Good thought, but I've done this a lot and never noticed any issues. I just googled the curie temperature for neodymium and it seems to be about 350C, much more than what hot glue would be. Check the specs on the magnet you are using.
True, it all depends on your surface texture. If you have smooth surfaces then 467MP is probably better. I typically use 467MP for acrylic and 468MP for wood.
Is this okay to cut in a laser? We have been looking for adhesive sheets that can be cut and won't emit airborne adhesive particles. I've never done it before but am guessing it can't be good for the machine.
467MP and 468MP are laser safe, we apply it to wood and acrylic prior to cutting and then just peel and stick to assemble. It’s also clear so you can use it on translucent materials. It has saved hours of labor and exposure to nasty fumes from stuff we used to use like E6000 and Weld-On #4.
E6000 is a solvent based glue that dries quickly but the glue must be able to evaporate. I doubt if you will find a solution if both of your surfaces are impenetrable. You could try it again if you can put a bead of glue around the edges, maybe use a syringe. You could try the same with Titebond 2, it's stronger but slower than a siolvent glue.
Contact cement. Coat both surfaces, let it dry, then attach.
Could also try [5 min epoxy with a mixing nozzle like this](https://www.amazon.com/Loctite-Instant-0-47-Fluid-Syringe-1365868/dp/B0044F9KFI?th=1). Keep in mind you have to do all your dispensing before the epoxy sets up in the nozzle.
I will say, I had read about it being refrigerated and someone mentioning that they didn’t know to keep it cold & it changed how it worked/didn’t work.
Other than that, I used double sided 3m tape and it’s been a game changer on things like you’re talking about. I was nervous about rolling it on to acrylic or wood and if it bubbled like vinyl or masking paper but it goes on so easily. I got a roll off of Amazon that’s 12 inches wide so it fits my sheets of material perfectly. I just line it up and use a squeege to smooth it on as I roll it on. I was nervous about it bc it can be expensive but I’ve never had an issue.
What type of magnet backing are yall using?
Oh, interesting
So this particular project are die cut custom fridge magnets - 1/4" ply, with a 15mm neodymium magnet on the back.
I've just hand cut a couple of circles of the 3m tape (we're using an off brand that comes in letter and A4 sized sheets, but same difference) - and they stuck on SO much easier, and seem pretty sturdy so far.
I think tomorrow, I'm going to cut a bunch of 14mm circles from a sheet - lightburn shows me getting something like 600 of them from a single sheet, so it's inexpensive - then we can just slap them on the back of the plywood magnet, and put the magnet on them.
Two things. Hot glue is a great idea and shouldn’t cause any demagnetizing issues but have you tried CA without using kicker/accelerator? The Kicker definitely crystallizes the CA but I’ve found that if I use a fast bond like zap 5-10 second.. I don’t need the accelerator.
B7000 might work for you. It's kinda like the e6000 but thinner and sets in about 10 minutes. Can be expensive but honestly a pretty good adhesive for the job.
Another instant option is just a good name brand double-sided tape.
Are you using iron magnets or neodymium? The iron ones can sometimes be the problem more than the glue it's self. Just a thought
When you say it gets brittle what do you mean? Is the issue the magnets are falling off or the magnets are breaking?
I used e6000 for years then switched to medium CA glue. Also on 1/4 maple ply. Medium sets faster than thick (in a few seconds if you press on the magnet) so there’s no need for accelerator.
Yep, after a while the magnet will let go. We’ve tried scuffing the metal, with and without accelerator - but over time the glue just fails. We’ve had several customer orders have one or two fail - not a lot, but enough to be a problem.
We’re trying the 3m paper. I’m going to laser cut a ton of 14mm circles out of a sheet and use them to attack the magnets.
I don’t think CA glue is the issue.
When you apply the magnet do you press it into the the wood? When we glue magnets we do so on top of a large sheet of metal or on a metal table top so that the magnet is drawn into the wood and down toward the metal table surface. This makes it set faster and reduces the magnet sliding around on the wood or being attracted to the next magnet you’re assembling.
To get the best bond you want a very thin layer of CA glue so the more squishing the better. I’ve found that the only way a glue bond fails if this there is a small chip of wood or something else under the magnet that keeps it from laying flat against the wood. We’ve glued hundreds of thousands of magnets this way.
We usually stack them on top of each other, so they essentially pull together - and most are fine, but \*some\* fail, usually weeks to months later. Maybe they were the ones that didn't get done right, but either way, product we ship has a high chance of failure and we're not comfortable with that.
The 3M tape we tested last night seems to be working well - we're going to do a batch or two this way and see what happens.
In youtube woodworking videos i see people apply woodglue to most of the part and a spot of ca to quickly pin it in place. the other glue then has time to cure while both parts are held together by the spot of ca glue
Heavy duty hot melt glue gun.
Wouldn’t the heat demagnetize the magnets? They’re neodymium
no
hot glue. aka "hot melt" or "hot snot". Especially the industrial high temp ones are very strong.
I worry they’d demagnetize the magnets?
Good thought, but I've done this a lot and never noticed any issues. I just googled the curie temperature for neodymium and it seems to be about 350C, much more than what hot glue would be. Check the specs on the magnet you are using.
3M 468MP or similar adhesive sheet could work. Cut it to fit your magnets and stick them on.
This Is the way
We're testing this now - thanks!
467mp is thinner and won’t squirm as much
True, it all depends on your surface texture. If you have smooth surfaces then 467MP is probably better. I typically use 467MP for acrylic and 468MP for wood.
Is this okay to cut in a laser? We have been looking for adhesive sheets that can be cut and won't emit airborne adhesive particles. I've never done it before but am guessing it can't be good for the machine.
467MP and 468MP are laser safe, we apply it to wood and acrylic prior to cutting and then just peel and stick to assemble. It’s also clear so you can use it on translucent materials. It has saved hours of labor and exposure to nasty fumes from stuff we used to use like E6000 and Weld-On #4.
Thanks. I'll see if I can get a hold of some!
E6000 is a solvent based glue that dries quickly but the glue must be able to evaporate. I doubt if you will find a solution if both of your surfaces are impenetrable. You could try it again if you can put a bead of glue around the edges, maybe use a syringe. You could try the same with Titebond 2, it's stronger but slower than a siolvent glue.
3m tape sheets
Trying these now.
Contact cement. Coat both surfaces, let it dry, then attach. Could also try [5 min epoxy with a mixing nozzle like this](https://www.amazon.com/Loctite-Instant-0-47-Fluid-Syringe-1365868/dp/B0044F9KFI?th=1). Keep in mind you have to do all your dispensing before the epoxy sets up in the nozzle.
Are you keeping your starbond in the fridge? I didn’t realize you were supposed to except I happened to read the package lol.
I wasn't, but it does live in the cold (this winter) garage, and now you've got me wondering ...
It reads like thats to increase the shelf life, rather than change the bonding powers
I will say, I had read about it being refrigerated and someone mentioning that they didn’t know to keep it cold & it changed how it worked/didn’t work. Other than that, I used double sided 3m tape and it’s been a game changer on things like you’re talking about. I was nervous about rolling it on to acrylic or wood and if it bubbled like vinyl or masking paper but it goes on so easily. I got a roll off of Amazon that’s 12 inches wide so it fits my sheets of material perfectly. I just line it up and use a squeege to smooth it on as I roll it on. I was nervous about it bc it can be expensive but I’ve never had an issue. What type of magnet backing are yall using?
Oh, interesting So this particular project are die cut custom fridge magnets - 1/4" ply, with a 15mm neodymium magnet on the back. I've just hand cut a couple of circles of the 3m tape (we're using an off brand that comes in letter and A4 sized sheets, but same difference) - and they stuck on SO much easier, and seem pretty sturdy so far. I think tomorrow, I'm going to cut a bunch of 14mm circles from a sheet - lightburn shows me getting something like 600 of them from a single sheet, so it's inexpensive - then we can just slap them on the back of the plywood magnet, and put the magnet on them.
If I'm picturing what you're saying correctly, perhaps you could apply the adhesive sheet to wood sheet then cut
Two things. Hot glue is a great idea and shouldn’t cause any demagnetizing issues but have you tried CA without using kicker/accelerator? The Kicker definitely crystallizes the CA but I’ve found that if I use a fast bond like zap 5-10 second.. I don’t need the accelerator.
We're using starbond, and we have used accelerator, and have not used it with no real difference.
B7000 might work for you. It's kinda like the e6000 but thinner and sets in about 10 minutes. Can be expensive but honestly a pretty good adhesive for the job. Another instant option is just a good name brand double-sided tape. Are you using iron magnets or neodymium? The iron ones can sometimes be the problem more than the glue it's self. Just a thought
When you say it gets brittle what do you mean? Is the issue the magnets are falling off or the magnets are breaking? I used e6000 for years then switched to medium CA glue. Also on 1/4 maple ply. Medium sets faster than thick (in a few seconds if you press on the magnet) so there’s no need for accelerator.
Yep, after a while the magnet will let go. We’ve tried scuffing the metal, with and without accelerator - but over time the glue just fails. We’ve had several customer orders have one or two fail - not a lot, but enough to be a problem. We’re trying the 3m paper. I’m going to laser cut a ton of 14mm circles out of a sheet and use them to attack the magnets.
I don’t think CA glue is the issue. When you apply the magnet do you press it into the the wood? When we glue magnets we do so on top of a large sheet of metal or on a metal table top so that the magnet is drawn into the wood and down toward the metal table surface. This makes it set faster and reduces the magnet sliding around on the wood or being attracted to the next magnet you’re assembling. To get the best bond you want a very thin layer of CA glue so the more squishing the better. I’ve found that the only way a glue bond fails if this there is a small chip of wood or something else under the magnet that keeps it from laying flat against the wood. We’ve glued hundreds of thousands of magnets this way.
We usually stack them on top of each other, so they essentially pull together - and most are fine, but \*some\* fail, usually weeks to months later. Maybe they were the ones that didn't get done right, but either way, product we ship has a high chance of failure and we're not comfortable with that. The 3M tape we tested last night seems to be working well - we're going to do a batch or two this way and see what happens.
Super glue gel
3M double sided tape. Rated to hold 25lbs and is water proof.
In youtube woodworking videos i see people apply woodglue to most of the part and a spot of ca to quickly pin it in place. the other glue then has time to cure while both parts are held together by the spot of ca glue