A Re-sealable Air Vent For Plastic Barrels.

[Dennis]

I mainly make small one-offs , but recently I have fretted about the lack of finish on the insides of my pieces, where hand tools can’t reach. So after all these years, I decided to buy a mini-barrelling machine with a two pound barrel and internal fins. I also bought some mixed stainless steel shot and for lubricant I have been using up my TSP left over from experiments with niobium.

The big problem with plastic barrels is that they rely on the accurate fit of the lids at each end, which means that closing them is quite a struggle. To achieve this , air has to be let out of the barrel by raising one edge of a lid and pressing down on its centre. After several attempts at this and some bent back fingernails, you might find that the opposite lid has come adrift, allowing shot into the gap, which will prevent it from being re-seated.

To avoid all this, I decided to make an air vent with an improvised seal using a stainless steel nut and bolt, which I found in my local ironmongers, two rubber washers punched out of neoprene (tap washers might have done) and some metal washers pierced from stainless steel sheet. I also brazed wings onto the nut, using silver solder and Tenacity No 5 flux, so that it could be tightened with my fingers.

What a relief! The lid now closes easily with a loud hiss of escaping air and the nut can be tightened to re-seal the vent. Dennis.

[ps_bond]

That looks a worthwhile mod, Dennis - if I'd thought of doing it I'd have probably tried to add a Presta valve (http://en.wikipedia.org/wiki/Presta_valve) onto the lid (but then I can usually over-complicate things). Meanwhile, I've just faffed about with trying to pry the edge open and push down to expel the air.

[Dennis]

Ye I was thinking about cycle valves, Peter, but I haven't had a bike since my school days, so I've had to reinvent the wheel, so to speak. Dennis.

[Patstone]

Thanks for your views on the plastic one, perhaps I will take George's advice and buy the rubber Lortone 3A. Presumably stainless steel shot is the best to go for, we make mostly earrings and pendants, but I think chain mail may be the new kid on the block after seeing the beautiful stuff that George makes. By the way, I got to grips (sort of) with the jumprings, its easy when you know how, all stuff we should have been taught at the evening class I suppose. Well a Koil Kutter is now not necessary, and we are putting our well earned money to getting a hallmark and a tumbler. I am sure one day I will be in a position to be able to help starters like you have helped us. Many thanks, Pat

[medusa]

I don't seem to have that problem with mine, it has a screw shut closure a bit like the one you just modded.

[lorraineflee]

Running some hot water over the lid sides will expand the plastic slightly and allow the lid to be taken off with no damage to finger nails! - honest!!
Lorraine