Technical Don't Alodine Your Carbs!

Can an Autolite 4100 body and airhorn be clear alodined ??

The body's have 4 pressed in br*** tubes, the vent tubes in the airhorn's can be removed

Several Folks have told me the stuff is dangerous if not used properly

What precautions do you guys use so it is safe if I may ask ??


Ricky.

 

They are also made of Zinc.

Same issues.

 

I used rubber gloves, good ones made for solvent and safety gl***es…..

 

Alodine is a brand name the stuff is actually Chromic Acid a high carcinogen

 

Great info, it explains a lots of things I've wondered about, I've always wondered what that primer is that you use on aircraft aluminum, that greenish stuff. What is it called (to OP, trying to avoid 'hijack' but this good stuff).

 

No problem, The Boeing drab olive green primer is zinc chromate, and is available in spray bombs. You should use Alodine to help it bite into alloys remember all Boeing aircraft god bless them use the old ms military spec and an army/navy part numbers.
The three types of primer are
Bms (Boeing military standard )
Bms 10-20 type 2 Light yellow in colour.used in fuel tanks ect
Bms 10-11 type 1 light green in colour and used almost everywhere on airframes
Bms 10-79 type 3 . This is the drab olive green chromate primer used traditionally on aircraft fuselage exterior, for its corrosive resistance. And a lot of the time used on ww11 military vehicle resto, and as slick111 said it’s all extremely carcinogenic, so safety gear is a must

 

Zinc chromate primer is designed to use on aluminum with no top coat
Top coat tends to not bond to and will peel off
Epoxy primers are really all that is being used today

 

Fuel rated primer is BMS 10-20 Type 2 yellow made by Akzo Nobel Aerospace. Any type 1 is water based mixed will not stand up to fuel.
The BMS 10-79 Type 3 primer is darker green fuel/chemical resistant only by PRC-Desoto Coatings . Also not water based.Also Alodine comes in 600 for T-3 aluminum and stronger 1200 on T-6 no idea how any of this would work on cast as both 600 and 1200 is only applied times of 3-10 min before rinse /neutralizing no doubt cast is much softer

 

The Autolite 4100 bodies and air horns are actually aluminum. The boosters, choke control and other attached pieces are zinc alloy, however.

 

Not to hijack but what coating, if any, was originally on Stromberg 97s?

 

Just edited my post 10/20 is type 2 .sorry not 1. Was just going from memory, . I checked some tins at work too find I’d made the mistake, slick111

 

Awesome stuff, guys. I have used epoxy primer on airframe tubing rather than zinc chromate. I think it makes airframes easier to inspect and clean(personal stuff).
For the skins, the alodine or zinc chromate looks cool though function is obviously the main point. It's not too easy to find the right vintage color though for the chromate. I have a vintage race plane project that will have zinc chromate wherever I can put it.
Currently trying to perfect the zinc plating for the carb steel parts.
D

 

My Dad got some cleaner call "Zap",he made a bucket of it up,and put a carb in it,he had me take apart,so he could clean it. He hated getting his hands dirty,so I was the take it apart { of anything with any dirt on it at all. so cleaner of every thing!!! He never told me,how long to put the parts in the bucket. I did ask,,but not told! So about a week later,he ask if the crab parts were clean yet?? "Lets look an see" I dumped out the bucket,but nothing on the carport floor,but some screws,br*** float,seat n pin,br*** shaft an ****erflys.
The carb body parts had become powder. Zap had dissolved the carb body parts.
Dad must of trash caned all the Zap,I never saw any again!!! LOL

 

Zap used to make great stuff and still might. What I have found recently has been much more "Karen-proof". I have not been able to find some to the stuff I could when I was younger. But, indeed, even Simple Green can do damage to aluminum over time unless you buy the "safe" version.
I'm sure your story was the situation here.
D

 

Annoying.

 

That formula is no longer on the market.

Think of what it does when not disposed of properly (and who actually did dispose of it properly?)

 

Annoying - do you mean the carbs being aluminum, or the post?

The aluminum is more corrosion resistant than zinc alloy, which is a nice feature when salvaging these old carbs. The 2100s were similar metallurgy.

 

Dichromate

To be more specific - Process BX-13 (New Jersey zinc dichromate)

Jon