Bridge dents

[FiddleMkr]

I’ve played my fiddle too long in the white resulting in dents in the spruce that is the size of the bridge feet. The dents are slightly deeper at the back than the front but not much. I only noticed that the fiddle wasn’t sounding good anymore. A view from the side revealed that the bridge was bowed backwards, instead of being flat on the rear surface with a 1 degree backwards lean, that was my initial set up. 
      The question is what to do.  
       I’ve tried putting water in the dents to let them swell up. This helped but there is still some residual dent left. I also worried that the fibers may be broken and using water will only be a very temporary fix at best.  
       My next idea was to finish the fiddle (varnish it) and then when the varnish is hardened to try and fill the dents with something and then level it all up before making a new bridge and fitting the feet to the top. But I didn’t know what to use. I got some advice to try fingernail polish. I did buy some quality clear fingernail polish but I’m concerned about it dissolving the (oil) varnish. 
      What are your recommendations? 
      What is the best thing to use as a filler of dents (on a varnished instrument)?  Can I use clear spirit varnish? Will that stick to oil varnish and since it dries fast I can get multiple coats on relatively quickly?
       Is fingernail polish useable with oil varnish or is the solvent for both the same, or too close?
       And is there a way to fix it before varnishing in a way that it doesn’t show afterwards? 
Thanks 

[Michael Darnton]

Put a pad of damp paper towel, maybe 5 layers about 20mm square over one spot, heat up a spoon on your stove, press the spoon down lightly right where the depression is to create steam. Repeat once or twice.

If that doesn't do it, don't worry about it.

[FiddleMkr]

6 hours ago, Michael Darnton said:

Put a pad of damp paper towel, maybe 5 layers about 20mm square over one spot, heat up a spoon on your stove, press the spoon down lightly right where the depression is to create steam. Repeat once or twice.

If that doesn't do it, don't worry about it.

Good idea. Thanks

why would you not worry about dents under the bridge feet? Wouldn’t that make fitting the feet nearly impossible? 

[Michael Darnton]

Virtually every older violin has such dents and has had a bridge fitted, so it's probably not impossible. :-)

[nathan slobodkin]

7 hours ago, FiddleMkr said:

Good idea. Thanks

why would you not worry about dents under the bridge feet? Wouldn’t that make fitting the feet nearly impossible? 

Most old violins have dents or dammage under the bridge feet. Fitting bridges to them is standard procedure for any repairman.

[HoGo]

I use ordinary clothes iron or soldering iron to steam out dents. Wet paper towel folded in half and gently apply tip of iron. The paper may burn a bit on surface but it won't affect wood (I mostly use it on dents on damaged finished instruments and most varnishes or lacquers can handle it if you keep the towel wet and use only second-long touches) repeat as many times as necessary moving the towel to fresh wet spot after each touch. New wood responds well to this. Don't do this anywhere near centerjoint if you don't want to unglue it.

[FiddleMkr]

8 hours ago, HoGo said:

I use ordinary clothes iron or soldering iron to steam out dents. Wet paper towel folded in half and gently apply tip of iron. The paper may burn a bit on surface but it won't affect wood (I mostly use it on dents on damaged finished instruments and most varnishes or lacquers can handle it if you keep the towel wet and use only second-long touches) repeat as many times as necessary moving the towel to fresh wet spot after each touch. New wood responds well to this. Don't do this anywhere near centerjoint if you don't want to unglue it.

Thank you!
 That should work really well on this unvarnished instrument. 
    And If I’m reading correctly, you also use this technique on varnished instruments? (I see now that is what you said.) 

     Since we’re on the subject; if you have a dent that you cannot get out using an iron, do you fill it with something? Or do you just fit the bridge feet the best you can? (I use a grease pencil and knife but it requires moving the bridge a little. It seems to me that because you have to move the bridge to get a mark that part of the feet won’t fit when you’re done. ?)

Edited June 24 by FiddleMkr
Added last question

[HoGo]

It's common technique on guitars and I've used it on mandolins (with oil and spirit varnishes). There's always possibility that delicate finish will get slightly damaged but so far I at worst got some haze that either lost after day of drying or after some french polishing. On most guitar lacquers you can steam out quite safely, just never touch the finish dry. And always lightly. I believe your dents will go completely away as they are just pressure marks and wood is bare and allows steam do it's job. Very light sanding or scraping should get you back to clean surface.

Here is article that covers it: https://www.frets.com/pages/vb7i32xw/Steaming-Out-Dents.php

[FiddleMkr]

12 hours ago, HoGo said:

It's common technique on guitars and I've used it on mandolins (with oil and spirit varnishes). There's always possibility that delicate finish will get slightly damaged but so far I at worst got some haze that either lost after day of drying or after some french polishing. On most guitar lacquers you can steam out quite safely, just never touch the finish dry. And always lightly. I believe your dents will go completely away as they are just pressure marks and wood is bare and allows steam do it's job. Very light sanding or scraping should get you back to clean surface.

Here is article that covers it: https://www.frets.com/pages/vb7i32xw/Steaming-Out-Dents.php

Thank you! 
I got a lot of the dents out with just water (wet towel ) but I have an iron that I can use on top of the wet paper towel and I feel this will take out what’s left.

      Have you ever had to use a filler? 
      If so what did you find to be most effective? 

[M Alpert]

Many shops use Deft as a clear varnish filler. It is acetone-based and dries rather quickly compared to alcohol-based spirit varnishes. Some say it is similar to clear nail polish, but I have not experimented to find the similarities/differences.

Evaporated thick sandarac varnish (just sandarac in alcohol) also works, but dries slower. As with the others, in this case I would steam it and go on with life...

[FiddleDoug]

55 minutes ago, M Alpert said:

Many shops use Deft as a clear varnish filler. It is acetone-based and dries rather quickly compared to alcohol-based spirit varnishes. Some say it is similar to clear nail polish, but I have not experimented to find the similarities/differences.

 

Deft was somewhat of a "go to" but has fallen out of favor in some areas. It was used more as a crack filler, rather than a pit filler. In any case, that was the"old" Deft. Several years ago, the company was sold. The new company still still produces Deft, but the new formula isn't even close to what the old formula was. I haven't tried the new stuff.

[M Alpert]

7 hours ago, FiddleDoug said:

Deft was somewhat of a "go to" but has fallen out of favor in some areas. It was used more as a crack filler, rather than a pit filler. In any case, that was the"old" Deft. Several years ago, the company was sold. The new company still still produces Deft, but the new formula isn't even close to what the old formula was. I haven't tried the new stuff.

Good to know. I'm not sure, but I guess we have the new deft, we keep buying it from a supplier in Germany. Still works better than anything else we have found...

Why has it fallen from grace?

Besides being clearly synthetic, which some see as a mortal sin. It's quick, functional and removable...

[M Alpert]

At least in Europe, numerous big-name restorers still use it and espouse its use...

[HoGo]

I try to fill with matched and fitted piece of wood whenever even slightly possible. I don't think I've used filler in my life on instrument.

I use thicker filler varnish only over glued cracks when the crack edges miss tiny bit of wood.

[Brad Dorsey]

4 hours ago, M Alpert said:

…Why has [Deft] fallen from grace?…

Some restorers have commented on this forum that they don’t use it because  it continues to shrink over time.

[M Alpert]

7 hours ago, Brad Dorsey said:

Some restorers have commented on this forum that they don’t use it because  it continues to shrink over time.

Oh, I see. But so does touch-up varnish, in my experience...

In fact, in my experience, sandarac/shellac/mastic spirit varnish, in typical formations, shrinks quite a lot over a few weeks, and dries slowly, making long turn around times on repairs. Deft on the other hand dries relatively quickly to a state from which it shrinks quite little over time... And this fills quicker, when such is necessary. Though I agree with @HoGo we don't usually fill unless it really looks bad without it!

Most of our customers are working players and don't like to leave their instruments for long- they rather bring it back for a little more touch-up if necessary.

But good to know there wasn't some worse reason not to use deft (I hope!)

To each his/her own...

[Nick Lewis]

20 hours ago, FiddleDoug said:

the new formula isn't even close to what the old formula was

They claim it is. Any experience otherwise? I've been taking the Iris Carr retouch course and was looking for Deft and could only find this stuff, so I asked if she had experience. She still has her old Deft, but commented that other restorers she knows have been using it fine. I unfortunately don't have experience with the old stuff, but I am getting tired of the long wait times for my filler varnish to really dry. 

[Michael Darnton]

I want to comment that a lot of people I know gave up Deft a long time ago, back to using spirit varnish. Irreversibility and adhesion of subsequent retouch, too long shrinkage period. Thers a lot to not like. I find that varnish levels much more easily also.

[Mike_Danielson]

Suggestion--forget Deft.  Go to your artist supply store and look at water-based varnishes--these should be very high solids content.  You can lay these into place with a very thin brush--they dry very rapidly which means the shrinkake wil take place very rapidly.  Do as many coates as necessary to get a build above the surface.  

[FiddleDoug]

15 hours ago, Nick Lewis said:

They claim it is. Any experience otherwise? I've been taking the Iris Carr retouch course and was looking for Deft and could only find this stuff, so I asked if she had experience. She still has her old Deft, but commented that other restorers she knows have been using it fine. I unfortunately don't have experience with the old stuff, but I am getting tired of the long wait times for my filler varnish to really dry. 

 

You definitely don't want the spray stuff!

The old Deft was a 100% Nitrocellulose lacquer. The new stuff has a significant portion of the nitrocellulose replaced with an alkyd resin. The solvent profiles are also quite different. This info can be found by looking at MSDS sheets.

[Nick Lewis]

3 hours ago, FiddleDoug said:

The old Deft was a 100% Nitrocellulose lacquer. The new stuff has a significant portion of the nitrocellulose replaced with an alkyd resin. The solvent profiles are also quite different. This info can be found by looking at MSDS sheets.

Good point, now I'm curious about all this! 

13 hours ago, Mike_Danielson said:

Suggestion--forget Deft.  Go to your artist supply store and look at water-based varnishes--these should be very high solids content.  You can lay these into place with a very thin brush--they dry very rapidly which means the shrinkake wil take place very rapidly.  Do as many coates as necessary to get a build above the surface.  

I started experimenting with this UV cure stuff: Clean Armor Classical Instrument 830 - UV Curable Buffable Topcoat Top Coat — Avant UV Coatings. Even better, it's almost instant cure, and zero shrinkage because 100% solids. I know a big part of retouch is reversibility, and this only has a mechanical reversibility once it's cross-linked. But I mostly work on student instruments, and the shop doesn't want to pay me hours and hours of labor to fix a student rental, so all my amateur "retouch" I try to finish in under an hour. So far I love how fast it cures and it scrapes really well, but doesn't adhere super well to under coats, and it's thin so it's hard to apply a bead. Next I'll try this stuff: Clean Armor Classical Instrument 837 Repair Paste — Avant UV Coatings

[FiddleMkr]

On 6/26/2026 at 12:11 PM, Nick Lewis said:

Good point, now I'm curious about all this! 

I started experimenting with this UV cure stuff: Clean Armor Classical Instrument 830 - UV Curable Buffable Topcoat Top Coat — Avant UV Coatings. Even better, it's almost instant cure, and zero shrinkage because 100% solids. I know a big part of retouch is reversibility, and this only has a mechanical reversibility once it's cross-linked. But I mostly work on student instruments, and the shop doesn't want to pay me hours and hours of labor to fix a student rental, so all my amateur "retouch" I try to finish in under an hour. So far I love how fast it cures and it scrapes really well, but doesn't adhere super well to under coats, and it's thin so it's hard to apply a bead. Next I'll try this stuff: Clean Armor Classical Instrument 837 Repair Paste — Avant UV Coatings

I was going to post about my “new find” clean armor paste Classical instruments 837, but I see you beat me to it! 
   I haven’t tried it yet and it doesn’t look like I’ll need it. Water and heat took most of the dents out. There may be a slight dent remaining on one side but I think I can work with it.

      Thanks everyone for all your help!

[Nick Lewis]

I tried the 837 for the first time today. I'll write up my thoughts once I've worked with it a bit more. 

[Will Turner]

On 6/22/2026 at 9:07 PM, FiddleMkr said:

Good idea. Thanks

why would you not worry about dents under the bridge feet? Wouldn’t that make fitting the feet nearly impossible? 

Chalk fitting the bridge is not a problem with dents, using the “non-recommended” method of sanding the feet with a jig would be difficult with the dents.

[LCF]

On 6/27/2026 at 1:41 AM, Nick Lewis said:

Good point, now I'm curious about all this! 

I started experimenting with this UV cure stuff: Clean Armor Classical Instrument 830 - UV Curable Buffable Topcoat Top Coat — Avant UV Coatings. Even better, it's almost instant cure, and zero shrinkage because 100% solids. I know a big part of retouch is reversibility, and this only has a mechanical reversibility once it's cross-linked. But I mostly work on student instruments, and the shop doesn't want to pay me hours and hours of labor to fix a student rental, so all my amateur "retouch" I try to finish in under an hour. So far I love how fast it cures and it scrapes really well, but doesn't adhere super well to under coats, and it's thin so it's hard to apply a bead. Next I'll try this stuff: Clean Armor Classical Instrument 837 Repair Paste — Avant UV Coatings

I love that it's available in 4 litre flagons. That should keep you going for a while.  

 

It probably resembles clear 3d printer resin, which is UV cure and can be brush-dipped on and re-arranged in a dimly lit room then zapped with a handheld uv torch, and has high build.