Ultimate Guitar Repair » Blog Archive

Regluing a Back Plate

March 31st, 2010

Re-Gluing a Guitar Back Plate
Source: Guitar Plate Repairs

Re-gluing a Back Plate:
For repair purposes, I’m assuming you have removed the back plate of the guitar already. I not, read the article on Guitar Back Plate Removal for information on how to remove it.

Tools and Materials Required:
Surface Sander
Sanding Sticks
Filament Tape
2-Part Epoxy Glue
Titebond III Glue
Spool Clamps
Wooden Cam Clamps

Getting Things in Shape:
If the reason for the removal was a major repair inside the guitar, double check that the repair is perfect and you are ready to assemble the back.

If the guitar back plate had an arch to it, determine what the rise is by placing a straight edge on the back plate and measuring at the edge.

Now grab a Surface Sander and shim it at the riding edge (opposite of the sanding edge) 2 x the dimension of your arch height measurement.

Carefully sand the back lining to receive the back plate. If there are any pieces of the lining missing carefully cut them out, with a sharp chisel, and glue in new pieces. Note: usually if you take the lining out in small sections you can make for a better looking job.

Cleaning The Back Plate:
Clean off the back plate, where it attached to the linings and head and tail blocks. Use sandpaper on a Sanding Stick and sand with the grain. Progress from 120 grit to 220 grit. Finish up with 000 steel wool.

Dry Fit The Back Plate:
Lay the mating surfaces back together and place a Wooden Cam Clamp on the Head Block and on the Tail Block. Make sure you use wood cauls with protective cork on the face of them and that they are sized to cover the surface of the blocks beneath.

Check All Alignments:
Check all of your alignments to be sure that everything is in place and aligned perfectly. Check all of the edges, where the back meets the sides. Are all of the joints perfect as they were when you took the binding off? If not check to be sure there are no obstructions and re-clamp. If necessary, bend the sides inward or outward and place a few Spool Clamps into position to make sure everything fits.

Make All Your Preparations:
Prepare your Clamps. Make sure your spool clamps are ready for instant use, are properly opened and you have enough of them to span the entire guitar perimeter.

Check to see you have your (2) Wooden Cam Clamps with the required cauls for the head and tail blocks.

Grab a roll of masking tape and cut about a dozen strips, each 4″ long. Have them ready to go too.

Glue:
If you are gluing an exotic wood back plate, you will want to use the slow set one hour epoxy glue. Mix the glue immediately prior to starting the gluing operation. If the plate is made from a non-resin sourced wood, you can use Titebond III.

Spread the glue over the linings and the tops of the block only. Use a thin piece of veneer to get the glue even. Clean up any spill over now, before to apply the plate to the guitar.

Set The Plate In Place:
Now take the Back Plate and drop it into place. Align the Plate over the Tail Block and place a piece of masking tape to the side and pull it over the back and adhere it to the back. Do this at the opposite block, at each waist and each bout.

Now take your Wood Cam Clamps and cauls and carefully clamp the Head Block and Tail Block areas. Check the alignments and adjust as necessary.

Take a Spool Clamp and clamp the waist. Make adjustments to the sides by applying pressure to align the surfaces. Now do the same with the opposite waist. Do this with each bout, both upper and lower. Now it is time to re-check everything. Make sure all edges are lined up and the back plate is seated properly. If you have excessive glue squeeze out, you used too much glue. Clean up as best you can.

Now apply spool clamps shoulder to shoulder all the way around the perimeter, checking that everything is lined up as you go. When done set aside to dry overnight.

Remove all clamps and tape and inspect your work.

Assembly of wood or plastic bindings will be the subject of another article. Finish touch-up will be covered elsewhere as well.

Ultimate Guitar Repair Tip: If you have an exceptional fit between the mating surfaces, do not hesitate to use tape to set the back plate. You can use masking tape with 3 to 4″ long strips. I prefer to have a drafting tape dispenser screwed to the side of my work bench so I can quickly dispense tape from it. If you want a stronger solution, use Filament Tape, where you can apply a lot more downward pressure.

Just start on the back plate surface, hold the plate into correct alignment with one hand and apply a downward pull with the tape and adhere it to the side of the guitar. Do this at about 4″ intervals around the whole guitar and then come back and fill-in. If you have a stubborn place, just apply more tape or use a helper clamp like a spool clamp.