Repairing Silicone

Factual Questions
1

Is there any glue like product that bonds to silicone so that it can be repaired?

I have a small pump with a silicone diaphragm. The diaphragm is attached to a piston and it creates a vacuum as the piston moves. The diaphragm has a small split, and I was hoping to repair it rather than buy a new pump for $200.

I tried duct tape… could barely get the tape to stay on the diaphragm in the first place, laughably useless.

I tried silicone caulk on the outside surface, it kind of sticks but doesn’t hold a vacuum.

Before I try to fill in the backside with caulk, which would probably make any other kind of repair impossible, I thought I’d ask the Dope for a better option.

2

Maybe the pump manufacturer sells replacement diaphragms?

3

If it is a Thomas compressor, replacements are certainly available. I picked up a pallet load of these free, most with blown diaphams.

I had a local gasket maker cut some replacements for me…Cheaper and faster than ordering them.

Are you sure it is silicone? Mine were neoprene.

4

Not with anything close to the strength and integrity you require, You need to replace it.

5

It’s actually for a Medela breast pump, I’ve been around and around with them and they don’t do replacement diaphragms for it, you have to buy a whole new pump, which is really annoying because it looks like a $5 part.

6

When I was making and repairing aquariums, it was pretty much taken as law that if the integrity of the silicone seal was compromised, the only way to repair it was to scraped it clean and reseal it from scratch.

7

Buy a kitchenaid brand pliable silicone cutting board and cut yourself a new one with an exacto knife.