What I found out about Galvanized Roofing Nails !

[ToddB64]

Hi All !

Attached is a scanner photo of three of the nails discussed below and a penny for size comparison.

I was metal detecting over grass about 12 feet out from the back of my son's house, using a White's Classic II, in AM mode.

After finding six galvanized roofing nails, I decided to switch into DISC mode. Laying one of the nails on top of the ground and scanning the coil about one inch above, I began to simultaneously dial-in discrimination, expecting the nail signal to disappear somewhere in the lower half of the DISC range. As I continued to turn the dial CW the nail signal became more spasmodic, with clicks and pops as the dial got closer to the end of it's range. When the dial finally stopped at Max, the detector was still picking up those spasmodic signals. So, the detector never did completely shut off the nail signal. Not being real familiar with the physical properties of galvanized coating at the time, I was surprised that the detector couldn't discriminate an "old roofing nail.....my gosh ! ".

After returning home, I researched "galvanization" and found out that it is a rust protection coating made from zinc, that lasts for a long time and the process is relatively economical. As you can see by the chart below, zinc has a high conductivity rating, right below aluminum, pure gold, copper and silver at the top-end of the scale. I assume the high conductivity of zinc makes it difficult to discriminate out completely, the same as silver coins.

CONDUCTIVITY OF VARIOUS METALS
(TEST SAMPLES OF EQUAL SIZE)

1 SILVER(PURE)
2 COPPER(PURE)
3 GOLD(PURE)
4 ALUMINUM
5 ZINC
6 NICKEL
7 BRASS
8 BRONZE
9 IRON(PURE)
10 PLATINUM
11 STEEL(CARBONIZED)
12 LEAD(PURE)
13 STAINLESS STEEL


Hope you got something out of this !

Todd

 

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[m bryan]

Thanks, I been digging nails that are over sixty years old at a site.......they wont discriminate out. they show up as dimes or quarters......

 

[Coin Digger]

Nice bit of information - it's good to know your targets.

 

[ivan salis]

listen to the unclean crackiling sound --a solid strong steady repeating sound = good target -- crackling = trash signal as a gen rule

 

[TORRERO]

These nails look green to me....
Green = copper = high conductivity...
I have dug copper nails in many church yards as they are used for roofing...
Galvanized nails are Iron with a coating that prevents most rust... I think...
A thin coating is not the same as a solid and the machine looks at these differantly...
like a copper penny reads high vis a copper coated zinc penny reads lower...

A better test is to go to the hardware store and get some real galvanized nails that you did not dig and test them....
see if there is any differance..
Richard

 

[ToddB64]

These nails look green to me....
Green = copper = high conductivity...
I have dug copper nails in many church yards as they are used for roofing...
Galvanized nails are Iron with a coating that prevents most rust... I think...
A thin coating is not the same as a solid and the machine looks at these differantly...
like a copper penny reads high vis a copper coated zinc penny reads lower...

A better test is to go to the hardware store and get some real galvanized nails that you did not dig and test them....
see if there is any differance..
Richard

Hi Richard !

Attached are two scanner photos as evidence to back my following statements.

The nail is not copper. Copper is nonmagnetic. As you see from the photo, the nail is attracted to the two little magnets. My guess would be the nail is steel with iron content and appears to have a galvanized coating.

The greenish appearance is just a reflection from the piece of cardboard I stationed above the nail and magnets, as a back screen. The cardboard has microscopic green dots that apparently resulted from either the base cardboard material or the manufacturing process.

Thanks for your reply.

Todd

 

[ToddB64]

Thanks, I been digging nails that are over sixty years old at a site.......they wont discriminate out. they show up as dimes or quarters......

Hi m bryan !

To begin, I normally hunt in All Metal mode, unless I get weary from digging trash and then I switch to discrimination mode, but not any higher on the setting than bottlecap. So don't have a lot of experience using discrimination.

I've been using a Tesoro Bandido II uMax metal detector, that has single tone audio and no visual.
My earphones are good ones, i.e. Ratphones Max, with individual volume control for each ear cup, made by Detect USA and cost me $123.00 + 6.00 Shipping.

I have difficulty discerning a positive difference between target signals, so usually dig everything. However, if I'm hunting a familiar area and know the ground has nails, I can usually avoid digging these by scanning lengthwise of the target and listening for the double-blip as the coil sweeps over the ends of the target. I'm always trying to improve my ability to discern any difference in the tone characteristics from targets of different metals. Most of the differences are just too subtle for me to make a positive determination. Digging 90% of my targets and trying to guess what they are before digging is good for learning.

Thanks for your reply !

Todd

 

[deepskyal]

Try detecting a house that's been burned and bulldozed! Nail city! Galvanized nails on that scale make detecting darn near impossible even with a small coil. Even that crackling/chirp I get makes me feel I'm missing the goodies.
And don't forget aluminum nails used for siding...just as bad.
Al

 

[m bryan]

Try detecting a house that's been burned and bulldozed! Nail city! Galvanized nails on that scale make detecting darn near impossible even with a small coil. Even that crackling/chirp I get makes me feel I'm missing the goodies.
And don't forget aluminum nails used for siding...just as bad.
Al

Al, I know thats right!.....burned ones are the worst. Melted pieces of metal everywhere.....

 

[ToddB64]

Thanks to everyone who replied to my topic.........all comments were interesting and I hope to see more !

ToddB64

 

[Coin Digger]

Try detecting a house that's been burned and bulldozed! Nail city! Galvanized nails on that scale make detecting darn near impossible even with a small coil. Even that crackling/chirp I get makes me feel I'm missing the goodies.
And don't forget aluminum nails used for siding...just as bad.
Al

+1
That's the truth.

 

[Bum Luck]

You can always use the nails for your next roofing job.................

 

[ToddB64]

You can always use the nails for your next roofing job.................

Bum luck...........You crack me up !

Thanks for the laughs.

ToddB64

 

[SusieQ]

Helpful information. Nails were thrown out on the ground/gravel in order to damage auto tires so I wanted to know if a metal detector could locate them after we use a magnet. Thanks for sharing your information. Have a sociopath neighbor/family member. The sociopath and their followers are basically like little children that have temper tantrums. Sociopaths do this for fun and for their entertainment. How sick is that? Thanks again.

 

[cudamark]

Helpful information. Nails were thrown out on the ground/gravel in order to damage auto tires so I wanted to know if a metal detector could locate them after we use a magnet. Thanks for sharing your information. Have a sociopath neighbor/family member. The sociopath and their followers are basically like little children that have temper tantrums. Sociopaths do this for fun and for their entertainment. How sick is that? Thanks again.

Welcome to Tnet! If the nails are ferrous, the magnet should do the trick. They make sweeper magnets for just that purpose. If you want to double check the area with a metal detector, search in all metal so you don't miss anything. The other option is to move! Life's too short to be in a constant feud with someone.

 

[skeeter86]

Being a nice guy does not get you too far they ring I a semi dump I asked one favor please pick up all the nails because I use the grass strip for my motorcycle to pass the cars parked in the driveway needless to say they left a 1pound can of nails in the grass used my metal detector to find them all So I was nice enough to return the favor by spreading the nails around the companies parking lot at 4:30 am.I hope they got the hint!!!!!!

 

[bzbadger]

Roofers normally use a rolling magnet bar to pick up the nails well responsible roofers do. You can get one of these rolling magnets at home depot or lowes for relatively little money..way cheaper than a tire.
Zinc is a protective coating as it serves a sacrifice to corrosion rather than the steel it protects.
On boats and ships large bars of zinc are placed on the hull so the salt water eats away at the zinc rather than the ship's hull.
We all call new pennies zincolns or at least I do and you see how they corrode in the soil.
Zinc is very close to silver in conductivity so no way to notch it out especially a zinc plated steel nail.
I found pounds of melted silver solder in my yard and melted it into bars thinking I was rich..ehhh wrong answer it was silver/ zinc solder 70% silver but silver and zinc are so close id have to pay to refine it and now with silver so low id lose money so I have pounds and pounds of 70% silver bars cant do a thing with.