Intermittent buttons

[ljcox]

Thanks Mr. RB. I'll keep that in mind.

I found that RS Components have the Keypad repair kit (CW2605) in stock locally.

However, according to the technical data sheet for the product, it has a "72 hour pot life".

I find this statement ambiguous.

Does anyone know what it means?

For example, does it mean that it has to be all used within 72 hours of opening the pot or that any solution that has been mixed must be used within 72 hours?

Any assistance will be appreciated.

 

[jpanhalt]

It means that once the components are mixed, the mixture must be used within 72 hours.

https://www.electro-tech-online.com/custompdfs/2013/04/0900766b80034919.pdf

You can usually extend pot life by refrigeration.

John

 

[KeepItSimpleStupid]

You have a liquid and a solid, so it may be hard to mix in lower proportions: See: https://www.electro-tech-online.com/custompdfs/2013/04/0900766b80034919-1.pdf

It takes 72 hours to cure.

 

[jpanhalt]

If you are planning only to mix up a portion, try contacting the manufacturer and find out what the weight ratio is. Then you can mix by weight. If you can't get that information, there are ways to estimate it fairly accurately, so long as you have an accurate (±10 mg) scale.

Pot life and full cure time might be the same length periods, but they mean quite different things. Pot life is the useful working time after mixing and before application.

Apparently, cure is in at least 2 phases. First is solvent evaporation. It dries to the touch in 1 hr. Second phase is apparently a polymerization. It is usable within 24 hours and completely cured at 72 hours. Epoxy primers have similar multi-phase cure times. But, instead of giving a period for complete cure, there is a recoat time, often something like 48 to 72 hours, which means that after that time, the hardening process has proceeded to an extent that finish coatings will not adhere. I am not saying this is an epoxy -- just saying that many catalyzed coatings have similar multi-step curing periods.

One thing one often sees with two-part finishes is the need for an "induction period." That means, one should wait a certain amount of time after mixing the components before application. It is usually 30' to 1 hour. An induction period is not mentioned for this product, but since the pot life is 72 hours, waiting 30' to 1 hour after mixing won't hurt.

John