How to glue silicone.

December 26, 2010 1:08 PM

What glue should I use to repair silicone? Silicone glue seems like the obvious choice but from what Google tells me it is not as simple as that.
posted by neksys to Home & Garden (12 answers total)

What are you trying to repair?
posted by ssg at 1:27 PM on December 26, 2010

Your choice of adhesive is definitely going to vary based on whatever it is you're trying to fix, and what you plan to do with it. Not to put too fine a point on it, if you're trying to repair the sort of silicone item that comes into close and extended contact with human mucous membranes, you should probably just replace it, no matter how expensive it may have been.
posted by Faint of Butt at 2:24 PM on December 26, 2010 [1 favorite]

Silicones rely on catalysis to polymerize. If you have a platinum-solution catalyzed base material and you use tin-catalyzed material to adhere it you will very likely have a faulty bond since the two catalysts interfere with one another.

Without pretty good knowledge of all the materials that go into the structure you want to repair, you are simply playing the odds.
posted by jet_silver at 2:34 PM on December 26, 2010

You'd need to tell us what two things you are trying to glue together.

ThistoThat is a great resource.
posted by special-k at 5:07 PM on December 26, 2010

Also, have you heard of Sugru?
posted by special-k at 5:09 PM on December 26, 2010

my experience with casting silicone is that if it is clean, it will definitely adhere to silicon
posted by compound eye at 7:15 PM on December 26, 2010

Response by poster: It is not a dildo, so lets just get that out of the way.

Its a tea infuser. Its a silicone leaf stalk.

Its not terribly expensive but it can't be returned and its useful and the ladyfriend likes it. Also, I like to repair rather than replace whenever possible.

It will, however, come into contact with drink, so any repair would need to be non-toxic.
posted by neksys at 8:13 PM on December 26, 2010

Unfortunately Sugru is not food-safe.
posted by special-k at 8:30 PM on December 26, 2010

Like compound eye, I've used casting silicone to repair molds. In my experience it's fine for gluing together larger faces, but isn't strong enough for joining small faces under stress - any small weakness or noncomformity & it starts to tear - unless you can build up a bit around the joint.

A product called Sil-Poxy worked better for small joints under tension; its about as strong and stiff as 40A molding silicone but 'grips' better. 2 issues:

1. It ain't cheap - 3oz looks to be ~US$30 (which is ~½ the Aus price, but still…)
2. I've got 3 different MSDS sheets which claim it's a) non-toxic, b) an irritant, and c) non-toxic once cured. Make of that what you will.

Regardless of what you use, the faces need to be scrupulously clean & preferably scuffed up to aid adhesion.
posted by Pinback at 11:20 PM on December 26, 2010

I understand the 'do not throw away unnecessarily' sentiment, but getting something like this reattached properly, while making it look original, is going to be a very tough exercise. The small surface area is a real problem.

Could you possibly just get the steam / stem+top replaced, instead of the whole infuser?
posted by defcom1 at 3:35 AM on December 27, 2010

I doubt that any silicone adhesive available to consumers is going to be completely food safe, especially when coming into contact with hot water. Additionally, there may be issues with the hot water destroying the bond itself.
posted by Thorzdad at 6:19 AM on December 27, 2010

Response by poster: Thanks for all the help. Sometimes no answer is still the best answer! I will contact the manufacturer and see what they can do for me.
posted by neksys at 12:27 PM on December 27, 2010