Advice on airline hose ... new fittings .. crimping issue.

[Submariner1]

Any experts on crimping ferrules. Max Pressure 150 psi.
I need to secure new stainless steel 1/2” BSP hose tails on a Rubber Alloy 1/2” ID 21mm OD hose.

Ideally I would like to use stainless steel ferrules ... but obviously do not have a swager.
Local people only use their hose and fittings, others want £12 an end to crimp ... plus a long drive.

Alternatively I could use these stainless ear clamps


not a great fan, as they leave protruding flattened ears, and I need to buy a crimp pliers like this Knipex 220 mm long. Circa £23

but I found an old pair of nail pullers 197mm long, which seem pretty similar.
Could I just clean up the ends and try and replicate the profile?, apart from being a tad shorter .. And requiring more pressure ... would they crimp the ears?

Alternatively if I bought a stainless ferrules like this


Could I put one of these on the hose, and then put a Couple of 2 ear O clamps over the ferrule and compress the O clamps, hoping to effectively ‘dent’ the ferrule in ... i.e. a sort of heath robinson crimp mechanisim. And then cut off the ear O clamps? Hopefully leaving a crimped Ferrule?

I suspect, because the ear clamp is 8mm wide, it would be very difficult to use this to dent/crimp in the stainless ferrule?
What do you think? Possible or highly unlikely?

Or would using an aluminium ferrule be easier to compress in a securing dent?

My gut feel is the only real home DIY option, is just to use a couple of the the 2 Ear O Clamps and live with the protrusions.

Right pain in the arse to fix up my air-filter to be bolted to the wall and also to be attached to the Compressor when mobility is needed. And have stainless fittings before the air-filter.

 

[LostKiwi]

I have an hydraulic battery terminal crimper that would probably work with those ferrules. Crimps to a hex shape.
Not sure what the max jaw width is.

 

[Craiglxviii]

Live with the protrusions. What hassle are they going to cause, really?

 

[Submariner1]

I have an hydraulic battery terminal crimper that would probably work with those ferrules. Crimps to a hex shape.
Not sure what the max jaw width is.

Thanks, I looked at those - they seem fine for 1/4” bsp but are a bit too small for the fatter 1/2” BSP ferrules that are 25mm oD.

 

[Submariner1]

Live with the protrusions. What hassle are they going to cause, really?

I Think its the only practical way.

 

[Tony Dyson]

I think you need to be speaking to the "Rubber Alloy" hose manufacturers for more specific details on what you need, DIY alternatives usually end up in numerous aborted attempts before settling on something that wasn't quite what you were looking for! Crimping tools for anything electrical are designed to crimp soft copper tube terminals not SS and the tools picture have cutting faces you would need to blunt, better suited would be a pair of mole grips.