Crack & Brace Repair
Source: Screw Jack Brace Repair Method
Repair a Loose Braces With Screw Jacks:
Tools and materials Required:
3″ Screw Jacks:
20 gage Hypodermic Needle:
Titebond III Glue
Mechanics Inspection Mirror
LED Work Light
Wooden Cam Clamps:
You have found a loose brace or loose braces and have clearly marked their locations. Now, the time has come for the repair process to stop the buzzing or to restore the strength back to the top or back plate.
Gluing the Brace:
Insert your LED Work Light and Mechanics Inspection Mirror inside the guitar after string removal.
Fill the 20 Gage Hypodermic Needle with Titebond III Glue and stick the needle between the plate and the brace and squeeze a liberal amount of glue into the crack. Now press the brace into place with your fingers and with the inspection mirror make sure that there is glue squeeze out on both sides of the brace for the entire length of the separation.
Ultimate Guitar Building Tip: You can pick up a Hypodermic at our link here. Use a needle with a Gage of 20 to 22 which will give adequate opening for the glue to flow. Other gages can be used if these are not available and you will need to find what works best for your use. They are very inexpensive so a variety of needle for different glues an be on hand.
Next sand the sharp tip off the needle so you don’t stab yourself.
Finally slip a section of electrical wire plastic insulation over all but about 1/4″ of the top of the needle and find a plug to fit into the tip so the glue does not dry.
Screw Jack Method:
These are small cast iron jacks you can pick up at a well stocked hardware center. They are about 3″ tall and extend out to about 4-1/2″ or so, depending on the make and model you purchase.
To repair a crack you need to determine what type of caul you will need on the top of the screw jack. It should be a small piece of wood shaped to fit over the brace to be glued to minimize damage to the top of that brace. Like the wooden jacks above, keep a supply of different shaped cauls to fit the profile of the brace you will be repairing. Also countersink the caul where to top of the jack fits into it, to hold it in place with a dab of glue.
Likes and Dislikes: What I like about the Screw Jack is it’s ability to adjust height through a wide range of guitar depths and minimizes the need for shims etc. to accomodate different height requirements. What I don’t like about the screw jacks is they often conflict with braces on the opposite plate, making it difficult or impossible to position the jack accurately.
Applying the Pressure With Screw jacks:
With the use of Screw Jacks – follow this procedure:
- After the glue in applied and the light and mirror is in place, fit the jack into position and “snug” it up to it is putting a slight mount of pressure on the brace and the opposite plate.
- Next Fit a Wooden Cam Clamp over the Guitar Plates, directly over the Screw Jack location and snug the clamp up enough to it stays firmly in place. If you find you are depressing the plates slightly, remove the cam clamp and apply a little more pressure on the Screw jacks.
- Now you should be able to apply more pressure on the cam clamp. (Refer to the diagram at the top of this article).
- Next take a small metal scraper and carefully clean the glue squeeze out from the guitar plate and the side of the brace. Follow up with a wet cloth.
- Set the guitar aside to dry overnight.
- Carefully remove the Wooden Cam Clamp and the Screw Jack in reverse order so the Screw jack does not damage the interior of the guitar.
Note: The other method of repairing a loose brace with with Wooden Jacks. Refer to the Article Repair Loose Braces With Wooden Jacks, for the methods using that tool.
Tags: how to repair guitar buzzes, repair braces, repair loose braces, repair loose braces with screw jacks
