Fixing a misaligned bridge

seangil · #1 01-27-2023, 12:09 PM

Advice sought...I tried attaching a bridge by drilling holes to use a Fox Bridge Clamp and attaching it with Titebond (original), but it came out off-square.

Any advice on where to go from here? I'm thinking that I probably have to remove the bridge, which is a bummer, but welcome opinions.

If I remove the bridge, then any advice on how to fill the holes most effectively? It is a sitka top with a maple bridge patch underneath. The bridge is zircote.

Thanks!

Skarsaune · #2 01-27-2023, 03:15 PM

It will have to come off if you want to change it's position / orientation.

Original Tite-Bond will come off with heat. I have shields made to isolate just a bridge, then a small halogen lamp to heat up just the bridge area.
Palette knives to separate the bridge. Work slowly and carefully so as not to damage the surrounding finish. Clean both surfaces of the existing glue.

Did you drill & ream the pinholes to final size? How far off-square are you talking? IE, just a smidge, half a hole, or completely out of whack?

redir · #3 01-27-2023, 03:40 PM

To fill holes I use a plug cutter and cut out a plug from laminated spruce and what ever the bridge plate material is. The plug cutter cuts the plug in a slight taper so glue it in such that the bridge plate material of the plug is flush with the plate. I do this in case the guitar needs a repair where the plate needs to be removed. That way you are not putting a dowel across the whole thing locking the plate in place. This is over kill for your personal guitar but a plug cutter is a good tool for the job and I would suggest you use spruce.

seangil · #4 01-28-2023, 02:45 PM

I think that one end of the bridge is 1/32" higher than the other and I may need to move the whole bridge forward about 1/32".

I wanted to get a tapered plug cutter, but Stewmac seems to be the only one that sells 3/16" plug cutters for a ridiculous $56. Any other sources?

phavriluk · #5 01-28-2023, 06:47 PM

Time out. 1/32" out of alignment is not a big problem to overcome. For playing, where the bridge is located is immaterial. Where the SADDLE is located matters. If OP's original saddle slot is not where it needs to be, it can be filled and a new slot cut in the right place. Factory saddles seem to be thin and don't allow much room for intonation or correction. 1/8" thick saddles are readily available and arr happier choices. Problem resolved. Bridge doesn't move, pins don't move.

If OP didn't locate the bridge with a pair of thin nails in drilled holes in the saddle slot, so it can't move around, next project is a good time to do that.

Fathand · #6 01-28-2023, 10:18 PM

I agree with Phavriluk, intonation adustments can be made at the saddle.

As for the 3/16" plug cutter, if you still need to move the holes, you can drill them to 1/4" and use a matching plug cutter. Your holes may already be larger than 3/16" from reaming the taper. You can try Harbor freight. https://www.harborfreight.com/plug-c...ece-60613.html

seangil · #7 01-30-2023, 09:12 PM

Sorry - my post was not specific. The saddle is out of location by 1/32". I considered re-routing the saddle slot, but I don't have a jig setup that would be appropriate for routing a bridge already glued onto the guitar. I also don't have ready access to power tools that could quickly make a jig with accurate lines. The current slot is 3/32" wide and angled properly for scale length if I put it in the right location.

I did try the technique of placing and then drilling holes/bolts for a bridge clamp. I am not quite sure where I went wrong, but I think a series of small mistakes added up to 1/32" in the final result.

Fathand · #8 01-30-2023, 11:00 PM

Quote:

Originally Posted by seangil

Sorry - my post was not specific. The saddle is out of location by 1/32". I considered re-routing the saddle slot, but I don't have a jig setup that would be appropriate for routing a bridge already glued onto the guitar. I also don't have ready access to power tools that could quickly make a jig with accurate lines. The current slot is 3/32" wide and angled properly for scale length if I put it in the right location.

I did try the technique of placing and then drilling holes/bolts for a bridge clamp. I am not quite sure where I went wrong, but I think a series of small mistakes added up to 1/32" in the final result.

Have you played the guitar and checked the intonation? I would do that before moving it 1/32", it might be good where it is.

I had a problem once where my bridge moved about 1/32" when installed. I placed the bridge and drilled 3/16" holes through the top and masked the top, then finished the guitar. When time came to glue on the bridge with my new bolt through clamp, the metric? bolts wouldn't fit through 3/16" holes. I re-drilled the two E string holes in the bridge with the next size up numbered bit, then the matching holes in the top and glued on the bridge. I wound up with a hair of unfinished top showing along the bridge. Because I drilled the bridge and top seperately, the drill must have wiggled slightly and put off the alignment. Next time I will drill them together, through the bridge and top at the same time. Lesson learned.

M_Piddly · #9 01-31-2023, 06:55 AM

Quote:

Originally Posted by redir

To fill holes I use a plug cutter and cut out a plug from laminated spruce and what ever the bridge plate material is. The plug cutter cuts the plug in a slight taper so glue it in such that the bridge plate material of the plug is flush with the plate. I do this in case the guitar needs a repair where the plate needs to be removed. That way you are not putting a dowel across the whole thing locking the plate in place. This is over kill for your personal guitar but a plug cutter is a good tool for the job and I would suggest you use spruce.

one needs to be sure they are acquiring a tapered plug cutter because traditionally the type that just cuts dowels is what is available at the local Borg