Hi All No not part of my shopping list although i do like a flinty pastry from the land of Melton Mowbray 8) I picked up this complete X246 with a pork pie fount for 99p from ebay locally as they would not post , good for me though After a quick brush down first to rid it of many years of cobwebs , dust & muck etc i popped a couple of seals in , oiled the leather that was there already , gave it a pressure test & then fired it up & too my suprise it works really well even the vapouriser is good Glad to say that it has the correct age related deep bottomed globe too , but the top plate looks like an embalmed orange The rest of the hood was straightened & acid stripped as was the burner which is still in the pickling bath I ran the lamp with a hood & burner off of the chrome Guardsman used earlier for testing the Stuman vapouriser Stu
Hi Brian I always use "citric acid crystals" available from chemists or the net , i find acetic acid like vinegar a bit harsh on brass just my preference though I use it in a gel form made with a large dessert spoon full of crystals , 1 pint of hot water & cheap wallpaper paste to get it to a yogurt consistancy for cleaning stripped tanks on the outside Or in hot water which i either soak items to be cleaned or quench really cruddy parts after heating with a blowlamp or propane torch ( burners mainly ) , this really gets the muck & oxidisation off Stu
Been using citric acid crystals but only a tea spoon in a pint. The hot make a difference to cold water. Need to try a bit stronger. Many thanks Brian
Do not go for too strong a mix Brian. If you do you get a very, very pink colouring on the brass, which is very difficult to polish out. A weaker solution and constant vigilance is the answer. Do not ever be tempted to leave in to soak overnight! It is better to do the pickling in mild but frequent dips as neccessary with a good scrub off and wash in soapy water in between. Steve.
Oooh no. Any acid treatment of a brass tank weakens the brass. The pink colour is beause the zinc has been etched away leaving the copper showing through which is why the metal turns pink. This leaves tiny cracks in the surface which you can't polish out and will cause stress cracks in time. Citric or any other acid is OK to clean nickel plated stuff because the single metal will just lose an outer layer and will not be damaged. Acxids are for use on cast brass such as burners and on plated parts but never on items made of brass sheet such as a lamp tank. ::Neil::
Stress cracking in brass is also well recognised in brass clock parts (another interest of mine). It happens when the zinc is selectively removed from the brass in parts that are already stressed from having been pressed, bent or improperly annealed. The main culprit in clock making is ammonia which is present in some old fashioned clock cleaning solutions. Ammonia is also in many brass polishes and sometimes in the environment. The problem of stress cracking in brass was documented by the British Army in India in brass cartridges: http://en.wikipedia.org/wiki/Brass#Season_cracking The problem is not only caused by ammonia but by any chemical that alters the alloy structure by reacting preferentially with the zinc. It may be off topic, but I had a door knocker that I cleaned very aggressively in strong ammonia about 5 years ago. Last week there was a loud clatter as the knocker had disintegrated and fallen off the door. It had cracked at a narrow and thin point in the casting. I have little doubt that I caused this by my foolish use of chemicals.
Thanks Steve and Stu. I'll stick with the teaspoon of citric acid in a pint of water. Must have misread as I thought Stu mentioned a tablespoon full. Cheers
Hi Guys I did say a dessert spoon full for the gel i make up , but this is applied sparingly with a brush to clean up a tank etc & can be washed off quickly when the tank or part comes clean before any chemical reaction damage is done I do leave some Tilley , Primus etc burner parts pickling over night in a warm water & citric acid solution after heating & quenching to clean off very heavy oxidisation & have had no adverse problems doing this ( also makes stripping down seized parts eaiser ) , but this must be down to the individuals own decision or experience with this method of cleaning I have only offered this advice as a basic guide you must always find what works best for you Best regards ,Stu
Completely agree with you Stu -it's up to the individual's judgement. In clock forums there are endless, often heated, arguments about this. The way I see it is that if something is common and can easily be replaced then it is acceptable to use aggressive chemicals with due care. Conversely, if something is rare or valuable it may not be a good idea. We also have to realise that what is common now may not be so in years to come especially if many are damaged and succumb to stress cracking. Best Wishes, Stephen
Quite right. What I offer is advice not instructions. Nice thing about advice is you don't have to take it and anyway I don't assume I am always right. So yes it's up to folk to decide what works for them. The effects of chemicals on brass are pretty well documented and our lamp tanks are always stressed during manufacture. A great deal depends on the quality of the alloy and how it is then heat treated to anneal it before completing the construction. ::Neil::
Not sure if this is any use but the last 2 tanks I stripped I used basic paint thinners. I'm thinking that the old paint is cellulose so thought I would give it a try. The second tank had more paint than the first and just took a little longer. Both came up a treat without having to use citric acid or paint stripper (have you seen the price of that stuff in B&Q!). I don't think there should be any chemical affects from thinners (but I've been wrong...once before) Cheers Brian
Hi All I've just cleaned the first part of the hood by heating & quenching in citric acid , this also had a good soak for an hour with "frequent" ( David ) checking until i could wipe away the oxidisation with a shard of wire wool , this was black before i started & looked like it was sprayed with matt black paint now the brass looks much better When re-lit it will discolour but what the hell Stu
