I just made a box that is secured by opposing magnets pocketed into both the top and the bottom of the box.
The magnets are a slight press fit into the pockets.
What is the best method to more securely attach the magnets into the pockets, recommendations as to type of glue or anything else?
What material are you gluing into?
For wood I usually use CA glue, for metal or plastic, epoxy such as J.B. Weld.
Small magnets into walnut
I like a adhesive called E6000, I’d test it in the wood first. It’s gooey stuff like silicone and is non conductive, but the reason I really like it is you can normally get it to come back off, like a post it note version of rubber cement. I have used it on a wooden 3D print, so your milage may very.
I usually go super glue like @WillAdams recommended. The only note there is that it’s thin enough it can pull into your wood with capillary action. This can cause some color distortion.
@Bee do you find E6000 does the same thing or is it thick enough to prevent that action?
If you can keep it from showing in your application, Loctite Black Max (380?) is an awesome CA glue that’s a little flexible so it might move better with the wood.
I used it to glue some extrusions together years ago for a temporary fixture to stack material for a robot to load one of our Brother CNC machines, but it never broke so I never had to make a real fixture.
@erica I’ve added a couple of flat magnets (9mm x 3mm) to the back of many small signs made from ¼” plywood and stuck them with CA glue. I haven’t heard of any problems, but I had a heavier piece where the CA glue popped loose.
I’ve also embedded the same magnets into the top and bottom of pieces designed to fit together. I use a 0.36” pocket for a 9mm magnet which leaves about 0.003” all the way around for the glue to squeeze upwards after pressing the magnet into the pocket. I think it gives a better hold to the plated magnet.
The problem you are trying to solve is to have enough magnetic field to hold a part but not so much that its difficult to release the hold. (Also, there’s no need to force fit the magnet into wood. A loose fit is so much easier, because you really can’t control tolerances like you can in metal.)
Having said that, I think the E6000 is flexible enough to eliminate the possibility of the wood swelling a little bit and breaking the bond of CA glue. I use E6000 now.
Thx, I used E6000 and it worked well
I use this stuff all the time on my projects. Just need a few drops and sets up in 30 seconds. A little pricey but well worth it. This is not superglue. Similar to CA glue but it isn’t two parts. But if your looking for something removable this wouldn’t be the one. This is also nice for repairing items that would need to be held together while the glue dries because the setup time is very short.
I was so interested that I looked it up at DAP RapidFuse. The only thing I can find “wrong” with it is this quote from the TDS:
Not suitable for use on polyethylene, polypropylene, or PTFE.
I think it will make that plastic melt worse than the Wicked Witch of the West! (1939 film The Wizard of Oz).
I think I’m going to stock this glue. Thanks!
I’ve never had to clamp anything because it sets up go quickly. Besides lots of things i have used it on were such that they couldn’t be clamped. Don’t know that i’ve ever used it on any polypropylene. But i did forgot to note about slighting wetting nonporous surfaces. The other important item was don’t use too much. A little bit will do it. When you do use it make sure to position the parts exactly where you want because you only have a few seconds to reposition the parts. I do all my work in an unheated garage so if the RapidFuse is cold I run it under hot water for a minute or so to bring it up to room temperature. Makes it easier to apply. If you don’t wipe the nozzle off after use and get some buildup around the nozzle where the cap wont close tightly. I just take a razor blade or sharp knife and trim any excess off. Now you know everything i do…about this.
Thanks to all for their experience and suggestions. I think I will get some RapidFuse for my next product.
I never expected so many varied opinions.
I wonder what would have happened if I asked Chevy or Dodge?
They make CNC’s? 
I have some of that and it’s a bear to get it out of the bottle. I don’t know if I just got a bad batch or if it’s all that way.
Run under hot water for a few minutes. Makes it much easier to use
Most adhesives bond by a combination of three core mechanisms:
Surface wetting and interfacial contact
Mechanical interlocking
Molecular/chemical attraction
Additional important factors:
Concise statement:
Most glues work by wetting surfaces, mechanically interlocking with microscopic texture, and forming molecular attractions or chemical bonds; cure chemistry and formulation then set the adhesive’s final mechanical and environmental properties. These are probably the most important parts:
Clean, dry, and appropriately roughened surfaces improve wetting and adhesion; contaminants reduce strength.
Thin, stiff bondlines transfer load better
Glues are meant to be squeezed like a partner under the mistletoe! 
You would break this partner’s back before you got it out of the bottle. I will try warm water tomorrow but it seems like that would shorten the life of the glue. I’m no chemist though.
This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.
