# Fixing Rusted C-Clamps



## GoboMan (Nov 19, 2013)

In my theatre, we do productions every summer in an outdoor venue. Over the years, several of our c-clamps have taken some abuse from the elements and the main tightening bolts have become very rusted and are now very difficult to move. 

Is there any way to "repair" a rusted clamp and make it move more easily, or is it pretty much shot? Also, is there a way to prevent clamps from rusting in our future outdoor productions?


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## LavaASU (Nov 19, 2013)

GoboMan said:


> In my theatre, we do productions every summer in an outdoor venue. Over the years, several of our c-clamps have taken some abuse from the elements and the main tightening bolts have become very rusted and are now very difficult to move.
> 
> Is there any way to "repair" a rusted clamp and make it move more easily, or is it pretty much shot? Also, is there a way to prevent clamps from rusting in our future outdoor productions?



Is this just surface rust? If it's deeper then they may need to be replaced.


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## GoboMan (Nov 19, 2013)

LavaASU said:


> Is this just surface rust? If it's deeper then they may need to be replaced.



From what I can see, yes. It's basically the threading on the bolt and the grooves that are rusted. When I try to turn them, they are very resistant and make a horrible squeaking noise (like nails on a chalkboard). I haven't noticed any cracks or fissures in any of the bolts, though.


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## derekleffew (Nov 19, 2013)

From the collaborative article Lighting Fixture Maintenance:

> 29) The clamp is often neglected. Why do factory send a ½-13 grade 2 screw that&#8217;s only 3/4" long with the fixture? Hmm, loose 1/8" worth of lock washer, and another 1/8" worth of yoke and that&#8217;s only ½" worth of thread within the C-Clamp. Not enough nor a strong enough screw in my opinion. Even if 7/8" or 1", it&#8217;s still not long enough. Most C-Clamps will accept up to a 2" long screw, use it. Where possible, replace all C-Clamp bolts with at least a 1-1/2" long screw of Grade 5. No the grade 2 won&#8217;t break, but as you move up in grade you also move up in rust resistance.
> 
> Oil your screws and clamp. Oil without mechanical locking help might make something come loose easier but in this case you are using a lock washer so it&#8217;s not coming loose. While it is acceptable to use both lock washer and washer on a clamp, the lock washer is what is most important in preventing the bolt from coming loose.
> 
> ...



See also the thread C-Clampery, as well as other found by typing C-Clamp into the CB Search box.


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## Floobydust (Nov 19, 2013)

If it squeaks, it's repairable; get some high viscosity thread lubricant and give it a big dose on both ends.
Let it set for a couple of days and try again.
WHen you get it working again, make sure to get all the oil and fluids off the clamp before using it; the heat will make the oil smoke.

If it doesn't squeak, time for a new one.


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## venuetech (Nov 19, 2013)

WD40 to get the threads working. for clamps used only outdoors a Marine Grade Anti-Seize Thread Lubricant such as Loctite 34395 prevents rust on the threads (not recommended for your indoor clamps) but once you have the bolts loosened you should just lightly oil the threads on the bolts wipe off any excess (repeat foe each outdoor season) 

the loctite only works to twenty-below after that get the torch out


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## FatherMurphy (Nov 19, 2013)

I'd use WD-40 if needed to completely unscrew the bolts, then clean the threads of the bolts with a wire wheel on a bench grinder. If the clamp body's threads are so rusty that the bolts are still tight, chase the threads with the appropriate sized tap to knock the rust out.

The squeaking is rust particles causing chattering inside the threads. Clean threads rarely squeak, regardless age, wear, or thread fit percentage.

I'd steer clear of anti-seize mostly due to the mess factor - the Permatex anti-sieze I use on tractor restoration projects tends to easily get tracked and smeared everywhere, especially when a thick coating has been smeared on a bolt. Oils and WD-40 type sprays are easier to apply thinly.


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## derekleffew (Nov 20, 2013)

One member's thoughts on WD-40:

cdub260 said:


> I wouldn't worry too much over the life span of a c-clamp. About half of my c-clamps are 40+ years old and in excellent shape. Given that I'm at an outdoor venue, you would expect that rust would be an issue, but it hasn't been. As @icewolf08 mentioned, just make inspecting your c-clamps a part of your routine maintenance and you should be fine. What you're looking for is signs of bending and stress fractures from over-tightening in the "C" part of the clamp, and any damage to the threads on the bolts. An additional step that I take with my c-clamps is to periodically hit the threads with Tri-Flow, a spray lubricant, this lubes up my bolts and gives them some minimal protection from the elements, but has the down side of making the threads more susceptible to collecting dust, as dust loves to stick to oil. Do not ever use WD-40. While it has its uses, lubrication is not one of them despite any claims they make to the contrary.


I like White Lithium Grease for _most_ of my lubrication needs. 


> BARON (_To Baroness_). My dear, if you could spare this young wench for a few minutes, she could grease my riding boots.
> 
> BARONESS. Of course, my Lord.
> 
> ...


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## bishopthomas (Nov 23, 2013)

How many clamps are we talking about here? If several = 4-5 maybe just buy more. They're $11 at full price. I don't know about you, but the amount of time spent spraying, sanding, twisting..... My time is worth more than $11.


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## church (Nov 25, 2013)

WD40 is intended for displacing moisture not lubrication - the WD40 means Water Displacement formula #40. Apply a penetrating oil to the threads and let it soak for an hour or so then work the bolt backwards and forwards until it starts to move more freely. Then turn the bolt fully in and out a few times.


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## venuetech (Nov 26, 2013)

WD40 is a multi use product that lubricates, penetrates, protects and displaces moisture. its not for every application.but for this it would work very nicely. http://wd40.com/faqs/

you should protect from over spray with a rag and wipe off any excess when done running the bolt.


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## bishopthomas (Nov 26, 2013)

venuetech said:


> WD40 is a multi use product that lubricates, penetrates, protects and displaces moisture. its not for every application.but for this it would work very nicely.



Yes. I have used it for similar applications and it works quite nicely. Don't knock it till you've tried it.


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## MikeJ (Nov 30, 2013)

derekleffew said:


> One member's thoughts on WD-40:
> 
> I like White Lithium Grease for _most_ of my lubrication needs.



White Lithium is great, and you don't need a lot of it either. You can get it in a gun tube, squeeze tube, or spray can. I like the spray for a lot of things. Spray a little on, wipe off with a rag, that's all you need for most things.


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## cdub260 (Dec 2, 2013)

Lately I've taken to using my handy tap and die set to restore the threads on my more rust laden c-clamps.

First I remove the clamp from the fixture, then I disassemble it and lay the parts out on a rag. Next I spray tri-flow on the threads and then I use the die on the bolts and tap all the threaded holes. Finally I reassemble the clamp and put it back on the lighting fixture.

While it's a time consuming and labor intensive process, I've been much happier with the results than I was when I was just lubing up the clamps.


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## Kelite (Dec 4, 2013)

Made specifically for damp environments-

http://www.apollodesign.net/Products/View/4380.aspx

The aluminum Get-A-Grip c-clamp is the strong and durable method of hanging your fixtures. The stainless steel 1/2" -13x3" square head pipe mounting bolt, along with the interior "teeth" of the clamp, bite onto pipe sizes ranging from 3/4" - 1 1/2" and tubing of 1" to 2" OD.


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## shakescar (Jan 15, 2014)

http://www.instructables.com/id/restore-a-rusted-shut-tool/


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## Dionysus (Mar 17, 2014)

Personally hate WD40 for lubrication or rust prevention. So many thins that work better. 
The town I am from is home to the worlds largest salt mine, after working on the lights down at the beach for years I've found the perfect product is Fluid Film, plus it's all natural and food safe if that matters to you. Find that a spray and wipe every 6 months prevents rust even right beside the mines boat loading boom.
Great stuff, will remove rust and keep it away. Lubricates way way way better than WD40 too


Sent from my iPhone using Tapatalk


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## Jay Ashworth (Mar 17, 2014)

For things which are already rusted, I'm pretty fond of PB Blaster, which is what WD 40 probably should have been.

"Those who do not understand Usenet are condemned to reinvent it. Poorly." -- after Henry Spencer; [email protected]


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## Beans45601 (Mar 18, 2014)

Is it really worth fixing? Might be the time to look into getting some Megaclamps


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## RedGreenBlue132 (Mar 18, 2014)

Soak your clamps in a bucket of kerosene, that's what we did, but our clamps where hanging out in the salty ocean air for 6 months out of the year, so that might be over kill. Use vaseline on the threads or lithium grease. Re-paint the rest of the clamp once a year to protect it from rust.


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