Plastic to Alumalite, what glue?

[bob]

I need to glue some plastic CNC letters to a chunk of painted Alumalite.

The plastic will be acrylic, probably, and the Alumalite is painted because is doesn't come in the color needed. Neither does any vinyl for a flood coat. Paint it has to be.

I don't want to use VHB tape unless I absolutely have to because I want the letters smack on the substrate, not stood off the thickness of the tape. Gorilla Glue works but it's messy and it foams up and will tend to expand beyond the letters unless I'm vastly more careful than I want to be.

So, what glue to use? Something readily available and less messy than Gorilla Glue would be a boon. Should I mask the positions of the letters on the substrate so I'm gluing to the original finish on the Alumalite or not?

 

[J Hill Designs]

LORDS adhesive, or scuff and silicone. Silicone may be better, as the thermal coefficients differ between the two materials

 

[Circleville Signs]

+1 for silicone - Although personally, I'd use Gorilla Glue. I know you have to be more careful with it in this application, but it does the job better than anything else.

 

[Shovelhead]

Mechanically fasten for peace of mind.

 

[SignosaurusRex]

3M's Pressure sensitive Transfer Adhesives are what we have been using very successfully for this type of application. 468 has been our main choice. It is essentially a layer of adhesive without an internal membrane on a coated transfer liner. Its thin, fast, clean and reliable.
http://www3.3m.com/catalog/ca/en001...uction_3_0/command_AbcPageHandler/output_html

 

[Jillbeans]

I agree about somehow fastening from the back with screws.
If the Alumalite is painted, anything you use will only be as strong as the paint bond.
And Gorilla Glue, while it does work, can be so messy and unpredictable.
I think the VHB might be a better option, after all, it is pretty thin.
Maybe if you weighted the letters while they adhere it would smash down the VHB?
Love...Jill

 

[bob]

I agree about somehow fastening from the back with screws.
If the Alumalite is painted, anything you use will only be as strong as the paint bond.
And Gorilla Glue, while it does work, can be so messy and unpredictable.
I think the VHB might be a better option, after all, it is pretty thin.
Maybe if you weighted the letters while they adhere it would smash down the VHB?
Love...Jill

Screws are out, the cut out letters aren't meaty enough.

I cleverly cut an inline 1/8 from the edge of the letters out of paint mask and applied it to the Alumalite before painting. This will leave enough of the original Alumalite finish exposed for bonding. And give me a clue as to just where to place the cut out letters.

I decided to go with VHB, foibles and all. Gorilla Glue is just too messy for smallish work. Moreover it didn't bond all that well on my test piece, the glue parted from the acrylic too easily for my liking.

Thanks all...

 

[Jillbeans]

Clever idea with the paint mask! Why am I not surprised?

 

[rm25x]

Can you use a thick CA glue (Cyanoacrylate glue or superglue as its sometimes refered to) on the backsides of the letters? A little down the middle, press it down and good to go. The thick glue has a longer cure time to help you out with adjusting it etc, and is not a runny mess.

 

[Marlene]

we use Goop glue and it works really great. the automotive and the marine are the ones we have used.

www.amazinggoop.com