Blocking a Floating Tremolo Bridge
Last time I talked about blocking an unused tremolo bridge to prevent it moving inadvertently. But there’s more to the story. What about fully-floating bridges?
Last week’s method requires at least one of two prerequisites:
The bridge base can be adjusted flat against the guitar top
In the bridge’s ‘zero position’, the front of the sustain-block makes a solid contact with the cavity wall facing it.
That’s not possible on many guitars. Sometimes the instrument and hardware mean the bridge has to float above the surface of the body and, in many of those cases, there’s a gap in front of the sustain-block to allow the player pull up on the whammy bar.
The gap at the front of the sustain-block is a problem when blocking a fully floating bridge.
Fully floating bridges in these situations will need two blocks. One behind, as explained last week, and another in front of the sustain-block. The two blocks wedge the sustain-block between them.
Fitting the blocks is more delicate here. Last time, we were able to just wedge in a block until we got a good tight interference fit. The sustain-block just pushed against the front wall and couldn’t go anywhere. When we’re using two blocks, we need them to insert with that same tight fit but, vitally, if they’re incorrectly sized, they can nudge the bridge balance one way or the other, upsetting its zero floating position.
Installing two wooden blocks can fix the bridge in the proper position.
Here’s what I recommend.
Measure the front gap—between the front of the sustain-block and its facing cavity wall. Stacked feeler gauges will usually do the trick, again with a known-size piece of wood if feelers alone aren’t enough.
Cut your front block as accurately as you can. This is an annoying job. You want to sneak up on the final thickness again but, because you’re trying to test-fit the block under the tremolo screws, it’s a pain in the ass. Keep at it. What you want is a really good fit for this front block—enough that it doesn’t throw off the tremolo balance but makes it impossible to pull up on the whammy when inserted. That requires some patience. Stick with it.
Because, if you get this fit perfect, you can afford to be a little more blasé about the rear block. Providing the front block stops the bridge from moving, you can wedge in the rear block.
Wooden blocks properly sized to fit in front and rear of sustain block, fixing bridge into the correct position.
To an extent. You’ll probably find that you won’t get it quite so tight as was possible last time. If the wedge-fit is too close, it can nudge the bridge up the posts as you insert the blocks. You’ll still be able to get snug enough that they blocks or bridge don't shift at all in normal use, though. You certainly don’t want them able to shake or vibrate loose.
When you’re all snug, tighten down those springs a little more and double check your bridge is floating exactly where it should. All going well, you should have a nicely secured bridge that still looks like it's floating freely.
This article written by Gerry Hayes and first published at hazeguitars.com
