Does Miliput go "off"?

[alcazar]

By which I mean, refuse to harden, once it's old?

 

The reason I ask is that I used some last week to add strengthen to the join of the probe of an air-charge-temperature gauge I'd fitted to my car. It was only tapped into 2mm alloy and I surrounded the area with a shaped bit of Miliput, but it was still the same four hours later. I eventually pulled it all off and used Devcon. A snake I modelled with the remains is STILL soft enough to mark with a thumbnail a week later.

 

The Miliput WAs quite old, but had been kept air-tight.

[Kenton]

http://www.rmweb.co.uk/community/index.php/topic/4468-milliput/page__pid__34793__st__0entry34793

[macgeordie]

I've had problems in the past with Milliput going off, but not the same experience as yours. In my two cases of difficulty the material had gone a bit hard in the packaging which was still original and unopened which made it very difficult to mix the two components together which in turn meant there were areas of the mixed Milliput which didn't harden properly. In your case it sounds like the hardener has as you said 'gone off' if it is still soft after such a long time.

 

I tend to use P38 car body filler in preference to Milliput these days.

[Pugsley]

I think it does after a long period of time - I've had problems with Milliput and Araldite taking forever to cure, or sometimes not curing at all.

 

One possible cause could be the hardener losing its effectiveness over time, or with exposure to air, so more is required to complete the hardening reaction, although that is just speculation on my part, I've not tried using more hardener.

[alcazar]

 

I tend to use P38 car body filler in preference to Milliput these days.

 

 

Wow! That doesn't give you much working time, does it?

[macgeordie]

Wow! That doesn't give you much working time, does it?

 

No, you only get about 5 minutes but it depends how much hardener you put in. If you use about 75% of the suggested quantity it still hardens O.K. but gives you more time. I tend to use it for filling large spaces rather than moulding into various shapes.

 

It's useful for kit building, particularly Silver Fox kits as you can fill the nose ends with the stuff then drill and tap it to take the fixing screws which hold in the donor chassis.

[DavidBelcher]

My pack of Miliput has finally run out after about 16 years of use, still usable to the end although the curing time did seem a tad longer.

 

David

[alcazar]

My Miliput snake is STILL mark-able with a fingernail after over a week:(

[Jenny Emily]

If the hardener is anything like the hardeners I've been using for setting polyester resin, it will contain a peroxide. Over time some of the peroxide may lose its extra oxygen molecule, thus reducing its effectiveness. Adding extra hardener might solve the issue, or using hardener from another source.

[SRman]

I think it does after a long period of time - I've had problems with Milliput and Araldite taking forever to cure, or sometimes not curing at all.

 

 

I have to say I have found, as others in this thread have, that the Millliput hardener does seem to lose its effectiveness over time. However, I have never had the problem with Araldite. One of the tubes' contents do tend to turn white and soapy in texture after a long time but all that is required to restore it to original texture and effectiveness is to soak the tube in hot water for a short time. I should add here that I always buy the larger tubes of Araldite as I use quite large amounts over time and the smaller tubes are really poor value for money in comparison.

 

I hope that this is not taking the thread too far off-topic.

[Jellicoe]

Check out the manufacturer's site for advice. They say it has a shelf life of about two years but I have used 12-year old-stuff and although it had become very hard to work, it gave good results. Some people revitalize it with a quick spin in the microwave but rather you than me.