Technical Derusting New Idea - make your own gel, this will blow your mind.

Ive been experimenting with citric and oxalic acid to make a gel, first trial worked great, except it dries out fast. Of course it could be rewet and rebrushed easily.

Trying a few other things to keep it wet longer and not effect the PH.

My intention is to provide instructions on an acid mix that can be brushed on, you control the thickness, you control what acid type ( citric, oxalic, phosphoric)

This would prevent the need to submerge parts in the mixture.

I have visions of an acid gel we can shoot on the bottom of a car with an undercoating gun to derust frame and floors, power wash off and neutralize the underside.

 

https://www.google.com/url?sa=t&sou...Vaw1kstpXnnDLSqBAkZCjdlX4&cshid=1592143966217

I have never tried naval jelly, i looked up the MSDS sheet to see what the hell it was. What caught my eye was xanthan gum, its a additive in food production, typically used an an emulsifier to keep water and oil based mixes in suspension (salad dressing), also a powerful thickener.

I ordered some up.

DISCLAIMER: this stuff is powerful, it gels hard with any water interaction, dont even think of rinsing this down your sink. I washed all my mixing tools in the yard with garden hose and a bucket.

Recipe for trial run:
2 cups water
2 tsp citric acid
1 tsp xanthan gum.
This HAS TO BE MIXED IN A BLENDER. The xanthan gum will ball up if mixed by hand, I have not tried a hand mixer ( for cakes) yet. I suggest mixing the xantham gum forst then adding acid.

Multiply all measurements by 8 for a gallon mix

Heres the consistency with that mix ratio. It brushes onto vertical surfaces and clings, similar consistency to paint stripper.

 

I used this mix on an OT project, it dried out in about an hour, spray bottle and water, rebrush it with some new gel and it comes back to life. Derusted well obver the course of 2 days reviving it. Tested the PH with a strip 1.5. After a week on the shelf, still 1.5 PH, so it seems stable.

Citric acid ratio is not real strong in this mix, can be kicked up.

Next steps:
Try with phosphoric acid
Try with oxalic acid
Try with diesel fuel

Diesel fuel is interesting, a clingy gel that will degrease. Brush it on, or shoot it thru an undercoating gun. I see a lot of possibilities there. Depends if the xantham gum will thicken oil based, it should since its used as the thickener for salad dressing.

 

More next steps, find another additive that will keep it from drying out so fast. Something that will not effect PH.

I considered dishsoap, but that is basic on PH and will likely neutralize the acid.

Any ideas there, let me know.

I have a few other things going and will not be able to experiment further for about 2 weeks. If anyone wants to jump in, lets compare recipes and results.

 

I love it when someone gets a crazy idea, a really cool crazy idea and shares it !!

I love the idea of a spreadable gel. Good luck in your endeavors !! And thanks for posting your findings !!

 

How will you get it out of all the cracks and crevices IF you ever get it to the point of being "spottable" on a real life undercarriage?

 

How does it compare to naval jelly?

 

Power wash the shit out of it, neutralize with baking soda, scrub it out. If you've ever layed under a car with a wire wheel, these are minor steps compared to holding the grinder all day.
Hire the sandblaster is the best way to go, just looking at alternatives.

 

Never tried naval jelly. My intent is to make a sprayable clinging solution. If this works with different acids the strength and thickness can be controlled by you, with a blender and a measuring spoon.
Brush on is a bonus. Keeping it wet is the missing link.
Still useable if you take the time to keep wetting and applying, I'm sure a layer of cling wrap will extend its working time.

 

Well thank you for the encouragement, I've made one test, need to try the other things, Im an engineer - love this trial and error. If no one else tries it, Im still having fun

 

Try using it with plastic wrap to stop it drying.

My BIL does this with paint stripper.

 

I remember my uncle using naval jelly a lot. Wasn't there a companion to that also? Gene

 

Where are you obtaining your supplies?

 

50 years ago (damn!) a friend in college's mom worked for the company that made naval jelly and they had put out an anniversary "gift" that was a 15" glass statue of a naked woman-filled with pink naval jelly. Really quite spectacular. Now that is a gift! I have never seen one since.

 

Try using corn starch and heating the mix. About a table spoon per pint of mix. I've used that with lye to strip paint. And cover with plastic wrap, that really helps. But would be difficult on a frame, from the bottom!

 

Power washing: there was a salt flat racer that ran a 32 Ford. When they got home, they would run a sprinkler under the car to gently wash out the salt. Using a power washer would force the salt deep into crevices.

 

Pictures!.... Or it never happened....

 

I’m in to try it. Have some xanthum gum in the cupboard and the oxalic acid in the garage.

Thanks for sharing!


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Like this one?

 

Thats a good one, it will make a paste. Ive also heard of people using wall paper paste.

Step 2 is finding an additive to keep it wetter - longer to increase working time...... KY jelly?? that should be PH neutral

 

Citric acid and xanthan gum are food additives, Amazon, ebay, many online stores sell them.

I originally bought xanthan gum as a minor additive when making homemade ice cream. What a difference, very creamy texture and its helps greatly with scoopability. Every major commercial icecream brand uses xanthan gum or guar gum except hagen daas.
I can start a thread just on ice cream recipes - not sure if the boss would approve.

 

Ill go down the chemistry rabbit hole. As I learn more, maybe we'll catch someone that actually has a background in this

Step 2 is increase working time and keep it wetter - longer.

Humectants are additives that prevent products from drying out. Glycerol, glycerin are common in food / makeup production to do this. Gelatin ( knox) is another possibility but it increases volume. I dont know if it will work in a highly acid mix.

I want to try these 2 in the mix to see what happens. Glycerol/ glycerine/ gelatin are all pretty PH neutral 7.5 to 8. I dont want to add anything that will neutralize the acid.

I ordered a new blender for my house so I can take my old one to the garage. Have a few house projects to tie up before I can spend more time experimenting. Ive been using citric in the trial due to this blender limitation.

I want to use straight phosphoric acid with xanthan gum and see if a stronger acid still thickens.
If you look at MSDS for naval jelly it has up to 30% phosphoric. Im confident and familiar with how well phosphoric etches rust and steel for paint prep.

 

Quick test

I applied 2 times yesterday one time today. Allowing it to dry between each, brushed more on to stir it up and revive.

The mix took out all rust peppering and etched the heavily scaled area. There is still red rust in the heavily scaled area.

I assume due to the drying - short working time, weak acid (citric vs phosphoric) that its not cutting all the way into heavily scaled areas.

Normally on brackets like this I would just dunk it in solution. This was a test to see if we're onto something.
1) Need to extend working window for more acid neutralization, prevent it from drying out.
2) need to test phosphoric.
3) try this mix, with plastic wrap cover, to see if it extends working time.

Intent is to be able to use this on things that are not easily dunked in a tank.

 

Good work there and great thread.....thanks for the effort !

 

Greetings indyjps and all!...when I bought livestock grade molasses it was a REALLY THICK liquid/barely pourable jell. I mixed it with water for a " dunk tank" years ago already and it works great but I have been wondering since how just smearing it on wire a paint brush would work....

 

Im with ya, considered citric acid powder in molasses to boost the strength, but provide a thick coating. Dont know if or would dissolve.

I think any of these acid solutions (molasses, citric, oxalic) having them wet, or submerging in a tank is key.

Molasses may stay wet/ gel much longer, not sure if it will cut the rust before it dries out. Its a very slow rust cutter in aqueous solution compared to others.

I have molasses left over. Ill do a test.

 

So I finally got to the point on my To Do list for prepping my bare sheet metal firewall and trans tunnel pieces. They had developed some light surface rust in the 3 months since purchase.

I mixed up a very thick corn starch solution on the stove, then added my oxalic acid solution. Apparently vegetable starches break down at very low and very high pH, so essentially this was a waste of time. It went from jelly to thick water real quick.

I did discover that POR-15 degreaser makes a good rust remover on its own, so I switched to that about half way through today’s work.

Panels are now resting comfortably with a fresh coat of primer.


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Cornstarch is a great thickener for gravy. Agree that many for the food based thickeners we reach for - don't work in highly acidic.
I tried Knox Gelatin. NO GO.

 

Bump Bump, new recipe, testing it now, will report results good or bad in real time no BS pretesting.

2 parts phosphoric acid
1 part diesel fuel
Xantham Gum added until thick
Mixed in a blender, required.

I was rereading about xantham gum and its used in salad dressing to ensure the oil suspends in the water based liquid. Hmm, Italian dressing.

Im looking for a way to keep the derusting solution from drying out to keep the acid working, an oil based additive should do that, diesel may give some grime cutting benefit, we'll give it a try.

After mixing, the PH is 1- 1.5 on a test strip. Diesel didnt impact the PH.

All mixed up it turned to a bright green goo, youll definitely know where you applied it.





Brushed some on my daily driver truck frame rail, i'll check in the morning if its still wet - allowing the acid to work, if the acid works, or if I created a super metal dissolver that melted the truck frame in half.