Mueller Electric Blog

Mona Weiss

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How Well Do Marine Clips Hold Up In Saltwater?

Posted by Mona Weiss on Mar 1, 2018 11:58:49 AM

When selecting a clip for an application, there are often environmental considerations that may affect the clips over time. One of the toughest environments is a marine environment where there is a lot of moisture and salt which corrodes many types of metal. 

I performed an experiment with our 46 series clips to see how well the marine clip actually withstands a salty marine environment. 

We already know that Stainless Steel and Copper both hold up in a marine environment pretty well, but how well? One of the primary uses for clips is for safety and electrical/grounding applications, so it's important that the clip holds up well and works the way it's supposed to. Clips that cannot hold up in a marine environment would need to be replaced often, which also adds a cost consideration. 

Stainless Steel and Copper are both excellent choices for a marine environment and the main difference when selecting a clip that is right for you would be if you need to solder to the clip. Stainless steel is nearly impossible to solder a wire to. Copper is easily solderable. In most cases the 46M (M for Marine) would be the clip of choice because of that soldering capability. 

Now onto the experiment!

The Setup:

I took 1 of each of the following clips and I put them in a plastic ziploc bag partially filled with with salt water to simulate a wet salty environment with both water and air. Salt water corrodes metal five times faster than fresh water does and the salty, humid ocean air causes metal to corrode 10 times faster than air with a normal amount of humidity.

I documented the changes in the clips over time with exposure to that environment. 

An introduction to the different clips taking part in this experiement:

BU-46A :  Copper Plated Steel with a Steel Rivet and Spring

BU-46C : Solid Copper with a Steel Rivet and Spring

BU-46X : Stainless Steel with a Stainless Steel Rivet and Spring

BU-46M :  Copper with a Stainless Steel Rivet and Spring

Note - these clips can also come with insulators. For the purposes of this experiment, none of the clips are used with insulators.  

Here's an image of the clips before they go into their salty environment - tops and sides. 

Clip Starting Lineup.jpg Clip Starting Lineup Tops.jpg

Day 0 (January 4th 2018): the clips were placed in their respective ziploc baggies with salt water. 

Day 1: There are some changes already! Baggies 2.jpg

The 46C bag shows green discoloration in the water from the salt reacting with the steel rivet, but the clip itself looks ok. The water in the 46A clip bag has taken on a slightly yellow tinge. No change in the 46M or 46X. 2 clips.jpg

 Day 5:

The bag with the BU-46C is pretty funky looking from the steel spring and rivet corroding. The BU-46A is also looking funky but not quite as much.  The BU-46M has a slight green tinge to the water as expected with copper, but the stainless steel rivets are not corroding. The BU-46X is looking fine!  

Clip Lineup Day 5.jpgbag lineup day 5.jpg

I took the clips out of their bags for a photograph. The two on top are the ones with the steel rivets that are corroding due to the salt, which is causing the discoloration that is coating the copper.  

 Day 8

Notice that 46 C appears to have less corrosion on it - that's because I photographed it lying on the other side. Since I have them lying on their sides in these baggies, the side with more air exposure seems to look worse. 

I also photographed them on their edge - the water line is more apparent. 

clip lineup day 8.jpg

 

You can also see the steel spring in 46-C is really starting to corrode. For comparison you can see the stainless steel spring in the 46M is holding up just fine. 

corrosion in spring of 46-C comparison1.jpg

 

Day 11

There's quite a bit going on in these bags. 46A and 46C have a lot of corrosion in the water. 46M's water has a green tinge from the copper, and 46X - the stainless steel one has clear water. 

Salt_bags_corrosion.jpgclip lineup Jan 15.jpg

Here's the clip lineup. The 46C has a ton of crusty corrosion on the side - this was the side that was in the water. It seems like the crust is coming from the rivet. Below is a closeup of the clip so you can see this corrosion. It's starting on the 46A but much worse on the 46C.  Compare with the stainless steel rivet on the 46M.

clip corrosion closeup.jpg

 

 

Day 14

Let's take a look at the bags. The reflection on the plastic makes it a little hard to read what's what. The top photo is the 46A and 46M clips. You can see the rust and corrosion in the water of the 46A. The 46M has a greenish tinge from the copper. 

The lower image is the 46C and 46X. The 46 C is also full of rust. No change in the 46X. 

clip bags.jpg

clip bags 2.jpg

Next, I took them out of the bags to photograph. The 46A has this black line going across the rivet - that's some crusty corrosion. 

clip lineup day 14 ss.jpg

Here's some up-close photos to look at the corrosion. 

First is the 46A - it appears that black crusty corrosion is coming right out of the rivet. It breaks off really easily. I have tried very hard to keep as much of it in place as possible but the slightest touch makes it crumble off. The spring inside is totally fused with rust. 

46 A corrosion side and back 2.jpg

Next is the 46C. There's so much rust and corrosion on the inside. This didn't take long to form at all. There's similar crustyness near the rivet that chipped off as I was removing it from the bag. 

46C corrosion.jpg

Next is the 46M. This is the copper with stainless steel rivet and spring. The outside actually looks rather pretty. It is starting to get a patina but it isn't crusty and gross. The spring and rivet are in excellent shape. 

46M.jpg

I was a bad scientist and forgot to photograph the 46X up close - mostly because there's no changes at all. It looks the same as when I first put it in its bag. It is entirely stainless steel and isn't corroded. 

Day 18

Its getting harder and harder to keep the board clean that I'm photographing these on. When I remove them from the bags to photograph I have some paper towels that I use to gently dry them off, but even when they are decently dry, they will still leave a mess when they touch the white board. 

clip lineup day 18.jpg

Day 25

The 46C fell apart. When I went to take it out of the bag, the rivet was gone. 46 c corrosion.jpg

Of course now we need to take a look at the other springs more closely. On the left is the 46X, the middle is the 46M and the right is the 46A. It's hard to get a good photo with detail but the two stainless steel springs on the left are in great shape. The steel spring on the 46A on the right is rusted and fused together. 

clip springs.jpg

 Day 29

Here are our lovely bags!

bag lineup .jpg

There is no visible change with the bags - until I picked them up. I did notice that there was quite a lot of salt crusted on the outside tops of the 46A and 46C bags. 

The 46A rivet disappeared completely as it did in the 46C. One difference I noticed between the 46A and 46C bags is that the 46A bag feels more crusty/sludgy. It was really gross. There was black rusty crusty sludge all over the clip when I took it out. Total tetanus soup. I really did not enjoy taking it out of the bag, and toweling it off. The 46C bag is like that too but much more liquidy. 

clip lineup day 29.jpg

The remaining clips that both have stainless steel rivets and springs are in great shape. 

stainless springs 1.jpg

 

 And the two winners are the 46M Marine clip and the 46X stainless clip! Both have stainless steel rivets and springs so they won't corrode in salt water. While the 46X looks the same as it did when we started the experiment, the 46M has started to develop a patina on the copper. 

This green color is copper chloride, and is a layer of corrosion that forms in a saltwater environment, like on the Statue of Liberty. The other copper clips likely have this copper chloride layer as well, but there is so much other rust in the water it doesn't show up. 

Why choose the 46M clip over the stainless? As stated at the beginning of the post, the all-stainless clip cannot be soldered to, so if you need to solder a wire to the clip, you need something that can be soldered to. So while the 46M looks worse than the stainless, it still provides an added utility that the other does not. When selecting a clip, consider if soldering is necessary. If not then the 46X would be your best choice. If you do need to solder, the 46M is the best choice. 

For a more general overview of different kinds of clips, check out our Guide To Clips.

 

 

Topics: Marine Clips

Top Considerations for a Custom Paint Line Grounding Assembly

Posted by Mona Weiss on Feb 19, 2018 8:30:15 AM

So you’re considering if you need a custom grounding solution for your automated paint/powder coat line, but you still have questions and concerns.  You’ve probably evaluated all your alternatives and realized it may be time to update your grounding process, and maybe you've even read our whitepaper on Static Electricity and Grounding in Industry. But there are still some questions and things to consider.  This infographic addresses the common questions and considerations that people have when evaluating grounding solutions.

 1.	How do I address paint build up on the clip? The Clips can usually be cleaned with chemicals or just replaced when paint builds up too much. They can also be cleaned in an oven but the springs will become soft and unusable after a few cleanings. 2.	Will I need to worry about the clip contaminating the substrate/paint? Maybe. In some applications any impurities will dislodge from the grounding assembly and potentially land on the substrate, especially during the clear coat process. 3.	How will it attach to the carrier?  Assemblies can attach to the carrier in a quick disconnect fashion, i.e., with a clip or be semi-permanently attached by bolting down a lug or ring terminal on one end of the assembly to the carrier itself.   4.	Can they be placed out of the direction of the spray? In many cases, yes. Most times the clip is placed on the opposite side of the spray. However, in some cases the clip is exposed. For these applications a clip designed with less surface area is desired.   5.	How long do they need to be? These can be as long or as short as necessary. The assembly needs to be able to attach to the substrate and carrier in a manor where they will not be too loose and get caught on anything but will not be too tight where they can become dislodged through simple vibration. 6.	How many do I need? The number of assemblies per substrate depends on size and material. The better the conductor a substrate may be (i.e. metal) the less clips / assemblies may be needed. 7.	What’s the best surface of the clip to attach to the substrate? Flat is usually the most preferred method, however, some customers use jaws with teeth for better connectivity.

 Ready to move ahead with a custom or ready-made solution for grounding to update your process? Click here and fill out the form to get the ball rolling!   

 

You can also read our free guides to grounding for plastic and metal painting below

                           Free Guide Grounding Plastics  for Painting      Free Guide Grounding Metals  for Painting

 

Topics: Plastic Painting, Painting Plastics, Paint Line Grounding, Electrostatic Painting,, Grounding Metal, Grounding Wires, Grounding, Powder coating, Grounding Plastic, Grounding Clamp, Static Control

Signs It's Time To Update Your Grounding Process

Posted by Mona Weiss on Feb 12, 2018 11:27:15 AM

When trying to determine the cause of problems encountered with electrostatic painting, it can be confusing. The problem is often solved by updating the grounding process, however this simple solution is often overlooked. 

Grounding Infographic.png

1. There is a drop in transfer efficiency

Your measurements and output are lower than they should be. 

2. Paint thickness is not what it should be

You may see a reduced paint thickness, uneven paint thickness, or both.  

3. There is a lot of scrap/rework

Lack of a good ground can result in much higher  amounts of scrap and rework than there should be. 

4. There's more paint on the surrounding surface than on the substrate

This can indicate you had a bad ground or no ground at all. 

5. Your cost of paint has gone up

You are going through more paint to coat the same number of items. 

6. Servicing the robots doesn't help

You may have thought there was something wrong with the paint robots, but they are in working order

7. There's a drop in weight

If your substrates come out weighing less than they normally do, this can indicate that less paint is making it to the surface which usually indicates there're something wrong with the ground.

 

If you think updating your grounding process will help, you can head over to this handy page which addresses the most common considerations and questions for updating your grounding process. 

For more information on grounding, read our whitepaper Static Electricity and Grounding in Industry

You can also take a look at our free guides for grounding plastic and metal for painting.

              Free Guide Grounding Plastics  for Painting                                Free Guide Grounding Metals  for Painting

Topics: Plastic Painting, Painting Plastics, Paint Line Grounding, Electrostatic Painting,, Grounding Metal, Static Electricity Grounding, Grounding Wires, Grounding, Grounding Plastic, Painting metal

PVC vs Silicone vs Rubber Wire Insulation

Posted by Mona Weiss on Feb 2, 2018 10:45:14 AM

There are many varieties of wire and cable insulation suited to a variety of needs.  Insulation is made of a non-conductive material that surrounds the wire and will resist an electric current.  Keep in mind that The thickness of the insulation determines the voltage rating. You can get high voltage from any kind of insulation depending on the thickness.

 Wire comparison chart (8).png

PVC is the most common type of insulation and the least expensive and has a wide ranges of uses. It’s very resistant to chemicals, corrosion, impact, abrasion, and weathering. The temperature range is -40°F to 221°F.  The wire is generally hard to the touch and doesn’t provide as much flexibility as other types of wire.

Silicone is highly flexible and heat resistant and is preferable to use for extreme temperature environments from -103°F to 482°F. It is soft to the touch. A downside of silicone is that it is generally more expensive and also attracts static so it has a tendency to get dirtier than other wires, as the dirt is attracted to the outside of the wire.

Natural rubber can be thought of as a cross between silicone and PVC in terms of some of its advantages and disadvantages. It has better abrasion resistance than silicone but not always as chemically resistant as PVC. It’s better suited to outdoor and industrial environments. Its temperature range is -13°F to 140°F which is less than the other two kinds of insulation.  

Topics: electronics, wires

How to Properly Crimp an Alligator Clip Onto A Wire

Posted by Mona Weiss on Dec 7, 2017 1:35:26 PM

 Many people don't know the right way to properly crimp an alligator (or crocodile) clip onto a wire. This blog post (and video) shows how to do it step-by-step.

  

stripped wire 2.jpg

 

 

 

 

Step 1: Strip the wire to about 3/8"

 

 

 

 

folded over 2.jpg

 

 

 

Step 2: Bend the stripped wire end over the outer jacket

 

 

 

 

wire is inserted.jpg

Step 3: Insert the wire inside the jacket

 

 

 

 

 

crimp 2.jpg

 

 

Step 4: Crimp

 

 

 

 

pull off.jpg

 

It's important to fold the wire over the insulation before inserting and crimping because it prevents the wire from being pulled off. 

 

 

 

 

 

 

To browse our alligator clips,click here to see our digital catalog and see where to buy, or click here for our clip selector to narrow your search.  

To learn more about different types of clips, check out our clip guide.

 

Topics: crimping, electronics, crocodile clip, engineering, alligator clip, crimp

An Introduction to Static Electricity in Industry

Posted by Mona Weiss on Nov 7, 2017 9:15:00 AM

Static electricity is all around us in everyday life and generally refers to an imbalance between positive and negative charges in objects. Most people have experienced it in some form or another whether it be with their laundry being particularly “clingy,” making a balloon stick to a wall after rubbing it on your clothes, or when walking around wearing socks on a carpet and getting a small shock when touching another object or person.

Positive and negative charges.jpgThe Science of Static

To understand static, it helps to understand some basic physics with atoms and magnetism.

All objects are made up of atoms which have positive and negative charges, like a magnet. Also like magnets, like charges repel each other (positive-positive, or negative-negative), while different charges attract each other (positive-negative).

Static electricity is a result of an imbalance between positive and negative charges when two objects or materials come into contact. The surface electrons try to balance each other while the two surfaces are together. When two materials or surfaces are touching, one surface gives up electrons and becomes more positively charged while the other object surface collects extra electrons and becomes more negatively charged. When the two materials are separated, an imbalance occurs when the surfaces are left with either a surplus or shortage of electrons, and the surfaces become electrically charged. These charges build up when they don’t have a direct path to the ground, and can eventually build up enough to cause a spark to a nearby grounded or less charged object in an attempt to balance the charge.  

800px-Lightning_over_Oradea_Romania_3.jpgExamples of Static Electricity

When you take off a wool sweater and the hair on your head and arms stand up, the hair acts this way because your body got an extra charge from the friction of the sweater being removed and your hairs are moving away from each other because they all have the same charge.  

With your laundry, your clothes in the dryer are rubbing up against each other (particularly when you have different types of fabrics in there, like cotton and polyester), those charges will cause the fabrics to cling to your body.   

Lightning is another example of static discharge. You see it because electricity is being produced between two clouds or between a cloud and the earth as the static electricity is discharged.

Static in Industry

Static electricity is very important in many industries as can used to our benefit, or it is a problematic issue that needs to be mitigated, reduced, or removed.  

For example, some helpful uses in industry are in pollution control – like air purifiers. The air purifier applied a static charge to dirt particles in the air and then passes the air over an electrostatic plate of the opposite electrical charge. The dirt then clings to the plates and can be easily removed. Factories use this same principle on a larger scale for their smokestacks to keep pollution out of the environment.

7DRM1502.jpg

Another use for static electricity is for spray painting car parts. This requires a specialized paint gun that applies an electrostaitc charge to the paint. The parts for painting need to be properly grounded using metal clips, clamps and wires. The charge causes the paint to be attracted to the car parts resulting in an even coat, less mess, and less wasted paint.

In other industries, static can cause a lot of problems. Sparks caused by static can cause fires and explosions. While hazards for fires may be obvious with flammable materials, this can also happen in industries where there is dust, like flour mills. Static electricity is also an issue where electronics are used and manufactured.

Static electricity in industry is caused by machinery where this is friction and contact and separation, as well as in instances where there are rapid heat changes. People can build up their own charges simply by the friction created when they walk, so when they move within proximity to a machine, they can receive a shock. Static sparks can be very serious in industry, not only can they cause an ignition or explosion but they can also cause a burn or stop someone’s heart.

Some other sources of static electricity production in industry can be liquid flowing through a pipe, hose or opening, blending or mixing, spraying or coating, filling drums, cans, pails, or tanks and conveyer belts.

Electrical charges can also build up in flammable liquids when they flow through pipe systems or when they splash due to being moved in their storage containers.

Humidity is a significant factor as moisture in the air helps to remove some charge. Dry environments are much more prone to static buildup. Different materials and production speeds also play a role in how much and how fast static is created.

Static Control

Static electricity in industry is controlled by several methods. We will focus on the most common of these methods, Bonding and Grounding

Bonding Cable.pngBonding is when two or more conductive objects are connected with a conductor like a wire, which helps to equalize the charge between them. Bonding doesn’t eliminate static electricity but it does ensure that a spark will not happen between the objects. An example of a cable used for bonding is to the left. In this example, two copper clips are on either end of a wire and clip directly to the items being bonded. 

Grounding is when objects that can gain a charge are connected directly into the earth using metal like grounding rods, copper, and steel. Grounding drains the static charges away as they are produced. Grounding and bonding connections are made with connectors using metal clips, clamps and wires.

Grounding Assembly

Grounding Cable with Easy Squeeze Alligator Clip.png

A grounding/bonding assembly is a clamp or clip with a grounding cable or wire. One end attaches to the item being grounded or bonded. The other end attaches to the ground, whether it be a ground rod or a grounding "bus" mounted on a wall. Ground connectivity of all devices, cables and connections must be checked at installation and regularly afterwards for safety and to ensure the connection is maintained. Many grounding clips and clamps have a paint-piercing ability to ensure a metal-on-metal connection. Check out Mueller Electric's catalog for more examples of grounding and bonding equipment.  

 

Other Websites For More Reading: 

Uses of Electrostatics on BBC.co.uk

GCSC Science / Uses of Static Electricity

Topics: Electrostatic Painting,, Grounding Metal, Static Electricity Grounding, Grounding Wires, Grounding, Grounding Plastic, Grounding Clamp, Static Electricity, Static Control, Static Electricity Industrial