Frank Elder Posted June 12, 2009 Report Posted June 12, 2009 It's called dissimilar metal corrosion, and the steel will eat up the aluminium much faster then the brass, not to mention the expansion and contraction rates are different too. I suppose finding aluminum replacements would be hard to say the least....... Quote
old woolie Posted June 13, 2009 Report Posted June 13, 2009 That is what I meant when I said steel and aluminum don't get along. Quote
T120 Posted June 13, 2009 Report Posted June 13, 2009 (edited) When his manifolds what? Sorry about that -a typo -,I should know better than to try and multi-task This particular manifold does not have steel tubing to pass coolant,(used for heating the manifold)I gather Edmunds made quite a few versions.Others have steel tubing cast in the aluminum manifold.I based my response on the experience of having worked in a shipyard for 10 years and seeing what happens when brass and aluminum come in contact.I've seen aluminum reduced to a powdery residue.A more correct term may be galvanic action. It doesn't take much moisture to get things happening.I don't claim to be an expert,but as a rule of thumb, I would not assemble anything placing aluminum and brass in direct contact.In a dry climate maybe not so much of a concern:) Edited June 13, 2009 by Ralph D25cpe Quote
Frank Elder Posted June 13, 2009 Report Posted June 13, 2009 galvanic corrosion is also a term I learned in the navy air wing, I'm pretty sure pipe dope slows both down as long as gas is not involved:eek: I've never heard of steel being cast into aluminum, but I don't mind broadening my knowledge. Quote
dezeldoc Posted June 13, 2009 Report Posted June 13, 2009 Don't forget salt water is a whole nother matter in the equasion, were are talking about fresh water and anti freeze. Quote
T120 Posted June 13, 2009 Report Posted June 13, 2009 Hi Frankie,You can take my word for it.- I have an Edmunds manifold, the coolant passage is steel Quote
Niel Hoback Posted June 13, 2009 Report Posted June 13, 2009 Aluminum pistons have steel webs cast inside them. Quote
Frank Elder Posted June 13, 2009 Report Posted June 13, 2009 There are steel crank girdles in A blocks sometimes and steel sleeved cylinder walls too, but these surfaces are coated in oil and not raw metal on metal. Once again I am learning.... Quote
T120 Posted June 13, 2009 Report Posted June 13, 2009 ..getting back to the original posting,it's nice to see that a couple more of the elusive electric gas caps have come up for sale Quote
old woolie Posted June 13, 2009 Report Posted June 13, 2009 It's funny how these threads get twisted off topic. Quote
blueskies Posted June 15, 2009 Report Posted June 15, 2009 Hi Frankie,You can take my word for it.- I have an Edmunds manifold, the coolant passage is steel My Edmunds has a copper coolant pipe cast into the aluminum. Here's the Galvanic table for reference... the farther apart two metals are on the list, the more they will corrode. The metal with the lowest number in the chart will act as the anode and will corrode. According to the chart, brass will cause the aluminum to corrode more than steel will. Looks like a Cad plated fitting would be best, from the chart. Pete The Galvanic Table Active (Anodic) Magnesium Mg alloy AZ-31B Mg alloy HK-31A Zinc (hot-dip, die cast, or plated) Beryllium (hot pressed) Al 7072 clad on 7075 Al 2014-T3 Al 1160-H14 Al 7079-T6 Cadmium (plated) Uranium Al 218 (die cast) Al 5052-0 Al 5052-H12 Al 5456-0, H353 Al 5052-H32 Al 1100-0 Al 3003-H25 Al 6061-T6 Al A360 (die cast) Al 7075-T6 Al 6061-0 Indium Al 2014-0 Al 2024-T4 Al 5052-H16 Tin (plated) Stainless steel 430 (active) Lead Steel 1010 Iron (cast) Stainless steel 410 (active) Copper (plated, cast, or wrought) Nickel (plated) Chromium (Plated) Tantalum AM350 (active) Stainless steel 310 (active) Stainless steel 301 (active) Stainless steel 304 (active) Stainless steel 430 (active) Stainless steel 410 (active) Stainless steel 17-7PH (active) Tungsten Niobium (columbium) 1% Zr Brass, Yellow, 268 Uranium 8% Mo. Brass, Naval, 464 Yellow Brass Muntz Metal 280 Brass (plated) Nickel-silver (18% Ni) Stainless steel 316L (active) Bronze 220 Copper 110 Red Brass Stainless steel 347 (active) Molybdenum, Commercial pure Copper-nickel 715 Admiralty brass Stainless steel 202 (active) Bronze, Phosphor 534 (B-1) Monel 400 Stainless steel 201 (active) Carpenter 20 (active) Stainless steel 321 (active) Stainless steel 316 (active) Stainless steel 309 (active) Stainless steel 17-7PH (passive) Silicone Bronze 655 Stainless steel 304 (passive) Stainless steel 301 (passive) Stainless steel 321 (passive) Stainless steel 201 (passive) Stainless steel 286 (passive) Stainless steel 316L (passive) AM355 (active) Stainless steel 202 (passive) Carpenter 20 (passive) AM355 (passive) A286 (passive) Titanium 5A1, 2.5 Sn Titanium 13V, 11Cr, 3Al (annealed) Titanium 6Al, 4V (solution treated and aged) Titanium 6Al, 4V (anneal) Titanium 8Mn Titanium 13V, 11Cr 3Al (solution heat treated and aged) Titanium 75A AM350 (passive) Silver Gold Graphite End - Noble (Less Active, Cathodic) Quote
blueskies Posted June 15, 2009 Report Posted June 15, 2009 I had a NOS electric gas cap for my '50. I didn't like the way it fit on the filler pipe, and over the rubber body gasket. It fits off center to the pipe, to fit the electromagnet latch inside the base. When it was on my car, it only covered about half of the rubber body gasket and looked like it was crooked in an odd way. I bought it on ebay for $70, and sold it on ebay for $200 a few years later. Pete Quote
T120 Posted June 15, 2009 Report Posted June 15, 2009 ..Glad to hear you had an enjoyable trip to Wyoming.Great photos.The Galvanic table you posted is a good reference.Interesting that your manifold has copper pipe -I have 2 Edmunds manifolds - both for long block sixes.They are a llittle different in height but both have steel cast in the manifold. Ralph Quote
DonaldSmith Posted June 15, 2009 Report Posted June 15, 2009 So graphite is at the far end of the list, and is not good for aluminum. That must be why specifications for fabricating aluminum architectural sheet metal say that the auminum should not be marked with a pencil! Your typical lead pencil is really graphite. You won't get lead poisoning licking the point, but don't mark my aluminum fabrications with your pencil. Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.