I'd like to attach a piece I printed out of PLA to a small titanium rod. I've previously used Superglue (cyanoacrylate) to glue PLA pieces to each other with great success, but the problem is that if you don't apply it perfectly cleanly, it leaves very noticeable stains on the PLA.
Can anyone recommend a good glue for this application that won't leave stains like that?
I've been a fan of epoxies for unusual adhesion problems. I found on Amazon a product with titanium in the name, but there's a caution regarding polypropylene plastics.
PLA is not of that family of plastic, which gives it a good chance of success. Epoxy is typically more viscous than cyanoacrylates, giving you a bit more control of the application, but also creating the need for care with "ooze-out."
The big glue company, Gorilla, also makes an epoxy that includes plastic and metal in the adhesion listing.
As PLA is somewhat sensitive to heat, one would consider that fast-cure epoxies generate more heat than slow-cure epoxy, but the amounts you'll be using are not likely to create enough for concern.
Try using one of the "gooey" forms of cyanoacrylate. Any of the major brands sells this-- it has the consistency of toothpaste, so it won't "run" along your pieces. Here's one that I've used with success: loctite goo
After perusing http://www.thistothat.com/ I decided to give J-B Weld epoxy a try.
Most glues will leave some type of visual stain. The glues that won't leave some type of visual stain probably won't stick as well. For example, you can use rubbery RTV type glues, but you will need surfaces designed to minimize the need for glue strength. However, an advantage is the glue will flex.
My favorite is Gorilla impact resistant superglue. Superglue breaks easily when flexed if not impact resistant. If you want to go to the trouble, epoxies are best. Rubbery type glues will work if you have enough surface area, especially if it is not all planar.
A glue gun would IMO work very well, and you can use transparent (or almost transparent) glue sticks to minimize ugly looking stains.
Things glued together usually break before the glue (in my experience) and it's cheap, you can get one for $10 with some glue sticks. It's fun too, I glue everything since I bought one :-)
