How to repair damage under the bridge

[tippie53]

This is more common than you may think , a bad repair , too many bridge reglues but at some point the damage needs to be addressed. As you can see that the bridge was thinned and the slot for the saddle ended up in the top

[tippie53]

The problems here were many. In fact I had to replace the bridge plate first You can see that looking in the pin holes. I needed to get a belly out of the top and with the new plate I had stability under this area. The next step was to fill the damaged areas. What you may not be able to see is how much wood was missing under the bridge..
I stated with making pieces to fill the voided areas. I then clamped them flat with a plastic cawl.

[tippie53]

I now needed to refill the missing wood under the bridge . There was a good bit and I had tried using dust to fill but found that technique never did well on a bridge. I cut some spruce and inlaid it into the lost area. Doing this in layers helps to add structure. The layers help much like plywood. You can also alter the grain direction.

[tippie53]

Now I have a stable and structural base. I then had to make a new bridge. I made the new one to fit the old footprint. I showed the high lights of the bridge making process. here is a link to making a bridge
viewtopic.php?f=5&t=4960&hilit=making+a ... ge+process

[Ben-Had]

Nice repair John.

[tippie53]

I received an email about this and I want to make an addition.

Most likely the damage is higher in the top and as you go into the top the wood will become more stable.

In this example I used plugs as the first veneer patch. In didn't alter the grain direction in this example but you may. I do about a 45 degree to the top grain. I like to fill the pin area and make them as tight as I can. Then the next layer will take out the more serious damage.

In really bad examples you may need to put a 3rd layer. If I need to do that I will want to work the layers so they are about .030 thick and I would do each one as I go , by that I mean
1 inlay glue sand down

In the glue process I have a cawl under and over the area and make it as flat as I can. Here tite bone HHG or any wood glue is fine. I try and avoid CA here as it may affect the wood for water based glues.

hope this helps and please ask any question you need. You can contact me anytime and I will be happy to answer any question you may have.

thanks agian guys and Gals
jh