what, it is really amazing at all the guitar and fiddle work out there. Since I've started building this guitar and letting my co-workers know, there has been no end to the repair work people have brought to me.

Anyway, THANK YOU everyone for all the responses.

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"After forty-nine years of violin building, I have decided that the search for a varnish is similar to the fox hunt. The fun is in the hunt."
Jack Batts Maker and Repairer of Fine Violins


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