PaulDaisy

That is the whole idea. In this case I will be happy to let it eat the aluminum and only then move on to the metal. "Electrolysis" due to dissimilar metals causes exactly that, dissolving of the more active metal first.
In fact that is where I initially saw how effective it was - found pictures on rv.net that showed an aluminum trailer with holes corroded around steel fasteners, just over the course of one winter (not that I didn't know about the sacrificial anode method before that, just never thought of it for a truck).
-P

Dieseldude4x4

You may be on to something here for northern trucks. Let us know how it goes. It would be interesting to have two samples on the truck, one bolted directly to the frame metal to metal and one bolted to the frame but isolated from the steel frame. Then see which one eats away the fastest without eating the frame.

1-2-3

This makes no sence. If some rood salts got splashed onto the back of the frame near the spare tire, a chunk of aluminum bolted to the front of the frame isn't going to magically have enough control over corosion to make that salt not do anything. What's going on is a chemical reaction between the salt and the metal where it happens to be splashed upon, not any kind of electrical erosion that an anode can stop.

PaulDaisy

I agree, the metal to be protected and the place(s) where the electrically contrasting metal is installed must have electrical continuity through the electrolyte (as in, wet all over), in order to complete the circuit. Therefore I expect it to work only when the roads are all wet with salt / Mag, when the road overspray covers most of the underbelly and the axles. Which should be, seems like, the time when the corrosion is at its greatest: not much rusting seems to be happening in the dry Colorado summer.
-P

steveh1155

Quote:

the metal to be protected and the place(s) where the electrically contrasting metal is installed must have electrical continuity through the electrolyte (as in, wet all over), in order to complete the circuit.

I use them on my boat to protect the submerged aluminum parts on the motor & they work great for that - because they're SUBMERGED - can't see how this would ever work on a truck.

Norm01

However you are attracting more corrosion in that particular area. Full aluminum trailers do better around here than aluminum and steel. I understand your basic thought process, the issue is the aluminum will not slow down the rusting of the metal in that area and be sacrificial, it will in fact promote it. Just my 2 cents.

PChouinard

I think you're setting yourself up for galvanic corrosion in a big way. Two dissimilar metals with a dielctric (moisture) inbetween will instantly begin the corrosion process. This is why we use aluminum washers under steel fasteners on aircraft. Just my two cents..

HOHN

ELECTRO-CHEMICAL is the key phrase there. There is no chemical reaction without corresponding electrical activity.

From Wikipedia:Salt water is an electrolyte. Hence, you have a "galvanic" situation when you bolt a zinc anode to your steel frame. It will corrode preferentially, as defined above.

It will corrode something-- the anode. That's why these are called "sacrificial anodes" and they are used in the marine industry all the time.

Good idea, Paul-- I might need to try this myself.

Justin

HOHN

Zinc, on the other hand, should be superb but I hear aluminum works pretty well too.

JMO and no more than that.

PaulDaisy

I am inclined to install magnesium instead, if it does corrode it will corrode faster and I want to post some photos for the guys here Walmart has those Mg fire starters for $6, looks perfect for the job (oops, I just caused a nationwide shortage of them!). Just don't drill it dry at high speed, anybody, or very bright sparks and quickly propagating fire may result
-P

Norm01

Will work in salt water only! You guys kill me, anyways, rust your trucks, it's up to you. I'll oil spray mine.

TIMMY22

Oil works great, not that environmentally friendly then again neither is the salt.

Rinse your trucks weekly in the salt belt. Wire brush and paint them in the summer.

Don't rinse your trucks at these do-it-yourself car washes because most of them use recycled water loaded with salt of the hundreds of cars before you!

Last but not least, don't park your truck in a heated garage after driving through the salt spray because the heat will double or triple how fast things will rust. This is why it is very important to rinse right away on late spring storms when the temps can rebound quickly when the sun comes up.

mini14

PC hit the nail on the head, the aluminum will cauz the frame to rust out, why do u think zinc is used as a sacrificial anode on boats ? W.T.F.** this isnt rocket science.............or is it...........for some.........please for the lack of a better term........idiot......take the aluminum off.

PChouinard

We can be a little more cordial than this; can we not?

PaulDaisy

Gee, thanks!
I didn't put it on your truck, did I?