Best adhesive or glue for mirror acrylic to other material?

Beyond the Manual
1

Hi, I am having a bit of time trying to find the best glue to adhere cut extruded mirror acrylic to cast acrylic.

I do a lot with mirror acrylic. For larger pieces, some Super 66 spray glue and I can glue a larger cut piece to say a piece of veneer, felt, other types of fabric, etc. But sometimes I am trying to adhere small cut pieces to cast acrylic pieces and I do not get a good enough hold. I’m guessing its something to do with the surface tension of the back of the extruded mirror and the surface tension of the cast acrylic and finding the right glue that will get a really tight grip of the two.

To bond cast to cast, I just use the Weld-On 4 with a 27 gauge needle and I love it. The capillary action really gets into the tight areas in between, its sets fast and once it cures, its on. But it does NOT work with the extruded mirror. Like, not even a little bit. The only thing it does is to basically eat away at the backing coat. There is zero adhesion.

Your average super glue also doesn’t seem to have a consistent hold. Yes, it will hold initially, but I have had pieces actually pop off (I do jewelry) and that is not good when a customer tells me that one of their pieces came off.

The Weld-On 16 seems to work OK but goddamn, its stringy and its a real pain in the ass to apply cleanly to very tiny pieces (we are talking pieces that might be only 3-4 mm wide). Doing a inlay set in piece isn’t sometimes possible because 1) getting the kerf right is unpredicatable and 2) sometimes I am going for a 3D affect where one pieces is sitting on top of the other so I need to be able to glue it on TOP, not try to set it IN

The other thing I have tried is UV resin but again, its doesn’t give me a predictable hold. Regular 2 part epoxy resin just takes too damn long to cure.

E6000 seems to do a pretty good job but it takes forever to cure and I will actually have pieces start to move and shift on me. So I need something that has a faster curing time.

I have NOT tried JB Weld. My understanding is that it is similar to the Weld On products but if anyone wants to correct me on that, feel free.

The super 66 spray works GREAT to spray my larger mirror acrylic pieces to felt and the E6000 works pretty decent if I’m doing mirror acrylic to cast and its a bit larger piece but these smaller cut pieces and letters are killing me trying to find a glue to be able to apply cleanly and not have to wait 100000000 hours for it to fully cure.

3 Likes
2

You might find this information helpful, in the adhesion world, there is the concept of “wetting out”. It might help to use the spray adhesive, and then take a minute or so to apply a consistent pressure to it to help it wet out better. Like smushing the tiny glue spray dots all flat and together.

It really matters how the finished piece will be used though, like a wall hanging vs jewelry that can get knocked easily. I have found that E6000, although stinky and taking 24- 36 hrs to cure has been the best jewelry glue, since it adds a tiny bit of bounce in the connection. Posting a picture of what you are doing may help in better suggestions too!

1 Like
3

My understanding is:

Weld-on is is mostly solvent that causes the acrylic surfaces to “melt” together a little to form a bond.

JBWeld generally refers to a 2-part epoxy that adheres surfaces together.

I have used JBWeld to attach plastic to metal. Weld-on won’t do that.

They are both brand names rather than specific products, though. So, there may be matching stuff from each line.

4

Another random thought: what about incorporating some sort of mechanical holding into your designs? Or, even partial holding to give an adhesive like E6000 time to set. e.g., engrave a shallow impression where the outward-facing bit will sit so that it keeps the mirrored piece from moving while it sets.

Oh! Also: roughing up surfaces to be connected (with sand paper, engraving a light pattern, etc.) may significantly improve the strength of the bond for the non-Weld-on adhesives. You may not be able to do that with back-mirrored acrylic but, you could rough up the other surface. I believe there is also front-mirrored acrylic available.

1 Like
5

Assuming you’re trying to adhere to the coated side of your mirrored acrylic, SciGrip (Weld-on) 4SC or 42 will not work because the coating is not acrylic and their acrylic adhesives depend on like-to-like contact. That’s like expecting a piece of wood wrapped in aluminum foil to bond to another using wood glue.

55 “Polyurethane” might, but so would many other more affordable adhesives.

1 Like
6

The E6000 seems to work fairly ok but its a pain in the ass. If I’m gluing like letters to a cast pieces, I do a score of those letters into the cast piece mostly to just make sure I am able to get everything properly placed. I was able to do the last piece using a glob of some e6000 on a plastic palette and then applied with a coffee stirrer onto the pieces.

1 Like
7

If i’m placing letters onto a piece, I just score the outline so I know where to put the pieces. But I might just try a really light engrave to rough up the surface

2 Likes
8

Have you tried 5 minute epoxy?

9

The biggest issue I’m having with 2 part epoxy is that it shrinks and also it’s not flexible. There are cases where I am gluing 1/8" mirror pieces onto a 1/16" (or thinner) and there might need to have a slight bend on the bottom piece. Like these hat plates I’m working on that are held to the hat front with nipple rivets. It’s not a huge amount of bend, maybe only a few degrees. I have the letters spaced out so that the center that has the most bend doesn’t have a letter on it and the outer edges are only having to bend a little. I used the e6000, let it cure for 24 hours but screwing the plate onto the hat front three letters just popped right off. The glue when dried is kind of rubbery and I could peel it right off.

From my understanding, there ARE 2 part epoxies that are a bit more flexible but the average 5 min 2 part you find at a hardware store is rather rigid. I guess I’ll go buy some to try. For 7 bucks I’ll experiment I suppose.

I’ll try making another one but actually do a light engrave of the letters so the surface is a bit rougher when I go to glue them on.

20200516_005025
20200516_005025707×707 208 KB

1 Like
10

I wonder if a mounting film to the back will be the best solution? If all those options aren’t working well. Trotec offers their materials with 3M for signs so I would assume you too could apply this to the back of the mirror and just peel and stick no dry time. I haven’t tested it myself but if it’s gonna hold a sign I’m sure it will hold jewelry. Where is May become an issue is it would lift the mirror a little higher than other materials if doing an inlaid piece.

11

Bend first (assemble your base plate to hat) then glue on the embellishments so you aren’t fighting the bend?

12

Although it is a slightly different design, you might try inlaying the text into the same thickness backer piece. You could then use a thin acrylic or wood veneer with adhesive on it to cover the back of the plate. No more bumping off of letters, and the letter placement would be perfect every time. Granted it won’t have the 3-d effect, but it would be a sturdier design that won’t break as easily.

13

I can’t really do that unless I buy entirely different/longer nipple rivets; I’m trying to make use of the ones I already have on hand (and waited 5 weeks for). This material is already a little under 2mm thick, plus having to go through the hat material. The rivets screw on, but barely.

These plates are needing to be able to be taken off if someone needs to wash their hat.

I ended up buying some Loctite 2 part and then some plastic glue from Dap and tried some on different pieces. It seems to be holding up and I was able to get the plate screwed in. I’m going to make a couple more to test before I feel comfortable selling them

20200518_211535-01
20200518_211535-01594×840 155 KB