Superzilla

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
91
Messages
11,490
It has been advertised on the local TV channels here but I am always leery of anything heavily advertised. But I do know WD-40 and PB Blaster both don't work as advertised. I have better luck with 2 cycle fuel mix and the acetone/transmission oil mix right now.

The problem with rusted on rims is the fact that there is also dirt and other organics involved. These absorb anything oil or water base swell therefore prevent the capillary action that is needed. The 2 cycle fuel seems to work a lot better but it get only so far and then slows to a creep.

After things are separated; for rust removal on ferrous metals I use Muriatic acid. For corrosion on aluminum I sulfuric acid (battery strength). Muriatic acid will destroy aluminum.

With both you have to be very careful with using them. Muriatic acid especially will produce toxic fumes as also reacts with moisture.
 

Scrubcadet10

Moderator
Staff member
Joined
Sep 24, 2017
Threads
266
Messages
6,633
I've had good luck with PB Blaster.
i don't understand why some people will spray a penetrant on a fastener, give it literally no time to penetrate, and remove the fastener.
I did 02 sensors on my dodge truck a few months ago. As far as i knew, original ones. started a week before hand spraying PB blaster on the 02 bungs. pulled the 02's out, easily, and they were saturated up and down the threads.
 

hlw49

Lawn Addict
Joined
Jul 11, 2021
Threads
42
Messages
1,598
Don't have time to wait 2 weeks this stuff works in minutes.
 

Scrubcadet10

Moderator
Staff member
Joined
Sep 24, 2017
Threads
266
Messages
6,633
Had to wait on dodge to get the 02s in that case.
 

clubairth

Well-Known Member
Joined
Apr 6, 2015
Threads
4
Messages
156
Another fan of ATF and Acetone mixture. I put it in a spray can with compressed air. Cheap and if you look at tests it usually comes out on top. But you will never see it in a commercial product because it's to common and has no special ingredients. I was very surprised too because I had always been a fan of Kroil which is good but also very expensive.

I gave it a try and never looked back. The biggest problem with all of these creeping liquids is if the joint is rusted solid nothing can get in there. The old melted candle wax does work but I never seem to have any space for it to "wick" into.

So I still use heat an awful lot of the time even though I don't want to because of possible damage from the torch.
.
.
.
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
65
Messages
24,995
First of all
1) penetrants wick in between crystals , grains & flakes to provide a pair of surfaces with a lower co-effent of friction that is all that they do
Or yo put it another way they simply wet the surface.
2) rust removers do just that remove Fe2OH ( red rust ) . and some can remove FeO ( mill scale )
They do that because they are acids that react with the oxides ( all metal oxides are alkaline ) forming a salt that is soluable in the rust removing solution.
3) Rust converters usually just replace the OH bits with a more stable compound POH for instance .

Now for the fun bit rust is physically bigger than steel so it occupies more space which is one reason why it bubbles up from under the paint
Note the bubble is not because of the H2 gas generated as H2 molecule is so small it passes through paint like it is not there .
One of the big reasons why we do not drive Hydrogen cars right now is the difficulty in keeping hydrogen inside the fuel tank .
Anyway the empty space between the threads on a nut & bolt for instance is finite so if the volume of rust produced is greater than the volume of the empty space the pressure on the threads becomes massive & you can not undo them so you get the same effect as those phone book joining experiments people like Myths Busters are so fond of , or the drop of water on two peices of glass that makes them impossible to pull apart .
Fe2(OH) is very uncommon as it usually has a few water molecules as well so we have Fe2(OH)6(H20) which is the loose flakey rust through to Fe2(OH)3(H20)
Then on top of that you get FeOHOFe happening where 2 irons bond to a single water and that is really tough to break free
There is more to it than most think and the important thing is to identify which route to take as once you have put a penetrant on the surface you can not use a deruster unless that deruster can break the bond between the penetrant and the rust
Any acid will react with rust the only difference is the speed and weather the acid is a reducing or oxidizing acid
Why ?
Reducing acids usually do not attack metals because they are the reduction product of an oxide ( usually ) so they tend not to consume the parent steel ( much )
Oxadising acids will do that, oxadize the reduced metal so eat into what you are trying to remove which can make a bolt hole way too large .

Then there are the chleating agents, of which Evaporut is the one most will be familiar with .
These have to be slightly acidic to work on rust
They work by dissolving the rust then precipitating it , EDTA & DMG are the most common of these and often found on the ingredients list
The A in EDTA stands for Acid & the G in DMG is gloxamine which also acts as an acid .

In my workshop it is citric acid because it is very very cheap
Vinegar ( Acetic acid ) if I run out of citric acid
Molassis if it is tools that I want to have a protective coating when finished .

Commercial mixtures are generally better than all of the home brews and remember a commercial mix has to be SAFE both to use & dispose of .
Home brews do not have to be either
 
Last edited:

Tiger Small Engine

Lawn Addict
Joined
Dec 7, 2022
Threads
2
Messages
1,106
First of all
1) penetrants wick in between crystals , grains & flakes to provide a pair of surfaces with a lower co-effent of friction that is all that they do
Or yo put it another way they simply wet the surface.
2) rust removers do just that remove Fe2OH ( red rust ) . and some can remove FeO ( mill scale )
They do that because they are acids that react with the oxides ( all metal oxides are alkaline ) forming a salt that is soluable in the rust removing solution.
3) Rust converters usually just replace the OH bits with a more stable compound POH for instance .

Now for the fun bit rust is physically bigger than steel so it occupies more space which is one reason why it bubbles up from under the paint
Note the bubble is not because of the H2 gas generated as H2 molecule is so small it passes through paint like it is not there .
One of the big reasons why we do not drive Hydrogen cars right now is the difficulty in keeping hydrogen inside the fuel tank .
Anyway the empty space between the threads on a nut & bolt for instance is finite so if the volume of rust produced is greater than the volume of the empty space the pressure on the threads becomes massive & you can not undo them so you get the same effect as those phone book joining experiments people like Myths Busters are so fond of , or the drop of water on two peices of glass that makes them impossible to pull apart .
Fe2(OH) is very uncommon as it usually has a few water molecules as well so we have Fe2(OH)6(H20) which is the loose flakey rust through to Fe2(OH)3(H20)
Then on top of that you get FeOHOFe happening where 2 irons bond to a single water and that is really tough to break free
There is more to it than most think and the important thing is to identify which route to take as once you have put a penetrant on the surface you can not use a deruster unless that deruster can break the bond between the penetrant and the rust
Any acid will react with rust the only difference is the speed and weather the acid is a reducing or oxidizing acid
Why ?
Reducing acids usually do not attack metals because they are the reduction product of an oxide ( usually ) so they tend not to consume the parent steel ( much )
Oxadising acids will do that, oxadize the reduced metal so eat into what you are trying to remove which can make a bolt hole way too large .

Then there are the chleating agents, of which Evaporut is the one most will be familiar with .
These have to be slightly acidic to work on rust
They work by dissolving the rust then precipitating it , EDTA & DMG are the most common of these and often found on the ingredients list
The A in EDTA stands for Acid & the G in DMG is gloxamine which also acts as an acid .

In my workshop it is citric acid because it is very very cheap
Vinegar ( Acetic acid ) if I run out of citric acid
Molassis if it is tools that I want to have a protective coating when finished .

Commercial mixtures are generally better than all of the home brews and remember a commercial mix has to be SAFE both to use & dispose of .
Home brews do not have to be either
It is common to see people on Youtube use WD-40 on rusty bolts, etc. They obviously haven’t spent the time I have in removing rusty stuff. My experience is that Kroil, PB Blaster, and 50%/50% mix of transmission oil and acetone work the best (not necessarily in that order). I mainly use PB Blaster. Even on bolts that are not stuck, just spraying it on really speeds up removal. I usually use 1/4” or 3/8” socket by hand for better feel over impact gun.
 
Top