Leather cup washers.

[Retired]

Hi,

I bought a paraffin blow lamp very cheaply at Rufforth Auto Jumble a few years ago and have finally got around to needing it. With the tank cap and valve tightly closed I tried to pressurize the tank but without success; upon removing the plunger I found the leather cup washer to be missing? No problem these cup washers are readily available and cheap so I browsed the web to find these washers are now difficult to buy so perhaps this was the reason I managed to buy the blow lamp so cheaply?

Rather than waste more time I decided to make a new cup washer and as expected there are tutorial videos on YouTube so I'm not alone. The next problem was finding suitable leather but a seller on eBay had just the leather I needed which arrived a few days after paying for it. This is the leather;

This size will easily make 12 cup washers. The bore of the cylinder is 5/8" diameter so I cut a 2" square of leather the leather in Imperial is 1/16" thick. I soaked the leather overnight in water. The bore at 5/8" and the leather at 1/16" meant I needed a round bar of some kind at 1/2" diameter; I have lots of metal so cut a short length of 1/2" diameter BMS (bright mild steel) ensuring sharp edges were well rounded. A piece of 3/4" thick plywood was drilled at 5/8" diameter and this then smoothed with abrasive paper removing the sharp edge around the opening and for good measure it was waxed.

It was a very easy job to force the steel into the plywood taking along the leather with it using my engineering vice. This was then put aside to allow it to dry. The following day I had a cup washer but the inside of washer had turned black due to reaction of leather tanning on the steel but this isn't detrimental. This was a success and allowed the tank to be pressurized but the new cup washer felt a bit loose; I had given the washer a good dose of light oil to soften the leather but as making these washers is so easy I made another this time with an outside diameter of 11/16" and again having oiled it this is now installed to my satisfaction.

Firing the blow lamp up for the first was interesting; the flame came out sideways so the jet needed cleaning which I did with a single wire from a wire brush; I've now got an old but excellent blowlamp costing very little to fuel up.

I thought it worth adding this because I'm sure many of these old blow lamps will be unused just because they require a leather cup washer; below is a YouTube video showing a guy making one of these cup washers; I'm pleased I don't fly in his plane though if he's known about a primer leak for a while?

Kind regards, Colin.

Leather cup washer just made but requiring some light oil to soften it.

The blow lamp was bought very cheaply and after a bit of interesting work it's now a welcome addition to my workshop.

Very simple tooling is needed.

This is the second cup washer I made but this time I protected the end of the steel with a layer of Sellotape hence a cleaner washer.

I struggled to trim the first cup washer but with the second I just popped it through the bandsaw taking care not to remove a finger or two. I'll now have a mug of tea before wandering down to the workshop for a day of uninterrupted pleasure during this virus lockdown.

 

[Doghouse Riley]

I've always been fairly practical. In my teens I worked in an office in the West End, one of the managers was an ex RAF pilot officer who won the DFC. He was quite self-effacing. Never talked about his war service, but one night in the pub, after a few pints when pressed, he told us how he won his DFC. He got his damaged Lancaster to and back from the target. He said "I was all for baling out, but the rest of the crew said, 'No skip, we can make it.'" How true this was is anybody's guess.


Anyway, he'd bought a house and at the week-end was painting the woodwork of the window frames outside. He had no experience of DIY but was having a go. He'd borrowed a parafin blowlamp, but he said it was a pain when it frequently blew out, having to come down the ladder and put the meths in the tray and light it again. He was a bit sheepish when I said it wasn't necessary, while he was up the ladder he just needed to use his lighter to light it again.

 

[Retired]

Hi,

Thanks Doghouse for the tip; as usual it's easy once known but I wonder how many use meths to relight a flame just blown out. I did a silly thing whilst trying the new cup washer out; I had just cleaned the jet and as I pumped up a bit of pressure I was greeted with a stream of paraffin shooting across the bench soaking everything; if there's an hard way to do anything I'll do it the hard way first.

Kind regards, Colin.