What do you put between aluminum and steel

[AJSFJ40]

I am getting ready to put some aluminum treadplate corners on my FJ 40. The original steel is rusted through somewhat , so I'm not so concerned with it as I am for the aluminum. Will there be some sort of reaction (electrolisis?) over time. Is there something that I should put between the two? Thanks for any help.

 

[Tofudebeest]

rubber. O rings, rubber washers...that kind of thing. It'll minimize the rattling too.

 

[KY Longhunter]

Good question...

My 81 came with front bib that was badly rusted not to mention pre-79 bezel.

I found a aqualu aluminum bib in mud classifieds and jumped on it, but now am wondering if I'm going to have an electrolisis problem where the bib meets the front fenders and side aprons, etc.

Should I use the aluminum bib or get rid of it and try to find a used steel bib?

Thoughts?

 

[AirCruiser]

Try Kemseal PRC

 

[laguna80]

I would put something in between the two metals. Galvanic corrosion is what happens when two dissimilar metals are put into contact with each other.

 

[bsmith123]

AC TECH Products - Cabin Pressurization/Fuselage Sealants

sealants are often used in aircraft, but they might be expensive I am thinking some zinc chromate primer might do the trick or even tape on hidden surfaces where they mate

you can install bolts wet with epoxy primer

anything that prevents metal to metal and lasts

 

[vk7ybi]

Sikaflex?

 

[KOOTENAY KRUZER]

Check the FAQ on Aqualu's websie - they recommend sikaflex and for some areas rubber.

 

[Archengine]

I did the aqualu tub and cowl, and used a rubber paint to isolate the metals. 6 years now and no issues. The paint is the rubber stuff you buy by the quart at lowes/hd to dip tool handles in. $4 a quart or so.


Rob

 

[Super Tico]

I´ve had a plate of diamondplate bolted on top of a Ford tool body for 35 years. Nothing in between but factory paint. SoFlo truck. No problem.
Dissimilar metal contact is more of a marine environment issue.

 

[bkfj40]

I´ve had a plate of diamondplate bolted on top of a Ford tool body for 35 years. Nothing in between but factory paint. SoFlo truck. No problem.
Dissimilar metal contact is more of a marine environment issue.

the paint is providing the insulating layer...


bk

 

[Michael Hanson]

If you want body panel sealant.

 

[shelfboy1]

nolox or other similar products are used in electrical panels to prevent chemical reactions when aluminum wire is used with steel .i use it on my battery terminals and it works well. it comes in a paste form and may help you .if you use it make sure the bolts you use are covered also good luck

 

[antFJ]

I'm pretty sure it would take many... many years before any sort of noticeable (compared to what we see with our steel parts) corrosion happened to the aluminum (unless you store the truck in the ocean). and as above said - something as simple as paint will stop the metals from reacting with each other.

 

[jm599]

undercoating in a can

spray the aluminums backside, let dry a hour then install with stainless rivets

 

[Bennett]

Bitchathane... thin waterproof rubberized membrane .. a roofing product, sticky on side.
Put on the steel and then attach corners and cut off overlap.

can be removed with heat later on if need... best part is 100% protection
http://www.bakor.com/images/content/RF200Roll.gif

 

[rusty_tlc]

I would put something in between the two metals. Galvanic corrosion is what happens when two dissimilar metals are put into contact with each other.

I believe you also need a current flow. If you place two dissimilar metals in contact in the presence of moisture there will be some current flow due to galvanic action. The larger the flow the faster/greater the reaction. With no external current flow you will see minimal galvanic corrosion. If you ground the body panels independently and protect the connections from moisture with terminal grease you will minimize the current flow, from grounding lights etc, between panels and hence corrosion between panels.