Rejuvenating old dried Firestar pyrogen?

[georgegassaway]

I have a lot of old Firestar pyrogen that dried up. Used Acetone to thin it, but it just does not "bond" like it used to when I try to dip it. Very thin coating. Then trying to double-dip to get it thicker, the acetone often removes most or all the first dip layer. Also what does bond is too crumbly when it dries.

Any ideas of something else I could add to make it bond better, not be crumbly, and yet not ruin the pyrogen's ability to ignite?

I'm considering clear dope as a plasticizer, but wonder if others have come up with other ways to address this.

 

[Steve Shannon]

I have a lot of old Firestar pyrogen that dried up. Used Acetone to thin it, but it just does not "bond" like it used to when I try to dip it. Very thin coating. Then trying to double-dip to get it thicker, the acetone often removes most or all the first dip layer. Also what does bond is too crumbly when it dries.

Any ideas of something else I could add to make it bond better, not be crumbly, and yet not ruin the pyrogen's ability to ignite?

I'm considering clear dope as a plasticizer, but wonder if others have come up with other ways to address this.

You might try PVC primer, or if it’s too viscous, PVC cleaner. I think they use MEK as their solvent.

 

[rcktnut]

Mix it thicker?? Coat of nitrocellulose lacquer after dipping to prevent crumbling??

 

[tfish]

old igniter man pyrogen freshened up much better with MEK compared to Acetone

H110 or 296 (types) of powder dissolved in acetone make a great 'base' ingredient for pyrogens

I hope this does not violate the no formulas clause..if so feel free to delete.

Tony

 

[dhbarr]

PVC primer is indeed largely MEK, just used some in the garage.

Saaaay, has anyone done Oatey + PVC for motor starter binder?

 

[georgegassaway]

An update. I had some nitrate clear dope, so added some of that. That allowed for the ignitors to "dip" a lot more consistently, and build up thicker with each dip. And when dry, it's not crumbly. I just did a test of one of the ignitors, and it sure went off well. The real test will be in some motors soon.

In any case, so far, the old Firestar Pyrogen seems to be more like it was when it was fresh.

 

[TomBroad]

Jerry Dyben's original FAQs say this about using dried up pyrogen: "Never put any dries Pyrogen back in the bottle (A). Once the rubber cross-links, its over. The Toluene can break the cross-link bond, but upon drying it will NOT possess bonding strength to hold together."

This seems to be what you are experiencing .
Sounds like the use of NC dope at least holds the crumbling pyrogen together (and possible adds its own bit of "encouragement" to the ignitor.

 

[Ronz Rocketz]

Be sure to use the MEK outdoors...

https://omnigp.com/wp-content/uploads/2018/01/Sherwin-Williams-MEK.pdf