To scrub or not to scrub

[Pirate pete]

Hi all was on another forum the other day and there was quite a debate as to weather you run your coil on the ground or if you keep it close to the ground but not rub the skid plate thought i would open it up here for discussion,be interested to see your reply's.

 

[LC76]

If im using the SDC2300 then yep I scrub as much as possible to get close to the ground as a few millimetres can mean hearing or not hearing a target.
But with the GPZ 7000 it makes too much noise if it gets scrubbed or bumped......dont need to scrub that machine anyway.

 

[LC76]

So i guess it depends on the machine you're using.

 

[walshie1000]

I scrub all day long, even with the Z. I've got it set up now so I can scrub it at almost the same speed as a gpx. This way I still get the smallest of nuggets that would be missed if the coil was only 5mm above the ground for instance. If you run more conventional settings around factory preset with the Z you have to go at snail pace if you want to scrub the coil.

 

[SCROUNGER]

I'm a scrubber! With the sdc of course

 

[old hand]

Look we are learning all the time ,until about 2 years ago I did not scrub and scrubbing is the way I go these days, Monday I was out with another member from PA I was using a 12 evo on a 4500 and ended up with a 1.1gram at 7 inches ,If I did not use the coil on the ground I would have come home empty handed regards john

 

[RM Outback]

I see it as common sense to scrub/skid given the fact you can replace the skid plates, I'm using a 23 and 5000 and have spares. Clean them (coil & skid plates, replace tape as needed) after a few times or as often as you like. The 5000 started playing up one day noisy so to speak had a 12 inch NF elliptical on tried a few settings thinking it was ground noise due to moisture/ mineral types what ever I tried it just didn't sound right. Ended up changing the coil and bingo ran like a happy cat, purred like usual after getting home I spoke to a bloke about the 12 inch and the hassles I was having. He said it could be build up on or under the tape of the skid plate, sure enough cleaned it up next time at same spot back on with the 12 inch and ran quiet as had in the past. Now I clean them which allows for an inspection at the same time, if you skid your skid plate it will wear a hole/cut/fracture in it from doing so after a while, replace as necessary hope this helps.

 

[bend]

I don't usually scrub unless there's very little undergrowth, the coils I have are older (all second hand) and I usually find their pretty prone to sounding off if you contact heavier undergrowth. I find it's easier to control the motion 5-10 mm above the ground and get in close to the thicker growth without falsing. Around surfacing and more open areas of bush, creekbeds etc. I scrape along though.
Mind you I don't get all that much with the detector in any case, the old SD2000 struggles a bit with the smaller stuff to be honest.

 

[casper]

My WHITES GMZ doesn't like scrubbing or bumping. In fact there is a particular tufted grass plant in the GT that the GMZ only has to lightly brush over and you get a strong signal.

Maybe i should collect this grass and burn it to release whatever mineral it is absorbing and storing......

casper

NB: the GMZ is a 18Mhz VLF detector.

 

[Heatho]

Scrubber here too.

 

[RM Outback]

I don't usually scrub unless there's very little undergrowth, the coils I have are older (all second hand) and I usually find their pretty prone to sounding off if you contact heavier undergrowth. I find it's easier to control the motion 5-10 mm above the ground and get in close to the thicker growth without falsing. Around surfacing and more open areas of bush, creekbeds etc. I scrape along though.
Mind you I don't get all that much with the detector in any case, the old SD2000 struggles a bit with the smaller stuff to be honest.

Good point regarding coil type bend, new technology has improved them beyond compare imo. Someone with a better understanding than I could add to this, the use of Litz wire & assembly process is what's made this possible is my understanding. I know you're feelings with the 2000 was my first detector "97" that was, same result mind you life got in my way not the machine until recently. I'm no expert far from it, best performance I got from the 2000 was dd coil as far as stability goes. Best of luck to you bend.

 

[Guest]

Interesting subject. I wonder why Minelab don't mention in the manual about scrubbing the coil on the ground. The do however say to ground balance lowering the coil as close to the ground as possible without touching it. And for maximum gold recovery "keep the coil as close to the ground as possible.

A guy with connections to Nuggetfinder coils once told me if you scrub the ground after balancing the machine you lose about 30% depth/sensitivity. This is something I haven't really tested for myself, but will try it next time I'm out.

I recently bought a bundle of books and maps and among them was an old Garrett VLF instruction manual. Something that caught my attention was a page about "Scrubbing". It says: "Keep search coil in contact with ground. This is called "SCRUBBING".

Wondering if the scrubbing method has just continued on from the VLF detector days. Be interesting to know if PI detectors actually work better with the coil slightly above the ground.

 

[nuggetino]

I mostly don't scrub the 4500 because it'd be too noisey to run my settings. If I dumb it down enough to allow scrubbing I lose a little depth/sensitivity so it counters the advantage of getting the coil that cm closer in the first place not to mention the added skid plate wear.

 

[PabloP]

I try to get as close as I can without scrubbing with either SDC or the Z. Mainly because of advice I think from JP that ML didn't recommend it and in fact said that dumping onto rocks was a no, no.

Rob.

 

[user 4485]

NB: the GMZ is a 18Mhz VLF detector.

18Mhz no wonder its touch sensitive :lol:
I think you'll find it runs at 48khz. From memory I used to scrub the coil on my GMT & had no major touch sensitivity issues unless bumped hard on something?

I'm a scrubber but depending on coil, machine & terrain tend to be fairly light. In highly mineralised ground lifting the coil a bit can settle it down (as per above from nuggetino) & for the GPZ it's recommended to not scrub the coil in those conditions. In rocky terrain you may not have a choice with the GPZ14 coil anyway & I've also seen a tip that running in fixed can be better in this type of uneven terrain.

I've seen & heard of many heavy handed scrubbers wearing out numerous skid plates + also causing other damage such as damaged coil lugs, worn/damaged knuckle SDC & I reckon it's also a factor in broken GPX handles (along with overtightening).

 

[Bjay]

If your not scrubbing with the sdc you will be missing gold guaranteed.

 

[Pirate pete]

thought this maybe of interest I thought i would go to someone who should know and so I asked Rohan from Nugget Finder this is his email

To Scrub or not to scrub...that is the question

My opinion...

Scrub When you Can... When the ground Mineralisation is light and the extra noise induced by close ground contact is minimal Scrub Away!

Raise the coil a little when required... When the Mineralisation levels are high and close contact is creating excessive background noise that could mask faint target signals, Raise the coil a little. Especially when seeking deeper gold with a large coil.

Heres the Thing - It really depends a lot on how good (Experienced) you are at picking out target signals from background noise.

Note Flat Wound Coils will saturate easily in Highly Mineralised Ground.

I was in a hurry...Hope it made sense...

Cheers
Rohan

found this very interesting and I think I will try it when i get out again, as i am in the GT and the ground is very mineralised so will see what it brings once the friggin rain stops lol

 

[user 4485]

If your not scrubbing with the sdc you will be missing gold guaranteed.

Yes but you don't have to try & push it through to China to be effective IMO & I found a few bits with the SDC

 

[Davent]

So Pete, from that, I understand the advice to be (for me and a 15"evo spoke) raise it a little from the (hot ground) and work slowly yeah? Makes sense, as I do get a bit of ground noise, maybe a cenremeter or so from the ground would be ok, or untill the background noise reduces?

 

[Bjay]

Depends on ya definition of scrubbing I suppose. To me just a light scratch along the surface keeping contact without undue pressure. Haven't worn a skid plate out yet but getting close. As opposed to the Missus probly not scrubbing close enough she always leaves me some to find after she's gone over a spot. Gotta be happy with that though . As one of the kids once said ( ya not very good mum but ya try your best) gold from the mouth of babes.