Hydroform die help?

[HomeSlice]

I’ve been forming 6mm fat rats from Grendel cases using a Whidden hydroform die. It works pretty well for a while, but eventually (75-100 cases or so)’ the o-ri gs on the plunger tear, then it won’t hold pressure.

I started lubing it with a light coat of grease, and this preserved the o rings a little longer, but they’ve torn again. Does anyone know what size and material the ori gs should be? I need to order some replacements, so a source would be great. It appears as if I’m going to need a lot of them.

Is this something I’m doing wrong? I’m forming with water if that’s relevant. I’m planning on calling Whidden tomorrow if I can catch some time at work, but I thought maybe you folks could offer some advice.

Thanks in advance for any guidance

 

[dkhunt14]

Something must be wrong. We have done thousands of cases and never had an o ring problem. I would contact Whidden. Something must be wearing or cuttimg them. Matt

 

[Mastershot]

This happened to me also, So I got a box of o-rings from harbor freight.

 

[Jet]

This happened to me also, So I got a box of o-rings from harbor freight.

Same here. Picked up a bunch more and replaced them as needed.

 

[Johnny_V]

Never did Hydroforming of cases, but worked as a diesel mechanic for 43 years and can tell you the best thing to prevent "O" ring tear is Silicone paste. Here's a link: Silicone Paste

 

[Terry O]

From my experience you need to control the amount of water such that when the plunger is inserted the orings are below the weep hole before the plunger is struck. It's the oring passing the edge that causes the damage.

 

[fguffey]

I do not know if they sell to reloaders but: I have a kit, no 'O' rings, the kit is set up to make up my own 'O' rings. If I do not like the diameter I changed the diameter of the material I make the 'O' rings from.

F. Guffey

 

[spclark]

Never did Hydroforming of cases, but worked as a diesel mechanic for 43 years and can tell you the best thing to prevent "O" ring tear is Silicone paste. Here's a link: Silicone Paste

I was gonna suggest this but thought about what it takes to get that stuff off when you want to move to the next stage....

(Petroleum-based grease & oils are death to rubber & neoprene eventually.)

What’s reasonably cheap as well as effective?
Dawn detetgent & hot water?
Maybe an acetone bath?
Any of the orange/citrus-based cleaners?

Silicone grease IMHO has a place in our world but nowhere near rifles or optics thankyouverymuch!

 

[HomeSlice]

I just spoke with Whidden's. She said that sometimes overfilling it can cause this to happen like Terry O said. She also told me that occasionally there can be a very small burr that will tear the o-ring(s). I used regular grease to lube the o-ring. Do I need to get some of that silicone stuff? Is lubing even a requirement? I forgot to ask her those things...

She's going to talk to one of their guys and let me know if they have any further advice.

These are great people to deal with. I'll let you all know if I hear more from them.