Need glue wisdom

[+beauxeault]

 

 

I've always thought that epoxy was the answer to just about any cache-customization problem related to adhesion, but I recently had an epoxy failure, so I'm here seeking the wisdom of the cache-creation wizards regarding how to solve my problem. I've formed a frog's head to attach to the lid of my container, so the junction between the lid and the container forms the frog's mouth and the container is its body (see the first photo). I had sculpted the frog's head with modeling clay and baked it, then I glued it to the container lid using an epoxy glue. But the bond didn't hold, and after just a few times opening the lid, the head came right back off (second photo, showing the underside of the sculpted head).

 

Here's some possibly relevant info:

 

1. The container is opened by squeezing the sides of the container, which causes the lid to pop open (it's hinged at the back). The lid seems to stay rigid during the opening process, but I suppose there's some chance that the lid flexes a little (but only a VERY little at the most), and if it does, that could contribute some to the problem.

 

2. When the bond failed, there was a layer of cured epoxy that remained adhered to the container lid, but peeled off easily in a single piece. No epoxy was adhered to the head after it came off.

 

3. The glued surface of the head felt greasy after the bond failed. Could this be uncured glue?

 

4. Neither surface was sanded prior to glueing, but neither surface is really smooth, either.

 

5. The modeling clay was baked a little above the recommended temperature (275 F), which discolored it somewhat. I doubt this is part of the problem, but mention it just in case someone knows something I don't.

 

 

So there's my problem. Anyone have any advice how I can get the baked-modeling-clay head to stick reliably to the plastic container lid?

[+kunarion]

Anyone have any advice how I can get the baked-modeling-clay head to stick reliably to the plastic container lid?

What a cool container!

 

This kind of plastic is similar to Teflon. Use whatever you use to glue Teflon . I might suspect the clay, since it could be the source of the greasy feeling. Just clean it all up and try something different.

 

With the amount of surface area you've got there, a strong flexible adhesive may work. I've had some luck with an industrial rubber cement. See if you can find that, or contact cement. Once opened, it starts to cure inside its tube, so it may be kind of expensive unless you can find someone with a tube of it to let you use some.

 

Another idea I use a lot is mechanical attachment. You could drill and drive a couple of screws through the lid into the frog head, then seal the holes in the lid with most any sealer on hand.

Edited August 29, 2015 by kunarion

[+Poker70]

Try JB Weld's "Plastic Bonder". But first use a good cleaner/degreaser such as MEK (available at any large hardware store in the paint section).

[+cerberus1]

Another idea I use a lot is mechanical attachment. You could drill and drive a couple of screws through the lid into the frog head, then seal the holes in the lid with most any sealer on hand.

+1

[+niraD]

Another idea I use a lot is mechanical attachment. You could drill and drive a couple of screws through the lid into the frog head, then seal the holes in the lid with most any sealer on hand.

+1

+2

[+Path Pacer]

Your problem might be a flexible lid. That'll break the seal. Try the mechanical attachment idea above.

[Luckless]

I glued something to a plastic lid. First I used gorilla glue, but after getting banged around a few times it came off. Then I tried silicone calking but that too came off. Then I drove in a couple of screws and that worked. I wonder how well screws would hold in that modeling clay, especially if it gets knocked around..--Cute container, hope you are able to find something that works.

[+coman123]

Glue it to the other end and re-paint

[+briansnat]

3M 5200 Marine adhesive is one of the best I've found so far. It's flexible. Always sand plastic surfaces before applying an adhesive.

[+NYPaddleCacher]

3M 5200 Marine adhesive is one of the best I've found so far. It's flexible. Always sand plastic surfaces before applying an adhesive.

 

+1

 

3M 5200 is alleged to be *permanent*. That means that once the bond is set you should consider that it won't *ever* come apart. That may be something to consider depending on what is being constructed. The 3M 3200 is supposed to be less permanent but still bonds really well.

 

I've seen quite a few plastic (polyethylene) kayak manufacturers that use 3M 5200 to bond the bulkheads to the inside of the kayak. Since the purpose of the bulkhead is to keep fore/aft compartments water tight (both to keep contents dry and to provide buoyancy) it's very important that there is a water tight seal. Consider what happens when one capsizes in a kayak. Although there are techniques for limiting the amount of water that will enter the cockpit when turning the boat back over there is still going to be a considerable amount of water in it. The bulkheads prevent water from going to the ends and will allow a re-entry in deep water and retain enough stability to pump out the remaining water. If a capsize has occurred in very cold water, even if one is only a few hundred feet from shore, getting back into the boat quickly can be a matter of life or death.

 

Several years ago I was kayaking with a group of people and noticed that woman had a recreational kayak without any bulkheads or float bags (used in the bow/stern to displace water in a boat that doesn't have bulkheads). I asked her why she didn't use float bags and she said that it was made of a material which "floats" and was told that they weren't necessary. I asked her if she had ever capsized her boat in deep water and she hadn't so I suggested that she try it under controlled conditions (with a group of people nearby to help). She paddled out 30 feet from shore or so and tipped it over. The cockpit filled with water and while it did still float trying to paddling it with the boat complete full of water it was pretty much impossible. She tried swimming it to shore and wasn't having much success doing that either. Eventually she got it close enough where she could stand and pull it up to the waters edge. It still took three people to tip it over and empty it completely. If it would have had water tight bulkheads only the cockpit area would fill with water and it's relatively easy for one person to empty out enough water to get back in and paddle to safety. If 3M 5200 is expected to be used under those conditions I'd trust it keep a geocache bonded and sealed.

 

 

 

 

[+kunarion]

3M 5200 Marine adhesive is one of the best I've found so far. It's flexible. Always sand plastic surfaces before applying an adhesive.

Using 3M 5200 Marine adhesive, I tried to glue a "rubber ducky" to a bottle cap (Polypropylene), and also tried gluing them to the tube (Polyethylene). The coating was about 1/8th to 1/16ths inch thick. After curing for two months, eight glued items popped off rather easily, and fortunately the glue peeled off in one piece leaving no residue on either surface. Roughing the surface seemed to make it worse. Maybe it wasn't rough enough, but a rubber ducky don't rough up so good. So I made them all Swag instead.

 

I've used many of the adhesives suggested in the Fori, and many seem great, at home. After the cache is placed, the dreaded "attachment fell off" log means it's back to the drawing board. Plastics that just plain resist "glue", Heat/cold, moisture, cachers who don't know their own strength , it's all a lot of trial and error.

 

The larger surface area may be the ticket, so the OP might try it anyway. Some adhesives are kind of expensive to test and find out they don't work.

 

I tested a combination of things using 3M 5200 Marine adhesive, with various tough-to-glue cache ideas. One thing that glued very well was a penny. That stuff just plain will not come off a penny. If I ever need to rubber-coat a penny, my search is over.

Edited September 1, 2015 by kunarion

[+J Grouchy]

Not that it's available or even useful for this application, but the topic reminded me of this story I recently read:

http://gizmodo.com/a-glue-that-only-hardens-when-electrified-will-even-wor-1726665509

 

As for my own experience, I've just learned to never trust a glue to be the sole method of holding anything. Maybe it comes from my own experience of seeing contractors think that just coating something with caulking will prevent leaks. Any time I need to glue something - like a magnet - to the outside of a cache, I always back up the attachment with duct tape or electrical tape. In the case of something ornamental, I would likely look for a way to do something similar...though, of course, I wouldn't just wrap it all in tape. Something a bit subtler.

Edited August 31, 2015 by J Grouchy

[+upearly13]

My favorite glue is E6000. It's like a super thick rubber cement and will bond almost anything.

[+hal-an-tow]

The mechanical fixing method sounds like the only likely solution to me, but it may not be possible to drive a screw into the 'head' without cracking it , or it may not be capable of holding a screw thread without crumbling. Maybe make another head with a couple of dome headed screws baked in with the heads protruding a little (showing some of the shank)and then bed that in to a thick layer of glue ?

 

I've found Shoe Goo to be a very good adhesive for sticking weird stuff ( e.g. fake turf) to clip box lids, as it is flexible, but I doubt it would work on this combination of materials .

[DMZX]

My go-to adhesive for stuff that has defied all else is Permatex RTV. It stays semi-rubbery, is water proof, heat <600 degrees) proof,and it holds for eternity.

[+beauxeault]

Many thanks to everyone for the advice above. I wanted to come back and let you know the cache published today. It's GC637RP, "Legend of the Frog."

 

It says on the container that the material is PP (polypropylene), and I was able to find elsewhere on the web that PP is a notoriously difficult surface for bonding. So as tempting as the numerous adhesive solutions were, I went with the screws, inserting one under each eyeball in the frog's head, which were the only two spots where there was enough material to anchor a screw. I have not had any problems with the screws holding in the baked clay so far, but if I have to replace this cache, next time I'll bake the head with the screws already in it.

 

I was a little surprised that no one asked about the markings on the container's lid (which are now hidden by the frog's head). I do not know first hand (as I picked the container up at a plastics trade show), but the graphics there seem to indicate that the container was intended to contain medical marijuana!

 

If you're ever in northeast Tennessee, come by and check out the Frog in person!

 

 

[+JohnnyVegas]

I glued something to a plastic lid. First I used gorilla glue, but after getting banged around a few times it came off. Then I tried silicone calking but that too came off. Then I drove in a couple of screws and that worked. I wonder how well screws would hold in that modeling clay, especially if it gets knocked around..--Cute container, hope you are able to find something that works.

Modeling clay. Do you mean the stuff that they sell in craft stores? I have tried using in the past. I never found any glue the worked on that stuff. If the base is flat you might try a very thin piece of wood from a hobby shop the is screwed to the base. Then glue the wool to the lid. Your might also have to change the container.

[+justintim1999]

The mechanical fixing method sounds like the only likely solution to me, but it may not be possible to drive a screw into the 'head' without cracking it , or it may not be capable of holding a screw thread without crumbling. Maybe make another head with a couple of dome headed screws baked in with the heads protruding a little (showing some of the shank)and then bed that in to a thick layer of glue ?

 

I've found Shoe Goo to be a very good adhesive for sticking weird stuff ( e.g. fake turf) to clip box lids, as it is flexible, but I doubt it would work on this combination of materials .

 

looking at the container I would agree. sometimes figuring out the mechanical way of attaching something turns out to be the best.