Knowing what a clever and sometimes devious lot we are here I was wondering if anyone had ever made a rubber seal thinner. I have found a coffee pot seal that is the correct inner and outer diameter for the Lucas calcia carbide bycicle lamp. However it is marginally too thick, which prevents the tank at the bottom screwing onto the lamp body. I think I only need to remove a little - say .25mm or 10 thou Many thanks, Chris
I never did such a thing, but maybe it could work in this way(?): stick the seal on a flat piece of wood with a double sided tape. Move the wood with the seal over a fine sand paper until it's thin enough. At the end just pull off the seal from the tape. Regards - Steven
@Fireexit1 I recommend cutting seals from nitrile sheet of the required thickness. It’s cheaper than viton (which I use exclusively for liquid-fuelled appliances) and won’t be affected by the carbide or water. Use scissors to cut marked inner and outer drawn circles then if needed, use a Dremel sanding drum to grind away any irregularities left by the scissors. John
Thank you @Steven67 @presscall - I am now looking for my carpet tape (it is about somewhere) and have ordered some 3mm Nitrile from ebay. thanks again, Chris
I have also today ordered a "circle cutter" - not sure if it will cope with 3mm nitrile. But for £5 i will try it out.
If you mean one of these yes it will cope but even with a little lubrication, you may have to cut from both sides.
Sooo.. managed to cut a new seal. A little undersized but workable. However at 3mm thick, which is thinner than the original it would not allow the lamp to be assembled. I think the original rubber is softer. But I have learned so no time and money was wasted. I will order up some thinner still.
That circle cutter looks very usefull! I don't knew, that they are available for such a reasonable price. So then: i ordered one just now to be prepared ... ;-) Thanks Chris @Fireexit1 to give me this inspiration!
@Fireexit1 Does it come with spare blades at all? Or are spare blades available for it? im not sure but in the last photo it looks like a disposable craft knife blade? The type that snap off ? thanks
It came with a couple of spares. They don't seem to be anything I recognise. But at £3.48 delivered I am not unhappy. Spare blades are available on Ebay as well. Not sure how interchangeable they are between brands tho. I did notice that you can flip them over so if you are a southpaw and want to cut in the other direction this will work. (the blade being angled)
I got my "Compass cutter" from an art shop, it came with 6 spare blades and 2 17mm long (pencil)leads.
Boehm punches are also excellent … and ‘twinnable’ so that with one mighty blow you can make a washer that is perfectly on center. Ulf.
@Ulf Yes, concentric punches are good, like my Maby (Sweden) set … … but while their expense is justified for the common lamp and stove seal sizes, it wouldn’t make economic sense to buy the large size required for that carbide lamp, given that there was no uniformity to carbide lamp gasket sizes, judging by those in my collection. John
Concentric punches is a great idea! My punches were the cheapest on eBay (£17) and when I need a washer I need to make at least 5 and then try and trim up the least off centre one. I have tried punching a small pilot hole and everything else I can think of but to no avail. Not a total waste of money as my lamps now run which was all I asked of it.
