Find's Treasure Forums

Welcome to Find's Treasure Forums, Guests!

You are viewing this forums as a guest which limits you to read only status.

Only registered members may post stories, questions, classifieds, reply to other posts, contact other members using built in messaging and use many other features found on these forums.

Why not register and join us today? It's free! (We don't share your email addresses with anyone.) We keep email addresses of our users to protect them and others from bad people posting things they shouldn't.

Click here to register!



Need Support Help?

Cannot log in?, click here to have new password emailed to you

Changed email? Forgot to update your account with new email address? Need assistance with something else?, click here to go to Find's Support Form and fill out the form.

Epoxy recommendation for coil ear fix

Natedogg

Member
So I have someone repairing my 11 inch stock coil for my Equinox. The ears have snapped on my 2 coils sometime ago and in the past I have tried numerous different coil stiffeners and epoxied them on with JB Weld it will hold up for several months then eventually snap off. We researched for an alternative, and found some L brackets on Amazon that look like they should do the trick. These were cut down to size and seem to be the perfect replacement. There made of vinal, and when epoxied the ears on and checked the next day the coil ears didn't stick to the coil. This was JB weld not the one that has bits of iron mixed in. Anyone have any ideas what else might works thanks,
Nate
 
The type of epoxy is probably less important then how you apply it. Best results come after scarifying the surfaces very well , use 50 grit sandpaper or coarser to increase the surface area as much as possible. Next be sure to have the surfaces completely clean of all oils , hit it with quick flame from a lighter and then wipe it down well with alcohol. Clamp as well as you can without squeezing all the epoxy out and then let it cure for 24 hours even if you are using the 5 minute stuff.
 
Thanks sprchng for your reply I appreciate the information. All instructions were followed exactly except for the quick flame from a lighter. We're usually able to get a good bond with the epoxy and the coil stiffeners, I think it may be the material these l brackets are made of possibly and there just not sticking to the coil. I think their made of some type of hard vinyl. They do look like a very good replacement however. Will do some further research.
Thanks
Nate
 
3m panel adhesive 08115. Its pricey might go by a body shop and have them mix some for you. surface prep is key like discussed.
HH Jeff
 
Gigmaster posted a great video on fixing the coil ears on a Nox. I did this repair over a year ago and it's still holding up 100%. Be sure to use the ABS plastic and the Gorilla 2 tube epoxy shown in the video. Use sandpaper to rough up all mating surfaces before gluing & clamping. Use needle files to contour the ABS plastic edges to fit against the coil before gluing. The Gorilla epoxy is made for ABS plastic. The coil is ABS.
I tried one of those 3D printed stiffeners and my coil ears broke while it was attached.,so much for that idea. Do the Gigmaster fix and be done.
 
Re-enforce the ears with fiber washers and epoxy….
 
I epoxied mine when new added a stiffener with JB weld plastic epoxy never broke solid as a rock I just sold my 800 the 900 is much better made.
Mark
 
The ears broke on both of my XTerra 705 coils when I first got the machine in 2009 or 2010. They didn't break at the base of the lug but right through the center of the bolt hole. I don't remember which adhesive I used to glue the broken bits back on. It may have been JB weld or it may have been Super Glue. Either way it was just to get the ears back together for the real fix which was a couple of layers of fiberglass laminated on the outside of the lugs. The repair has held up so far.
 
Natedogg --

sprchng's advice in his post is, in my view, ALMOST spot on. Abrading the surfaces with sandpaper, cleaning with isopropyl alcohol to remove dust/grease, etc. And yes, hitting it with a low flame from a propane torch is also valuable -- especially for many of the "harder to bond" plastics, such as Delrin, etc. These types of plastics, molecularly, make bonding difficult, and the flame "oxidizes," or "alters the surface molecular structure" of the plastic, allowing a better bond to be achieved.

Clamping, I'm not so sure. Most epoxies have a specified range of "gap width" that is most appropriate (i.e. space between the two parts to be bonded). Too large, OR too small, on that "gap width," and you won't achieve maximum bond strength. And while, along these lines, sprchng noted not to clamp it TOO tight so as not to "squeeze out the epoxy," I still think that the "gap" that would exist -- when clamping -- would be smaller than what most epoxies are spec'd at; that "gap" data is available from the manufacturer.

The one thing I will disagree with, is the idea that "the type of epoxy is not so important." I would counter-argue that the type of epoxy CAN -- depending upon the materials to be bonded -- be CRITICALLY important. Epoxy manufacturers offer DOZENS of different types of epoxies/adhesives, and there's alot of "chemistry" and such behind that...as certain adhesives are required for certain materials, and others, for other materials. Plastics are NOTORIOUSLY difficult to bond, and then plastic-to-plastic is VERY difficult, in terms of achieving a very high-strength bond.

The one I would try -- but it requires an epoxy gun -- is Scotch-Weld DP125, in "gray" (it comes in both a translucent amber color, and a gray color). It's a two-part epoxy, requiring the appropriate gun for the size of epoxy cartridge you buy; I buy the ones that are like 48.5ml, as those are the ones that fit my gun. You'll also need mixing nozzles (the 1:1 green nozzles) if you choose to go this route.

Otherwise, for plastic-to-plastic bonding, it's tough, with off-the-shelf epoxies. You could try the JB Weld "PlasticWeld" syringe, but I've not tested it, so can't recommend. But, it is at least SUPPOSED to be "optimized" for bonding "plastic." If that doesn't work, you might try the ORIGINAL JB Weld steel-reinforced 4-6 hour formula (not the KwikWeld 6-minute version).

Hopefully this helps a bit.

Steve
 
Thanks Steve, and Gary for your feedback it's much appreciated. I plan to contact a few of the epoxy manufacturers and send them the vinyl L bracket to see what they recommend. It looks like they should be a good replacement part as long as I can find a good bonding epoxy. Thier the black colored brackets on Amazon I believe they sell 40 pieces for like nine dollars or so. It's my Stepdad that's been doing the repairs. We have tried numerous coil stiffeners because the ears had snapped off on both my Nox stock coils. The fix usually lasts several months then the stiffer breaks off. I also have the 6 inch coil the 15 inch, and recently purchased the Coil Tek I believe is 9x5 or something no issues with the smaller coils, although the 15 inch worries me a little bit that I could break. The 9x5 is killer on small jewelry and rings.
Thanks again.
 
I bought a used E-trac and it came in with the corner broke off of one ear and they had one of those block adapters setting on top of the coil. It worked just setting there but was hard to get the mounting bolt to line up.
So I gave in a good cleaning and I put E6000 glue on the area that was against of what was left of the coil ears and a coat on the base area that sets on top of the coil. I pushed it together until I could get the bolt through the hole and snugged it down and let it set over night. The next day I removed the bolt and worked a drill bit through the hole until I could get the bolt through it without pushing.
Elmy is the one that told me about the E6000 glue and I love it. Half of my house is glued together with this stuff. LOL Anyway it works for me and my coil is as good as new and going on year two now.

Ron in WV
 
Thanks for the info Ron I will have to do some further research on that. I have several other detectors and have never had any issue with the coil ears breaking.
Nate
 
Natedogg --

sprchng's advice in his post is, in my view, ALMOST spot on. Abrading the surfaces with sandpaper, cleaning with isopropyl alcohol to remove dust/grease, etc. And yes, hitting it with a low flame from a propane torch is also valuable -- especially for many of the "harder to bond" plastics, such as Delrin, etc. These types of plastics, molecularly, make bonding difficult, and the flame "oxidizes," or "alters the surface molecular structure" of the plastic, allowing a better bond to be achieved.

Clamping, I'm not so sure. Most epoxies have a specified range of "gap width" that is most appropriate (i.e. space between the two parts to be bonded). Too large, OR too small, on that "gap width," and you won't achieve maximum bond strength. And while, along these lines, sprchng noted not to clamp it TOO tight so as not to "squeeze out the epoxy," I still think that the "gap" that would exist -- when clamping -- would be smaller than what most epoxies are spec'd at; that "gap" data is available from the manufacturer.

The one thing I will disagree with, is the idea that "the type of epoxy is not so important." I would counter-argue that the type of epoxy CAN -- depending upon the materials to be bonded -- be CRITICALLY important. Epoxy manufacturers offer DOZENS of different types of epoxies/adhesives, and there's alot of "chemistry" and such behind that...as certain adhesives are required for certain materials, and others, for other materials. Plastics are NOTORIOUSLY difficult to bond, and then plastic-to-plastic is VERY difficult, in terms of achieving a very high-strength bond.

The one I would try -- but it requires an epoxy gun -- is Scotch-Weld DP125, in "gray" (it comes in both a translucent amber color, and a gray color). It's a two-part epoxy, requiring the appropriate gun for the size of epoxy cartridge you buy; I buy the ones that are like 48.5ml, as those are the ones that fit my gun. You'll also need mixing nozzles (the 1:1 green nozzles) if you choose to go this route.

Otherwise, for plastic-to-plastic bonding, it's tough, with off-the-shelf epoxies. You could try the JB Weld "PlasticWeld" syringe, but I've not tested it, so can't recommend. But, it is at least SUPPOSED to be "optimized" for bonding "plastic." If that doesn't work, you might try the ORIGINAL JB Weld steel-reinforced 4-6 hour formula (not the KwikWeld 6-minute version).

Hopefully this helps a bit.

Steve
The JB weld plastic one works great I’ve used it on my coil
Mark
 
Thanks Steve, and Gary for your feedback it's much appreciated. I plan to contact a few of the epoxy manufacturers and send them the vinyl L bracket to see what they recommend. It looks like they should be a good replacement part as long as I can find a good bonding epoxy. Thier the black colored brackets on Amazon I believe they sell 40 pieces for like nine dollars or so. It's my Stepdad that's been doing the repairs. We have tried numerous coil stiffeners because the ears had snapped off on both my Nox stock coils. The fix usually lasts several months then the stiffer breaks off. I also have the 6 inch coil the 15 inch, and recently purchased the Coil Tek I believe is 9x5 or something no issues with the smaller coils, although the 15 inch worries me a little bit that I could break. The 9x5 is killer on small jewelry and rings.
Thanks again.
Nate -- I'd be curious to see what type of epoxy the manufacturers recommend.
.
A report back, if you think of it, on what you find out, would be interesting, and possibly helpful to others.

Steve
 
No problem Steve, as soon as I hear something I will post it. Usually it's JB weld that we use, I have also used Gorilla epoxy and it works for only so long. These vinyl L brackets are more pliable, and seem like they should do the job. So basically trying to bond vinyl to abs plastic.
Thanks for all the replies. I have passed along the recommendations for the epoxy, and glue to my Stepdad, but he thinks contacting the manufacturers might be the best bet.
Thanks,

Nate
 
revzoom,

Here is a technical comparison, from 3M Corporation's website, comparing DP420 (left side) with the DP125 Gray that I suggested. Note that as you scroll down, and get to the part where it discusses substrates. ABS and vinyl, the two materials that the OP is wanting to bond, are specifically mentioned within the list that DP125 is designed for. These are not mentioned in the list of substrates that DP420 is mentioned for...

Steve

https://www.3m.com/3M/en_US/p/c/adh...t/?rt=comp&R=B40066483_en_US+7000121264_en_US
 
Thank you both for that information very good to know, will have to read up on that. I'm still waiting to have my 2 coils repaired.
Nate
 
Top