Cracked coils on Infinium

[panama rich]

I just talked to Garrett on my Infinium that I sent in for repairs. I got the Hee Haw sound and
couldn't get it to tune up with either the 8 inch Mono or the Stock 10x14 DD. I figured an internal
problem was at fault but I sent in both coils anyhow. So I am told that BOTH coils had cracks
and were the problem. Mostly I used the 10x14 at the beach for coverage and the 8 inch mono
a few times, once for nuggets. Why would the coils crack? Don't know, but maybe something
to watch out for, I find it odd, I didn't beat rocks or anything. Bottom line, I ordered the 10x14
MONO only for now, mostly beach hunting. Any idea about how small a nugget the 10x14
MONO would go on a nugget compared to the 8 inch MONO?
Thanks,
Rich

 

[Fishers Ghost]

All of the Infinium coils will respond to the same minimum size small nugg.
What the 3 x 7 will respond to so will the mono's. The big DD is a bit wishy washy on the very smal nuggs and is not a coil that I use any more.
I have a the full range of Infinium coils and all will respond to a 0.15gm nugg, however the average size smallest nug that all coils will signal on is around the 0.5 gm mark. The only difference you will find is the max depth that each coil will go to on the smallest nugg. Small coil less depth

 

[panama rich]

Thanks on the coil info. It was a money is tight decision to get only one coil. I mostly beach hunt so
the 10x14 will cover a greater area and hopefully make enough to order the 8 inch Mono also. I really
liked the one I had, easy to pinpoint with. I was concerned about the larger mono on nuggets, good
to know it will work on the smaller nuggets as well. I also have a Compass Gold Scanner Pro for nuggets
so I think I am covered both ways.
Yes, I agree on the 10x14 DD, not a favorite.
Rich

 

[ivanll]

My 10x14" mono used on beaches in Australia had hairline cracks, rest it on a wet beach.............. Hee Haw, Hee Haw and the hunt was over.
The Only help I got in resolving the problem was via Mash Detectors Oregon............twice.

0.3 gram is the smallest I have ever detected on hot ground, both the 8" mono and 10x14"DD could do it.
Backyard home tests with smaller pieces have been done with all available coils but I have never met or seen anybody actually find a piece smaller than 0.3 gram while using an Infinium LS.

My 0.3 gram nugget on one scale was actually 0.39 gram on another more sensitive scale................................So, check your scale before selling some small gold.

ivanll

To give the Infinium LS a boost I would wish for a 6x12"DD coil like the present 5x10"DD and dump the heavy 10x14"DD altogether.

 

[panama rich]

Thanks for the input Ivanil,
Still seens strange that the coil's epoxy would crack. At least now we know what to look for.
It did seem like an intermittent problem, if if does it again, look for a crack and coat it with a
better epoxy after the moisture evaporates out.
Rich

 

[ivanll]

The inner shell of the coil is coated with a conductive slippery gray spray (like graphite? or molybdenum disulphide ?)
The coil of wire is placed in the shell and coated with an app 1/4" very clear hard and brittle epoxy?................. probably another coat of the conductive spray, then a layer of app 1/4" dark grey hard wear resistant epoxy? that might possible also have another purpose due to the nature of its composition and placement .?
Description above is from my dissected coil.
My question was, how did they manage to get the epoxy to adhere to the inner part of the shell after it was sprayed with a slippery conductive spray ??? maybe they didn't ??
Also two different layers of epoxy with perhaps different cure rate could cause stress ..............and cracks.??

Just guesswork and speculation on my part.

When the coils work, they work.


ivanll

 

[panama rich]

Well Ivanill, at least that gives us an idea on what they are facing to build larger coils for the Infinium!
Also know where there is a 2nd coil to test your detector if if starts HeeHawing. If you don't have a
2nd coil, find a friend you can borrow from. I can't wait to get it back, this is the season for the heavy
surf to throw coins and rings up on the beach.
Thanks for the post.
Rich

 

[bearkat4160]

Yeh the Infinium is not great on small nuggets below .5 gram. It might pick up a .3 gram nugget, but at maybe an inch - inch half...that's not performance that's an accident. I hope Garrett will catch up with Whites TDI and Minelab on small gold performance because they have got WAY behind. It is still a great machine but compared to those is is getting OLD.

From my experience with Garrett's epoxy coils...I have had 3 that have cracked. Epoxy gets more brittle the older it gets and that is I believe why mine got weaker as they age and when bumped they cracked easier. Of course it could be number of factors. The new epoxy that comes with the non-submersable coils are different and lighter epoxy. It is softer and not as dense, which means it weighs less and is more flexible.

I rememeber those cracked coils of yours Ivan!