Rusted parts

[Spectrobassman]

Hello guys,

I hope you can help.

I've got a bridge that has saddles and screws all stuck in one position. They don't move. I've tried wd40- nothing happens. I think some water got into it or some sort of lubricant. I've given it to a luthier, he couldn't do anything, however mentioned to try and deep the bridge and knobs in coca cola for 24 hours. Luthier said if that doesn't work you need to buy a new bridge and knobs.

Any advise you can give to reincarnate that bridge and screws? Also screws in the knobs?

I've attached the photos.

 

[Beej]

I'd be soaking that in a little plastic tub with PB blaster for a few hours. That has never failed me.

 

[JRA]

I'd be soaking that in a little plastic tub with PB blaster for a few hours. That has never failed me.

i hadn't heard of "PB blaster" until your post, beej, so i googled it --- and google also led me to this "kroil" stuff:
https://www.kroil.com/?gclid=CjwKCA...AIsHT5HW6fm2vCAIC5p9LiFw9IgYnxMBoCCCkQAvD_BwE

any good? TIA

 

[Slidlow]

I de-rust parts for my antique cars in vinegar. Very cost effective.

 

[Beej]

I've never used Kroil so can't speak to it, but PB works well as a penetrant to get frozen parts apart quickly.

 

[dwizum]

I like lube/solvent based approaches (PB blaster etc) for rusty things with delicate fasteners. Like saddles with screws in them. Or acid based (cola, vinegar, phosphoric acid) for stuff that's less delicate and just needs to not be rusty.

 

[JRA]

thanks, @Beej.

i would never have thought to use vinegar, either, @Slidlow.

i learn something every time i read a thread in LC. you cats are "ornery good!"

 

[bholder]

I read somewhere about using an ultrasonic cleaner with some sort of solvent, but I forget what the solvent was...

 

[WI Short Scaler]

When I first got my Fender MM, parts looked like this too, tuners and bridge.

I tried coke on one tuner. Worked but then I realized I had to do it again in vinegar to clean the sticky sugary cola out it. Maybe diet coke would have worked but vinegar is easier.

 

[RichterScale]

Don't use cola. It's the citric acid in cola that dissolves the rust and breaks it free from the surface.
Any acid will work. Household white vinegar is perfect. It's cheap and safe to use.
If I wanted to save that bridge, I'd soak it in vinegar over night. If that doesn't completely break it free, I'd heat up the barrels with a little butane torch and/or try using something as a hammer and give it a few good whacks, like a screw driver, large allen wrench, etc. Sometimes just a good whack will break it free. But that's a small area to work in.
Once you get the screws out, soak all the parts overnight in vinegar again.
Try to clean up the surfaces as best you can and just make sure everything is bone dry before reassembling.
Are you having it replated, or do you just want to clean it up and get it functional?

 

[RichterScale]

You can also buy a bottle of CLR and soak it in that overnight.
Just make sure you wear gloves with that stuff. It's a lot more hazardous to you than vinegar, but will probably work much quicker.

 

[Bruce Johnson]

I have many years of experience with Kroil, and it's the best product I know of for penetrating and freeing up rusted parts. I've never tried PB Blaster, but I hear that it's a similar product.

Soaking in vinegar also works, as RichterScale describes, for generally removing rust.

If I'm handed a bridge with rusted screws, I'll spray it with Kroil and let it soak a bit. Then carefully get the screws out without damaging the bridge. Clean out the threads with taps and replace the screws. If you are in a very humid environment, put a dab of anti-seize compound on the threads of the new screws.

 

[dbsfgyd1]

Hello guys,

I hope you can help.

I've got a bridge that has saddles and screws all stuck in one position. They don't move. I've tried wd40- nothing happens. I think some water got into it or some sort of lubricant. I've given it to a luthier, he couldn't do anything, however mentioned to try and deep the bridge and knobs in coca cola for 24 hours. Luthier said if that doesn't work you need to buy a new bridge and knobs.

Any advise you can give to reincarnate that bridge and screws? Also screws in the knobs?

I've attached the photos.

I would not soak in Coke, but a good penetrating oil for a day or two or until they free up might help.

 

[RichterScale]

I'll have to find some of that Kroil stuff and give it a try.
Most of the rusty stuff I've dealt with was larger scale, so a hammer and a torch usually did the job.
I've only used vinegar and CLR to dissolve the rust off of small parts a few times, but never to get tiny parts separated. Based on what I saw the CLR do to the rust on some skid plate bolts from under my truck, I'd say an overnight soak in it would certainly work on this. The only thing I'm not sure of is what it would do to the plating, or whatever that bridge is coated in.

 

[Pings Bass]

When I did band instrument repair i used stuff from Ferree's (band repair suppler) simply called "corrosion cracker." Basically industrial strength solvent. Probably really bad to breathe the fumes, but it never failed me.

(I'd go with the vinegar suggestion first though, cheaper and safer on multiple axes.)

 

[WarwickE36]

PB Blaster or GM heat valve lubricant are my 2 faves and I deal with this on a MUCH bigger scale every day. PB blaster is easy to get. GM heat valve lube is sadly a challenge but it's the best IMO (you can call your local GM/Chevy dealership.

 

[Slidlow]

The great thing about vinegar is the acetic acid reacts with iron oxide to create ferric acetate. Ferric acetate can be used to stain woods especially walnut and other tannin rich woods. So you get clean parts and wood stain to boot.

 

[T_Bone_TL]

You can order Kroil direct from Kano Labs, or most any well-stocked metal-work place, and your better auto parts places. I bought a gallon, it's far less expensive than the spray cans per volume, and it lasts just fine.

PB Blaster is considerably easier to find retail.

WD-40 is great if you need to displace water, but not a penetrating oil at all. Good for your 1950's distributor cap that stops working in the rain, but misused a lot.

Citric acid is generally preferred for acid-based rust removal - other acids work, but it has a good balance of hazard level, how dire the consequences are if you leave it too long and speed of working.

Electrolysis with washing soda and a battery charger (or other low volt supply - has to be a "dumb" battery charger, not a clever one) will derust things you wouldn't believe could be derusted, but if it's that rusty there can be fit issues from loss of metal anyway.

 

[JuanB]

Another vote for PB blaster. I've used that stuff on car work (exhaust manifold studs/nuts) which is much more extreme in terms of corrosion than your bridge.

 

[farace]

I've read comparative testing on penetrating oils, and I believe that it rated Kroil slightly ahead of PB Blaster. Kroil can be tough to find on shelves. However, even better rated was a homebrew mix of 50/50 automatic transmission fluid and acetone. Only problem is that it separates and needs to be shaken before use.

WD-40 was never meant to be used as a penetrating oil. No idea why people think it is. It's lousy for that. It was developed as a water displacement (hence the WD).

For rust removal I love Evapo-Rust. It won't affect paint or finishes, and won't eat through your skin.