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  #1  
Old 07-04-2020, 09:25 PM
scstill scstill is offline
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Default Belly Sag and Bridge Repair Vintage Washburn Parlor

I have had this New Model Washburn Parlor for many years and finally have decided to make it playable. The bridge was lifting (even with silk and steels) and the top has a belly sag of about 1/8".

I was able to remove the bridge using a thin spatula heated with an iron. Not too much wood lifted out. I used water to clean the glue off the bridge and smoothed the top with light sanding filling the low spots with #20 superglue. Its pretty much ready to reglue once I address the top. Would it have been better to use water to get the bridge off?

Do I need to do any repair to the peg holes on the top (it is smooth and fits well to bridge)? the grooves for the strings seem really wide and long;
Do I need to do any repair to the bridge plate? somehow there are gouges from hole to hole.

So now to the top...
Does the 1/8" sag need to be repaired?
The top has four parallel braces. One at the neck, two between the soundhols and bridge and one in the lower bout that is somewhat angled.
I have read about Thompson Belly Reducer tools, and like other hobbists It is very pricey for me.
Can the top be flattened without Thompson and without bridge doctor?
Did old school luthiers have any tricks?

I have pics but need to figure out how to add them. Is the only way to pictures is to add an internet link to the picture??

Last edited by scstill; 07-04-2020 at 09:37 PM.
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  #2  
Old 07-05-2020, 08:11 AM
oldduc oldduc is offline
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The early Washburns with the ladder bracing for the top were not made to be used with steel strings. They were strictly gut (nylon) string guitars. The tension of silk and steels is still too much in my experience. I have 1898, 1900, and 1906 models. I took the 1898 apart and replaced the ladder bracing with X bracing, and put a now top on the 1900, so that they would support steel strings. The 1906 had the top replaced before I bought it. There are really two options if you want the guitar to survive steel stings. You can put a tailpiece on the body and use the bridge like a "floating" bridge (glued, or not) or you can replace the bracing inside the body. Replacing the bracing will require that the top, or the back, be removed. They pretty much all require a neck reset, also. On my 1900, the top was trashed so I removed and replaced it. The 1898 had a really nice top, so I removed the cracked backed and repaired and replaced it after X bracing the top. 120 year old wood is difficult to work with and unless you are a somewhat skilled luthier, your best (and cheapest) bet might be to leave it alone and get another guitar.

Last edited by Kerbie; 07-06-2020 at 09:03 AM. Reason: Please refrain from profanity
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  #3  
Old 07-06-2020, 08:36 AM
scstill scstill is offline
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Here is a picture of the bridge plate
https://www.flickr.com/photos/189275...posted-public/

Holes are damaged and there is a split with missing wood between holes. I believe that this needs to be repaired to flatten the top and keep the strings seated right.

Seems that the brass BridgeSaver would work to repair the holes but doesn't seem that it would flatten the top. Thinking that bridge plate replacement is necessary to flatten top. This would be siginifacnt as the plate goes accross the top on one side. Or could I used the Thompson Belly Reducer heating technique?

Last edited by scstill; 07-06-2020 at 02:27 PM.
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Old 07-07-2020, 08:30 AM
oldduc oldduc is offline
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"Repairing" the bridge plate alone will not flatten the top. I have never seen a "BridgeSaver" so I don't know if it will work, or not. Heating techniques won't hold without additional bracing. If you want to use steel strings, either the top or the back will have to come off and have bracing added to the top and a new bridge plate, or as I said before, get a tail piece and just run the strings over the bridge and the bridge plate is then irrelevant. I have rebuilt a couple that had tailpieces added and they played ok, just not original looking. OR, just put nylon strings on it and play it and don't worry about it.
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Old 07-07-2020, 10:37 AM
JonWint JonWint is offline
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Only one photo found.

The bridge plate is not curved nor split. Repair the hole chip-out with glue and sawdust and redrill.

Post photos of top belly/sag with straight edge. 1/8" isn't excessive.

Silk and steel strings are not low tension. Martin Silk and Steels are 122 lbs and Extra Lights are 130. Classical nylons are 89 to 92 lbs.

I use Thomastik Infeld KR-116 steel rope cores (91 lbs tension) or steel Newtone NHS-010 (94 lbs) on my 19th century gut-string Martins.
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Old 07-07-2020, 06:57 PM
scstill scstill is offline
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Quote:
Originally Posted by JonWint View Post
Only one photo found.
The bridge plate is not curved nor split. Repair the hole chip-out with glue and sawdust and redrill.
Post photos of top belly/sag with straight edge. 1/8" isn't excessive.
Silk and steel strings are not low tension. Martin Silk and Steels are 122 lbs and Extra Lights are 130. Classical nylons are 89 to 92 lbs.
I use Thomastik Infeld KR-116 steel rope cores (91 lbs tension) or steel Newtone NHS-010 (94 lbs) on my 19th century gut-string Martins.
Here is a picture of the sag. I measure 1/8 at the deepest point. When I dry fit the bridge and saddle and straight edge to the nut I get very good a good 2/32 at the 12 fret. So don't think it is affecting playability. This hasn't been played for many years.
https://www.flickr.com/photos/189275...posted-public/

With glue and sawdust, could I use liquid hide glue or something else?

Bridge came off clean but wonder how I could fix the small top chips around the bridge?
https://www.flickr.com/photos/189275...posted-public/
https://www.flickr.com/photos/189275...posted-public/

What do you think about the following approach?
1) clamp heated aluminum plates to bridge and plate, allow to cool in effort to relax the small hump on the top under the bridge.
2) option - add a small maple plate in front (toward soundhole) of existing bridge plate to further reinforce top (will this help structually? Will it likely affect sound?)
3) Add a maple cap to the plate with grain running parallel to top. Would also cover #2 if that is added
4) Fix chips on the top that occurred as bridge was removed. Should I leave or touch up with amber varnish? Then polish
5) Reglue bridge
6) string with Thomastik-Infeld Plectrum extra lights (AC110 are ~92lbs by my calc)

Last edited by scstill; 07-07-2020 at 07:42 PM.
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  #7  
Old 07-07-2020, 07:36 PM
scstill scstill is offline
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appreciate all the great ideas
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Old 07-07-2020, 07:37 PM
scstill scstill is offline
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Quote:
Originally Posted by oldduc View Post
"Repairing" the bridge plate alone will not flatten the top. I have never seen a "BridgeSaver" so I don't know if it will work, or not. Heating techniques won't hold without additional bracing. If you want to use steel strings, either the top or the back will have to come off and have bracing added to the top and a new bridge plate, or as I said before, get a tail piece and just run the strings over the bridge and the bridge plate is then irrelevant. I have rebuilt a couple that had tailpieces added and they played ok, just not original looking. OR, just put nylon strings on it and play it and don't worry about it.
Thank you for the great ideas. I do not want to add a tail piece though. Trying to keep as close to original as possible. And I love the original bridge (pic provided in another reply). Nylon will be my last resort.
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  #9  
Old 07-08-2020, 07:26 AM
JonWint JonWint is offline
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Quote:
Originally Posted by scstill View Post
Here is a picture of the sag. I measure 1/8 at the deepest point. When I dry fit the bridge and saddle and straight edge to the nut I get very good a good 2/32 at the 12 fret. So don't think it is affecting playability. This hasn't been played for many years.
https://www.flickr.com/photos/189275...posted-public/

With glue and sawdust, could I use liquid hide glue or something else?

CA is harder. I use medium viscosity.

Bridge came off clean but wonder how I could fix the small top chips around the bridge?

Drop fill with shellac or lacquer with some tint.

What do you think about the following approach?
1) clamp heated aluminum plates to bridge and plate, allow to cool in effort to relax the small hump on the top under the bridge.

Usually recommended if bridge is rotated more than 2 degrees. Doesn't look too bad.

2) option - add a small maple plate in front (toward soundhole) of existing bridge plate to further reinforce top (will this help structurally? Will it likely affect sound?)

Not needed. No visible damage.

3) Add a maple cap to the plate with grain running parallel to top. Would also cover #2 if that is added

Not needed.

4) Fix chips on the top that occurred as bridge was removed. Should I leave or touch up with amber varnish? Then polish

Drop fill with shellac or lacquer with some tint. Black perimeter lines look like oxidized wood. Could be bleached with oxalic acid.


5) Reglue bridge

Don't remove splinters from bottom of bridge. They will lock into the top.

6) string with Thomastik-Infeld Plectrum extra lights (AC110 are ~92lbs by my calc)
I'm not a luthier and my recommendations may have the same value as their cost to you.

Last edited by JonWint; 07-08-2020 at 07:43 AM.
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  #10  
Old 07-08-2020, 07:57 AM
scstill scstill is offline
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For CA and sawdust, should I mix a paste then apply?
In addition to filling the top, should I also apply to the bridge plate?
Do you drill after the bridge is reglued?
How to cut the string slots (pins are solid)?

BTW - any thougts on a source for hardwood sawdust? I live in SoCal so not many shops here.

It's too late for the bridge splinters. Already cleaned botton of bridge with water and CA filled and smoothed the bridge area of top. Was thinking to use pins to align for gluing.

The bridge slopes away from the saddle where the pins are so unless there is a clamping trick, I will need to make a special angled top caul.
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  #11  
Old 07-08-2020, 10:08 AM
JonWint JonWint is offline
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Quote:
Originally Posted by scstill View Post
For CA and sawdust, should I mix a paste then apply?

I place dust, add glue, stir in-place.

In addition to filling the top, should I also apply to the bridge plate?

I thought that's what we doing? Tape bridge plate and fill chip-out from above.

Do you drill after the bridge is reglued?

Yes, how else would you match holes?

How to cut the string slots (pins are solid)?

Same as always; saw and file. https://www.stewmac.com/luthier-tool...and-files.html

BTW - any thoughts on a source for hardwood sawdust? I live in SoCal so not many shops here.

You don't have one scrap of wood? CA glue will make softwood dust hard. Go to Home Depot and grab a handful from their cutting area?

It's too late for the bridge splinters. Already cleaned bottom of bridge with water and CA filled and smoothed the bridge area of top. Was thinking to use pins to align for gluing.

OK if you remove pins after clamping. Make sure to measure for correct saddle location (scale length) before regluing.

The bridge slopes away from the saddle where the pins are so unless there is a clamping trick, I will need to make a special angled top caul.
………………………………...
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