I will be installing a 12"x12"copper sheet on the hull of my boat to be attached to my mast via # 4 copper wire for lightning protection. My question is if I use stainless screws will I have a problem with dissimilar metals in salt water.
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Silicon bonze
Don, use silicon bronze fastners they are over 95 percent copper. You mentioned screws, I would suggest bolts to keep the cross section area up to handle the possible current from a strike. Flat head if the copper is thick enough or carrage bolts for thinner material. You might also consider soldering the bolt heads to the copper for good conductivity. I used a 8x16x1/4" copper plate with 4- 1/2" bolts. As far as I know it has not been put to the test.
Don, use silicon bronze fastners they are over 95 percent copper. You mentioned screws, I would suggest bolts to keep the cross section area up to handle the possible current from a strike. Flat head if the copper is thick enough or carrage bolts for thinner material. You might also consider soldering the bolt heads to the copper for good conductivity. I used a 8x16x1/4" copper plate with 4- 1/2" bolts. As far as I know it has not been put to the test.
Frank is right,
use Silicon Bronze, available as "Durium" from electrical wholesalers (& others). Don't fair the plate, you want the sharp edges. Gord
use Silicon Bronze, available as "Durium" from electrical wholesalers (& others). Don't fair the plate, you want the sharp edges. Gord
Question for Frank
I like the idea of a 8"x16 piece of copper bolted to the hull with bronze bolts but where do I buy the copper? I can only find copper sheet metal. Help! I also live in FL.
I like the idea of a 8"x16 piece of copper bolted to the hull with bronze bolts but where do I buy the copper? I can only find copper sheet metal. Help! I also live in FL.
Gnd Plate
You proposed a 12" x 12" (144" Sq) plate, which is the minimum. Frank used a 8"x16" (128" Sq), which is inadequate. Look in yellow pages, under metals. Regards, Gord
You proposed a 12" x 12" (144" Sq) plate, which is the minimum. Frank used a 8"x16" (128" Sq), which is inadequate. Look in yellow pages, under metals. Regards, Gord
Ground Plate attachment
Hi, I am the inventor and manufacturer of the Strikeshield Lightning Protection System and just wanted to suggest that your copper plate be at least 1/4" thick. A copper sheet will not work as it is too thin. As well, the interconnection between your cable and the plate is critical. You are going throughull I assume and the connection needs to be perfect. If not, you will create resistance to ground which can translate into heat which may damage the fiberglass in the event of a strike. As well, the No.4 wire is inadequate in our estimation. Our systems use as a minimum 1/0 AWG multi-strand tinned copper marine shipboard cable. All the connections are swaged with a 5 ton press, soldered and covered by a thermo-retractable shield. We use and recommend assembly techniques that are UL and IEEE approved for the power industry. Anything less is a farce and more hazardous to your health. If you do not build your ground circuit to the highest industrial standards, you might as well not do it as it will fail and cause serious damage. You know, doing what you are doing has not been done by manufacturers as a matter of course which is why I got involved in this project. It really irks me that manufacturers taking $100k + for a fiberglass tub can't get their heads together to put in a decent lightning ground system. If you are going to take this project on, then do it under the rules of the art. Use proper materials and fabrication techniques. Do some research with the power industry and how they build things. Ensure all your copper is tinned. You can get this done in a tinning shop prior to assembly. Please use a larger wire diameter and get industrial tinned copper connectors. Don't jury rig the system because you are taking risks. And after doing all of this work, you can still get hit by lightning and it can still cause serious damage or injury. Grounding the mast is essential, but not being on the water when lightning hits is even safer. If I can answer any more fabrication questions, don't hesitate to ask. regards, Christian L.
Hi, I am the inventor and manufacturer of the Strikeshield Lightning Protection System and just wanted to suggest that your copper plate be at least 1/4" thick. A copper sheet will not work as it is too thin. As well, the interconnection between your cable and the plate is critical. You are going throughull I assume and the connection needs to be perfect. If not, you will create resistance to ground which can translate into heat which may damage the fiberglass in the event of a strike. As well, the No.4 wire is inadequate in our estimation. Our systems use as a minimum 1/0 AWG multi-strand tinned copper marine shipboard cable. All the connections are swaged with a 5 ton press, soldered and covered by a thermo-retractable shield. We use and recommend assembly techniques that are UL and IEEE approved for the power industry. Anything less is a farce and more hazardous to your health. If you do not build your ground circuit to the highest industrial standards, you might as well not do it as it will fail and cause serious damage. You know, doing what you are doing has not been done by manufacturers as a matter of course which is why I got involved in this project. It really irks me that manufacturers taking $100k + for a fiberglass tub can't get their heads together to put in a decent lightning ground system. If you are going to take this project on, then do it under the rules of the art. Use proper materials and fabrication techniques. Do some research with the power industry and how they build things. Ensure all your copper is tinned. You can get this done in a tinning shop prior to assembly. Please use a larger wire diameter and get industrial tinned copper connectors. Don't jury rig the system because you are taking risks. And after doing all of this work, you can still get hit by lightning and it can still cause serious damage or injury. Grounding the mast is essential, but not being on the water when lightning hits is even safer. If I can answer any more fabrication questions, don't hesitate to ask. regards, Christian L.
Christian,
Sounds like a great product. Please be careful of your claim that it meets or exceeds UL standards. To be approved by UL the product must go through tests. I agree that the more area in the diameter of the wire the better it conducts. A lightning system is one of those things that can never be under designed............we are talking the fury of nature. As quite as water can lay, it can also be very powerful. I believe this is also true lightning. I do believe some protection is better than none. r.w.landau
Sounds like a great product. Please be careful of your claim that it meets or exceeds UL standards. To be approved by UL the product must go through tests. I agree that the more area in the diameter of the wire the better it conducts. A lightning system is one of those things that can never be under designed............we are talking the fury of nature. As quite as water can lay, it can also be very powerful. I believe this is also true lightning. I do believe some protection is better than none. r.w.landau
Performance vs Approval...
Approval requires testing - performance just is (or isn't). Christian claims performance, not approval. Approval does not always substantiate performance. Why do I bother with these semantics? Lightning protection (amelioration?) is poorly understood, and poorly regulated. You have to do your own research, and "caveat emptor". Christian's website presents some good information, including links to some good scholarly works (by others). OMO
Regards, Gord
Approval requires testing - performance just is (or isn't). Christian claims performance, not approval. Approval does not always substantiate performance. Why do I bother with these semantics? Lightning protection (amelioration?) is poorly understood, and poorly regulated. You have to do your own research, and "caveat emptor". Christian's website presents some good information, including links to some good scholarly works (by others). OMO
Regards, GordApproval vs Performance
R.W., I don't know if I had a slip of the typewriter finger, but when I described the Strikeshield system, I was stating that the construction and material sizes, design etc. meet and/or exceed ABYC recommendations not UL. Sorry if there was confusion. Our product has not been UL tested. The National Marine Manufacturer's association didn't even have a category for it other than general safety when we asked them to test and approve it! The only tests we did perform were done at the outset to confirm the effectiveness of the design and convince us in our minds that the road we were taking was a valid one. The tests were performed at the "Institut de Recherche en Électricité du Québec" (IREQ) in their high voltage lab (An ISO Guide 25 accredited test site)(http://www.ireq.ca/en/laboratories/high_voltage/index.html). There, we worked with a world renowned scientist in the lightning / grounding field (A sailboat enthusiast as well) who designed the test specifications. We configured the equipment to reproduce a strike i.e. 1.2/50 micro-second wave with a total peak voltage of 720kv and peak current at 15ka. Now this is not your typical lightning strike energy level (They range from 8ka to 300ka), however, with the prototypes made of a standard aluminium alloy, the calculated extrapolation with the use of copper confirmed that the system worked. We had three catamarans struck by lightning two years ago in Florida, two of which sustained NO damage to anything and the third sustaining electrical damage, but nothing visually identifiable. This third cat was struck one year before and had a perforated hull without the Strikeshield. This time, no physical damage. I received a Canadian Patent and am waiting on the US patent which is pending. As well, we also received Sail magazine's Freeman Pittman award for best new innovation in sailing safety which we are very proud of (http://www.strikeshield.com/Pittman.html) So, don't want to bragg...but we did our homework. I certainly don't expect people to run out en masse and buy the Strikeshield as the cost can be unnerving for some (This is somewhat out of our control BTW), but if we can convince people to place more attention on material selection and fabrication methods when they decide to build their own system, if that is the way they wish to go, then we will have served to perhaps save a life or a boat. But then again, if they just call we'll take the headache out of the project for them ;-) cheers, Christian L.
R.W., I don't know if I had a slip of the typewriter finger, but when I described the Strikeshield system, I was stating that the construction and material sizes, design etc. meet and/or exceed ABYC recommendations not UL. Sorry if there was confusion. Our product has not been UL tested. The National Marine Manufacturer's association didn't even have a category for it other than general safety when we asked them to test and approve it! The only tests we did perform were done at the outset to confirm the effectiveness of the design and convince us in our minds that the road we were taking was a valid one. The tests were performed at the "Institut de Recherche en Électricité du Québec" (IREQ) in their high voltage lab (An ISO Guide 25 accredited test site)(http://www.ireq.ca/en/laboratories/high_voltage/index.html). There, we worked with a world renowned scientist in the lightning / grounding field (A sailboat enthusiast as well) who designed the test specifications. We configured the equipment to reproduce a strike i.e. 1.2/50 micro-second wave with a total peak voltage of 720kv and peak current at 15ka. Now this is not your typical lightning strike energy level (They range from 8ka to 300ka), however, with the prototypes made of a standard aluminium alloy, the calculated extrapolation with the use of copper confirmed that the system worked. We had three catamarans struck by lightning two years ago in Florida, two of which sustained NO damage to anything and the third sustaining electrical damage, but nothing visually identifiable. This third cat was struck one year before and had a perforated hull without the Strikeshield. This time, no physical damage. I received a Canadian Patent and am waiting on the US patent which is pending. As well, we also received Sail magazine's Freeman Pittman award for best new innovation in sailing safety which we are very proud of (http://www.strikeshield.com/Pittman.html) So, don't want to bragg...but we did our homework. I certainly don't expect people to run out en masse and buy the Strikeshield as the cost can be unnerving for some (This is somewhat out of our control BTW), but if we can convince people to place more attention on material selection and fabrication methods when they decide to build their own system, if that is the way they wish to go, then we will have served to perhaps save a life or a boat. But then again, if they just call we'll take the headache out of the project for them ;-) cheers, Christian L.
Christian,
It is good to know that someone out there is starting to set standards. Is there anyone else in the business that makes any manufactured grounding systems for boats right now? I have seen the brush for the mast that in my opinion is like trying to drain the ocean with a teaspoon. I am asking about true lightning protection. A question: I was told that the charge is most effeciently dispersed from the corners of the plate. Also, that silicone bronze should not be used because it has a tendency to explode with high amperage. Also how are you dealing with fresh water since it does not conduct like salt water? What size plate or strip should be used in fresh water? thanks, r.w.landau
It is good to know that someone out there is starting to set standards. Is there anyone else in the business that makes any manufactured grounding systems for boats right now? I have seen the brush for the mast that in my opinion is like trying to drain the ocean with a teaspoon. I am asking about true lightning protection. A question: I was told that the charge is most effeciently dispersed from the corners of the plate. Also, that silicone bronze should not be used because it has a tendency to explode with high amperage. Also how are you dealing with fresh water since it does not conduct like salt water? What size plate or strip should be used in fresh water? thanks, r.w.landau
Is this correct
But let me get this straight. 144 square inches of quarter inch copper fastened to the hull with silicon bronze bolts and a # 0.1 copper wire leading up to the mast. Not necessary to bond all metal deck fittings to the ground wire. Now where do I find this size copper for less than $150.00. I have tried. I want to install this system once and do it right the first time.
But let me get this straight. 144 square inches of quarter inch copper fastened to the hull with silicon bronze bolts and a # 0.1 copper wire leading up to the mast. Not necessary to bond all metal deck fittings to the ground wire. Now where do I find this size copper for less than $150.00. I have tried. I want to install this system once and do it right the first time.
caution
There is so much missinformation about lightning protection I have seen in 30 years of boatbuilding.Look up the web sit link. Yes they sell equipment but they have a wealth of infomation on this subject. Regarding the bolt attachement silicon bronze is likely your best choice to attach with. Realize that any attachment will endure superheating in a lightning strike that will vaporize a connection with any resistance ,resulting in a spectacular event with devastating results. Be informed.
There is so much missinformation about lightning protection I have seen in 30 years of boatbuilding.Look up the web sit link. Yes they sell equipment but they have a wealth of infomation on this subject. Regarding the bolt attachement silicon bronze is likely your best choice to attach with. Realize that any attachment will endure superheating in a lightning strike that will vaporize a connection with any resistance ,resulting in a spectacular event with devastating results. Be informed.
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