What sort of metal detector do I need?
 

I have some land, on which there used to be a castle - in ireland. The story was, my great grandfather blew it up with dynamite in 1912 while drunk, after being told there was "treasure" hidden in the walls. Of course, he didn't find a thing, and what used to be a ruined castle is now just stones scattered all over the place.
I'm going up there next week, and thought I would hire a metal detector to check for anything interesting - the place is remote, nobody but me and my family will have been there. I mean a castle, surely there must be something worth finding? Of historical interest, if not gold!
Is there anything in particular I should be looking for in a metal detector to hire? Given that there will be a very small range of stuff to hire - but I don't want to waste money hiring something that will be totally useless. I know absolutely nothing about metal detectors, the only "metal detecting" I have ever done was by hand, acting on my father's advice to "rake the sand under the seafront wall, people sit on it and coins drop out of their pockets" when I was 9 years old. I made a pretty penny - to a 9 year old.:D
Any advice? This is pretty much the only thing I have come across - http://www.hss.com/g/49530/Metal-Detector.html

Re: What sort of metal detector do I need?
 

I don't know what make detectors are available to you but I can tell you that you want the very best detector you can get your hands on, and you want it electronically designed to detect one specific type target, NOT multiple types of targets.

Detectors are designed to locate (1) ferrous/magnetic metals (magnetic metals = "relics"/iron, steel, brass, copper), (2) non-ferrous (non-magnetic metals = "treasure"/coins/jewelry), and specifically gold.

If you can help it don't use a detector that is "multi-function"; that is one that has a setting that lets you select target types: relics, treasure, coins, etc. Multi-function detectors use circuitry that is shared by the different types of metal targets. This decreases the detertors sensitivity which comparatively significantly decreases it's ability to detect any metal.

Here in the U.S. the best detectors to get IMO are MineLab and Fischer models that are designed to locate one type of target (ferrous, non-ferrous, & gold). Folks who are familiar with and serious about the investment of time and effort they are going to spend with detectors will ALWAYS tell a person they need to get the very best detector they can afford, and they need to get one that is designed to locate one type of target. And if in the future they want to try and find another type target then they need to get another detector...and again the best one they can afford.

It sounds like you want to look for (1) "treasure" - gold and silver coins jewelry, and other objects, and (2) "relics" - old metal artifacts like weapons, tools, and other ferrous/magnetic items that were in daily use.\

If you can get your hands on a high quality MineLab model designed for "treasure", it will do a marvelous job finding the non-magnetic metals you seek. MineLab, Fischer, and White also make high quality detectors designed to find the ferrous/magnetic relics you seek.

Regardless of what detector you end up using, use a good set of head phones and spend a good amount of time getting familiar with it and learning to use it to the point that you know and trust what it is telling you. For treasure items, put some gold and silver jewelry items and coins around on the ground at home and practice, practice, practice with it.

Don't load yourself down with equipment you don't need but have immediately available the detector, high quality head phones, a good sturdy hand trowel and long handled shovel, a stiff long bladed semi-pointed knife-type tool to cut sod and dig a bit, a good 1/4" maybe 15" framed screen that you can use to sift away/separate debris, dirt, and small gravels to find a target you are digging, and a lightweight plastic five gallon pail to put & carry your small gear. Sense you are going to be working in and around rock debris you probably will want to have a long pinch or crow bar that you can use to move rocks aside to check underneath them.

Another thing you want to do is to set up some kind of a "grid" using visable objects or other some other system to make sure that you cover the area well by not skipping over ground and not checking the same ground twice. When beach detecting it is a good idea to drag your shovel behind you leaving a line marking in the sand that shows you precisely the path you just took so when you turn around to make another pass back the way you came, you know where you need to walk to cover adjacent ground without unwittingly wasting time with the coil over an area that you have already checked.

When you are detecting move slowly and sweep the coil along lightly touching the surface of the ground in an arc in front of you, and overlap your sweeps by about 25%. Don't get in a hurry and be careful that you don't lift the coil higher off the groun when it reaches the left and right extremes of the arc.

It is advantageous to have a belt-mounted battery pack to lighten the weight of the detector...so it is less tiring on your arm.

Hope this helps and I wish you successful hunting!

Re: What sort of metal detector do I need?
 

I would think a metal detector with good discrimination would be best as there will be trash present - small bits of old rusted junk that is no longer recognizable as anything in particular.

THere are several detector tareted to this market - one of these is the MXT by whites Electronics. I own one and have done up a website on using the MXT:
Using Whites MXT Detector

Best of luck to you - I hope you do find a treasure!

Chris

Re: What sort of metal detector do I need?
 

"...I would think a metal detector with good discrimination would be best..."

Good point...all very good detectors provide good discrimination. My MineLab discriminates against all ferrous metals. When the coil passes over something that is magnetic like an old bottle cap, nail, steel wire, horseshoe, etc. the low volume detector signal actually hanges to a mute "hum". The circuit is automatically reset and returns to the normal search tone when the coil is quickly passed over another metallic object. When the coil detects a non-metallic object like a coin or gold or silver the tone changes to a distinctly higher pitch.

It saves a lot of digging because the rule is that a person has to dig every target because you never know what it is. A good discrimination capability eliminates a lot of unnecessary digging = wasted time and effort.

Re: What sort of metal detector do I need?
 

Many thanks, all - and in particular Goldminer for your very long and informative post!
I decided not to bother with that hireable detector, as it looks like trash compared to the sort of stuff you are all talking about. I'll be up there again in a few weeks, so will have a hunt for a local metal detecting club (if such things exist!), and see if I can borrow something fancy!

Re: What sort of metal detector do I need?
 

If this is private property that has never seen much of the littering public, you may well not have any junk there that you would want to tune out of your detection. You might want to dig every target you hit. I have seen aerial photos showing many many many old ruined castles over there. I wouldn't pass on any detector I could get my hands on. I have a 30 year old 50$ White 5500 that will pick up metal as deep as any in non discrimination mode. Oftentimes I use a little handheld 4 ounce $15 GB Instruments detector that is made for detecting nails wires and pipeing in walls,etc.etc. durring construction. With it I can climb and detect on cliffs, reach back into holes, under rocks and walls, many places that other detectors can not go; and most importantly always have one with me[I own three]. It might not be able to pick up a penny 7 inches down like the White's can, but it will do almost 4 inches.

Re: What sort of metal detector do I need?
 

Did you ever go? Pictures?

Re: What sort of metal detector do I need?
 

I've been there a few times but not with a detector - too busy cutting wood and maintaining the engines!
There should be no junk there - there are no trespassers for the last 100 years or so. About all I see are old beer bottles my grandfather must have dropped in the forest...

Re: What sort of metal detector do I need?
 

Not true IMO. Of course those who claim that good discrimination eliminates unnecessary digging wouldn't really know now, would they? A lot of good targets (read, GOLD rings) fall into trash/pulltab territory.

If you want the goods ya gotta get on your knees and get diggin.

Anything of great value/collectability i've found would still be in the ground if I relied on fancy descrim.

Especially if we're talking a friggin castle in ireland............dig it all my friend.

Re: What sort of metal detector do I need?
 

It's spread over a fairly wide area, I suppose dynamite will do that for you! And invisible from an aerial view as it is forested. I do have a map though, which gives the latitude and longtitude of it's borders - so may be worth a crack!