Plunger seal failing when filtering

[ToneDaBone]

I've successfully homebrewed several times before. Finished product always came out great, never had any issues. Yesterday I was brewing some test and was ready to filter. I use 60ml syringes, .2 um 25mm PVDF filters, and an 18 gauge needle, which I've used every time in the past. I also warm my oil for mixing and filtering. The only thing I tried differently this time was initially using an electric caulking gun. I filled the first syringe with about 50ml and into the caulk gun. Got about halfway through filtering and felt a pop. I could see some oil had gotten behind the plunger. Took that as a sign to ditch the caulk gun. Was still able to push most of the remaining oil through the filter by hand. I dumped the excess oil that had gotten behind the plunger. The rest of the test I filtered by hand. New syringe and filter each time, and the plunger seal broke 2 out of 3 times when filtering by hand as well. Ended up making a huge mess and having to dump a ton of product.

Any idea what could be causing this? I figured it had to be the caulk gun initially, but the other syringes still failed when hand filtering.

 

[narta]

Faulty batch of syringes with bad tolerance. Happens some times.

 

[buck]

Likely to be the syringe. If too much pressure was used i would expect filter failure.
Was it from the same batch of syringes you have used in the past?
Was it a good high quality syringe?

 

[H&M]

I assume the pressure was to hard,or the oil was too hot for syringe or both.

 

[Spaceman Spiff]

what brand?

 

[ToneDaBone]

Likely to be the syringe. If too much pressure was used i would expect filter failure.
Was it from the same batch of syringes you have used in the past?
Was it a good high quality syringe?

I can't say for sure if I've used these same syringes before. Can't seem to track down an order from Amazon or one of the medlab sites. Not sure if these are even considered high quality. Looks like they're made by a company called Global.

 

[ToneDaBone]

I assume the pressure was to hard,or the oil was too hot for syringe or both.

Could be. But from everything I've read, I thought the filter would be the point of failure from too much pressure. I've never heard of this happening.

 

[narta]

Could be. But from everything I've read, I thought the filter would be the point of failure from too much pressure. I've never heard of this happening.

I had this happen with a combination of hot oil, pressure and bad silicon plunger. And it was definitely a defect in the plunger because temp and pressure was the same as every time.