Google [alum, food] = 7th hit:
http://www1.foodtv.com/terms/tt-r2/0,4474,89,00.html
Definition: [AL-uhm] In cooking, these highly astringent crystals of potassium aluminum sulfate were once widely used as the crisping agent in canning pickles. Alum can cause digestive distress, however, and modern canning methods make its use unnecessary.
--Copyright (c) 1995 by Barron's Educational Series, from The New Food Lover's Companion, Second Edition, by Sharon Tyler Herbst
I don’t know what the proper concentration would be to perform the task of dissolving a ferrous tap without hurting the surrounding aluminum. I would also suspect that this might be a bad thing to do to anything involving structural aluminum. It might cause small cracks or otherwise weaken the aluminum. Definitely do not try this on your airplane.
http://www1.foodtv.com/terms/tt-r2/0,4474,89,00.html
Definition: [AL-uhm] In cooking, these highly astringent crystals of potassium aluminum sulfate were once widely used as the crisping agent in canning pickles. Alum can cause digestive distress, however, and modern canning methods make its use unnecessary.
--Copyright (c) 1995 by Barron's Educational Series, from The New Food Lover's Companion, Second Edition, by Sharon Tyler Herbst
I don’t know what the proper concentration would be to perform the task of dissolving a ferrous tap without hurting the surrounding aluminum. I would also suspect that this might be a bad thing to do to anything involving structural aluminum. It might cause small cracks or otherwise weaken the aluminum. Definitely do not try this on your airplane.
You might want to read the article. Perhaps it might be of help....Well at least worth a try.
http://www.focuser.com/atm/anodize/anodize.html
it says...Note: if the aluminum part has other metal steel parts pressed into it, do not re-anodize the part. Metals other than aluminum will dissolve away during the anodizing process.
http://www.focuser.com/atm/anodize/anodize.html
it says...Note: if the aluminum part has other metal steel parts pressed into it, do not re-anodize the part. Metals other than aluminum will dissolve away during the anodizing process.
Planes...
Like Peter mentioned, you don't generally tap aluminum in aircraft. Its just too soft as far as mechanical strength - so you use nut plates. These are secured with rivets.
There are other times that parts are made of forged aluminum. These got made during the manufacture and you generally won't be doing anything to them. If you have to do anything to them, well its work, it often means inspection too. So most of that gets sent back to its maker.
These are generalities - there must be a thousand ways to attach two parts together.
(boy I wish I could just make an one hour run through the cage we used to keep all the good stuff in. I would have all I need to build enclosures for years.
Like Peter mentioned, you don't generally tap aluminum in aircraft. Its just too soft as far as mechanical strength - so you use nut plates. These are secured with rivets.
There are other times that parts are made of forged aluminum. These got made during the manufacture and you generally won't be doing anything to them. If you have to do anything to them, well its work, it often means inspection too. So most of that gets sent back to its maker.
These are generalities - there must be a thousand ways to attach two parts together.
(boy I wish I could just make an one hour run through the cage we used to keep all the good stuff in. I would have all I need to build enclosures for years.
JohnG
that's a good tip, I'll try that. The only problem I can see is evaporation.
Sawzall,
tapping and airplanes was a cheap shot intended for Peter. Not meant to be taken literally.
Having said that, it's not the first time I see broken threads and things of the kind excaping quality control on equipment costing millions of dollars. Avionics maybe different but I doubt it.
that's a good tip, I'll try that. The only problem I can see is evaporation.
Sawzall,
tapping and airplanes was a cheap shot intended for Peter. Not meant to be taken literally.
Having said that, it's not the first time I see broken threads and things of the kind excaping quality control on equipment costing millions of dollars. Avionics maybe different but I doubt it.
For machining aluminum, aluminum cutting fluid works wonders. I find surface finishes improve the most (in addition to lowering cutting forces, and therefore broken tools). I've used a bunch of different types and find they all work. Tapmatic, Relton A9, Tap Magic all work well. WD40 is surprisingly good in Aluminum for not being a cutting fluid.
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